Showing papers by "North Carolina State University published in 1971"
TL;DR: In this paper, the randomized response technique of reducing respondent bias in obtaining answers to sensitive questions is extended from the situation where response is categorical to that in which the response is quantitative, and results are reported on the application of the method to estimating mean number of abortions in an urban population of women, and mean income of heads of households.
Abstract: The randomized response technique of reducing respondent bias in obtaining answers to sensitive questions is extended from the situation where response is categorical to that in which the response is quantitative. Results are reported on the application of the method to estimating mean number of abortions in an urban population of women, and mean income of heads of households. The efficiency of estimators based on the method of moments in the randomized response procedure is studied and representative results are reported and discussed.
300 citations
TL;DR: Dormancy of trees can be divided arbitrarily into three phases: early rest, winter rest, and after-rest, and each of these phases is marked by a distinct set of physiological processes.
Abstract: Early dormancy involves a number of phenomena: cessation of active growth, formation of terminal buds, formation of abscission layers in leaves, development of cold resistance, development of winter rest (a chilling requirement), and leaf fall. The buds of some tree species (or some races of a species) have a true rest or winter chilling requirement; usually the roots do not; perhaps the cambium does not. There is a wide range of genetic variation within and between species in response to photoperiod, winter chilling, water nutrients, and other environmental factors which affect the dormancy condition of plants. During the period of winter rest there are many metabolic and developmental processes going on in the buds and twigs. These processes include respiration, photosynthesis, some cell division, enzyme synthesis, production of growth stimulators, and dissipation of growth inhibitors. Dormancy of trees can be divided arbitrarily into three phases: early rest, winter rest, and after-rest. Each of these phases is marked by a distinct set of physiological processes. The transition between the three phases is gradual. Some processes of after-rest can proceed even though the winter chilling requirement (winter rest) of a tree has not been completed fully. Evidence from grafting experiments and chemical treatments to break winter rest, and studies of genetic variability indicate that the processes and phenomena of dormancy are at least partially independent of each other. Different buds and branches and other parts of the same plant may initiate dormancy, break dormancy, and renew vegetative growth independently. Initiation and cessation of dormancy can be triggered by a number of environmental variables: photoperiod, temperature, nutrition, water, an array of chemicals, and shock treatments. Dormancy regulation must either involve a variety of receptors or involve receptors that are responsive to a variety of stimuli. Unless dormancy is defined in a highly restricted sense (that is, possession of chilling requirement), it is hard to conceive of a single receptor or regulator that controls all of the phenomena of dormancy. A large number of genes are definitely involved and hence a large number of enzymes. The kinds of enzymes, their numbers, and their concentrations can be regulated by manipulating the environment.
299 citations
TL;DR: The distribution of deuterium at the reduced carbon atoms shows an isotope effect and leads to the speculation that reduction occurs by addition of a proton and hydride ion mediated by an unknown carrier.
263 citations
TL;DR: It was apparent that the ionic strength of the preparative medium is more important than either molarity or pH for obtaining microsomes of maximum N- and O-demethylating activity.
173 citations
159 citations
TL;DR: In this article, the adequacy of describing results by the log normal distribution was investigated, and the results showed that the distribution yielded a good practical description in all cases, and that the variance of the variance was less than 14% for mean particle size.
149 citations
TL;DR: In this paper, the orthogonal nature of the Fourier transform (FT) is maintained by using the trapezoidal rule for the mechanical quadrature of the FT of one, two, and three dimensions.
128 citations
TL;DR: Piperonyl butoxide produces a typical type I substrate difference spectrum with cytochrome P-450 in the oxidized state, however, the inclusion of NADPH with piperonyL butoxide effects a spectrum similar to that of ethyl isocyanide.
109 citations
TL;DR: Three computer programs applied to data from phylogenetic trees and protein polymorphism can be used to find the rate of molecular evolution of different species and it is shown that this is slower for higher primates than for other mammals.
Abstract: Three computer programs applied to data from phylogenetic trees and protein polymorphism can be used to find the rate of molecular evolution of different species. It can be shown that this is slower for higher primates than for other mammals.
103 citations
TL;DR: The medieval approach to the quantification of qualities that has so far received the most attention from modern historians is that of as mentioned in this paper, and it is this approach that has been considered as the basis for the present paper.
Abstract: According to Aristotelian theory, quantities and qualities belong to separate categories. One might suppose, therefore, that Aristotelian theorists would not attempt to quantify qualities.1 During the later Middle Ages, however, theorists who were basically Aristotelian in their approaches did attempt to quantify qualities. The medieval approach to the quantification of qualities that has so far received the most attention from modern historians is that of
89 citations
TL;DR: A hypothetical model for the ecology of avian malaria, in which the parasite, vector, and susceptible host populations reach a maximum in an apparently favorable sequence, with provision for occasional failure of transmission, has obvious survival value.
Abstract: Although studies on Plasmodium infections of wild birds have been reported frequently in the literature, our knowledge of the ecology of these parasites remains incomplete. A synthesis of data and ideas from these field studies, and recent experimental work led to the construction of the following hypothetical model for the ecology of avian malaria: During the late spring, summer, and early fall susceptible birds (young of the year or previously uninfected adults) contract the infection from the bite of an infected mosquito on the breeding ground. The birds migrate or remain in the area and infections become latent over the winter. In the spring, migratory birds return to the breeding area and all birds commence reproductive activity. With the onset of migration and breeding activity, parasite populations become elevated in the birds. This relapse of malarial infections coincides with emergence of vectors. The mosquitoes obtain the parasite, passing it on to susceptibles in the population (whose numbers a...
TL;DR: The analytical expression for the solid angle for n-sided, regular polygon of area equal to that of the disc is given in this article. And the average solid angles subtended by circular discs from circular discs are calculated and given in tabular form for a range of disc sizes.
TL;DR: Because young chickens with aflatoxicosis frequently have a pale, enlarged, and friable liver the possibility that dietary aflatoxin can induce the fatty liver syndrome in laying hens was investigated.
TL;DR: The specificity of linoleic acid isomerase from Butyrivibrio fibrisolvens for cis-9,cis-12-dienoic fatty acids with an ω chain length varying from 4 to 8 carbons has been examined as discussed by the authors.
TL;DR: A Flatoxicosis in chickens has been characterized mainly by lowered growth rates and inefficient conversion of feed and the possibility of interaction of aflatoxicosis with other diseases has been studied since the disease was discovered.
TL;DR: An organophosphorus-resistant strain of the predaceous mite, Neoseiulus (Typhlodromus)fallacis (Garman), degraded more azinphosmethyl than a susceptible strain both in vivo and in vitro, indicating that the mechanism of resistance was not associated with a modified cholinesterase.
TL;DR: There are several reports in the literature which indicate that dietary alterations have an influence on the severity of aflatoxicosis, and a more economical solution would be the development of a dietary additive or modification that would make the birds more resistant to aflatoxin.
TL;DR: Tarsal bristles of the tick Amblyomma americanum (L.) (Acarina: Ixodidae; nymphal stage) were studied by means of scanning and transmission electron microscopy and apparently serve a dual function: mechano- and chemoreception.
Abstract: Selected tarsal bristles of the tick Amblyomma americanum (L.) (Acarina: Ixodidae; nymphal stage) were studied by means of scanning and transmission electron microscopy. All sensilla are multi-innervated and have thick cuticular walls containing either an elaborate pore canal system or a single slit opening at the tip. These sensilla, often equipped with two mechanoreceptive dendrites attached to the bristle base, apparently serve a dual function: mechano- and chemoreception. The fine structure of each sensillum is similar to that of other arthropod setae except for the ciliary region of the dendrite. Instead of the common 9 double-tubules, the tick sensilla usually have 11 (“11+0”). Compared to insect or spider tarsal bristles, tick setae are less abundant but more complex in structure and of greater variety.
TL;DR: In this article, a laboratory technique for the preparation of small batches of sausage emulsion was developed for a comparative study of the effectiveness of fresh and frozen beef in achieving emulsion stability.
Abstract: SUMMARY— A laboratory technique for the preparation of small batches of sausage emulsion was developed for a comparative study of the effectiveness of fresh and frozen beef in achieving emulsion stability. The technique consisted of three basic steps: (1) low speed chopping and blending of ingredients at −2° to +2°C; (2) low speed blending with the gradual addition of soybean oil at 2°−8°C; and (3) high speed chopping to a temperature of 15°-16°C. The preparation and evaluation of emulsions with widely varying compositions revealed that the lean and fat percentages could be varied over wide ranges without significantly affecting emulsion stability, but the range for percentage of water was narrow and critical to stability. The relative stability for fresh and frozen lean was influenced by the amount of added water. For example, at 30% fat level, there was a sharp drop in stability as the added water was reduced below 16% for fresh beef; whereas, an equivalent drop in stability was found as the added water was reduced below 21 % for frozen beef. The theory is proposed that emulsion instability is highly dependent upon the level of added water based on results of this investigation.
TL;DR: In this paper, it is shown that the differences in structure arise because of the manner in which the yarn is made, and that the difference in structure arises due to the way in which it is made.
Abstract: If open-end spun yarns are to find wide use, it is necessary to understand more fully the structure of the yarns. The differences in structure arise because of the manner in which the yarn is made....
TL;DR: A population of Escherichia coli ML30 cells was exposed to a quaternary ammonium compound, and injury to the cells was measured by a comparison of counts on Trypticase Soy Agar and Violet Red Bile Agar.
Abstract: A population of Escherichia coli ML30 cells was exposed to a quaternary ammonium compound, and injury to the cells was measured by a comparison of counts on Trypticase Soy Agar and Violet Red Bile Agar. Substantial injury could not be detected with a minimal medium. The ingredients of Violet Red Bile Agar were tested against damaged cells. The bile salts mixture alone in the medium prevented as many injured cells from growing as did any combination of the selective agents and inhibited as many injured bacteria as were inhibited by Violet Red Bile Agar itself. These dyes and salts were similarly assayed in minimal agar, and comparable results were obtained. Individual bile salts and other potential selective agents were added to the minimal medium, and the media were tested for inhibition of injured E. coli. Sodium deoxycholate was the bile salt most inhibitory to damaged E. coli cells.
TL;DR: The sudden occurrence of a high incidence of bruising on two poultry farms in North Carolina and the finding of a flatoxin in the chicken feed used on these farms suggested that aflatoxin might be involved in the hemorrhagic syndrome of chickens.
TL;DR: Injury of test cultures was quantitated by differences in colony counts obtained with a complete medium and those obtained on conventional selective media, and sanitizer concentration appeared to be the main factor in the cause of death and injury.
Abstract: Injury of test cultures was quantitated by differences in colony counts obtained with a complete medium and those obtained on conventional selective media. Staphylococcus aureus, Streptococcus faecalis, and several strains of Escherichia coli were injured when exposed to the quaternary ammonium compound methylalkyltrimethyl ammonium chloride. Representative hypochlorite sanitizers also caused injury of E. coli ML30. Sanitizer concentration appeared to be the main factor in the cause of death and injury, a higher concentration being needed to cause death. Increases in temperature did not result in substantial increases in injury; however, the lethal effect was greater at higher temperatures. Varying the cell concentration from 107 to 109 cells per ml did not change the fraction of cell population killed or injured. The inability or failure of common selective media to detect injured bacteria in food could have serious public health consequences.
TL;DR: In this paper, the effects of polymer molecular weight, molecular weight distribution, and orientation on the rate of relaxation-controlled sorption of n-pentane by glassy polystyrene were studied.
Abstract: The effects of polymer molecular weight, molecular weight distribution, and orientation on the rate of relaxation-controlled sorption of n-pentane by glassy polystyrene were studied. The sorption follows Case II kinetics but for films which sorb slowly the sorption rate increases at relatively long times until sorption is sharply terminated. This rate increase may be explained by the development of dispersed microvoids within the unrelaxed film core. Overshoot of the equilibrium n-pentane content occurs in sorption experiments in which accelerated sorption is pronounced.
The sorption rate is independent of polymer molecular weight and molecular weight distribution per se over a broad wrange of these parameters. Essentially identical vapor sorption kinetics were observed for well annealed polystyrene films of different molecular weights and distributions. Conversely, for vapor sorption by uniaxially oriented films and for liquid sorption by partially annealed films, high molecular weight film (1,880,000) exhibits greater sorption rates than low molecular weight film (ca. 200,000). These differences in rate are not due to molecular weight differences per se, but are a consequence of the dissimilar response of free volume and strain development for films of different molecular weight prepared with a given time-temperature-strain history.
Crazing of carefully annealed polystyrene films occurs during desorption of n-pentane from partially saturated films. The depth of craze penetration reflects the point of advance of the discontinuous Case II sorption boundary.
TL;DR: This paper presents a historical and pathological description of aflatoxicosis in broiler chickens in Western Australia and reports on its symptomology and widespread occurrence in ducks and chickens in South Africa.
TL;DR: In this paper, it is shown that in an unconstrained situation under certainty, with complete freedom to borrow or lend at one rate of interest, the present worth index and its equivalents are correct while indices inconsistent with present worth are wrong.
Abstract: In the traditional literature of engineering and managerial economics, a variety of different and not generally consistent indices have been proposed for deciding whether a given capital investment project should be undertaken. Using mathematical programming, it is shown herein that in an unconstrained situation under certainty, with complete freedom to borrow or lend at one rate of interest, the present worth index and its equivalents are correct while indices inconsistent with present worth are wrong. However, in the presence of further constraints, e.g., on allowed borrowing or on available scarce material, even the present worth index is unsatisfactory, and, in general, a complete mathematical programming solution is required.
TL;DR: Differential cross sections were measured at four angles for proton elastic scattering from 54, 56, 58Fe at energies ranging between 18 and 33 MeV using the TUNL 3 MV Van de Graaff accelerator and high-resolution analyser-homogenizer system, a total resolution of 300-400 eV was achieved for thin solid targets of enriched iron isotopes as mentioned in this paper.
TL;DR: In this article, the authors identify the major air pollutants and discuss the nature and extent of air pollution problems, and describe the symptoms of injury caused by these pollutants, especially on crop plants.
Abstract: Publisher Summary The investigations of air pollution injury to vegetation began near the middle of the 19th century. Injury from leaking illuminating gas mains also was an early problem. Ethylene was identified as the toxicant in the illuminating gas. The complete loss of vegetation may be avoided in the future, but interest in the problem has continued, primarily because of the increased number of large power plants that burn sulfur-containing fuels and emit high concentrations of sulfur oxides. This chapter identifies the major air pollutants and discusses the nature and extent of air pollution problems. It also describes the symptoms of injury caused by these pollutants, especially on crop plants. Air pollution problems have increased because of multiple sources and mixtures of pollutants. There is increased concern about chronic injury and reduced growth attributed to air pollutants such as photochemical oxidants and sulfur oxides. The response to pollutants may be altered by many factors such as genetic, environmental, cultural conditions, time-concentration relationships, and the presence of mixtures of pollutants. The identification and use of tolerant varieties, including resistant varieties developed by breeding, will help reduce losses and assure maximum agricultural production.