Showing papers by "University of Maine published in 1973"

Seasonal changes in thermogenesis, organ weights, and body composition in the white-footed mouse,Peromyscus leucopus.

Abstract: 1. Seasonal adjustments in wild-caughtPeromyscus leucopus include autumn increases in basal metabolic, nonshivering thermogenesis, and interscapular brown fat and decreases in weights of gonads, liver, adrenal glands, and total lipid. Body weight and nonextractable dry weight do not change. 2. Basal metabolic rate, nonshivering thermogenesis, and interscapular brown fat increase following initial cold exposure in mid-September and are maintained at similar levels through January. 3. There is a positive correlation between nonshivering thermogenesis and interscapular brown fat, and negative correlations for both nonshivering thermogenesis and interscapular brown fat with body weight. 4. These seasonal changes in wild-caughtP. leucopus are compared with laboratory studies on the effects of chronic exposure to differences in temperature and photoperiod on these characters. It is concluded that disparities between the effects of cold acclimatization and cold acclimation could result from the influence of additional environmental cues, such as photoperiod, in cold acclimatized mice.

The Differential Effect of Increased Arousal on Creative and Intellectual Performance

Abstract: It was hypothesized that increases in level of arousal should lead to improvement in the performance of intellectual tasks and to decrements in the performance of creative tasks because of the effect of drive level on range of cue utilization and availability of remote associates. Subjects were given the Remote Associates Test (RAT) and a version of the WAIS Similarities subtest under low arousal (relaxed), medium arousal (stress), and high arousal (white noise) conditions. Trends were as predicted, but reached acceptable levels of significance only for the effects of high arousal on creative performance. Evidence for the validity of the RAT was provided by the finding that RAT and intellectual performance are affected in opposite ways by the same experimental manipulations. It is suggested that flexibility in changing level of arousal may be a determinant of both creativity and intelligence and that this common trait may explain the tendency of tests of the the two to correlate.

SALINITY ADAPTATION BY DUNALIELLA TERTIOLECTA. I. INCREASES IN CARBONIC ANHYDRASE ACTIVITY AND EVIDENCE FOR A LIGHT‐DEPENDENT Na+/H+ EXCHANGE1,2

Abstract: SUMMARY When Dunaliella tertiolecta, previously adapted to medium containing 0.5 M NaCl, is transferred to higher salinities, there is a lag in growth, suggesting an adaptation period. Since there is no significant difference in the Na+ content of cells grown between 0.5 and 3.5 M NaCl, a mechanism for Na+ extrusion or exclusion is indicated. Increasing the salinity of cell suspensions stimulates an incorporation of H+ by the cells, suggesting an H+/Na+ exchange. Cells adapted to higher salinities have, increased carbonic anhydrase activity, suggesting that increased CO2 or HCO3− transport may be required at higher salinities. Growth, of D. tertiolecta at salinities above 2.5 M requires continuous illumination; therefore a light-driven H+/Na+ exchange accompanied by a HCO3− influx is proposed.

Proposed Model for the Peroxidase-Catalyzed Oxidation of Indole-3-acetic Acid in the Presence of the Inhibitor Ferulic Acid

Abstract: Linear increments in ferulic acid concentration produce logarithmic increases in the ferulic acid-induced lag periods prior to the peroxidase-catalyzed oxidation of indole-3-acetic acid in a system containing 2,4-dichlorophenol and MnCl(2) in acetate buffer at pH 5.6. Maintaining the ratio of indole-3-acetic acid to ferulic acid constant at 100 while linearly raising the ferulic acid concentration results in linear increases in the lag period. Both indole-3-acetic acid and ferulic acid are substrates of horseradish peroxidase in the presence of H(2)O(2), and indole-3-acetic acid competitively inhibits the oxidation of ferulic acid. A model for the enzymatic oxidation of indole-3-acetic acid catalyzed by peroxidase is proposed.

Relationship between self-esteem and internal-external control for men and women.

Abstract: Fish and Karabenick ( 1971) investigated the relationship between Rotter's (1966) Internal-External Control Scale and Janis and Field's (1959) Feelings of Inadequacy Scale for males only. AS predicted, there was a significant correlation of -.28 (p < .001), indicating that men with higher self-esteem tend to be internally oriented. Such an outcome is not surprising since earlier investiga[ions have indicated that internals describe themselves as being self-confident, independent, assertive, persevering and insightful, while externals tend to describe themselves unfavorably, as being self-pitying, anxious and inadequate. In light of recent studies which indicate that many of the correlates of locus of control differ for men and women (Hjelle & Clouser, 1970; Platt, Pomeranz, Eisenman, & DeLisser, 1970; Ryckman, Martens, Rodda, & Sherman, 1972), it was decided to administer the same measures to 178 men and 204 women registered in introduccory psychology during a class to check the correlation for women.

Immunofluorescent study of the replication of infectious pancreatic necrosis virus in trout and Atlantic salmon cell cultures.

Abstract: Cell cultures of trout gonad tissue (RTG-2) and Atlantic salmon heart, kidney, liver, and spleen tissue were inoculated with 50 50% tissue culture infective doses (TCID50) of infectious pancreatic necrosis (IPN) virus per cell, and the titer of cell-associated and released virus was determined from 2 to 16 h postinoculation (PI). Cover slips were collected over the same period and stained for IPN viral antigen by the direct immunofluorescent (FA) technique. Viral replication was detected after a latent period of approximately 2 to 4 h and reached a peak titer of 108.2 to 108.4 TCID50 per ml at 8 to 10 h PI. The release of virus was more rapid in Atlantic salmon cells than in RTG-2 cells. Viral antigen was first detected by FA from 3 to 4 h PI. Approximately 75 to 80% of the cells contained antigen in the cytoplasm 9 to 11 h PI. The direct FA technique was found to be a sensitive method for detecting IPN virus in infected cells. Three strains of IPN virus were tested for serological cross reactions by FA and virus neutralization tests.

A View of Electrolyte Solutions

Abstract: The uncertainties in the route to infinite dilution for 2–2 electrolytes are discussed in relation to the practical difficulties of determining the standard emf’s of simple reversible cells containing ZnSO4 in H2O and D2O solutions. These difficulties are due to uncertainties in the theory of highly charged ions in aqueous solution. Recent developments in theories of electrolytes, especially those for which numerical results are available, are critically evaluated for their accuracy and adaptability to changes in the solute potential. Simple refinements to the model (i.e., the solute potential) are described, and the changes are interpreted, in terms of the molecular interactions between sets or pairs of ions in the pure solvent. Recent work on the effect of solvent granularity and other molecular properties of the solvent (e.g., dipole moment) on the solute potential is reviewed.

Effects of differential rates of nitrogen and phosphorus on early blight in potatoes

Abstract: The Kennebec variety of potato was exposed toAlternana solani inoculum during the 1970 and 1971 seasons to determine the effects of differential rates of nitrogen and phosphorus on the incidence of early blight. Both high nitrogen and low phosphorus treatments significantly reduced the incidence of early blight and the combination of high nitrogen and low phosphorus consistently gave the lowest incidence of the disease during both years. The data suggest that this combination of nutrients may be related to early blight resistance in the plant by extending the period of meristematic activity permitting the plant to wall off infection. Yield data indicated that there was too great a yield difference between fertilization for optimum early blight control and fertilization for optimum yield. Therefore, in Maine, potatoes should be fertilized for optimum yield with a reasonable specific gravity, and early blight should be controlled by the application of fungicides and sanitation measures.

Universal Approximate Analytical Solution of the Thomas-Fermi Equation for Ions

Abstract: The great utility of the Thomas---Fermi (TF) theory of atoms lies in the fact that it gives a solution of the TF equation that is valid for for all neutral atoms. In contrast to this situation, the TF equation for positive ions has to be solved separately for each degree of ionization of each atom. Using a previously obtained approximate analytical solution of the TF equation for neutral atoms (which is based on a variational principle), and a series-expansion approach (which relates the parameters in the ionic solution to those in the neutral-atom solution), the present paper derives a universal approximate analytical solution of the TF equation for ions. This solution, in addition to being valid for positive ions, is also applicable for negative ions for which the original TF theory does not furnish a solution. Furthermore, the approximate solution obtained here is not associated with finite ionic radii, and gives an exponentially decreasing radial electron density, which is not the case in the original TF theory. For this reason, the electron densities and potentials of ions that result from the present work are expected to be in better agreement with the quantum-mechanical data for these quantities than the electron densities and potentials obtained with the original TF theory. To show that this is so, the accuracy of the universal approximate analytical solution is investigated by calculating the diamagnetic susceptibilities of singly and doubly charged positive and negative ions of noble-gas electron configurations. It is found that, in most cases, calculated and experimental values for ions of the Ar, Kr, and Xe electron configurations agree to within a factor of 2, while for ions of the Ne electron configuration the agreement is somewhat worse. This is about the same accuracy as that found using the Lenz-Jensen approximation to the TF theory which, like the universal approximation, also makes use of variational electron density but, unlike the universal approximation, has to be separately obtained for each particular ion. As a further check on the usefulness of the universal ionic solution, the diamagnetic susceptibilities of the isoelectronic ions ${\mathrm{Ga}}^{3+}$, ${\mathrm{Ge}}^{4+}$, and ${\mathrm{As}}^{5+}$ are also calculated and found to agree only slightly worse than within a factor of 2 with the experimental data. After further comparison with data obtained from more-refined statistical models, the conclusion is that the universal solution for ions may be useful in a variety of problems where quantum-mechanical accuracy may be traded for a simpler approach.

Parelaphostrongylus tenuis (Dougherty) in Maine. I. The parasite in white-tailed deer (Odocoileus virginianus, Zimmerman).

Abstract: Annual prevalence of Parelaphostrongylus tenuis for white-tailed deer in Maine varied from 63 to 80 percent during 1968-70. Prevalence was significantly lower (P<.01) in fawns than older deer. Adult females had a significantly higher (P<.01) prevalence of P. tenuis than adult males. Females also had a slightly greater average number of P. tenuis per infected animal. An area of relatively low deer density had the highest overall prevalence (81.2 percent), while a region of relatively high deer density had the lowest (59.1 percent). P. tenuis was most frequently found in the tentorium cerebelli, the falx cerebri and the dura mater. No significant differences in distribution were noted in deer of various sexes and ages. However, 2 percent of the P. tenuis found in does apparently had penetrated the neural parenchyma of the brain.

Anomalous Alignment and Dynamic Scattering in Liquid Crystals Exhibiting a Positive Dielectric Anisotropy

Abstract: Molecular alignment owing to ionic conductivity anisotropy, Williams' Domains and dynamic scattering have been observed in the nematic phase of p-butyloxybenzoic acid which exhibits positive dielectric and conductivity anisotropies. This was observed for both dc and ac electric fields. Other nematic materials with positive dielectric anisotropies which do not show strong ac effects are discussed. The possibility of hydrogen bonds breaking at the transition temperature to account for a change in the microwave dielectric loss is mentioned.

Voluntary Self-Help Organizations: an Exploratory Study:

Abstract: position to &dquo;go down into&dquo; the slums, endeavoring to use moral persuasion and role-modeling to deflect the &dquo;deviant&dquo; from their downward course (Farber, 1968; and Lubove, 1965). Even the concurrent settlement house and social reform movements (roughly 1880s to World War II) depended upon moral and intellectual leaders from the &dquo;more fortunate classes&dquo; to establish the successful politics by means of which some of the conditions under which the poor lived could be modified. The major contrast between moral and social reformers was the degree to which the latter committed themselves to the life and the condition under which the poor lived. But social reform did not succeed in resolving--if, indeed, it ever attempted to do so--the issue of assigning primary leadership to an intellectual and social

Second-order schedules: Manipulation of brief-stimulus duration at component completion

Abstract: In a second-order schedule, fixed-interval components were reinforced according to a variable-interval schedule. A brief stimulus accompanied the completion of each fixed interval. Brief-stimulus duration was varied across conditions from 0.5 to 8 sec. Patterning was greater the longer the duration of the stimulus. Additionally, exposure to relatively long brief-stimulus durations enhanced patterning upon reexposure to shorter brief-stimulus durations.

Selected Schedules of Reinforcement in the Mongolian Gerbil

Abstract: Gerbils acquired bar-pressing when water or rat Noyes pellets were contingent. Responding was analyzed under intermittent, time-contingent schedules of reinforcement—FI, VI, and DRL—as well as a variation of a mixed FR schedule. Gerbils responded well above operant level for prolonged periods of time under all schedules examined. Gerbils bar-pressed at 80 to 90% ad lib. body weight for conventional rewards if operant sessions were under 30 min. Also gerbils showed consistent high rates of response under the mixed FR schedule.

Deviant behaviors in rural elementary schoolchildren.

Abstract: A sample of 1567 third- and fourth-grade children in rural Illinois were rated on the Behavior Problem Checklist. The mean frequency of conduct problems, inadequacy-immaturity, personality problems, and socialized delinquency were analyzed by grade, sex, and age. Fourth graders and older children tended to have more problems than did third graders and younger children. Boys had more problems than did girls except on the personality-problem dimension.

A Comparison of Initially Teaching Division Employing the Distributive and Greenwood Algorithms with the Aid of a Manipulative Material.

Abstract: Division of whole numbers is traditionally accepted as a part of the elementary school mathematics program and is considered to be the most difficult of the four basic operations with whole numbers. The Greenwood algorithm is employed in most contemporary elementary textbooks to initially develop the recording process. The common usage of the Greenwood algorithm for division of whole numbers today is largely due to the study by Van Engen and Gibb, General Mental Functions Associated with Division (1956). Later, in almost all textbook series, the standard algorithm is used for the final recording process. Van Engen and Gibb, however, did not recommend converting to the standard algorithm after learning the Greenwood algorithm. This transition stage is the source of substantial difficulty for many pupils. If the standard algorithm is to be the terminal algorithm, then perhaps an approach that initially employs the standard algorithm should be used.