Showing papers by "University of New Hampshire published in 1987"
TL;DR: It is hypothesized that soluble phenolics that do not inhibit digestion but are absorbed and reduce intake through their toxicity are more important in defending some plant parts against ruminants than are digestion-reducing tannins.
Abstract: We tested the hypothesis that tannins defend plants against large herbivores by decreasing protein availability. Digestion trials were conducted with mule deer (Odo- coileus hemionus) and results from previous trials with white-tailed deer (O. virginianus), moose (Alces alces), caribou/reindeer (Rangifer tarandus), and elk (Cervus elaphus) were summarized to evaluate dietary factors affecting protein availability. The digestibility of plant protein in feeds with minimal tannins, such as grasses and agriculturally produced legumes and grains, was a highly predictable function of the total protein content and the amount of nondigestible, fiber-bound protein. Digestible protein in plants containing sig? nificant tannins was lower than predicted from regressions for low-tannin feeds. The re? duction in digestible protein was proportional to the protein-precipitating capacity of the plant tannins. Deciduous browse stems collected in winter had very low levels of protein- precipitating tannins and only a slightly lower protein availability than predicted. Tannins are not important in the defense of most deciduous tree and shrub stems consumed by these herbivores. Tannins in flowers and forb, tree, and shrub leaves markedly reduced protein availability. Tannins must be considered in understanding the defensive strategies of leaves and flowers. Voluntary intake of the high-phenolic forages was significantly re? duced below ingestion rates for grasses, legumes, and pelleted diets. It is hypothesized that soluble phenolics that do not inhibit digestion but are absorbed and reduce intake through their toxicity are more important in defending some plant parts against ruminants than are digestion-reducing tannins.
669 citations
TL;DR: This article examined the belief that physical abuse of wives is strongly determined by drunkenness and socioeconomic status using interview data from a nationally representative sample of 5,159 families and found that excessive drinking is associated with higher wife abuse rates, but alcohol use is not an immediate antecedent of violence in the majority of families.
Abstract: We examine the belief that physical abuse of wives is strongly determined by drunkenness and socioeconomic status using interview data from a nationally representative sample of 5,159 families. Our findings show that excessive drinking is associated with higher wife abuse rates, but alcohol use is not an immediate antecedent ofviolence in the majority of families. The combination of blue-collar status, drinking, and approval of violence is significantly associated with the highest rate of wife abuse. Of the three factors, cultural approval of violence by men against women has the strongest association with wife abuse. Although our results provide support for the drunken bum theory of wife beating, they also demythologize the stereotype because they show that alcohol is far from being a necessary or sufficient cause of wife abuse.
490 citations
Book•
01 Jan 1987TL;DR: This is it, the designing efficient algorithms for parallel computers that will be your best choice for better reading book that will not spend wasted by reading this website.
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424 citations
TL;DR: Experimental mesocosms used to grow Eelgrass in substrata of varied nitrogen composition showed the dramatic effect of insufficient nitrogen on eelgrass growth, abundance and leaf morphology, demonstrating the supposition that nitrogen is limiting in terrigenous environments.
407 citations
TL;DR: The use of a general learning algo rithm for the dynamic control of robot manipulators promises to provide good performance in complex situations at a reasonable cost as measured in terms of both hardware and software development.
Abstract: In this paper, we discuss the use of a general learning algo rithm for the dynamic control of robot manipulators. Unlike some other learning control schemes, learning is based solely on observations of the input-output relationship of the system being controlled and is independent of control objectives. Information learned previously can be applied to new control objectives as long as similar regions of the system state space are involved. The control scheme requires no a priori knowl edge of the robot dynamics and is easy to apply to a particu lar control problem or to modify to accommodate changes in the physical system. The control scheme is computationally efficient and well suited to fixed-point implementation. The learning controller is evaluated in a series of computer simu lations involving a two-axis-articulated robot arm during simulated repetitive and nonrepetitive movements. We inves tigate the effects of varying learning algorithm parameters as well as control system performance in the presen...
379 citations
TL;DR: A recent analysis of land use change in the tropical regions and in the temperate and boreal regions of the earth was combined to yield a global estimate of 1.0 -2.6 x 10I5 g C for the net release of carbon to the atmosphere in 1980 from changes in land use.
Abstract: Recent analyses of land-use change in the tropical regions and in the temperate and boreal regions of the earth were combined to yield a global estimate of 1.0 - 2.6 x 10I5 g C for the net release of carbon to the atmosphere in 1980 from changes in land use. Deforestation in the tropics accounted for nearly all of the flux; the net release of carbon from temperate and boreal regions was only 0.1 x loi5 g C. The average global value of 1.8 x IOl5 g C in 1980 was distributed geographically among tropical countries and other regions on the basis of deforestation rates and carbon stocks. The net release of carbon from changes in land use worldwide is inconsistent with the results of geochemical models of the carbon cycle. The discrepancy is smaller than in previous analyses, but is large enough to exceed the errors of the analysis. Possible explanations for the discrepancy include the possibility of a net accumulation of carbon in undisturbed ecosystems as a result of C02 fertilization or changes in climate. Even if the terms of the global carbon equation were to appear balanced at present, current knowledge is insufficient to predict whether terrestrial ecosystems will act as a positive or negative feedback on the anticipated C0,-caused global warming.
329 citations
01 Apr 1987
TL;DR: The results of two learning experiments using a General Electric P-5 manipulator are presented and control system performance was found to be limited by the resolution of the sensor feedback data, rather than by control structure limitations.
Abstract: A practical learning control system is described which is applicable to the control of complex robotic systems involving multiple feedback sensors and multiple command variables during both repetitive and nonrepetitive operations. In the controller, a general learning algorithm is used to learn to reproduce the relationship between the sensor outputs and the system command variables over particular regions of the system state space. The learned information is then used to predict the command signals required to produce desired changes in the sensor outputs. The learning controller requires no a priori knowledge of the relationships between the sensor outputs and the command variables, facilitating control system modification for specific applications. The results of two learning experiments using a General Electric P-5 manipulator are presented. The first involved learning to use the video image feedback to position the robot hand accurately relative to stationary objects on a table, assuming no knowledge of the robot kinematics or camera characteristics. The second involved learning to use video image feedback to intercept and track objects moving on a conveyor. In both experiments, control system performance was found to be limited by the resolution of the sensor feedback data, rather than by control structure limitations.
315 citations
TL;DR: Correlative field evidence suggests that large grazers such as Daphnia pulex promote the growth of colonial cyanobacteria by selectively eating competitive phytoplankton, supporting the generalisation that calanoid copepods seem best adapted to utilising large cyanob bacteria.
Abstract: Correlative field evidence suggests that large grazers such as Daphnia pulex promote the growth of colonial cyanobacteria by selectively eating competitive phytoplankton. This is supported by experimental evidence that (1) in eutrophic lakes dominated by cyanobacteria grazing by zooplankton on small particles is often > 100% day‐1, and (2) colonial cyanobacteria are generally not grazed as rapidly as smaller phytoplankton. Cyanobacteria generally have deleterious effects on grazing zooplankton. Filamentous cyanobacteria such as Anabaena and Oscillatoria can inhibit filtering by cladocerans, reducing growth and reproduction. Detrimental effects on zooplankton via nutritional deficiencies and toxins of cyanobacteria have been demonstrated in the laboratory but not in the field. Grazing on colonial cyanobacteria by zooplankton appears to be an important trophic link in tropical lakes. Generally, calanoid copepods seem best adapted to utilising large cyanobacteria. The generalisation that, with incre...
232 citations
TL;DR: In this article, interest in subjective values and decision responses is investigated empirically, including statistically testing the predictive relationships between subjective values, other independent variables such as level and area of executive responsibility, and decision response.
Abstract: Interest in subjective values and decision responses are investigated empirically, including statistically testing the predictive relationships between subjective values, other independent variables such as level and area of executive responsibility, and decision responses.
227 citations
TL;DR: In this paper, the authors discuss two aspects of the informal venture capital market: questions of scale and market efficiency, and they draw upon existing research to extract and synthesize data that provide a reasonable basis for inferences about scale and efficiency.
139 citations
TL;DR: In this article, the authors describe the extent of missing data within the Supplementary Homicide Report (SHR), collected as part of the Uniform Crime Reporting Program of the FBI, and propose computational procedures designed to compensate for missing data and empirically evaluate the impact of these procedures on comparative analyses of homicide rates.
Abstract: This paper describes the extent of missing data within the Supplementary Homicide Report (SHR), collected as part of the Uniform Crime Reporting Program of the FBI. The yearly SHR provides coded information on the victim, the offender, and the circumstances of all reported homicides in the United States. Thus, the data allow the computation of specific kinds of homicide rates, such as those involving family members, acquaintances, and strangers. However, missing data within reported events, primarily on offender characteristics and thus the victim/offender relationship, present a serious obstacle to the accurate calculation of such rates. The authors propose computational procedures designed to compensate for missing data and empirically evaluate the impact of these procedures on comparative analyses of homicide rates for cities, metropolitan areas, and states.
TL;DR: No variation appeared at any of the loci, although this sample was sufficient to detect any variant alleles with a frequency of 5.2 percent or more with 95 percent probability, probably due to founder effects accompanying the original postglacial establishment and subsequent repeated episodes of population establishment and local extinction along the St. John.
Abstract: Endemic species are commonly hypothesized to have little genetic variation because of inbreeding, genetic, bottlenecks, and/or other factors. We investigated genetic variation in, Pedicularis furbishiae(Scrophulariaceae), an endangered endemic of the St. John River valley in northern Maine, by examining electrophoretic patterns at 22 loci in 28 individuals distributed among four populations. No variation appeared at any of the loci, although this sample was sufficient to detect any variant alleles with a frequency of 5.2 percent or more with 95 percent probability. This lack of variation is probably due to founder effects accompanying the original postglacial establishment and subsequent repeated episodes of population establishment and local extinction along the St. John.
Resumen: Existe la hipotesis comuum de que las especies endemicas tienen una poca variacion genetica, debido a la endogamia, cuellos de boca genetica, y/u otros factores. Investigamos la variacion genetica de la, Pedicularis furbishiae (Scrophulariaceae), una especie endemica en peligro de extincion en el valle del St. John, al norte de Maine, examinando los patrones electroforeticos en 22 loci de 28 individuos distribuidos entre 4 poblaciones. No se detecto variacion en ninguno de los loci, a pesar de que esta muestra fue suficiente para detectar qualquier alelo variante con una frequencia de 5.2% o mas, con una probabilidad del 95%. Esta falta de variacion es debida, probablemente, a los efectos del fundador acompanndo el establecimiento post glacial original y la subsecuente repeticion de episodios de establecimiento de la poblacion y extincion local a lo largo del St. John.
TL;DR: This article investigated the effects of spatial training upon calculus achievement, spatial visualization ability, and the use of visualization in solving problems on solids of revolution, and found that spatial training may benefit performance in certain areas of calculus for women more than for men.
Abstract: This study investigated the effects of spatial training upon calculus achievement, spatial visualization ability, and the use of visualization in solving problems on solids of revolution. After pretesting, 250 college students participated in one of two spatial-training treatments or in a control treatment. Multivariate analyses of covariance revealed no treatment effect on calculus achievement or spatial visualization ability, but there were significant sex differences favoring women in calculus achievement and favoring men in spatial visualization ability. There were interaction effects for calculus achievement and the use of visualization in solving solid-of-revolution problems and a significant treatment effect for visualization of solids of revolution. Spatial training may benefit performance in certain areas of calculus for women more than for men.
TL;DR: In this article, an idealized morphology of the biogenic crystals is based on an elongated cubo-octahedral form comprising a hexagonal prism of {111} and {100} faces capped by ( 111) and (111) faces with associated truncations.
Abstract: Bacterial magnetite particles of anisotropic morphology have been studied by high-resolution transmission electron microscopy. Lattice images of individual crystals are consistent with a well-ordered magnetite cubic inverse spinel structure. The idealized morphology of the biogenic crystals is based on an elongated cubo-octahedral form comprising a hexagonal prism of {111} and {100} faces capped by (111) and (111) faces with associated {111} and {100} truncations. Analysis of many particles of diverse size suggests that crystal growth takes place in two stages. The first stage is associated with the formation of well-ordered, isotropic, single-domain crystals of cubo-octahedral morphology. In this stage the crystal length and width develop concurrently up to a size of 20 nm. The second stage involves the anisotropic growth of the isotropic particles along the [112] direction. A crystal growth mechanism is postulated which involves the specific nucleation of the (111) face on a surrounding organic membrane. Unidirectional growth then occurs by selective suppression of certain crystallographic axes through spatial and chemical constraints induced by the adjacent organic boundary.
TL;DR: The knowledge gap hypothesis suggests that a sudden infusion of information into a social setting serves to increase, rather than decrease, the gap in knowledge between high and low-status voters as discussed by the authors.
Abstract: The knowledge-gap hypothesis suggests that a sudden infusion of information into a social setting serves to increase, rather than decrease, the gap in knowledge between highand low-status voters. Political campaigns represent an especially appropriate setting to test this hypothesis, because of (1) the increased information that generally characterizes campaigns and (2) the important political consequences to lower status voters if the hypothesis is correct. A two-wave panel survey during the 1978 New Hampshire gubernatorial campaign finds that on one issue the knowledge gap increased during the campaign, while on another, perhaps less complex issue, the gap remained constant. These differences are hypothesized to be a function of different diffusion curves of the highand low-status voters, with implications for the varying lengths of time states allow for campaigns between the primary and general elections. In recent years, the scholarly literature on mass communications has introduced the concept of a "knowledge gap." It is of prime significance to students of politics, for it suggests that the effect of the mass media in transmitting political messages is to increase the gap in knowledge between highand low-status voters, and thus further enhance the significant information (and thus power) advantage that high-status voters already enjoy. As first presented by Tichenor, Donohue, and Olien (1970:159), the knowledge gap hypothesis states that "as the infusion of mass media information into a social system increases, segments of the population with higher socioeconomic status (SES) tend to acquire this information at a faster rate than the lower status segments, so that the gap in knowledge between these segments tends to increase." The consequence of this "relative deprivation of knowledge," argue the authors, is that it may also lead to the "relative deprivation of power" (Donohue, Tichenor, and Olien, 1975:4). DAVID W. MOORE iS Professor of Political Science at the University of New Hampshire. Public Opinion Quarterly Volume 51:186-200 ? 1987 by the American Association for Public Opinion Research Published by The University of Chicago Press 1 0033-362X/87/0051-00I$2 50 This content downloaded from 207.46.13.164 on Sun, 26 Jun 2016 06:15:13 UTC All use subject to http://about.jstor.org/terms Political Campaigns and the Knowledge-Gap Hypothesis 187 The finding that high-SES people are more informed and more likely to participate in politics than low-SES people is pervasive in political science literature, as is the conclusion that such information and participation gaps work to the advantage of the higher-status groups (Verba and Nie, 1972). But there are few studies that deal explicitly with the hypothesis that knowledge gaps increase as publicity increases. Cross-sectional studies are, of course, not able to examine such a dynamic change because of their one-time-point design. And of the several panel studies (at two or more points in time) that have examined the knowledge-gap hypothesis, the results do not in general support the notion of an increasing gap. In her comprehensive review of the relevant literature, Gaziano (1983) points out that among ten panel studies of knowledge-gap phenomena, four indicate declining gaps (Brown, Ettema, and Luepker, 1981; Douglas, Westley, and Chaffee, 1970; Galloway, 1976; and Genova and Greenberg, 1979); another three indicate stable gaps (Star and Hughes, 1950; Bogart 1957; Abbott, 1978); and one showed no gaps at either time of measurement. Only two panel studiesboth dealing with Sesame Street viewing-showed increasing gaps (Cook et al., 1975; and Minton, 1972, cited by Liebert, 1976). None of these studies, however, deals with election campaigns, yet such activities should represent an ideal setting to test the knowledgegap hypothesis. Campaigns almost always represent periods of significantly increased "infusion of mass media information into a social system," the type of context within which the knowledge gaps should increase, according to the authors of the hypothesis. Furthermore, the democratic implications of increasing knowledge gaps are perhaps more evident in electoral settings that in other periods of increased information. At the end of an election campaign the voters must make a decision, and the less-informed voters are presumably less able to vote in their own interests than are the better-informed, a case where the relative deprivation of knowledge does seem to translate into a relative deprivation of power. This paper reports on a study of the knowledge-gap hypothesis in a campaign setting in New Hampshire: the gubernatorial election of 1978. The results show that on the two most important issues of the contest, knowledge gaps did exist at both the beginning and end of the campaign. On one issue the gap increased, while on the other issue the gap remained constant. These results are tentatively "explained" within the framework of an information diffusion model, with important implications for the "ideal" length of time devoted to electoral campaigning. This content downloaded from 207.46.13.164 on Sun, 26 Jun 2016 06:15:13 UTC All use subject to http://about.jstor.org/terms
TL;DR: Responsible pigeons were trained to peck keys with equal food-reinforcement schedules in components that ended with either non Contingent or contingent transitions to a third component with a five-fold richer schedule, suggesting that response-contingent reinforcement does not increase resistance to change.
Abstract: In Experiment 1, pigeons were trained to peck keys with equal food-reinforcement schedules in components that ended with either noncontingent or contingent transitions to a third component with a five-fold richer schedule. Response rates were higher in the initial component with contingent transitions, but resistance to prefeeding or extinction was not consistently greater. Experiment 2 also included noncontingent or contingent transitions to a signaled period of nonreinforcement. There was no effect of the contingency on transitions to nonreinforcement, but the difference in response rates maintained by contingent versus noncontingent transitions to the richer schedule was replicated. In addition, response rates were higher in components that preceded nonreinforcement than in components that preceded the richer schedule. However, resistance to extinction was greater for noncontingent transitions to the richer schedule than to nonreinforcement, implicating stimulus–reinforcer relations in the determination of resistance to change. Resistance to change was also somewhat greater for noncontingent than for contingent transitions to the richer schedule. The latter result, together with the results of Experiment 1 and related research, suggests that response-contingent reinforcement does not increase resistance to change.
TL;DR: In this article, spectral and cross spectral analyses were applied to vocal activity and heart rates recorded during 12 conversations, and indexes of rhythmicity and strength of coupling were derived and used as predictors of observer ratings of affect and degree of involvement.
Abstract: Many investigators have speculated that a high degree of rhythmic patterning of social interaction and close coupling between the activity rhythms of partners are associated with positive affect, attachment, and interpersonal attraction. Others suggest that predictable or rhythmic patterning is an indication of inflexibility, and that close linkages between the physiological arousal of partners are associated with negative affect. In the present study, spectral and cross spectral analyses were applied to vocal activity and heart rates recorded during 12 conversations. Indexes of rhythmicity and strength of coupling were derived and used as predictors of observer ratings of pleasantness of affect and degree of involvement. There was a curvilinear relationship between affect and rhythmicity of vocal activity, such that moderately rhythmic social interactions were evaluated most positively. This relationship remained statistically significant even when other variables (such as mean and standard deviation of amount of vocal activity) were statistically controlled. Strength of coupling between partner vocal activity patterns and strength of coupling between the vocal activity and heart rate within speaker were not statistically significant predictors of ratings of pleasantness. Results suggest that there may be an optimum degree of rhythmicity in social interaction, with moderately rhythmic interactions evaluated most positively.
TL;DR: Testes were obtained from 34 Hereford or Angus bulls at about 1.5 yr of age and were used to investigate the relationship between the absolute number of Sertoli cells vs testicular size and daily spermatozoal production (DSP), which found a positive linear relationship.
Abstract: Testes were obtained from 34 Hereford or Angus bulls at about 1.5 yr of age and were used to investigate the relationship between the absolute number of Sertoli cells vs testicular size and daily spermatozoal production (DSP). Quantitative determination of DSP was based upon enumeration of elongated spermatids in testicular homogenates. The ratio of step 8 spermatids to Sertoli cells (S:SC) was established by direct counts of these cells in each of 20 round stage VIII seminiferous tubular cross sections for each bull. The number of Sertoli cells per paired testes was calculated as (total spermatids divided by S:SC)/.394, where total spermatids equalled the number of homogenization-resistant spermatids. The factor of .394 adjusted for the fact that the latter cells are present for only 39.4% of the spermatogenic cycle. All data were subjected to simple linear and second-order regression analyses. A positive linear relationship (P less than .005) was found between testicular weight (Y, in grams) and the absolute number of Sertoli cells per paired testes (X, in billions), which was characterized by the equation Y = 315.2 + 10.74X and a coefficient of correlation (r) of .56 (P less than .01). A similar relationship was observed between DSP (Y, in billions) and Sertoli cell numbers (X, in billions). This was characterized by the equation Y = 1.36 + .222X (P less than .005) and a coefficient of correlation of .70 (P less than .01). Daily sperm production was unrelated to the S:SC ratio (P greater than .05).(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: It was suggested that total Sertoli cell number may be an important determinant of a bull's spermatogenic potential.
Abstract: Testes from 37 Holstein bulls, 38-99 mo of age, were used to investigate the relationship of Sertoli cell number, Sertoli cell-germ cell ratios and other related factors to daily sperm production (DSP). DSP was assessed by enumeration of spermatids in testicular homogenates, whereas Sertoli cell and germ cell ratios were based on direct counts in 20 round Stage VIII seminiferous tubular cross sections per bull. Numbers of Sertoli cells were calculated as (total homogenization resistant spermatids:spermatid:Sertoli cell ratio)/0.394; the factor of 0.394 adjusted for the presence of homogenization resistant spermatids during only 39.4% of the spermatogenic cycle. Data were subjected to simple linear and second-order regression analyses. Positive linear relationships were observed between DSP and testicular parenchymal weight (p less than 0.005, R = +0.71), DSP per gram (p less than 0.005, R = +0.79), total Sertoli cells (p less than 0.005, R = +0.83), Sertoli cells per gram (p less than 0.01, R = +0.47) and the yield of Step 8 spermatids per Type A spermatogonium (p less than 0.05, R = +0.34). DSP was not related (p greater than 0.10) to the number of germ cells supported per Sertoli cell. Testicular parenchymal weight and DSP per gram were unrelated to each other (p greater than 0.10), but both were related (p less than 0.005) to the total Sertoli cell number (R = +0.61 and +0.62, respectively). Total number of Sertoli cells accounted for more of the variation in DSP between bulls (R2 = 68.2%) than did any other factor examined. It was suggested that total Sertoli cell number may be an important determinant of a bull's spermatogenic potential.
TL;DR: The hypothesis that the inhibitory effect of DHEA on energy storage as fat is mediated, at least in part, by increased beta-oxidation of fatty acids in peroxisomes is supported.
Abstract: The present study is a follow-up to the report that dehydroepiandrosterone (DHEA) acetate treatment in rats stimulated metabolic heat production and suppressed serum triglycerides, adiposity and weight gain without affecting food intake. Activities of peroxisomal fatty acyl-coenzyme (CoA) oxidase and catalase as well as mitochondrial citrate synthase were assayed in liver tissue of 24 young adult male and female Wistar rats fed a nonpurified diet containing 0.6% DHEA (6 g/kg) for 6 wk. DHEA-treated animals gained less weight but had heavier liver weights than did the controls. Hepatic activity of fatty acyl-CoA oxidase of the experimental male and female animal was 1058 and 946% higher, respectively, than that of the controls. For catalase activity, only the female groups were different (30%). Activity of citrate synthase was not affected by DHEA. These data support the hypothesis that the inhibitory effect of DHEA on energy storage as fat is mediated, at least in part, by increased beta-oxidation of fatty acids in peroxisomes. The peroxisomal beta-oxidation pathway is uncoupled from oxidative phosphorylation; electrons are transferred directly to molecular O2 because of cycling of NAD/NADH resulting in the expenditure of chemical energy as heat.
TL;DR: The weakly closed algebras generated by certain sets of composition operators are shown to be reflexive as discussed by the authors, and a structure theorem for invertible composition operators on H2 is obtained and used to show that such operators are reflexive.
TL;DR: Bilateral asymmetry in gallop stride limb contact patterns of four Quarter Horse fillies was documented by high-speed cinematography and laterality may have an important influence on equine gallop motion patterns and thereby influence athletic performance.
TL;DR: Ovoid magnetotactic bacteria extracted from the Exeter River, New Hampshire, U.S.A., contain chains of 20-35 anisotropic magnetic inclusions running longitudinally in each of three lateral cell positions adjacent to the inner surface of the cytoplasmic membrane as mentioned in this paper.
Abstract: Ovoid magnetotactic bacteria extracted from the Exeter River, New Hampshire, U.S.A., contain chains of 20-35 anisotropic magnetic inclusions running longitudinally in each of three lateral cell positions adjacent to the inner surface of the cytoplasmic membrane. The inclusions are bullet-shaped and have characteristic flattened end faces. Some particles show kinking and curvature in their morphology. In cross section the particles have a hexagonal shape. The length of the inclusions varies over a wide range (45-135 nm) with a mean value of 97.8 nm. In contrast, the width of the particles is restricted to a range of 30-45 nm with a mean value of 36.9 nm. Many particles are surrounded by an organic electrondense envelope. The crystallographic structure of the inclusions has been determined by electron diffraction and corresponds to the mineral magnetite (Fe$_{3}$O$_{4}$). The dimensions of the crystals fall within the magnetic single-domain range for magnetite and the magnetic moment of one cell is approximately 4 $\times $ 10$^{-12}$ emu (4 fJT$^{-1}$).
TL;DR: In this paper, the spatial, temporal, source and physical controls on chloride, nitrate, sulfate and sodium in south Greenland snow are presented based on chemical data from snowpit and fresh snow samples.
TL;DR: In this paper, the potential and practice of action research in education are discussed. But the authors focus on collaborative action research: teachers' stages of development and school contexts, and do not discuss the role of teachers in this research.
Abstract: (1987). Collaborative action research: Teachers’ stages of development and school contexts. Peabody Journal of Education: Vol. 64, The Potential and Practice of Action Research Part 1, pp. 96-115.
TL;DR: Possible reasons for the lower rates in 1985 are examined, including increased reluctance to report and changes in American society and family patterns that would have produced lower rates of violence toward children even without ameliorative programs.
Abstract: This article compares the rate of violence toward children from a 1975 study with the rates from a 1985 replication. Both studies used nationally representative samples (1,146 families in 1975 and 1,428 in 1985), and both found extremely high incidence of severe violence against children. However, 1985 rates, although high, were substantially lower than 1975 rates; the rate of severe violence weas 47% lower in 1985. Possible reasons for the lower rates in 1985 are examined and evaluated, including (a) increased reluctance to report; (b) differences in the method of study; (c) reductions due to ten years of prevention and treatment efforts; and (d) reductions due to changes in American society and family patterns that would have produced lower rates of violence toward children even without ameliorative programs.
TL;DR: This is a story about the New Psychologists who strove at the turn of the century to institutionalize a new science and to create a new set of professional roles and the rhetorical fabric they wove around the nascent science of psychology is examined.
Abstract: This is a story about the New Psychologists who strove at the turn of the century to institutionalize a new science and to create a new set of professional roles. More particularly, it is about the rhetorical fabric they wove around the nascent science of psychology. The article focuses, one by one, on different strands of this fabric – on (1) what persuaded the first generation of American psychologists to take an interest in the New Psychology; (2) the arguments these aspiring psychologists presented to presidents and trustees to insure that they could pursue their interest within particular institutional settings; (3) the arguments they put forth against the rights of other persons to engage in similar, competing pursuits; (4) the arguments they laid before various administrators, officials, interest groups, and the general public to guarantee continued and even increased support; and (5) the arguments they presented in the form of theories and practices developed between approximately 1880 and 1920. In this way, it attempts to construct a likely story about the establishment of the New Psychology in America.1
TL;DR: In this paper, a dynamic stiffness matrix formulation for circular curved members of constant section, including the effects of rotary intertia, shear deformation and extension of the neutral axis, is presented for determining natural frequencies of continuous curved beams undergoing in-plane vibrations.
TL;DR: In this article, the authors compared discrimination and detection in the parafovea for oblique, cathode-ray-tube-generated, square-wave gratings, and found that the site of the aliasing is neural rather than receptoral.
Abstract: We compared discrimination and detection in the parafovea for oblique, cathode-ray-tube-generated, square-wave gratings. There is a band of frequencies between roughly 10 and 20 cycles/deg wherein such gratings are detected only in an apparently aliased form. The existence of aliasing is consistent with the cone density and optical quality of the parafoveal visual system, but the spatial frequency at which the aliasing is observed is only about half of what is suggested by cone density. The reason for this result is unclear, but one provocative possibility is that the site of the aliasing is neural rather than receptoral.