Showing papers by "University of Maine published in 1972"
103 citations
TL;DR: In this paper, the Debye-Waller factors have been calculated for a number of zinc-blende-type crystals from the eigenfrequencies and eigenvectors of the phonon states as obtained from the modified-rigidion model of lattice dynamics.
Abstract: The Debye-Waller factors have been calculated for a number of zinc-blende-type crystals from the eigenfrequencies and eigenvectors of the phonon states as obtained from the modified-rigidion model of lattice dynamics. On the average the contribution from the acoustic-phonon states to the mean-square displacements of the constituent atoms was found to be more significant than that from the optical-phonon states. However, the relative optical-phonon-state contribution was found to be more significant in the lighter atom, and in fact in some cases at low temperatures, it was found to exceed the acoustic-phonon-state contribution. In all the cases studied, the mean-square displacements of the lighter atom were found to be larger. Lindeman's criterion for melting was tested by evaluating the ratio of the sum of the root-mean-square displacements of the constituent atoms to the nearest-neighbor distance. This ratio is approximately constant for the zinc-blende compounds. However, the average ratio for the II-VI compounds was found to be slightly larger than that for the III-V compounds. The calculated results are discussed in relation to available experimental data.
88 citations
TL;DR: In this article, the Brooks-Yu theory is applied to the calculation of the band structure of some III-V semiconductors at finite temperatures, and the temperature dependence of several band gaps are determined and compared with available experimental data and good agreement is obtained.
Abstract: The Brooks-Yu theory is applied to the calculation of the band structure of some III-V semiconductors at finite temperatures. The theory is applied in the context of the empirical pseudopotential method, and utilizes a recent lattice-dynamical calculation of the Debye-Waller factors. The temperature dependence of several band gaps are determined and compared with available experimental data and, in general, good agreement is obtained.
78 citations
62 citations
TL;DR: In this paper, the authors investigated the incidence of test cheating under various situational conditions and found that the highest incidence of cheating occurred in groups under the combination of conditions of low probability of test success, low risk of detection, and high test importance.
55 citations
TL;DR: In this paper, an integrated field and marine study of the Guadeloupe region of the Lesser Antilles Island Arc concentrated on that area where the island arc ridge abruptly becomes a double row of islands in contrast to a single row to the south.
51 citations
TL;DR: Ratings of degree of psychopathology and of probability of cross-sexual identification were made on temporally stratified samples of 42 eminent English and French poets.
Abstract: Ratings of degree of psychopathology and of probability of cross-sexual identification were made on temporally stratified samples of 42 eminent English and French poets. 55% of Ss had life histories indicating some possibility of cross-sexual identification; of these, 30% came from father-absent homes. 48% exhibited some symptoms of psychopathology; of these, 15% were rated as psychotic. Psychopathology and cross-sexual identification were highly related. Reasons why temporally stratified samples should yield high incidence rates on the variables were explored.
45 citations
TL;DR: American eels, long-distance migrating fish, consistently exhibited conditioned cardiac deceleration responses to electric fields as small as 0.167 x 10-2 microampere per square centimeter in water of resistivity 4000 ohm centimeters and 400 ohmimeters, indicating sufficient sensitivity to utilize geoelectric information for orientation.
Abstract: American eels, long-distance migrating fish, consistently exhibited conditioned cardiac deceleration responses to electric fields as small as 0.167 x 10 -2 microampere per square centimeter in water of resistivity 4000 ohm centimeters (6.7 microvolts per centimeter) and 400 ohm centimeters (0.67 microvolt per centimeter). Fewer responses were shown at this current density (0.167 x 10 -2 microampere per square centimeter) in more saline water (40 ohm centimeters, 0.067 microvolt per centimeter) and at a lower current density (0.167 x 10 -3 microampere per square centimeter) in fresh water. Thus, eels have sufficient sensitivity to utilize geoelectric information for orientation.
41 citations
TL;DR: The ultrastructure of the centriolar satellite complex in the spermatozoon of the hydroid, Pennaria, is presented and a new model for the structure is proposed.
Abstract: The ultrastructure of the centriolar satellite complex in the spermatozoon of the hydroid, Pennaria, is presented. The complex consists of nine spoke-like arms which emanate from the distal centriole and of nine wedgeshaped connectives which extend into the flagellum joining each of the alpha doublets and the flagellar plasmalemma. Based upon these observations a new model for the structure of the centriolar satellite complex is proposed. In addition, similar centriolar satellite complexes are reported in the spermatozoa of two echinoderms, Ctenodiscus crispatus and Thyone briareus, in support of the proposed model.
35 citations
TL;DR: In this article, the authors describe the differential response to new economic opportunities in Cuanajo, a Tarascan Indian community in Michoacan, Mexico, and argue that blocks to development are primarily economic in nature, not cultural or cognitive.
Abstract: This article describes the differential response to new economic opportunities in Cuanajo, a Tarascan Indian community in Michoacan, Mexico. It is argued here that blocks to development are primarily economic in nature, not cultural or cognitive (e.g., “limited good”) as has been asserted by others working in the area. When real opportunities became available, some individuals responded to them. Such positive forces lead us to reevaluate some basic premises concerning development which have been suggested in the areal literature.
34 citations
TL;DR: The results suggest that pairing of a stimulus is not a necessary condition for within-component patterning under some second-order schedules.
Abstract: Pigeons performed on a second-order schedule in which fixed-interval components were maintained under a variable-interval schedule. Completion of each fixed-interval component resulted in a brief-stimulus presentation and/or food. The relation of the brief stimulus and food was varied across conditions. Under some conditions, the brief stimulus was never paired with food. Under other conditions, the brief stimulus was paired with food; three different pairing procedures were used: (a) a response produced the simultaneous onset of the stimulus and food; (b) a response produced the stimulus before food with the stimulus remaining on during food presentation; (c) a response produced the stimulus and the offset of the stimulus was simultaneous with the onset of the food cycle. The various pairing and nonpairing operations all produced similar effects on performance. Under all conditions, response rates were positively accelerated within fixed-interval components. Total response rates and Index of Curvature measures were similar across conditions. In one condition, a blackout was paired with food; with this different stimulus in effect, less curvature resulted. The results suggest that pairing of a stimulus is not a necessary condition for within-component patterning under some second-order schedules.
TL;DR: It was found that decreased salinity correlated with increased vesiculation and branching, and increased wave action correlated with decreased vesICulation.
Abstract: The vesiculation and branching of Fucus vesiculosus L. were examined on plants from three different locations on the Maine Coast, USA. These localities varied in exposure to wave action and salinity. Statistical analysis of population differences was computed for 10 morphometric characteristics. It was found that decreased salinity correlated with increased vesiculation and branching. Increased wave action correlated with decreased vesiculation. Position within vertical range was not a factor in either vesiculation or branching.
TL;DR: In the decade which followed, both antislavery political moderates and Garrisonian radicals evolved a new style. Openly defying government, deliberately and persistently breaking the law, and explicitly tolerating violence, they desperately searched for a new tactic to embrace and achieve their aims.
Abstract: X\/HEN the reality of events runs counter to the moral imperative of an era, reasonable men join fanatics in rejecting quiet argument and compromise for more vigorous action. The passage of the Fugitive Slave Act in 1850 marked such an occasion. Long uneasy with the drift and thrust of public action, antislavery men had been alarmed by the threat and then the reality of Texas annexation and war with Mexico. The hopes which the Wilmot Proviso and the Free Soil party had momentarily raised were rudely dashed by the Compromise of 1850. In the decade which followed, both antislavery political moderates and Garrisonian radicals evolved a new style. Openly defying government, deliberately and persistently breaking the law, and explicitly tolerating violence, they desperately searched for a new tactic to embrace and achieve their aims. Abolition had always been radical. From the adoption of immediate and uncompensated emancipation and the organization of the American AntiSlavery Society in 1833, subgroups continually emerged going beyond majority opinion within the antislavery societies and demanding ever more extreme programs. By 1840, Garrisonian perfectionism and multi-reform millenialism had driven both orthodox clericals and Liberty party supporters from the American Anti-Slavery Society's ranks. But the rump did not long remain coherent. During the 1840s, it too shattered and divided over the issues of "coming out" and disunion. By the late 1830s ultra-Garrisonians had developed a strong anticlerical and apolitical position. They had sought to purge churches of fellowship-
TL;DR: The strongest evidence that could be found against this rise would be pollen diagrams up toward 17 m which showed continuously freshwater conditions late in the last interglacial as discussed by the authors, and features that might be explained by a surge occur in the Camp Century ice core, in Atlantic, Caribbean and Gulf of Mexico marine cores, and in the Orgnac stalagmite.
TL;DR: The morphological differences between the spermatozoa of Eudendrium and those of closely related species are discussed with particular reference to sexual life history.
Abstract: Spermatozoa of the colonial marine hydroid, Eudendrium were examined with the electron microscope. The spermatozoa of this species were found to differ greatly in structure from previously described spermatozoa in the phylum. The mature sperm are acrosomeless and retain a considerable amount of perinuclear cytoplasm following their maturation. The perinuclear cytoplasm contains numerous organelles: Golgi apparatus, endoplasmic reticulum, multivesicular bodies, ribosomes and membranous vesicles. The nucleus is elongate and cylindrical, rather than conical, in shape. The four wedge-shaped mitochondria which lie posterior to the nucleus form a fossa which contains proximal and distal centrioles. Centriolar satellites are associated with the distal centriole. The relatively short (15 μ) flagellum consists of two distinct segments: a proximal thick portion and a distal thin portion. The thick segment contains the typical 9+2 arrangement of tubules plus a variable number of peripheral, supernumerary tubules. The thin segment contains from one to eleven tubules.
TL;DR: A population of Porthetria dispar exposed to low winter temperatures in Maine was examined to determine the amount of egg mortality and the fate of the surviving population through one generation and an epizootic of nuclear-polyhedrosis virus further reduced the size of the subsequent population.
Abstract: A population of Porthetria dispar (L.) exposed to low winter temperatures in Maine was examined to determine the amount of egg mortality and to determine the fate of the surviving population through one generation. Eggs protected by snow survived temperatures that reached −32.2°C (−26°F). The height above ground that egg masses were deposited was critical. A high percentage of egg masses (81%) was deposited below a height of 5 feet, but most hatch occurred in egg masses found below 1 foot. Egg mortality due to low temperature was 85%. An epizootic of nuclear-polyhedrosis virus further reduced the size of the subsequent population.
TL;DR: One factor influencing business decisions in Cuanajo, Michoacan is the native system of accounts as mentioned in this paper, which gives a highly inaccurate view of opportunities and can be seen in the fact that individuals continually attempt to enter businesses which are "emically" good, but which, in reality, are saturated.
Abstract: One factor influencing business decisions in Cuanajo, Michoacan is the native system of accounts. While accounting systems influence many areas of business decision making, their impact can be most readily seen in analyzing business entry choices. The degree to which accounting systems influence perceptions of opportunities is demonstrated by comparing the local view of business possibilities derived from the native system of accounts (the "emic" view) with the very different picture we get utilizing conceptual tools from formal economics (the "etic" view). Contrasting these two outlooks allows us to see that the native accounting system gives a highly inaccurate view of opportunities. Evidence that the businessmen of Cuanajo are strongly influenced by the local system can be seen in the fact that individuals continually attempt to enter businesses which are "emically" good, but which, in reality, are saturated. It is not suggested that the native accounting system permanently blocks responsiveness to opp...
TL;DR: Four species are discussed for subsection Mixtini of the genus Pluteus, which is subdivded into two subsections, Mixtine and Celluloderma, the latter of which is concerned with crustaceans.
Abstract: Section Celluloderma of the genus Pluteus is subdivded into two subsections, Mixtini and Celluloderma. In the following account, four species are discussed for subsection Mixtini. Pluteus eugraptus...
TL;DR: The morphology of the following eight major ossicle types is described and illustrated for the goniopectinid asteroid Ctenodiscus crispatus: terminal plates, superomarginals and inferomarginal ossicles, adambulacral and ambulacral oss particles, odontophores, oral intermediate plates, and superambulACral oSSicles.
Abstract: The morphology of the following eight major ossicle types is described and illustrated for the goniopectinid asteroid Ctenodiscus crispatus: terminal plates, superomarginal and inferomarginal ossicles, adambulacral and ambulacral ossicles, odontophores, oral intermediate plates, and superambulacral ossicles. Development, variation, and relationships with soft body-parts and with other ossicles are embphasized. Each ossicle type is distinguished by numerous structures related to its function and to articulation with adjoining skeletal elements. Because major structures (such as pustules, alveoli, and articulation surfaces) distinguishing ossicle types develop early during ontogeny, immature ossicles are readily identifiable. However, changes in form and orientation of these structures occur during ossicle growth. Ontogenetic changes are influenced by development of associated skeletal and soft parts. Ambulacral and adambulacral ossicles near the peristome are highly modified but retain the basic characteristics of structure and orientation which define these major types of skeletal elements.
TL;DR: Ulasonic tracking of mature cutthroat trout (Salmo clarki) from Little Thumb Creek displaced to the open water of Yellowstone Lake in 1969 suggested, but did not conclusively demonstrate, that trout from the west side of the lake have a westward compass mechanism, similar to the eastward Compass mechanism of east side trout.
Abstract: Ultrasonic tracking of mature cutthroat trout (Salmo clarki) from Little Thumb Creek displaced to the open water of Yellowstone Lake in 1969 suggested, but did not conclusively demonstrate, that trout from the west side of the lake have a westward compass mechanism, similar to the eastward compass mechanism of east side trout. Anosmic trout from Clear Creek made variable movements, but some exhibited the same patterns as control trout and horned. Experimental trout and control trout from Clear Creek retained prior to ultrasonic tracking under a 6 hr early photoperiod and a normal photoperiod, respectively, exhibited similar movements, most of which were eastward or southeastward as is typical of Clear Creek trout. Either they do not use a time-compensated sun compass mechanism, or we were unsuccessful in shifting the biological clock. Cloud cover apparently did not alter fish movement patterns. Half (49.5%) of 299 mature Clear Creek trout tagged and displaced to five release points homed. One thi...
TL;DR: The specificity of proline for intestinal absorption in chicken small intestine is complex in that approximately 40 per cent of the uptake of 0·8 mM proline takes place in a leucine-shared transport system(s), while a smaller component of its uptake occurs in a separate system shared with other secondary amino acids.
TL;DR: A system is described for the phage typing of Salmonella thompson based upon a number of bacteriophages that were isolated from sewage.
Abstract: A system is described for the phage typing of Salmonella thompson. The system is based upon a number of bacteriophages that were isolated from sewage.
TL;DR: A satisfactory understanding of political motivation can provide a powerful analytical tool for explaining why different groups of participants behave as they do; ultimately it can suggest why they adopt and sustain different political institutions as mentioned in this paper.
Abstract: Why are people in politics? Behind this deceptively simple question lies a promising realm of research and analysis. A satisfactory understanding of political motivation can provide a powerful analytical tool for explaining why different groups of participants behave as they do; ultimately it can suggest why they adopt and sustain different political institutions. The basic axiom which, in principle, yields such explanations is simple: participants behave in a manner consistent with their incentives.
TL;DR: In this paper, strong sharp-line luminescence has been observed for Re +4 (5 d 3 ) in single cubic crystals of the host lattice Cs 2 ZrBr 6 at 20°K.
TL;DR: White perch under 201 mm long from a lake not having crayfish fed mostly upon insects but also ate fish, and young-of-the-year O. limosus were rarely utilized as forage by white perch.
Abstract: White perch (Morone americana) under 201 mm long from a lake containing the crayfish Orconectes limosus ate mostly insects Perch from 201 to 280 mm long fed upon insects, fish, and crayfish White perch over 280 mm fed mainly upon crayfish Young-of-the-year O limosus were rarely utilized as forage by white perch White perch under 201 mm long from a lake not having crayfish fed mostly upon insects but also ate fish Perch over 200 mm long were almost exclusively piscivorous, the main forage fish being the rainbow smelt (Osmerus mordax)
TL;DR: In this paper, an event recorder was used to measure velocities and painted particles as tracers, verify the validity of applying the Hjulstrom curve to the marine environment landward of the breaker-zone for the cobble to boulder-size range.
TL;DR: Pancreatic secretions were successfully collected on a 24 hour basis for as long as three months after cannulation and no chickens lost weight and most gained weight during the experiment.
TL;DR: A graph of genus 2 which is irreducible with respect to this property must have at least eight vertices as discussed by the authors, and it is shown that there are exactly three such 2-irreducibly connected graphs having 8 vertices, and that these three graphs, together with the Kuratowski theorem, leeds to a determination of the genus of each graph having fewer than nine vertices.
Abstract: A graph of genus 2 which is irreducible with respect to this property must have at least eight vertices. It is shown here that there are exactly three such 2-irreducible graphs having eight vertices. The description of these three graphs, together with the Kuratowski theorem, leeds to a determination of the genus of each graph having fewer than nine vertices.