Equal Increments Research Articles

Frequency functions of Venus nightside ion densities

The frequency with which the total ion density Ni and constituent densities O+, H+, and molecular ion density O2++M29+ (= [O2+] + [NO+] + [CO+] + [N2+]) fall between equal increments of the logarithm of the density is derived. The individual measurements are first normalized by dividing them by their median value at the altitude of measurement. This process removes the known altitude variation from the sets. The resulting frequency functions are assumed to result from temporal variations alone. The data used in deriving the functions are restricted to 120°–180° solar zenith angle (SZA) and altitudes between 140 and 900 km. The frequency function derived for Ni is found to be insensitive to division of the parent set into two approximately equal subsets representing division into dawn and dusk hemispheres, an upper and lower altitude interval, or two SZA intervals. The Ni function is found to be reasonably well peaked near the median value, and 78% of the normalized values fall within a factor of 2.8 of the median value. The frequency of occurrence decreases more rapidly on the high side of the median than on the low side. The frequency functions for the constituent ions are similar to that for Ni, with the percentage of normalized densities falling within a factor of 2.8 of the median value ranging from 82% for O2+ + M29+ to 71% for H+. The similarities and dissimilarities between the frequency function for O+ and those for H+ and O2+ + M29+ are discussed in relation to the role of O+ in producing the H+ and O2+ + M29+ constituents.

Envelope generating circuit for an electronic musical instrument

An improved envelope generator circuit for an electronic organ provides a musically correct attack rate, i.e., the volume of a musical note is increased by an equal number of decibels for equal increments of time. The envelope generating circuit comprises a constant current source for charging a capacitor to generate a linearly increasing voltage signal upon the initial activation of any one or more keys of an electronic organ keyboard. A regulator circuit comprising an operational amplifier and a matched pair of transistors with one transistor connected into the feedback path for the operational amplifier generates an anti-logarithmic control signal in response to the linearly increasing voltage signal. The antilogarithmic control signal is used to control the amplification of a controlled amplifier to which music signals from the organ are passed. The amplifier amplifies the musical signals in accordance with the control signal to generate an output which increases in volume an equal number of decibels for equal periods of time.

The probabilistic nature of synaptic transmission at a mammalian excitatory central synapse

The synaptic connection between single group I afferents and dorsal spinocerebellar tract (DSCT) neurons in the cat spinal cord has been studied in an attempt to gain insight into the mechanisms of excitatory synaptic transmission in the mammalian CNS. Fluctuations in the amplitude of single group I fiber EPSPs in DSCT neurons were examined using a numerical deconvolution procedure to reduce the effects of contaminating noise. In general, it was found that single fiber EPSPs fluctuate in peak amplitude between discrete levels separated by equal or quantal increments. Many previous studies have proposed simple binomial statistics as a general model of quantal synaptic transmission. In the present study we show that simple binomial statistics do not describe the fluctuations in amplitude of single group I fiber EPSPs in DSCT neurons. It is suggested that nonuniformities in the probability of transmitter release from release site to release site explain the failure of the binomial model to describe the EPSP fluctuation pattern at this synapse. Nonuniform quantal transmission is proposed as a more adequate description of excitatory synaptic transmission in the mammalian CNS.

Chromosome weights and measures in Petunia

The 2C nuclear DNA amounts in diploid Petunia species are low, ranging from 1·73 to 3·00 picograms. The nuclear dry mass and the total chromosome volume are closely correlated with the nuclear DNA amount. So also is cell size measured in pollen grains. Increase in the total nuclear DNA within the genus is achieved by the addition of equal increments of DNA to all members of the chromosome complement irrespective of their size. It is suggested that the correlations and distribution patterns of DNA changes displayed by the natural species may serve as standards for monitoring and interpreting changes in genetic material which are associated with regeneration from protoplasts and callus.

Residual Depth Profile in the Evaluation of Granular Adsorbents

The penetration of radioactive CH3131I through adsorbent carbon was studied in air flow systems as a function of bed depth. The count profile in equal increments of depth was found to be exponential with depth along the line of flow for the air-vapor mixtures. The slopes (lognormal count versus depth) were determined for a number of weathered and used carbons as well as for new materials. A large numerical magnitude of the slope is characteristic of new and good carbons; a low value signifies poor retention by the test column. The profile measurements correlate with the percent of penetration. The residual depth profile can serve as an index for the need to replace or to regenerate the carbon bed.

Distributive Justice and the Public Good

Many philosophers and some economists value economic equality on the ground that transfers from the relatively rich to the relatively poor increase the utility of the poor more than they reduce the utility of the rich. These philosophers and economists are assuming the ethical principle that a pattern of economic distribution is justified by maximizing aggregate utility. They are also assuming the truth of an empirical generalization proposed in the eighteenth century by Daniel Bernoulli–that successive equal increments of income produce ever-diminishing increments in an individual's level of utility. In the first part of this essay I will argue against Bernoulli's hypothesis, and suggest an alternative view of the relation between income and utility.

A microcomputer-based deep-level transient spectroscopy (DLTS) system

A totally automated, microcomputer-based deep-level transient spectroscopy (DLTS) system developed at the University of Arkansas is described. The hardware and interfaces are discussed in terms of their accuracy and contribution to the requirements for performing DLTS measurements. The software developed to control the hardware, as well as that used to acquire, reduce, and manipulate the data, is explained. The software introduces the concept of building a database by sampling the transient decay at equal intervals over a temperature scan of equal temperature increments. This method allows for cycling the hardware and test device only once through a temperature scan and storing the data for later analysis.

Nitrogen balance in relation to energy intake in entire male pigs weighing 75 kg

1. Nitrogen balance (NB) was determined in entire male pigs weighing 75.6 (SE 0.56) kg and given 1.43 MJ metabolizable energy (ME)/kg live weight (LW)0.75 per d of semi-synthetic liquid diets which varied in crude protein (N x 6.38):ME from 2.5 to 14.5 g/MJ. Maximum NB of 20.8 g/d was reached with diets containing at least 6.2 g protein/MJ ME. 2. The relation between energy intake and NB was then examined in pigs of comparable live weight (mean 73.8 (SE 0.39) kg) and receiving a liquid diet not limiting in protein. The diet, containing 10.0 g protein/MJ ME, was given at eight rates from 0.24 MJ ME/kg LW0.75 per d to ad lib. by approximately equal increments. Two animals were allocated to each level and two animals were fasted during the balance period. 3. The animals fed ad lib. achieved a mean intake of 1.84 MJ ME/kg LW0.75 per d. NB increased linearly as ME intake increased up to 27.6 MJ/d (1.096 MJ/kg LW0.75 per d) but thereafter remained constant at 22.8 g N/d.

Time series analysis of fatigue crack growth rate data

Previous treatments of fatigue crack growth rate (FCGR) statistics have sought to determine the best testing and data analysis techniques with which to process fatigue crack growth data. The best techniques were denned as the ones that produced the least scatter in the data. Recent studies suggest that the scatter in FCGR data has physical significance, which must be understood in order to predict the growth of small cracks. This paper presents a stochastic model which treats the material's resistance to fatigue crack growth as a spatial stochastic process evolving along the path of the crack. The parameters of the model are found by a time series analysis which accounts for the statistical correlation that has been observed between adjacent FCGR measurements. The data to be analyzed is assumed to consist of an ensemble of replicate crack growth tests sampled at equal increments of crack growth. The model is shown to be useful for explaining the moderate scatter observed in mid-range ΔK tests. It is also likely to be useful for understanding the large scatter observed in small crack tests.

Use of Logrank Tests and Group Sequential Methods at Fixed Calendar Times

This paper presents simulations to determine the operating characteristics of several group sequential boundaries when applied to the repeated analysis of survival data at equal intervals of calendar time. Because the group sequential boundaries of Pocock (1977, Biometrika 64, 191-199) and O'Brien and Fleming (1979, Biometrics 35, 549-556) were constructed on the assumption that each interim analysis provides an equal increment of statistical information, these boundaries are not theoretically appropriate for interim analysis at prescheduled calendar times. Nonetheless, our simulations show that these boundaries yield size and power near nominal levels for repeated logrank analyses at equal intervals of calendar time.

Characterization of segmental collateral blood flow in the small intestine.

Collateral blood flow and the pressures and resistances determining that flow were measured between two adjacent segments of canine jejunum following acute occlusion of the arterial branch perfusing one of the segments (the "recipient" segment). Collateral flow was approximately 55% of control flow in the recipient segment. This flow was provided by an equal increment in arterial flow to the nonischemic ("donor") segment, such that pressures, resistances, and flows in the donor segment were not affected. Virtually all of the total collateral flow was derived from precapillary channels and was therefore available to the capillary bed of the recipient segment. Collateral flow was adequate to maintain the recipient segment in a nonischemic state, as indicated by the absence of a reactive hyperemia following release of the arterial occlusion. Selective occlusions of intramural or extramural collateral channels indicate that about two-thirds of the total collateral flow is derived from the extramural (marginal) vessels, while the remainder is supplied by intramural collaterals. For the most part collateral flow between adjacent segments is determined simply by the pressure gradient between connecting collateral channels.

Continuous Convolution With Hydrologic Data

The integral form of the convolution equation can be used for hydrologic data sampled at equal time increments if simple functional forms are assumed for the change in the hydrologic variables between sampling points. The forms studied here are a step function, linear segment, and sliding polynomial, and algorithms are presented for convolution of all combinations of these functions. The effect of the different assumptions is demonstrated by a sample data set. These algorithms have three advantages: an appropriate functional form can be selected for the two variables to be convolved, different time increments may be used for the two variables, and the output may be calculated at any point in continuous time, not just at multiples of the sampling increments. The algorithms may also be applied to deconvolution but suffer many of the difficulties of matrix inversion techniques when the data contain errors or are derived from a system which is only approximately linear.

A modeling strategy for the growth projection of managed stands

Using a large data base of permanent research plots in coastal Douglas-fir, a growth projection strategy is developed. The emphasis is on stratifying growth influences into potential and modifier functions for components of diameter and height growth within a stand table. Growth periods are defined as equal increments of top height through time. The model developed is an individual-tree, distance-independent, stand-projection model.

Brief separation elevates cortisol in mother and infant squirrel monkeys

The pituitary-adrenal response of mother and infant squirrel monkeys was assessed under basal conditions and after 5, 10, or 20 min of separation followed by 30 min of reunion. All separation conditions produced equal increments of cortisol (approximately 50%) in both mothers and infants. These increments were lower than would have occurred in the absence of reunion. These results extend previous reports that reunion ameliorates the psychoendocrine effects of separation and indicate that mother-infant attachment can be studied with shorter periods of separation than have been used customarily.

A Stochastic Model of Dimensionless Thunderstorm Rainfall

A concise stochastic model for the nondimensional thunderstorm rainfall process at a point is proposed. The accumulated precipitation process for individual thunderstorms is nondimensionalized by dividing the precipitation at any time by the total precipitation and the elapsed time by the total duration. The dimensionless process is divided into 100 equal time increments, and the depth increments are rescaled to range between 0 and 1. The sequence of rescaled increments Z1, Z2,…, Z9 are assumed to represent a nonhomogeneous Markov process in discrete time with continuous state space. The expected value of the kth rescaled increment, given the k‐1st increment, is assumed to be a linear function of that increment, and the marginal distribution of the first increment and the conditional distributions are assumed to be described by the beta distribution. An analyses of data for 275 thunderstorms observed at the Walnut Gulch Experimental Watershed in southeastern Arizona showed that the proposed model structure is a good approximation for this region. The number of model parameters can be reduced from 26 to a minimum of 10 by approximating the 2 parameters in the conditional expectation function and the conditional beta parameter as polynomial functions of the dimensionless time. Likelihood ratio tests and the Akaike information criterion suggest that the dependence parameters are independent of storm amount and duration, but the conditional beta parameter αk is larger for short‐duration storms than for long‐duration storms. A 13‐parameter model is recommended for disaggregating thunderstorm rainfall in southeastern Arizona.

Measurements of despin and yawing moments produced by a viscous liquid

The behavior indicated in Figs. 3 and 4 suggests that a small shape change would occur with each pitch oscillation of the vehicle, so that the resulting trim moments would tend to cancel out. If the net trim remained sufficiently small, then the epicyclic motion would persist until it damped out from inherent pitch and normal force damping. Because successive points of minimum ! I and presumed shape change occur on essentially opposite meridians (from the point of view of an observer fixed in space), the lift nonaveraging dispersion associated with equal increments of shape change should be minimal.' It is emphasized that these conclusions are based on the assumption that very small incipient ablation or erosion asymmetries exist which do not influence the motion. A more rigorous treatment of the problem should include the effects of these shape asymmetries on the coupling between the angle of attack and windward-meridian rotation rate.

Timing and Rate of K Application for Wheat‐Soybean Double Cropping on a Sandy Soil1

AbstractThe wheat [Triticum aestivum (L.) em. Thell.] and soybean (Glycine max (L.) Merr.] double cropping sequence is an important cropping system in the Southern Coastal Plain of the USA. A study was conducted for two crop cycles to determine the optimum timing of supplying adequate K on a Bonifay sand (loamy, siliceous, thermic grossarenic, Plinthic Paleudult). Treatment variables consisted of five K application timings at two Mg rates (0 and 40 kg ha−1) in the first crop cycle, and four K application timings at four rates of K (90,135,180, and 225 kg ha−1) in the second crop cycle. Significant leaching of K from the 0 to 15 and 15 to 30 cm depth was measured when all of the K fertilizer was applied at wheat planting. Potassium uptake and grain yield of wheat were significantly greater for treatments in which one‐half of the total K fertilizer was applied at wheat planting and the remainder in February or as one‐fourth at wheat planting, one‐half in February and the remainder at 6 to 8 weeks after soybean planting compared with the application of all of K fertilizer at wheat planting, application of K at planting of both crops or split application of K in four equal increments on both crops. However, soybean yields were not significantly affected by the treatments in either cropping cycle. Application of Mg in the first cycle increased both soil and plant Mg concentrations but had no significant effect on yields. Increasing rates of K linearly increased wheat yield and soil K at soybean planting but had no significant effects on soybean yield or soil K at the end of the season. We concluded that delaying the application of at least one‐half of the K fertilizer until spring is essential for maintaining adequate K in the rhizosphere of wheat plants on deep sands.

Increased vasopressor responsiveness to angiotensin II in type 1 (insulin-dependent) diabetic patients without complications.

The blood pressure response to infused angiotensin II (0.3 to 3 ng X kg-1 X min-1) was investigated in six normotensive patients with Type 1 (insulin-dependent) diabetes free of complications and in six healthy subjects matched for age, sex and weight. Basal blood pressures (111/68 and 114/72 mmHg) and basal plasma angiotensin II levels (18.0 +/- 5.2 and 14.1 +/- 2.4 pmol/l; mean + SD) were similar in the diabetic and control groups as were 24 h urinary excretions of sodium (157 +/- 88 and 154 +/- 84 mmol/24 h). Equal increments in plasma angiotensin II were produced during the infusions in the two groups. Increases in both diastolic and systolic blood pressure were significantly greater in the diabetic patients throughout the infusion. Mean diastolic increments were: 6.7 versus 1.3 mmHg (0.3 ng dose), 11.0 versus 6.9 mmHg (1 ng dose) and 16.7 versus 12.3 mmHg (3 ng dose) (p less than 0.001). Corresponding figures for systolic pressure were: 8.7 versus 1.3 mmHg, 10.3 versus 3.7 mmHg and 15.3 versus 8.7 mmHg (p less than 0.001). Vasopressor responsiveness to angiotensin II is thus increased in Type 1 diabetic patients without complications; it may, therefore, be a consequence of the diabetes rather than of the presence of microvascular disease or hypertension.

Fourier shape analysis of Upper Cretaceous Normapolles from southern Sweden

Abstract Pollen grains of three previously described species of Upper Cretaceous dispersed Normapolles from souther Sweden, Extratriporopollenites (Oculopollis) triceps Skarby, E. (Trudopollis) artifex Weyland & Krieger and E. (Trudopollis) firmus Skarby, and specimens extracted from a single anther (identified as E. artifex), have been analyzed by Fourier analysis. The purpose was to assess quantitatively the diagnostic significance of the outer and inner equatorial contour, and also the validity of the species. Seventy-two radii were measured at equal angular increments along the outer and inner contour, and Fourier series were fitted to the resulting curves. The shapes of the pollen grains may be described by the average radius (zeroth harmonic) and a series of cosine curves relating to their three-fold symmetry (third, sixth, nineth through twenty-fourth harmonic). Multivariate analyses of these harmonics show that E. firmus, which lacks prominent apertures, stands out as a distinct species. The specimens from the single anther fall within the range of T. artifex. Some specimens identified as E. triceps overlap with T. artifex, indicating that the apertures in this species, described as well-developed, may approach the less prominent apertures of T. artifex. The results emphasize the difficulties in separating the genera Oculopollis and Trudopollis Pflug. Typical specimens can be identified, but not intermediate forms. In order to solve this problem a thorough quantitative analysis of dispersed specimens and pollen from anthers is necessary.

Predicted values for clinical exercise testing.

Following thorough evaluation at rest, 265 of 400 current or ex-shipyard workers rode a cycle ergometer with equal work increments each minute to exhaustion while continuous multiple noninvasive cardiorespiratory measures and intermittent intra-arterial blood pressure and blood gas measures were made. Seventy-seven men, with a mean age of 54, including some who were smokers, obese, or hypertensive, were judged to have normal cardiorespiratory systems based on history, physical, electrocardiogram during rest and exercise, chest X-ray, pulmonary function tests, and exercise performance. Their responses to exercise are given. It was unusual to find at maximal exercise a breathing reserve less than 11 L/min, arterial PO2 less than 80 mm Hg, alveolar-arterial PO2 difference greater than 38 mm Hg, arterial-end tidal PCO2 difference greater than 1 mm Hg, respiratory frequency greater than 60, or a dead space/tidal volume ratio greater than 0.28. The normal anaerobic threshold/maximal O2 uptake ratio exceeded 40%. With maximal exercise, the intra-arterial systolic and diastolic pressures rose an average of 68 and 13 mm Hg, respectively. For predicting maximal oxygen uptake and oxygen pulse in an overweight man, we find it preferable to use age and height rather than age and weight.