Showing papers by "University of Nevada, Reno published in 1976"

Finite Element Solution of Saint-Venant Equations

Abstract: A finite element solution based on the Galerkin method was developed for the Saint-Venant equations that approximately govern unsteady flow in rigid open channels. A predictor-corrector solution scheme produced theoretically stable and convergent results, and applications to test problems confirmed stability provided that time steps were not so large as to render invalid the Newton linearization scheme used for the friction factor. Linear elements were adequate for all problems solved. Time step limitations to produce accurate results were closely related to: (1) The degree to which piecewise linear functions describing the variation of depth and discharge in time could be fit to the actual curvilinear functions; and (2) the value given to the time step weighting factor. Values of this factor near 0.5 gave the best results.

Age of the Cardenas Lavas, Grand Canyon, Arizona

Abstract: Six whole-rock specimens of basalt from the Cardenas Lavas of the younger Precambrian Unkar Group yield a Rb-Sr isochron of 1.09 ± 0.07 b.y. This age is believed to approximate the time of extrusion of the lava. Potassium-argon age determinations of the lava are considerably younger and may reflect either diffusive loss of 40Ar or a period of heating about 800 m.y. ago.

A Defensible Maximum for Inorganic Sulfate in Drinking Water of Cattle

Abstract: Twelve Hereford-Angus weanling heifers were used in a split:plot design incorporating a randomized complete block to determine physiological effects of subtoxic concentrations of inorganic sulfate in drinking water. Treatments were tap-water (110 mg/liter sulfate), 1,250 rag/liter sulfate and 2,500 rag/liter surface. The sulfate was added to the tap water as sodium sulfate. The sulfate-waters did not affect feed consumption, water consumption or growth during the 90-day experiment. No overt toxicity was observed. Heifers drinking sulfate-water had tendencies to accumulate methemoglobin and sulfhemoglobin without affecting total hemoglobin. Sulfate loading did not induce diuresis although heifers drinking 2,500 mg/liter sulfate-water increased renal filtration of sulfate by 37.7% and decreased renal reabsorption of this ion by 23.7%. Therefore, in these animals the percentage of filtered sulfate reabsorbed was decreased by 44.8%. The heifers were subsequently used in a taste response experiment in which they were offered either sodium chloride or sodium sulfate in a twochoice preference situation. The choice was the salt solution or tap-water. The salts were added to tap-water in increasing but estimated equal anionic concentrations in six increments from 275 to 4,400 mg/liter of anion. The animals discriminated against drinking water containing 1,620 mg/liter chloride or 2,018 rag/liter sulfate. Concentrations at the estimated rejection threshold were 5,524 and 3,317 rag/liter for chloride and sulfate, respectively. On a molar basis, discrimination and rejection thresholds for suffate were 21.0 and 34.5 raM, respectively. Those for chloride were 45.6 and 155.6 mMolar. Apparently, sulfate was more unpalatable than chloride when compared on an equimolar basis. It appears that these heifers were able to tolerate 2,500 rag/liter sulfate in their drinking water without adverse effects, and that this concentration of sulfate represents a safe tolerance concentration. (

Timing of late Tertiary deformation in the Andes of Peru

Abstract: Radiometric (K-Ar) dating of a reconnaissance nature conservatively brackets late Tertiary deformation throughout Peru between about 20 and 5 m.y. ago. Folding appears to have begun about 15 to 17 m.y. ago. If the timing for Huancavelica Department, central Peru, is applicable to other parts of the country, then deformation and considerable uplift and erosion had taken place by 10.5 m.y. ago. Intense deformation and uplift in Peru is one of many major igneous and tectonic events that affected the western parts of North, Central, and South America and other parts of the globe during middle Miocene time. These events appear to be associated with first-order changes in the movement patterns of lithospheric plates and thus may reflect a major perturbation of the lithosphere-asthenosphere system.

Plant Test Systems for Detection of Chemical Mutagens

Abstract: In Vol. 2 of this series Ehrenberg(1) reviewed several aspects of chemical mutagenesis in higher plants. He described the reaction of plant cells to numerous chemical mutagens and three of the major plant test systems used for detecting mutations and chromosome aberrations.

The fine structure of the chinchilla placenta.

Abstract: The structure of the placental labyrinth, interlobular or "coarse" syncytium, visceral (splanchnopleuric) yolk sac, giant cells and subplacenta of the chinchilla was studied with the electron microscope. The fine structure of the interhemal membrane of the placental labyrinth was found to be hemomonochorial, consisting of a single layer of syncytial trophoblast. In this respect, the placental labyrinth was similar to that of another caviomorph rodent, the guinea pig. The labyrinthine trophoblast had pinocytotic vesicles as well as larger vaculoes and multivesicular bodies. The interlobular syncytium contained granular endoplasmic reticulum, and in one case from early in gestation there were intracisternal granules in the ER. The visceral endodermal cells of the inverted yolk sac placenta had a well-developed system of apical vesicles and tubules as well as larger cytoplasmic vacuoles. Their appearance was similar to that of endodermal cells found in other rodents which are known to absorb proteins and other substances from the uterine lumen. Towards term the giant cells were often vacuolated and contained large deposits of glycogen as well as lipid droplets. The syncytial trophoblast of the subplacenta contained numerous moderately electron-dense granules which may be secretory in function; cytotrophoblastic cells lacked these granules. The subplacental syncytium often surrounded spaces or lacunae which contained an electron-dense granular material.

A multidimensional look at sex and target differences in disclosure.

Abstract: The roles of sex and target differences in behavioral samples of disclosure were examined using a multidimensional procedure for five major parameters: amount, intimacy, rate, affective manner of presentation, and self-disclosure flexibility. Females did not disclose a greater percentage of information than males but did disclose more intimate information and at a higher rate than did males. Significant differences in affective manner of presentation and rate of disclosure were also demonstrated between interview conditions. The multidimensional assessment of disclosure in terms of basic parameters seemed to allow a more meaningful and systematic explanation of the effects of independent variables upon self-disclosure within the context of specific relationships and settings than previous single dimensional approaches.

The three-dimensional aspect of mammalian lung multilamellar bodies

Abstract: The three-dimensional aspect of rat and monkey lung multilamellar bodies was demonstrated in lipid retained thin sections. The glutaraldehyde and urea lipid retention embedment and an Epon 812 resin polar dehydrant procedure were utilized to retain lamellar lipids for precise morphological study. The unextracted multilamellar bodies were found to conform to a general, though complex, threedimensional structure. A model that demonstrated that structure was derived. Freezeetch and extracted material were shown to support the model. Mature multilamellar bodies were from 1.2–1.6 μ in diameter and were 1.0–1.6 μ high. Each body contained a matrix core that included from 2–25 vesicular bodies and was in contact with the limiting membrane at the matrix plate. Most bodies had from 25–70 lamellae attached for 360 ° to the projection plate. Microtubules were seen in communication with the matrix core. When sectioned in longitudinal section, lamellae projected from the base plate and coursed parallel to the limiting membrane of the top half of the body. Any cross-section produced circular lamellae without apparent attachment. Oblique sections sometimes produced both ‘stacked’ and ‘circular’ lamellae. Four postulates of multilamellar body formation were discussed in light of these findings.

The high resolution ultrastructure of the periodicity and architecture of lipid-retained and extracted lung multilamellar body laminations

Abstract: High resolution electron microscopy was utilized to study the periodicity and architecture of rat and monkey, lung multilamellar bodies. In lipid retention embedments and polar dehydrants, the lamellar width (LW) was defined as a lipid bilayer. The osmiophilic band that contained two layers of phospholipid heads (PH) of adjacent lipid bilayers in immediate opposition and the translucent band or fatty acid tail layer (FA) were also measured: glutaraldehyde and urea embedment, LW = 66 A, PH = 35–38 A, FA = 31 A; hydroxyethyl methacrylate glutaraldehyde and urea embedment, LW = 55 A, PH = 18 A, FA = 37 A; Epon 812 resin polar dehydrant, LW = 66 A, PH = 35–38 A, FA = 31 A; hydroxypropyl methacrylate polar dehydrant, semihomogeneous matrix without laminations. There was no interlamellar space, so the lamellar width was also the periodicity. In slightly extracted material the PH layer was usually the site of extraction. These results were considered in light of the previously reported measurements of extracted, lipid retained and frozen etched material. In vivo lamellae are probaly 66 A wide, composed of 35–38 A PH and 31 A FA layers and do not exhibit an interlamellar space. Lamellae were observed to fracture at the FA layer at bends, to bifurcate and to anastamose.

Vibrational Energy Transfer

Abstract: The theory of energy transfer in molecular collisions is of importance for the understanding of a great variety of physical problems.(1–7) In many of these problems we are interested in determining probabilities of energy transfer between the translational motion and one or more of the internal motions of the molecules. There has been much work done in recent years on the calculation of vibrational transition probabilities and inelastic scattering cross sections in which vibrational and/or rotational states are excited. Such collisions are a characteristic process in a simple molecular gas in the temperature range from 100° to 5000°K. Electronic transitions during collision will take place to a significant extent only at higher temperatures. For a gas in thermal equilibrium, individual molecules are constantly gaining or losing energy through collisions, but the total energy is unchanged. If conditions of equilibrium are suddenly changed, the gas finds itself seeking a new state of equilibrium; the rate of adjustment is governed directly by the collision efficiency, which measures the amount of energy either gained or lost per collision. At large separations, the colliding molecules attract slightly so their electron cloud overlapping is not important. However, as they approach each other to close range, where the overlapping of electron clouds is appreciable, repulsive forces are set up.

Wind shear observations in thunderstorm density currents

Abstract: Acoustic sounder observations of thunderstorm density currents reveal a complicated but ordered internal structure. Fast-response anemometers on a 150-m tower reveal a succession of internal shear layers which occur following the leading portion or nose of the current. The measured wind shear revealed by the anemometers is found to be a function of the temperature differential between the ambient air and the interior of the gust, measured near the surface. An heuristic model is developed to explain this observation.

Pivoted blade barrel rotor wind turbine

Abstract: The disclosed wind turbine has zero mean camber airfoil blades vertically pivoted at the outer ends of pairs of radius arms. The inner ends of the radius arms are fixed to a rotating mast. Each blade is provided with a steering vane. The deflection of each vane with respect to its associated blade is controlled by a cam toggle mechanism. The disclosed cam toggle mechanism includes a double-faced face cam, having a closed cam track on its upper face and another closed cam track on its lower face. Each cam track consists of two circular dwell portions.

The investigation of vinylcyclohexane dioxide as a polar dehydrant for the improved retention of lipids in the Spurr embedment.

Abstract: The use of vinylcyclohexane dioxide (VCD) as a polar dehydrant with subsequent embedment in Spurr was studied. The utilization of Epon 812 resin (E 812), hydroxyethyl methacrylate (HEM) and hydroxypropyl methacrylate (HPM) as polar dehydrants for Epon embedment were re-examined, and a polar Epon mix was introduced. The most effective dehydration sequence was: first 90%, then 95% VCD in water for 5 min, followed by two 20 min changes of 100% VCD. After 1 hr in equal quantities of VCD and Spurr mix, tissues were infiltrated with Spurr embedment (two 1 hr changes and overnight) and finally embedded in Spurr and polymerized at 60 °C for 16 hr. The most utilizable polar Epon mix was determined to be Epon 812 = 50 ml, NMA = 42 ml, DMP-30 = 1.2 ml. It was somewhat brittle but cut well with both glass and diamond knives. All four polar dehydrants were found to retain lipids and carbohydrates equally well in thin section in striated and cardiac muscle, liver, kidney and brain from the rat. The E 812 was the only dehydrant that retained lung multilamellar bodies. The possible carcinogenic effects of VCD were considered and the probable metabolism and excretion of VCD were discussed.

Sequence of centromere separation of mitotic chromosomes in Chinese hamster.

Abstract: Chromosome preparations in late metaphase cells from bone marrow of colcemid treated male Chinese hamsters were used to analyse the sequence of separation of sister centromeres. Chromatids of chromosomes 2 and 1 are the first ones to separate at centromeres, followed by members of group B, D and C. Some acrocentric chromosome is always the last one to separate at the centromere. The data point to a possible correlation between the position of a centromere in the separation sequence in the genome and the amount of centromeric heterochromatin as well as relation to the phenomenon of non-disjunction.

Elemental and isotopic geochemistry of nonhydrated quartz latite glasses from the Eureka Valley Tuff, east-central California

Abstract: The Eureka Valley Tuff, erupted from the late Miocene Little Walker volcanic center, east-central California, includes two major ash-flow sheets: the more voluminous, widespread, and more silicic Tollhouse Flat Member and the overlying By-Day Member. Nonhydrated quartz latitic glasses from the Tollhouse Flat and By-Day Members have, respectively, 65.5 and 63.3 wt percent SiO 2 and are extremely rich in large-ion lithophile elements. The K 2 O contents and K/Rb ratios are 5.3 wt percent and 195 for the Tollhouse Flat glass and 5.5 wt percent and 190 for glasses from the By-Day Member. FeO*/MgO (FeO* = total Fe as FeO) ratios are transitional between values characteristic of basaltic and calc-alkalic suites. Initial 87 Sr/ 86 Sr ratios of 0.7054 to 0.7055 are consistent with the pattern of northwestward decrease in 87 Sr/ 86 Sr observed for Mesozoic plutonic and Cenozoic volcanic rocks in the western Great Basin and Sierra Nevada provinces. The glasses are higher in Rb than are Mesozoic granitic rocks of the Sierra Nevada batholith that have comparable Sr contents and initial 87 Sr/ 86 Sr ratios. Pb isotopic compositions fall at the upper end of arrays found for upper Cenozoic calc-alkalic rocks from the Cascade Mountains and nearly on trends found for rocks of the Sierra Nevada batholith. The moderately high FeO*/MgO ratios, very low Co, Cr, and Ni contents, high Ba/Sr and K/Sr ratios, and approximately 25 percent negative Eu anomalies demonstrate that the glasses are the products of appreciable crystal fractionation. This in turn strongly suggests that the Eureka Valley Tuff was derived from a hypersthene-normative or only slightly quartz-normative parent magma. A model is outlined in which a potassic mafic parent magma was produced by a moderate degree of partial melting of diapirically upwelling, undepleted ultramafic mantle material followed by zone refining of upwelling mantle and other material within the asthenosphere and lithosphere. Extensive fractional crystallization and crystal separation subsequently enriched the melt further in large-ion lithophile elements. The evidence for appreciable plagioclase separation demonstrates that much fractionation took place well within the Earth9s crust. The Tollhouse Flat and By-Day Members were erupted from discrete — although closely related — bodies of magma. Lower water and halogen contents of the By-Day magma may have prevented the intratelluric crystallization of biotite and thereby allowed the magmatic liquid to become richer in K and Rb than that of the more highly fractionated Tollhouse Flat Member.

The Joint Use of Experiential and Cognitive Learning in the Classroom: Teaching With Personal Relevance.

Abstract: symbols. This was a weekly assignment and was the family member's most useful means of tracking the relationship patterns in the family over the 8-week period. The exercises of \"spit-back,\" \"family crisis,\" and \"dilemma dialogue\" all helped the members confront negative feelings and problems in the families. In \"spit back\" each member has the right to receive feedback and \"spit back\" what does not fit. \"Family crisis\" developed techniques of communication by helping an imaginary family member, and \"dilemma dialogue\" dealtwith real family problems in a structured manner. The connection between these exercises and Virginia Satir's ideas on family rolesand communication patterns should be apparent, but the psychoanalytic concepts of defenses and resistance were also involved. The \"creative project\" was an assignmentforthe family to create a gift from the family for the rest of the class. These gifts ranged from cookiesto songs, paintings, sculpture, and poetry. The \"miniature growth actions\" were creations of a different sort. Each family member created two brief growth producing exercises for himself and each member of his family. From this pool of exerciseseach member selected six which fitted his or her needs to do with the rest of the family. \"Family reunion\" is described in detail by Malamud (1971). This ,nonverbal exercise which involves coming together, separation, and resolution of the family was carried out in the context of the whole class. Most students evaluated this exercise as the most significant experience in the class. Finally \"farewell\" provided a structured means of saying good bye. Feedback and Evaluation. Each family member gave a written report on experiences in the families each week. These reports provided an evaluation of the experiences. In addition, at the end of the course each student anonymously evaluated the specific exercises, the \"second chance family\" experience and the course generally. The evaluations of the specific exercises varied considerably and seemed to reflect the individual needs of the students. All were rated moderately high by the majority of students, but the family creative project, the \"miniature growth actions\" and the \"family reunion\" were rated as having the most personal impact. Almost all of the participants wished the selection of families had occurred earlier so that the experience could have lasted longer. The evaluation of the course wasalso very high. Numbers derived from self report measures have to be viewed with caution, but 89% of the students who participated indicated they would choose a class with a \"second chance family\" experience. Only 11% reported they would prefer a more traditional class if presented with the opportunity again. Both of the students who chose the independent study contract at the beginning of the course indicated they would choose the \"second chance family\" experience next time. From an instructor's viewpoint the impact of the family experiences on the more traditional parts of the class, the lectures and demonstrations, was significant. Students sat together in their family groups. Discussions of the concepts were lively and participation by initially silent students increased noticeably after the families were formed and had functioned for awhile. Class attendance was not required but a frequency count was conducted each class period. During the first seven weeks of the course, attendance on the lecture and demonstration days averaged 73%. During the last eight weeks of the course, attendance on the lecture and demonstration days averaged 94%. Attendance on the group participation and family days averaged between 90-96% consistently throughout the semester. Concl~~s ions and Implications Techniques have been illustrated for using a cognitiveexperiential approach to the teaching of personality theory and counseling theory. This approach appeared to enhance student involvement in the courses described and contributed to both personal enrichment and the mastery of course content. Students reported being able to apply the theories to their own personal development as a result of the group experiences and stated that they learned significant things about themselves and others. The discussion of the theories themselves was distinctly different from most classroom interactions in that the students were more involved, active, and self-disclosing. It is felt that this approach provides opportunity for personal introspection and exploration, while at the same time making formerly \"abstract\" theories personally relevant. It is obvious that a combination of experiential and cognitive learning is appropriate for such courses as personality theory, principles of counseling, abnormal psychology and most other social science courses. It may not be as obvious that this corrbined approach is also appropriate for courses in other areas. However, any course which has a strong element of human learning can be taught using these techniques. A large pool of structured exercises is available (e.g., Jones & Pheiffer, 1973; Blank, Gottsegen, & Gottsegen, 1971) which can be adapted to a variety of course contents. Ultimately, the use of these techniques is limited only by the creativity of the instructor.

Serological diagnosis of petriellidiosis (allescheriosis). I. Isolation and characterization of soluble antigens from Allescheria boydii and Monosporium apiospermum.

Abstract: Soluble antigens in culture filtrates of three strains of Petriellidium boydii and three strains of Monosporium apiospermum were examined. Antigens were separated from concentrated crude filtrates by anion-exchange chromatography. A single major peak (Antigen 1), constituting a significant proportion of the total recoverable carbohydrate, was the only product isolated from each of four chromatographed filtrates. Depending on the fungus strain, Antigen 1 consisted of 90–96% carbohydrate, 3–4% protein, and 2–4% nucleic acid. Antigen 1 was found to consist of a population of molecules with a heterogeneous molecular size when assayed by gel filtration chromatography; however, isolated fractions of Antigen 1 proved to be immunologically identical when examined by Ouchterlony immunodiffusion. In addition, Antigen 1 from each strain was immunologically identical to similar preparations of Antigen 1 from the other five fungus strains. Chromatography of culture filtrates from two strains of M. apiospermum revealed a second peak (Antigen 2), which was found to consist of 70% carbohydrate, 16% protein, and 4% nucleic acid. Although Antigen 2 contained four times as much protein as Antigen 1, the two preparations were immunologically identical by immunodiffusion tests. Ion-exchange chromatography proved to be a useful procedure for isolating antigens of P. boydii and M. apiospermum from culture filtrates.

P- and sv-wave corner frequencies over low-loss paths: a discriminant for earthquake source theories?

Abstract: Seismic data recorded at Jamestown, California, provide P- and SV-wave spectral corner frequencies for 18 trans-Sierra Nevada events in the range 3.2≤ML≤4.0. These include most of the available earthquakes from 06 July 1974 to 31 August 1975. The ratio R of P- to SV-wave corner frequency was 0.96±0.17 for these events, which sample a wide range of source azimuths and focal mechanisms, Assumptions of a flat far-field source spectrum and frequency-independent attenuation in the 1-20 Hz band lead to Qβ not less than 480. Many recent source theories predict factor-of-two or more variation of R with azimuth, and significant deviation of its average value from unity; we conclude that such source models do not apply to these earthquakes. Previous studies of R by MOLNAR et al. (1973), STUMP (1974), and BAKUN et al. (1975), also based on excellent data, find different results. We interpret this discrepancy not as a contradiction, but as an indication that R may be an extremely useful source-model discriminant, its variation indicating that different models need be applied to different source regions. R may lead to a clearer understanding of the physical processes associated with earthquakes; for example, the only source models that predict a value of unity for R at all azimuths are those in which the corner frequency measures the time duration of motion at the source, thus indicating that this duration is as long as the rupture propagation time across the source.

The effects of training and effortfulness on rats’ choice behavior in a modified T-maze

Abstract: Rats were trained and tested in a modified T-maze in which one path to a goalbox was twice as long as the other. Both goal boxes contained food. One group of four rats received 60 training trials in the short alley alternated with 60 trials in the long alley before choice testing. Another group of six rats received 45 training trials in the short alley followed by 90 trials in the long alley. All animals received 120 choice trials in which both paths were available, conducted in eight blocks of 15 trials each. The equal-training group chose the short alley in all choice blocks, gradually increasing this preference. The second group, which received unequal training, chose the short path on only20% of the first 15 choice trials and then preferred the short alley in subsequent blocks. The results are compared to studies of contrafreeloading.