Showing papers by "Colorado State University published in 1977"
TL;DR: In this paper, a new soil test was developed for simultaneous extraction of NO3, P, K, Zn, Fe, Cu and Mn from alkaline soils, which can be stored under mineral oil.
Abstract: A new soil test was developed for simultaneous extraction of NO3, P, K, Zn, Fe, Cu and Mn from alkaline soils. The new extraction solution is 1 M in ammonium bicarbonate (NH4HCO3), 0.005 M in Diethylene Triamine Pentaacetic Acid (DTPA) and has a pH of 7.6. The new extracting solution should be stored under mineral oil. Ten grams of soil are weighed out into 125 ml Erlenmeyer flasks. Two 2.5 ml scoops of Fisher G carbon black (to remove color for colorimetric determination of nitrates) are added to each soil, followed by 20 ml extracting solution. The soil mixture is then shaken on an Eberbach reciprocal shaker for 15 minutes at 180 cycles per minute. The extract is then filtered through a Whatman 42 filter paper or its equivalent for NO3, P, K, Zn, Fe, Cu and Mn determinations. The results obtained with the new procedure are highly correlated with results obtained with Olsen's P test, ammonium acetate K test, and Lindsay and Norvell's DTPA‐Zn, Fe, Cu and Mn test. Regression equations between the ...
761 citations
TL;DR: In this paper, a review of literature on model and field data is presented, and the empirical data are compared with theoretical considerations, together with a set of design suggestions together with possibilities for protection against scour.
Abstract: A “state of the art“ report on the subject of local scour around cylindrical piers is given here. After a description of the scouring process, a critical review of literature on model and field data is presented, and the empirical data are compared with theoretical considerations. The final result is a set of design suggestions together with possibilities for protection against scour.
608 citations
TL;DR: In this paper, the authors present observational evidence in support of the existence of a large diurnal cycle (one daily maximum and one daily minimum) of oceanic, tropical, deep cumulus convection.
Abstract: This paper presents observational evidence in support of the existence of a large diurnal cycle (one daily maximum and one daily minimum) of oceanic, tropical, deep cumulus convection. The more intense the deep convection and the more associated it is with organized weather systems, the more evident is a diurnal cycle with a maximum in the morning. At many places heavy rainfall is 2–3 times greater in the morning than in the late afternoon-evening. Many land stations also show morning maxima of heavy rainfall. The GATE observations show a similar diurnal range in heavy rainfall, but the time of maximum occurrence is in the afternoon. This occurrence is 6–7 h later than in most other oceanic regions and is probably a result of downwind influences from Africa and the fact that the GATE heavy rainfall was often associated with squall lines. Diurnal variations in low-level, layered and total cloudiness show a much smaller range. The variability of deep convection and heavy rainfall is not readily obs...
572 citations
TL;DR: Eggs of Crocodilia and Chelonia have a pair of egg membranes separating a thick layer of albumen from the calcareous shell, while eggs of oviparous Lepidosauria have only a single shell membrane, upon which relatively small amounts of calcium carbonate are deposited.
Abstract: SUMMARY
1. Eggs of Crocodilia and Chelonia, like those of birds, have a pair of egg membranes separating a thick layer of albumen from the calcareous shell. In contrast, eggs of oviparous Lepidosauria have only a single shell membrane, upon which relatively small amounts of calcium carbonate are deposited; and the volume of albumen in eggs is extraordinarily small at the time of oviposition.
2. With the possible exception of certain geckos and some chelonians, eggs of oviparous reptiles seem always to absorb water from the substrate during the course of normal incubation. In so far as the rate of water absorption exceeds the rate of water loss by transpiration from exposed surfaces, the eggs swell during incubation. The term ‘cleidoic’ cannot be used to describe eggs of this type.
3. Embryos of lizards and snakes influence the water potential of extra-embryonic fluids contained within their eggs, thereby maintaining or increasing the gradient in water potential that drives water absorption.
4. Embryos of Crocodilia and Chelonia obtain a substantial portion of the calcium used in ossification of skeletal elements from the inner surfaces of the eggshell. In contrast, embryonic lizards and snakes draw upon extensive reserves of calcium present in the yolk, and obtain little (if any) calcium from the eggshell.
5. All reptilian embryos seem to produce substantial quantities of urea as a detoxification product of protein catabolism. Contrary to expectation, uricotelism may not be common among reptilian embryos, even in those few instances where development takes place within a hard, calcareous egg.
6. In eggs of Crocodilia and Chelonia, respiratory gases seem to pass by diffusion through pores in the calcareous eggshell and through spaces between the fibres of the pair of egg membranes. No pores have been observed in the shell of lepidosaurian eggs, and so gases presumably diffuse between the fibres of the single (multilayered) shell membrane.
7. Metabolism of reptilian embryos is temperature-dependent, as is true for most ectothermic organisms. For each species, there appears to be a particular temperature at which embryonic development proceeds optimally, and departures from this optimum elicit increases in developmental anomalies and/or embryonic mortality.
8. Viviparity has evolved on numerous occasions among species of the Squamata, but seemingly never among Crocodilia or Chelonia. Since the evolution of viviparity entails a progressive reduction in the eggshell, only those organisms whose embryos do not depend upon the eggshell as a source of calcium may have the evolutionary potential to become viviparous.
9. Evolutionary transitions from oviparity to viviparity could have been driven by selection related to (i) thermal benefits to embryos consequent upon retention of eggs within the body of a parent capable of behavioural thermoregulation; (ii) protection of the eggs from nest predators and/or soil microbes; and (iii) more effective exploitation of a seasonal food resource by early emerging young.
536 citations
TL;DR: A composite study of 10 years of northwest Pacific rawinsonde data is used to analyze the large-scale structure of tropical cyclones as discussed by the authors, where temperature, height, moisture, wind and vertical motion fields are analyzed for various storm regions.
Abstract: A composite study of 10 years of northwest Pacific rawinsonde data is used to analyze the large-scale structure of tropical cyclones. The temperature, height, moisture, wind and vertical motion fields are analyzed for various storm regions. Mean soundings for all regions from the eye through 12° radius are presented. Rainfall characteristics of the area inside 4° radius are discussed. Hurricane flight data are used to augment the analyses in the inner regions. Many important features are noted. Strong persistent asymmetries in storm structure exist, particularly at large radii. The storm circulation has very broad horizontal extent and appears to conform to a constant scale regardless of inner core intensity. Inflow in the middle troposphere is substantial from 4° outward. A mean subsidence region is observed from about 4–6° radius. Humidities are extremely high in the inner regions, and conditional instability exists everywhere outside the eye. Significant diurnal variations in rainfall and temp...
389 citations
TL;DR: In this paper, sufficient and sufficient conditions for weak convergence of the maxima are given for extremal processes generated by multivariate DF's and conditions for the limit joint DF to be a product of marginal DF's.
Abstract: Let
$$\{ (X_n^{(1)} ),...,X_n^{(k)} ,{\text{ }}n\} \underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{ \geqslant } 1\} $$
be k-dimensional iid random vectors. Necessary and sufficient conditions are found for the weak convergence of the maxima
$$\left\{ {\mathop {\text{V}}\limits_{j{\text{ = 1}}}^n X_j^{(1)} ,...,\mathop {\text{V}}\limits_{j{\text{ = 1}}}^n X_j^{(k)} } \right\}$$
suitably normed to a non-degenerate limit df. The class of such limits is specified and conditions stated for the limit joint df to be a product of marginal df's. Some results are presented concerning extremal processes generated by multivariate df's.
380 citations
201 citations
TL;DR: Over the 24-day experiment, respiration was significantly higher in the microcosms containing the bacterial grazers and the amoebae allocated more carbon to tissue production and correspondingly less to CO2, with partitioning of available carbon by the microfauna varied considerably.
Abstract: Flows of biomass and respiratory carbon were studied in a series of propylene-oxide sterilized soil microcosms. One-half of the microcosms received three pulsed additions of 200 ppm glucose-carbon to mimic rhizosphere carbon inputs. Biotic variables were: bacteria (Pseudomonas) alone, or amoebae (Acanthamoeba) and nematodes (Mesodiplogaster) singly, or both combined in the presence of bacteria. Over the 24-day experiment, respiration was significantly higher in the microcosms containing the bacterial grazers. Biomass accumulation by amoebae was significantly higher than that by nematodes. The nematodes respired up to 30-fold more CO2 per unit biomass than did amoebae. Similar amounts of carbon flowed into both respiratory and biomass carbon in microcosms with fauna, compared with the bacteria-alone microcosms. However, partitioning of available carbon by the microfauna varied considerably, with little biomass production and relatively more CO2-C produced in the nematode-containing microcosms. The amoebae, in contrast, allocated more carbon to tissue production (about 40% assimilation efficiency) and correspondingly less to CO2.
196 citations
TL;DR: The Tropic Haze refers to turbid layers of air which are found regularly over the pack ice north of Alaska during periods of clear weather as mentioned in this paper, and can occur as single or multiple bands of different heights at nearly any level in the troposphere.
Abstract: ‘ARCTIC haze’ refers to turbid layers of air which are found regularly over the pack ice north of Alaska during periods of clear weather1. These layers are diffuse, hundreds to thousands of kilometres wide, 1–3 km thick, and can occur as single or multiple bands of different heights at nearly any level in the troposphere. They are invisible from the ground, but may limit horizontal and slant visibility within a layer to as little as 3–8 km. Their colour is grey–blue in the antisolar direction and reddish–brown in the solar direction, suggesting that they are true aerosol rather than ice crystals.
190 citations
TL;DR: In this paper, measurements of longstream and cross stream velocities carried out across sections of a river perpendicular to the outer banks of several bends using an electromagnetic flow meter are reported.
Abstract: FLUIDS flowing through pipes or channels can develop secondary currents. These are defined as currents which occur in the plane normal to the local axis of the primary flow. Their development in straight channels has been ascribed to anisotropic turbulence and the non-uniform distribution of boundary shear stress1–3 but in meander bends they are generally caused by skewing of the flow3–5. Secondary currents distort the distributions of primary isovels and boundary shear stress from those expected in simple flows and, therefore, have important implications for bed and bank erosion and for resistence to flow. We report here measurements of longstream and cross stream velocities carried out across sections of a river perpendicular to the outer banks of several bends using an electromagnetic flow meter.
181 citations
TL;DR: Using a conceptual model, a series of papers are introduced which ascertain the role of microfloral-faunal trophic interactions in carbon, nitrogen, and phosphorus transformations in soil microcosms.
Abstract: The dynamics of nutrient transformations at the soil-root interface are complex but amenable to controlled experimental study. Using a conceptual model we introduce a series of papers which ascertain the role of microfloral-faunal trophic interactions in carbon, nitrogen, and phosphorus transformations in soil microcosms.
TL;DR: In this paper, the propagation characteristics of various types of shallow water waves in open channel flow are calculated on the basis of linear stability theory, and the celerity and attenuation functions of kinematic, diffusion, convective dynamic, dynamic and gravity waves are derived.
Abstract: The propagation characteristics of various types of shallow water waves in open channel flow are calculated on the basis of linear stability theory. The celerity and attenuation functions of kinematic, diffusion, convective dynamic, dynamic and gravity waves, are derived. For the most general case, i.e., the dynamic wave model, the propagation characteristics are expressed as a function of the steady uniform flow Froude number and the dimensionless wave number of the unsteady component of the motion. For the dynamic model, the wave number spectrum is divided into three bands: 1)A gravity band corresponding to large wave number, where the wave celerity is the gravity wave celerity; 2)a kinematic band corresponding to a small wave number where the wave celerity is the kinematic wave celerity; and 3)a dynamic band corresponding to mid-spectrum values of the wave number, where the wave celerity falls between the gravity and kinematic celerity values.
TL;DR: Melatonin was measured by radioimmunoassay in jugular vein plasma and lateral ventricle cerebrospinal fluid collected from calves at 12 times of the day and night and plasma concentrations of melatonin increased sixfold.
Abstract: Melatonin was measured by radioimmunoassay in jugular vein plasma and lateral ventricle cerebrospinal fluid collected from calves at 12 times of the day and night. Melatonin in cerebrospinal fluid increased 17-fold from an average (+/- standard error) of 38 +/- 8 picograms per milliliter during the day to an average of 637 +/- 133 picograms per milliliter during the night (P less than .001). Plasma concentrations of melatonin increased sixfold from an average, per milliliter, of 19 +/- 4 picograms during the day to 121 +/- 24 picograms during the night (P less than .001).
TL;DR: A major role of microfauna in nutrient cycling is suggested in terrestrial ecosystems, where evidence from aquatic ecosystems indicates that bacteria release little phosphorus, for which they have high demand, whereas bacterial grazers play an important role in regeneration of bacterial phosphorus.
Abstract: Regeneration of nutrients from relatively nutrient-poor organic residues is essential for overall operation of an ecosystem. Nutrients thus released are, however, inadequate for the needs of the decomposer populations, and a much faster nutrient turnover involving bacterial immobilization and release occurs concurrently. Evidence from aquatic ecosystems indicates that bacteria release little phosphorus, for which they have high demand, whereas bacterial grazers play an important role in regeneration of bacterial phosphorus. Our studies extend these relationships to terrestrial ecosystems. We studied phosphorus immobilization and mineralization in soil incubations, simulating rhizospheres with combinations of bacterial, amoebal, and nematode populations. Bacteria quickly assimilated and retained much of the labile inorganic phosphorus as carbon substrates were metabolized. Most of this bacterial phosphorus was mineralized and returned to the inorganic phosphorus pool by the amoebae. Nematode effects on phosphorus mineralization were small, except for indirect effects on amoebal activity. The observed remineralization may reflect direct excretion by the amoebae, physiological effects on the bacterial populations, or both. These results suggest a major role of microfauna in nutrient cycling.
TL;DR: In this paper, the effect of radioiodination, antisera and sera on levels of endogenous gonadotropinreleasing hormone (GnRH)-like activity in serum as quantified by radioimmunoassay was investigated.
Abstract: Studies were undertaken to determine the effect of method of radioiodination, antisera and sera on levels of endogenous gonadotropinreleasing hormone (GnRH)-like activity in serum as quantified by radioimmunoassay. GnRH was radioiodinated by the chloramine T or lactoperoxidase procedure and purified on columns of Sephadex G-25 (0.8 × 20 cm, eluted with 0.0lN acetic acid) or on columns of QAE Sephadex G-25-120, an anion exchange resin (0.6 × 25 cm, eluted with 0.1M borate buffer, pH 9.2, containing 0.1% gelatin). Unlabeled GnRH, monoiodo-GnRH and diiodo-GnRH were separated on the QAE Sephadex columns. Levels of immunoassayable GnRH-like activity in sera of ewes were lower (P < 0.05) when antiserum R-42 (high affinity) was used for quantification than when antiserum R-31 (low affinity) was used. Furthermore, levels of immunoassayable GnRH-like activity in sera were lower when monoiodo-GnRH from the lactoperoxidase radioiodination was used for quantification than when other radioiodinated preparations were u...
TL;DR: In this paper, it is shown that cross-polarization spectra obtained with dipolar decoupling display chemical shift anisotropy which interferes with attempts to distinguish the resonances of aromatic and aliphatic carbons.
TL;DR: For instance, this article found that personality probably influences the choice of a recreation activity in which a person engages the most frequently (direct associations were weak, and further research is needed), personality characteristics are significan...
Abstract: Results of exploratory research on relationships between personality characteristics (measured by Jackson's Personality Research Form), choice of recreation activities engaged in actively, frequency of participation in those activities, and the desired consequences (i.e., satisfying experiences) expected from that participation are reported. Ss were test groups of 50 recreationists per activity engaging in one of nine different activities when interviewed on-site. Ss were classified by sex into active and nonactive participants in each of the activities. Participation was measured using respondents' recall of total days of having engaged at least once in specified activities during the preceding 12 months. The results are tentative because of small sample sizes. The indicate that (1) personality probably influences the choice of a recreation activity in which a person engages the most frequently (direct associations were weak, and further research is needed), (2) personality characteristics are significan...
TL;DR: Dietary supplementation of either vitamin E or vitamin A significantly reduced E. coli caused mortality, but the combination of the two vitamins did not, partially explaining the lack of protection in vitamin E and A supplemented chicks.
TL;DR: In this article, the Eppley pyrgeometer performance was compared to the desired theoretical performance due to battery voltage uncertainties, nonlinearity of circuitry at extreme temperature and differential heating of the instrument.
Abstract: The actual performance of an Eppley pyrgeometer is compared to the desired theoretical performance. Several systematic errors are identified and evaluated in detail. The three most significant errors identified are due to 1) battery voltage uncertainties, 2) nonlinearity of circuitry at extreme temperature and 3) differential heating of the instrument. The elimination of the error due to differential heating is found to be essential to the successful calibration of the instrument. A pyrgeometer laboratory calibration technique is described. Pyrgeometer measurements made from aircraft are shown to have potential errors as large as 60 W m−2. These errors, however, do not significantly affect the net radiation provided the upward and downward facing pyrgeometers are at the same equilibrium temperature, and may be largely eliminated by making accurate temperature measurements of the KRS-5 dome and the cold junctions of the thermopile. The corrections considered in this paper not only reduce the absol...
TL;DR: In this article, it was shown that the animals compensate for increased weight-specific thermogenesis in winter by lowering body weight, which may allow tolerance to lower thermal exposures, and that the increase in weightspecific rates of oxygen consumption is a decrease in body weight.
Abstract: The weight-specific oxygen consumption ([Formula: see text]) of prairie voles caught in winter is 24% higher at 27.5° C and 29% higher at 7.5° C than that of summer animals, thus affording a higher weight-specific thermogenesis in winter than in summer which may allow tolerance to lower thermal exposures. Coincident with the increase in weight-specific rates of oxygen consumption is a decrease in body weight. When total energetic cost to maintain an animal per unit time is calculated, the cost at 27.5° C is the same for both summer and winter animals. Further, the cost to maintain an animal at 7.5° C is less in winter than in summer. Arguments are presented suggesting that prairie voles compensate for increased weight-specific thermogenesis in winter by lowering body weight. The responses to thermal acclimation are quite different in summer and winter animals, thus implying different sorts of metabolic organization. Acclimation to 5° C effects a 26% increase in [Formula: see text] at 27.5° C of winter voles, and acclimation to 30° C does not change [Formula: see text]. In contrast, [Formula: see text] at 27.5° C of summer animals is unaffected by 5° C acclimation, and depressed 20% by 30° C acclimation. Thus, the animals are capable of considerable physiological adjustment to varying thermal conditions in different seasons.
TL;DR: After 24 days the nematode populations in the treatments without carbon additions were dominated by resistant dauer larvae indicating the unavailability of food, and the adult component of the population was still increasing at the end of the 24-day experiment.
Abstract: Bacteria (Pseudomonas), amoebae (Acanthamoeba), and nematodes (Mesodiplogaster) were raised in soil microcosms with and without glucose additions. Nematode and amoebal grazing on bacteria significantly reduced bacterial populations by the end of a 24-day incubation period. Amoebal numbers decreased in the presence of nematodes with a corresponding increase in nematode numbers which reached a maximum of 230 nematodes/g of soil in the treatment with amoebae and glucose additions. After 24 days the nematode populations in the treatments without carbon additions were dominated by resistant dauer larvae indicating the unavailability of food. Although larval numbers were high in the treatments with glucose additions, the adult component of the population was still increasing at the end of the 24-day experiment. The effect of the presence of amoebae on nematode abundance was of the same magnitude as addition of 600Μg glucose-C.
TL;DR: In this article, tracer gas was measured in a 400:1 scale model of an idealized city with variable geometry placed within a wind tunnel at various orientations to the mean flow for a free stream velocity of 68 ft/sec.
Abstract: Steady state mean concentrations of tracer gas were measured in a 400:1 scale model of an idealized city with variable geometry placed within a wind tunnel at various orientations to the mean flow for a free stream velocity of 68 ft/sec The tracer gas was released from two parallel line sources to simulate lanes of traffic in an effort to quantify the persistence of pollution as well as the mean values realized at street levels An aerodynamically rough turbulent boundary layer of neutral thermal stratification was employed to simulate the atmosphere Values of concentration measured in the model city were converted to prototype concentrations in ppm and compared to National Ambient Air Quality Standards It was shown that single isolated structures may cause favorable mixing of pollution downwind but very high concentrations exist in the immediate leeward vicinity of the building Two favorable geometries for city blocks tested were found to reduce pedestrian exposure to pollution both near heavy traff
TL;DR: It is shown that the resonant frequency observed in these spectra will vary as the cardiac pressure changes, so the variations of the resonance can be calibrated to give the pressure excursions in a cardiac chamber.
Abstract: We suggest and analyze a new technique for making non-invasive cardiac measurements. The technique involves measurement of the spectrum of ultrasound scattered from small bubbles injected into the circulatory system as they pass through the heart. We show that the resonant frequency observed in these spectra will vary as the cardiac pressure changes. Thus the variations of the resonance can be calibrated to give the pressure excursions in a cardiac chamber. Preliminary bench tests of the method are described which show the predicted shift with pressure of the resonance frequency of bubbles in water.
TL;DR: In this paper, a set of simultaneous equations are developed which solve for cloud-top temperature (Tcld) and cloud amount (Acld) within the geometric field of view of the sensor.
Abstract: A technique is presented for determining cloud heights and amounts through the use of simultaneous. infrared and visible satellite radiance data. A set of simultaneous equations are developed which solve for cloud-top temperature (Tcld) and cloud amount (Acld) within the geometric field of view of the sensor. The cloud height is determined by comparing Tcld to upper air soundings, An error analysis is also presented showing the accuracy that can he obtained in Tcld and Acld when uncertainties exist in the measured visible and infrared radiances and in the assumptions required. Actual satellite measurements taken from the NOAA Scanning Radiometer (SR) are input into the technique and run for three specific geographical locations during several seasons where ground-based cloud observations are available. Results show an rms error in cloud amount of 0.2 and in cloud height of 0.5 km for a 75 km×75 km area for all cloud types except cirrus. For this case we have developed alternate solutions which ac...
TL;DR: In this article, a sensitive Colpitts oscillator circuit monitored the spatial and temporal variations in magnetization in a vertical 11 cm column of magnetic fluid, and the results are consistent with the hypothesis that spherical agglomerates of 10 7 -10 9 particles are formed and settle gravitationally.
TL;DR: In this paper, the authors examine consequences of the dependence of survival on the causes of censorixg and the testability of a set of data for the importance in survival inferences of the underlying censoring mechanism as well as the consequences of falsely assuming that the mechanism does not affect inferences about survival.
Abstract: SUMMARY In the analysis of survival-type variables arising from medical investigations, one is often faced with incomplete or right-censored observations. In many cases the mechanisms leading to censoring are intrinsically related to the survival variable and standard methods of analysis are not appropriate. In this paper we examine consequences of the dependence of survival on the causes of censorixg. Also examined are the testability of a set of data for the importance in survival inferences of the underlying censoring mechanism as well as the consequences of falsely assuming that the censoring mechanism does not affect inferences about survival. The special case in which survival is exponential is discussed in detail.
TL;DR: In this article, the authors used the data composited in Paper I to analyze the dynamics and energetics of a mature tropical cyclone in terms of budget studies of moist static energy, angular momentum and kinetic energy.
Abstract: This study uses the data composited in Paper I to analyze the dynamics and energetics of a mature tropical cyclone in term of budget studies of moist static energy, angular momentum and kinetic energy. Sea surface to air fluxes of moisture and sensible heat are found to be much smaller than the estimates of most previous researchers. Horizontal eddy fluxes of momentum and kinetic energy are substantial at outer radii in the upper troposphere. The Coriolis torque term in the angular momentum equation does not integrate to zero over the large-scale storm circulation but rather becomes a dominant term. Tropical cyclones are net sources of kinetic energy over their large-scale circulations. This probably results from strong transient eddy generation of kinetic energy within the storm.
TL;DR: In this paper, a series of discontinuous, unpaired terraces were formed below the level of the old valley floor by discontinuous downcutting that apparently was not related to changes of base level, climate or land use, although the initial incision was probably due to the introduction of large numbers of livestock.
Abstract: Channel incision began after 1880 in Douglas Creek, a tributary of the White River in northwestern Colorado. This modern erosion produced a complex series of discontinuous, unpaired terraces below the 1880 valley floor. As many as four of these surfaces were formed below the level of the old valley floor by a process of discontinuous downcutting that apparently was not related to changes of base level, climate, or land use, although the initial incision was probably due to the introduction of large numbers of livestock. The progress of incision was impeded as large quantities of sediment were flushed from steep tributary valleys into the main channel. Temporary storage and flushing of the sediment by episodic erosion produced a complex post-1900 terrace sequence. This phenomenon may be expected following rejuvenation of areas of high relief and high sediment production, and episodic incision may be a normal part of the erosional evolution of such areas.