bluuebunny/crossref_metadata_2025 huggingface dataset:
Figuring out a scientific understanding
Authors: Sutton Clive
Published: October 2006

This article attempts to place analogy and metaphor within the wider context of all figurative language, and to trace the relationship between that kind of expression and the supposedly literal and direct accounts of nature that scientists have built up.

I explore the functions of figures of speech in the development of new scientific ideas, and trace how they fade or die as each area of scientific knowledge matures. What we then take to be the literal words of scientific description are in effect the remnants of old figures of speech that have grown so familiar that their earlier metaphorical quality is easily overlooked. The conventional separation of figurative and literal cannot be sustained, and a new understanding of their relationship is needed.

The practical implications of this analysis are to do with how we can reactivate the dormant metaphors in ordinary scientific language, so that learners may hear again the human voice of scientists who developed the ways of talking we now take for granted. To reactivate the system of thought behind any established way of talking, we must be able to get the learners to understand that language works as a medium of interpretation and persuasion, and not simply a system of descriptive labeling. These two views of language are compared and contrasted.
Neural principles of memory and a neural theory of analogical insight
Authors: Lawson David I. , Lawson Anton E.
Published: October 2006

Grossberg's principles of neural modeling are reviewed and extended to provide a neural level theory to explain how analogies greatly increase the rate of learning and can, in fact, make learning and retention possible. In terms of memory, the key point is that the mind is able to recognize and recall when it is able to match sensory input from new objects, events, or situations with past memory records of “similar” objects, events, or situations. When a match occurs, an adaptive resonance is set up in which the synaptic strengths of neurons are increased; thus a long term record of the new input is formed in memory. Systems of neurons called outstars and instars are presumably the underlying units that enable this to occur. Analogies can greatly facilitate learning and retention because they activate the outstars (i.e., the cells that are sampling the to‐be‐learned pattern) and cause the neural activity to grow exponentially by forming feedback loops. This increased activity insures the boost in synaptic strengths of neurons, thus causing storage and retention in long‐term memory (i.e., learning).
Physics students' epistemologies and views about knowing and learning
Authors: Roth Wolff‐Michael , Roychoudhury Anita
Published: October 2006

Classrooms are complex environments in which curriculum, students, and teachers interact. In recent years a number of studies have investigated the effect of teachers' epistemologies on the classroom environment, yet little is known about students' epistemologies and how these interact with those of teachers. The purpose of this study was to document students' epistemologies and their concurrent views about knowing and learning. Using a written essay, short‐answer responses to statements, a preferred classroom environment inventory, and interviews, students' views on scientific knowledge and their own knowing and learning were collected from 42 students in three sections of an introductory physics course. Our rather broad, qualitative inquiry provides a dynamic view of students' understanding of knowing and learning in high school physics. Our analyses reveal a spectrum of epistemological commitments commensurable with positions from objectivism to relativism, most of them with experientialist coloring. Even within individuals, these commitments could be at once commensurable and incommensurable with the same epistemological position. We also find rather significant inter‐ and intra‐individual differences with respect to the consequences of a specific epistemological stance to learning, the learning strategies employed, and the learning environment preferred. Students' views on knowing and learning in physics are presented in the form of an emergent theory. The findings are discussed in terms of their application to classroom environments.
Construction and validation of a computer‐based diagnostic module on average velocity
Authors: Andaloro G. , Bellomonte L. , Lupo L. , Sperandeo‐Mineo R. M.
Published: October 2006

This article describes the process of building a computer‐based diagnostic module concerning the understanding of the average velocity concept. The first step consists of the production of a student model that takes into account student errors and reasoning paths. The computer module formulates its diagnosis by leading users along different patterns foreseen according to the hypothesized student model. Results are reported concerning a correlation analysis between automatic and human diagnoses.
The effect of levels of cooperation within physical science laboratory groups on physical science achievement
Authors: Chang Huey‐Por , Lederman Norman G.
Published: October 2006

The purpose of this study was to investigate the effect of the levels of group cooperation on students' achievement during a series of physical science laboratory activities. Six intact seventh‐grade physical science classes taught by two teachers, with each teacher instructing three classes, were selected from two middle schools. For each teacher, one of the classes was taught with a traditional approach (no cooperative goal structure). The other two classes were assigned to a cooperative goal structure (role assignment and nonrole assignment). For the role assignment class, each student was assigned a specific role, but students in both traditional and nonrole assignment classes were not assigned roles. The Classroom Observation Instrument in Science Laboratory Activity (COISLA), which includes investigative skills (i.e., managing, manipulating, observing, reading, writing, and reporting); social skills (i.e., discussing, encouraging) and nonlearning behaviors (i.e., waiting, off‐task), was used to measure the levels of group cooperation. The grades on lab reports and lab quizzes of students who were taught by the same teacher were compared to assess the effects of the different learning conditions. No significant differences on the students' final achievement were found with respect to the three instructional approaches followed by each teacher. The teacher effect was more significant than either instructional approach on managing, manipulating, observing, reading, and writing behaviors. No significant teacher effect was found for the other behaviors. Only one treatment effect was significant, writing behavior. Overall, the teacher effect was more influential than instructional approach on students' behaviors. In teacher A's classes, reading behavior predicted 21% of students' achievement. However, no significant correlations existed between the 10 collaborative behaviors and students' achievement in teacher B's classes.
Literacy learning in secondary school science classrooms: A cross‐case analysis of three qualitative studies
Authors: Dillon Deborah R. , O'Brien David G. , Moje Elizabeth B. , Stewart Roger A.
Published: October 2006

The purpose of this cross‐case analysis is to illustrate how and why literacy was incorporated into science teaching and learning in three secondary classrooms. Research questions guiding the analysis include: (a) How were literacy events shaped by the teachers' philosophies about teaching science content and teaching students? and (b) How was literacy (reading, writing, and oral language) structured by the teachers and manifested in science lessons? The methodology of ethnography and the theoretical framework of symbolic interactionism were employed in the three studies on which the cross‐case analysis was based. The researchers assumed the role of participant observers, collecting data over the period of 1 year in each of the three classrooms. Data, in the form of fieldnotes, interviews, and artifacts, were collected. In each study, data were analyzed using the constant comparative method (Glaser & Strauss, 1967) to determine patterns in the teachers' beliefs about learning and how these influenced their choice of literacy activities. The cross‐case analysis was conducted to determine patterns across the three teachers and their classrooms. The findings from this analysis are used to compare how the teachers' philosophies of teaching science and their beliefs about how students learn influenced their use of literacy practices during lessons. Specifically, each teacher's use of literacy activities varied based on his or her beliefs about teaching science concepts. Furthermore, reading, writing, and oral language were important vehicles to learning science concepts within daily classroom activities in the three classrooms.
Verbal and nonverbal behavior of ability‐grouped dyads
Authors: Jones M. Gail , Carter Glenda
Published: October 2006

In this study we describe the social interactions of ability‐grouped dyads as they constructed knowledge of balance concepts to elucidate the relationship between interactions and conceptual growth. The verbal and nonverbal behaviors of 30 fifth‐grade students were recorded as they completed three activities related to balance. These student interactions were examined within a framework of social cognition. For each dyad, characteristics of ability‐grouped dyads were identified. Results revealed that high‐achieving students effectively used prior experiences, maintained focus on the learning task, and were able to manipulate the equipment effectively to construct knowledge. Low‐achieving students exhibited off‐task behavior, lacked a metacognitive framework for organizing the learning tasks, centered on irrelevant features of the equipment, and were unable to use language effectively to mediate learning. Within low‐high student dyads, high‐achieving students typically modeled thinking processes and strategies for manipulating equipment. In addition, they focused the low‐achieving students on the components of the tasks while verbally monitoring their progress, thus enabling low students to identify the critical features necessary for concept construction. These results highlighted the differences that students have in the use of language and tools. Low students' inefficient use of tools has implications for the ways science teachers structure lessons and group students for laboratory work.
High school students presenting science: An interactional sociolinguistic analysis
Authors: Bleicher Robert
Published: October 2006

Presenting science is an authentic activity of practicing scientists. Thus, effective communication of science is an important skill to nurture in high school students who are learning science. This study examines strategies employed by high school students as they make science presentations; it assesses students' conceptual understandings of particular science topics through their presentations and investigates gender differences. Data are derived from science presentation given by eight high school students, three females and five males who attended a summer science program. Data sources included videotaped presentations, ethnographic fieldnotes, interviews with presenters and members of the audience, and presenter notes and overheads. Presentations were transcribed and submitted to discourse analysis from an interactional sociolinguistic perspective. This article focuses on the methodology employed and how it helps inform the above research questions. The author argues that use of this methodology leads to findings that inform important social‐communicative issues in the learning of science. Practical advice for teaching students to present science, implications for use of presentations to assess conceptual learning, and indications of some possible gender differences are discussed.
Motivation and strategy use in science: Individual differences and classroom effects
Authors: Anderman Eric M. , Young Allison J.
Published: October 2006

This study examines individual and classroom‐level differences in motivation and strategy usage in sixth‐ and seventh‐grade middle school science. Results suggest that students who experience academic difficulties differ from both high achieving and special education students on measures of self‐efficacy, goal orientation, expectancy, value, and self‐concept of ability in science, with students who experience academic difficulties occasionally demonstrating less adaptive patterns of motivation and cognition than special education students in science. We used hierarchical linear modeling to examine between‐classroom differences in learning‐focused goal orientation. Findings indicate that students who have science teachers that use ability‐focused instructional practices (e.g., pointing out the best students as an example to others) are less learning focused, and exhibit a diminished relation between self‐concept of ability and being learning focused in science. Implications for science education reform are discussed.
Gender differences in response to questions on the australian national chemistry quiz
Authors: Walding Richard , Fogliani Charles , Over Ray , Bain John D.
Published: October 2006

In contrast to the attention given to the relative levels of achievement of boys and girls in mathematics, the question of whether there are sex differences in the solution of chemistry questions has not attracted much attention. This study compares the performance of boys and girls in the Australian National Chemistry Quiz (Chem Quiz), a multiple‐choice test conducted by the Royal Australian Chemical Institute. The analyses were based on results from 27,000 students in Years 11 and 12 and 16,000 students in Year 10 who completed the Chem Quiz in 1991. Although some questions in the Chem Quiz were solved equally well by boys and girls, on many questions boys outperformed girls. The extreme case was a question answered correctly by 67% of Year 10 boys in contrast to 48% of Year 10 girls. Several reasons why boys and girls might differ in the rates they solve at least some chemistry questions are discussed, and directions for identifying the nature, extent, and basis for sex differences are outlined.
Learning from physics text: A synthesis of recent research
Authors: Alexander Patricia A. , Kulikowich Jonna M.
Published: October 2006

Learning from physics text is described as a complex interaction of learner, text, and context variables. As a multidimensional procedure, text processing in the domain of physics relies on readers' knowledge and interest, and on readers' ability to monitor or regulate their processing. Certain textual features intended to assist readers in understanding and remembering physics content may actually work to the detriment of those very processes. Inclusion of seductive details and the incorporation of analogies may misdirect readers' attention or may increase processing demands, particularly in those cases when readers' physics knowledge is low. The questioning behaviors of teachers also impact on the task of comprehending physics texts. Finally, within the context of the classroom, the information that teachers dispense or the materials they employ can significantly influence the process of learning from physics text.
Interpreting pragmatic meaning when reading popular reports of science
Authors: Norris Stephen P. , Phillips Linda M.
Published: October 2006

Ninety‐one Grade 12 science students were asked to read five popular reports of science. The students were within 4 months of graduation, and all were taking at least one course of senior biology, chemistry, or physics. On average, the students had completed about four high school science courses. The reports were chosen from widely available published work appearing in newspapers, science magazines, and general interest magazines. The tasks given to students required them to interpret the pragmatic meaning of the reports, that is, the meaning of the reports in relation to the goals and intentions of the authors and the context set by the reports. The students interpreted statements in the reports with a bias towards truth ascription by attributing to the statements a higher degree of certainty than was expressed by the authors. Also, no more than one half of the students accurately understood the scientific status and role of statements when that understanding required contextualized interpretation on the basis of the relationships among statements in the reports. Implications for the development of scientific literacy follow from the fact that these students were top science students, yet they did not fully grasp the fundamentals of interpreting texts that are major sources of new scientific knowledge for most laypeople.
Effects of knowledge and persuasion on high‐school students' attitudes toward nuclear power plants
Authors: Showers Dennis E. , Shrigley Robert L.
Published: October 2006

Researchers report finding correlational data to identify a positive relationship between nuclear knowledge and positive attitudes toward the use of nuclear energy. This study investigated the relationship between nuclear knowledge and nuclear attitudes and to the understanding of Science‐Technology‐Society attitudes involving technological attitude objects. This quasi‐experimental study tested the causal relationship between knowledge about nuclear power plants and attitudes toward their use in electrical generation. Subjects were presented with systematically designed communications developed to change either their knowledge about or attitude toward nuclear plants. The Standard Events of Instruction was the basis of the knowledge instruction, whereas the Learning Theory Approach and the Theory of Reasoned Action were the theoretical bases of the persuasive communication. The principal finding was that nuclear knowledge and nuclear attitude each can be changed independently of the other. Although knowledge and attitudes are correlationally linked, this study shows no evidence of a cause‐effect relationship.
Development and application of a two‐tier diagnostic test measuring college biology students' understanding of diffusion and osmosis after a course of instruction
Authors: Odom Arthur Louis , Barrow Lloyd H.
Published: October 2006

This study involved the development and application of a two‐tier diagnostic test measuring college biology students' understanding of diffusion and osmosis after a course of instruction. The development procedure had three general steps: defining the content boundaries of the test, collecting information on students' misconceptions, and instrument development. Misconception data were collected from interviews and multiple‐choice questions with free response answers. The data were used to develop 12 two‐tier multiple choice items in which the first tier examined content knowledge and the second examined understanding of that knowledge. The conceptual knowledge examined was the particulate and random nature of matter, concentration and tonicity, the influence of life forces on diffusion and osmosis, membranes, kinetic energy of matter, the process of diffusion, and the process of osmosis. The diagnostic instrument was administered to 240 students (123 non‐biology majors and 117 biology majors) enrolled in a college freshman biology laboratory course. The students had completed a unit on diffusion and osmosis. The content taught was carefully defined by propositional knowledge statements, and was the same content that defined the content boundaries of the test. The split‐half reliability was .74. Difficulty indices ranged from 0.23 to 0.95, and discrimination indices ranged from 0.21 to 0.65. Each item was analyzed to determine student understanding of, and identify misconceptions about, diffusion and osmosis.
Predicting who will major in a science discipline: Expectancy–value theory as part of an ecological model for studying academic communities
Authors: Sullins Ellen S. , Hernandez Delia , Fuller Carol , Tashiro Jay Shiro
Published: October 2006

Research on factors that shape recruitment and retention in undergraduate science majors currently is highly fragmented and in need of an integrative research framework. Such a framework should incorporate analyses of the various levels of organization that characterize academic communities (i.e., the broad institutional level, the departmental level, and the student level), and should also provide ways to study the interactions occurring within and between these structural levels. We propose that academic communities are analogous to ecosystems, and that the research paradigms of modern community ecology can provide the necessary framework, as well as new and innovative approaches to a very complex area. This article also presents the results of a pilot study that demonstrates the promise of this approach at the student level. We administered a questionnaire based on expectancy‐value theory to undergraduates enrolled in introductory biology courses. Itself an integrative approach, expectancy‐value theory views achievement‐related behavior as a joint function of the person's expectancy of success in the behavior and the subjective value placed on such success. Our results indicated: (a) significant gender differences in the underlying factor structures of expectations and values related to the discipline of biology, (b) expectancy‐value factors significantly distinguished biology majors from nonmajors, and (c) expectancy‐value factors significantly predicted students' intent to enroll in future biology courses. We explore the expectancy‐value framework as an operationally integrative framework in our ecological model for studying academic communities, especially in the context of assessing the underrepresentation of women and minorities in the sciences. Future research directions as well as practical implications are also discussed.
Diagnosing and altering three aristotelian alternative conceptions in dynamics: Microcomputer simulations of scientific models
Authors: Weller Herman G.
Published: October 2006

This is a report on the investigation of a microcomputer‐based system for the diagnosis and remediation of three Aristotelian alternative conceptions of force and motion held by eighth‐grade physical science students. Diagnosis and posttesting were done with computer‐displayed, graphics‐based, multiple‐choice questions. The two remediation simulations were designed to present scientific idealizations and to be perceived by the student as anomalous to the three alternative conceptions. Structured interviews were employed at several points during the study to obtain indications of the conceptions of force and motion of students with different achievement rankings, as well as to determine the students' reactions to the computer pretest questions or the simulations. A student's possession of alternative conceptions was unrelated to whether the student was a strong or weak learner of science. Students who were currently studying dynamics in their classes exhibited a very different pattern of nonscientific answers on the computer diagnostic test than did students who had completed that topic. The completed students who were selected for possession of alternative conceptions were facilitated by the computer simulations in altering their naive conceptions to a significant degree.
Evolution and validation of a personal form of an instrument for assessing science laboratory classroom environments
Authors: Fraser Barry J. , Giddings Geoffrey J. , McRobbie Campbell J.
Published: October 2006

The research reported in this article makes two distinctive contributions to the field of classroom environment research. First, because existing instruments are unsuitable for science laboratory classes, the Science Laboratory Environment Inventory (SLEI) was developed and validated. Second, a new Personal form of the SLEI (involving a student's perceptions of his or her own role within the class) was developed and validated in conjunction with the conventional Class form (involving a student's perceptions of the class as a whole), and its usefulness was investigated. The instrument was cross‐nationally fieldtested with 5,447 students in 269 senior high school and university classes in six countries, and cross‐validated with 1,594 senior high school students in 92 classes in Australia. Each SLEI scale exhibited satisfactory internal consistency reliability, discriminant validity, and factorial validity, and differentiated between the perceptions of students in different classes. A variety of applications with the new instrument furnished evidence about its usefulness and revealed that science laboratory classes are dominated by closed‐ended activities; mean scores obtained on the Class form were consistently somewhat more favorable than on the corresponding Personal form; females generally held more favorable perceptions than males, but these differences were somewhat larger for the Personal form than the Class form; associations existed between attitudinal outcomes and laboratory environment dimensions; and the Class and Personal forms of the SLEI each accounted for unique variance in student outcomes which was independent of that accounted for by the other form.
The effect of practical work on students' understanding of combustion
Authors: Watson Rod , Prieto Teresa , Dillon Justin S.
Published: October 2006

This paper describes a study which investigated 14 and 15 year old students' understanding of combustion in both England and Spain, and explores the effect of practical laboratory experience on students' understanding. The teaching and learning styles used with the students in the study were explored using questionnaires and interviews. The students' understanding of combustion was explored using a questionnaire. The responses of English and Spanish students are significantly different. The quality of the responses is explored in terms of the awareness of students of the involvement of gases in combustion, and it appears, however, that the more extensive use of practical work in English schools has had only a marginal effect on their understanding of combustion.
Tugboats and tennis games: Preservice conceptions of teaching and learning revealed through metaphors
Authors: Gurney Bruce F.
Published: October 2006

Black (1979) writes about the inextricable interrelationships among language, perception, knowledge, experience and metaphor. An extension of this, grounded in Wittgenstein's (1953) notion of the symbolic, experiential basis of “first language,” is the view that metaphors are windows into this primitive, personal framework. The purpose of this paper is to take an exploratory look at preservice teachers' metaphors of teaching and learning and to examine some components of student teachers' own intuitions in this area. In this study, a questionnaire was administered to one hundred and fifty‐one science education students at the beginning of their preservice training on which they were challenged to generate a personal metaphor for “teaching and learning.” Descriptive elements within the responses were differentiated and applied to the development of a classification scheme. Both the technique and the categorization are seen as useful devices for the identification of common conceptions about the teaching and learning process. The metaphors have been seen to communicate a richness of meaning which convey elements of mood, control, roles, attitudes and beliefs as they apply to teaching and learning and which, it is argued here, are grounded on more deeply rooted symbols than literal language. In the light of constructivist pedagogy, the elicitation of students' preconceptions is seen to be germane to the organization of learning experiences.
Teaching and learning distillation in chemistry laboratory courses
Authors: Van Keulen Hanno , Mulder Theo H. M. , Goedhart Martin J. , Verdonk Adri H.
Published: October 2006

This study investigates the problems chemistry majors have with learning distillation in traditional chemistry laboratory courses. Using an interpretive cyclic research design, we collected and interpreted data, mainly in the form of observation notes and transcriptions of the discourse that takes place during laboratory courses. It was found that students experience numerous problems; these are described and interpreted. We summarize students' problems in four categories: (a) students use an independent component conception; (b) they have insufficient understanding of the properties of vapor; (c) they regard distillation from a physical point of view; and (d) they do not have a practical understanding of thermodynamics. The main origin of these problems was found to lie with the traditional curriculum structure. Lecture courses and textbooks treat distillation in a generalized and decontextualized way, whereas decisions in actual distillations are always based on contextual features. It was found that textbooks and teachers often do not discriminate carefully and explicitly among five different contexts for distillation: organic synthesis, chemical analysis, analytical chemistry, physical chemistry, and preparation of products. Students take the generalized concepts at face value and apply them to all distillations regardless of context. They cannot interpret their observations or make reasoned decisions based on the theoretical framework of a specific context.
Evaluating prospective elementary teachers' understanding of science and mathematics in a model preservice program
Authors: McDevitt Teresa M. , Troyer Rod , Ambrosio Anthony L. , Heikkinen Henry W. , Warren Erica
Published: October 2006

Two cohorts of students preparing to become elementary teachers participated in a model program in science and mathematics. These students were compared to other students taking similar courses on their conceptual understandings of science and mathematics, their investigative proficiencies, and their beliefs about effective methods of teaching these subjects. Instruments included newly developed tests of understanding, existing standardized achievement tests, and instruments devised for the evaluation to elicit conceptions of appropriate ways to teach science and mathematics to elementary children. Results from individual courses indicated that students participating in the model program developed more thorough understandings and more reform‐minded beliefs related to teaching science and mathematics. Issues associated with the assessment and evaluation of innovative programs in science and mathematics are discussed, and recommendations for teacher preparation are offered.
Cognitive conflict as a teaching strategy in solving chemistry problems: A dialectic–constructivist perspective
Authors: Niaz Mansoor
Published: October 2006

The main objective of this study was to evaluate the effect of teaching experiments within a dialectic‐constructivist framework based on the following considerations: (a) Cognitive conflicts used in the teaching experiments must be based on problem‐solving strategies that students find relatively convincing: (b) after having generated a cognitive conflict, it is essential that the students be provided with an experience that could facilitate the resolution of the conflict; and (c) the teaching strategy developed is used by an interactive constructivist approach within an intact classroom. The study was based on two sections of freshman students who had registered for Chemistry I at the Universidad de Oriente, Venezuela. One of the sections was randomly designated as the control group and the other as the experimental group. To introduce cognitive conflict, the experimental group was exposed to two teaching experiments dealing with stoichiometry problems based on the concept of limiting reagent. Students in the control group were exposed to the same problems—however, without the cognitive conflict teaching experiments format. To evaluate the effect of the teaching experiments, both groups were evaluated on five different problems at different intervals during the semester, referred to as posttests. All posttests formed part of the regular evaluation of the students. Results obtained show the advantage of the experimental group on four of the posttests. It is concluded that the experimental treatment was effective in improving performance on the immediate posttests. It was observed that some students protect their core belief [see Lakatos, I. (1970). Falsification and the methodology of scientific research programmes. In I. Lakatos & A. Musgrave (Eds.), Criticism and the growth of knowledge (pp. 91–196). Cambridge: Cambridge University Press] in stoichiometry (establishing equivalent relations between different elements or compounds) by ignoring the conflicting data, just as conflicting (anomalous) data do not necessarily convince a scientist to abandon a particular theory.
A population study of Stenocranus minutus (Fab.) (Hemiptera: Delphacidae)
Authors: May Yin Yin
Published: October 2006

The seasonal and annual fluctuations in a population of the delphacid, Stenocranus minutus (Fab.) on Dactylis glomerata L. were studied from March 1968 to September 1970. The study involved the comparison of several sampling methods to estimate the egg, nymphal and adult numbers and an investigation into causes of mortality within each stage. A population budget was made for the years 1969 and 1970.
Temporal patterns of food‐availability and their effect on Tribolium populations
Authors: Wool David , Sverdlov Eliyahu
Published: October 2006

The effects of two temporal food‐availability regimes were examined on populations of flour beetles (Tribolium): (1) Food given once only and never renewed; (2) Food added in fixed intervals.

In Case 1 there was a single peak in population size (and biomass) followed by a slow decline. The amount of biomass and numbers of adults produced were inversely related to the number of adult founders.

In Case 2, the production of adults and biomass was not proportional to the amount of food; thus food was not the limiting factor in the experimental populations. The effect of medium conditioning may have been important in limiting population growth.

Differences in productivity among the strains in Case 2 reflected their relative genetic variability following different mating systems in their past history.

A measure of the food cost of maintaining 1g of biomass for 1 day (MC) is suggested. All strains showed a rather uniform MC, approximately 0.1g flour/1g biomass/day, except in the growth phase when most of the biomass was larval biomass. During this phase, food is utilized not only for metabolism but also for building new tissues, and the energy requirement must be higher.
Extensions to Southwood and Jepson's graphical method of estimating numbers entering a stage for calculating mortality due to parasitism
Authors: Bellows T. S. , Van Driesche R. G. , Elkinton J. S.
Published: October 2006

Seven methods of estimating percentage parasitism using graphical estimates of host or parasitoid recruitment are presented.

Biases affecting these percentage parasitism estimates arise from the effect of mortality on graphical estimates of numbers entering a stage. These biases result in underestimation of parasitism in some of the methods examined and overestimation in others.

The methods and their biases are discussed and illustrated with reference to data from four generations of Pieris rapae (L.) parasitized by Cotesia glomerata (L.).

The general impact of these biases are discussed with reference to situations where the methods might be applied.
Estimation of european corn borer egg masses density by sampling of runs
Authors: Vaillant J. , Derridj S.
Published: October 2006

Spatial distributions of individuals may be considered in two ways: Firstly, individuals are situated on a continuum. Secondly, individuals are situated on discrete units, for example, insect eggs on plants. The aim of this paper is to show that sometimes, in the latter case, sampling methods based on infestation runs can be of interest in estimating population density. Analytical results are obtained under complete spatial randomness hypothesis and alternative hypotheses. Sampling procedures with limited cost are discussed and the European corn borer (ECB) case is mainly considered.
Spatial distribution and mortality process of Anoplophora malasiaca (Coleoptera: Cerambycidae) eggs in citrus groves
Authors: Adachi Ishizue
Published: October 2006

The study was carried out in two (A and B) citrus groves to clarify the spatial distribution patterns of eggs and larvae, and to analyse the mortality process of eggs. From the analysis by using the mean density and the mean crowding, it was clarified that the distributions of eggs were contagious and that larvae were more contagiously distributed than eggs. The τ and z indices showed that the operation of egg mortality was inversely density‐dependent in both groves, and that the degree of inverse density‐dependence was greater in A than in B grove. The spatial correlations between the emergence holes and the eggs or larvae in each tree, which were analysed by using ω index, showed that the distributions were more overlapping between the emergence holes and the larvae than the eggs. As the result of dividing trees into several groups according to the number of emergence holes, it was clarified that the survival rates of eggs were positively correlated with the number of emergence holes. In conclusion, inversely density‐dependent mortality process was considered to be caused by lower mortality rates of eggs in the trees with more emergence holes. Especially in A grove, because the trees with more emergence holes were larger in diameter and more egg oviposition, the inversely density‐dependent mortality process was considered to be detected more conspicuously than in B grove.
Modelling the effects of population aggregation on the efficiency of insect pest control
Authors: Barclay Hugh J.
Published: October 2006

A methodology is developed to assess the effects of spatial distribution on the efficiency of insect pest control. This methodology is especially applicable to pest control methods whose efficiency of action depends either positively or negatively on pest density It is applied here to the sterile insect technique and pheromone trapping for male annihilation, which both depend negatively on density. This methodology relies on quantifying clumps of various size and then relating this to efficiency of control and predicting the total pest production given the information on clump sizes and efficiency of control for each clump size. It is found that control is about four times as difficult for a population that is highly clumped (k of the negative binomial distribution=0.25) as for a regularly dispersed population.
On the stability of the stock‐harvesting system controlled by a feedback management procedure
Authors: Harada Yasushi , Sakuramoto Kazumi , Tanaka Syoiti
Published: October 2006

Stability of the stock‐harvesting system regulated by a feedback control procedure of catch quota is examined. In the procedure considered, catch quota is changed proportionally to the difference between current and the target stock level (with a proportionality constant h) and to the annual stock growth rate (with a proportionality constant g). Condition for the local stability of the target equilibrium is obtained as a function of the stock‐recruitment relation, survival probability of adults, target stock level, time lag before implementation of regulation, age of sexual maturity of the stock, and proportionality constants g and h. It is shown that, (1) the procedure has the stabilizing effect; it can stabilize the target stock level that is unstable under constant harvest, (2) lower target stock level favors larger g and smaller h, when the target is set around MSYL (the stock level that gives MSY), (3) the degree of stability, measured by the time required to recover the target stock level, is an increasing function of the target stock level, (4) stability and sustainable yield are in trade‐off, (5) time delay caused by the time needed before sexual maturity does not affect the stability significantly, but the effect of the time lag before implementation of regulation is significant. Comparison between harvest‐control and effort‐control procedures is also made, and the advantage of the latter in terms of stability is shown.
The influence of the social environment on sexual maturation of female deermice (Peromyscus maniculatus bairdi)
Authors: Lombardo Donna L. , Terman C. Richard
Published: October 2006

Female deermice housed from weaning with groups of five females, five males or five males plus five females had significantly smaller uteri at 35–38 days of age compared to females reared alone. The uterine weights of females reared in the three grouped treatments did not differ significantly among themselves nor did those reared alone or with another animal of either sex. Uterine and ovary weights revealed no significant inhibition or stimulation of sexual maturation dependent upon sex of the adult conspecific with which young females were housed. The number of conspecifics (five or more of either sex) housed with young females was of primary importance in the retardation of uterine development observed.
Continuous population estimates for Dendroctonus frontalis Zimm. (Coleoptera: Scolytidae) occurring in infestations
Authors: Coulson R. N. , Pulley P. E. , Pope D. N. , Fargo W. S. , Edson L. J.
Published: October 2006

Infestations of Dendroctonus frontalisZimm. are often observed to enlarge continuously by the colonization of new hosts in a pattern similar to a forest fire. This pattern of infestation growth presents unique problems in quantitatively estimating populations of D. frontalis. Beetle populations on each infested tree in an infestation go through five processes: attack, oviposition, reemergence, survivorship, and emergence. These processes, which have been described mathematically in the literature, each take several days for completion. In order to follow the distribution and abundance of D. frontalis throughout the course of development of a spot, we need a daily estimate of the number of beetles involved in each process on every tree. Since it is not practical to sample each tree daily, we developed a procedure whereby quantitative estimation procedures for within‐tree populations were used in combination with the mathematical models for the life processes to produce a daily record of the number of adults successfully attacking trees, the number of eggs oviposited, the number of beetles reemerging, number of beetles surviving within the trees, and the number of beetles emerging. These daily estimates were then summarized for all trees in the spot for the duration of the infestation.

The daily record of populations of D. frontalis, used with information on infestation geometry, were suggested to be of value in describing and elucidating several important facets of population dynamics including dispersal patterns within infestations, between tree beetle loss (mortality), and time lags among the various population processes. The information reported can be used to develop simulation models of population dynamics or to validate existing models.
Comparative population studies of three Pieris butterflies, P. rapae, P. melete and P. napi, living in the same area
Authors: Ohsaki Naota
Published: October 2006

Utilization of patchy habitats by adult populations of three Pieris butterflies, P. rapae, P. melete and P. napi was studied throughout the flight season in an area of their coexistence, about 3×1.5 km, in a farm village in the mountains in Inabu, Aichi Prefecture. Field study was by the mark‐recapture method. Results were analyzed by dispersal distances and recapture duration decay curves for adults of different age‐classes estimated on the basis of physical condition of their wings, together with supplementary information of daliy egg‐laying rate of females, obtained in field cages.

Sexually immature, mated femals of P. rapae after teneral stage showed a migratory flight. On the other hand, reproductive females and all males of P. rapae were strongly resident within suitable habitats, and reproductive females begun to lay eggs abundantly at sunny places of newly suitable areas within a short period. P. melete seemed to disperse gradually from emerged stites and females of this species continued to lay some constant numbers of eggs for more than ten days over a wider area. P. napi appeared more like P. melete than P. rapae.

The habitats of the three species can be characterized as follows:P. rapae, temporary, continued for pre‐reproductive females but localized for reproductive females and all males, and unstable;P. melete, permanent, widespread, and stable;P. napi, permanent, localized, and stable.

The numbers of generations of P. rapae, P. melete and P. napi were estimated to be about six, three and three, respectively. Seasonal fluctuations in the number of adults were influenced by the stability of their habitats, i. e., the population size fluctuated sharply in P. rapae, but it was much more stable in P. melete and P. napi. In view of these results, it can be said that P. rapae fits the general characteristics of a r‐strategist whereas P. melete and P. napi are more K‐strategic than P. rapae.
Ecological studies of Roparidia fasciata in Okinawa island I. Distribution of single‐ and multiple‐foundress colonies
Authors: Suzuki Hiroshi , Murai Minoru
Published: October 2006

To compare between a single‐foundress colony and a multiple‐foundress colony at the pre‐emergence state of a social wasp, R. fasciata, nest distributions and colony terminations were investigated in 8 sites with different environmental conditions. Marking experiments were also conducted in two sites at high wasp density.

Foundress populations were composed of single‐foundress colonies in sites C, D and E, new environments where have recently suited for inhaviting, at low wasp density. In sites like A and B which were used year after year, at high wasp density, coexistence of multiple‐and single‐foundress colonies was observed.

From the marking experiment, nests initiated by a single foundress were more distant away from the nest where the original foundress emerged the fall before, compared to multiple‐foundress nests which were initiated by multiple foundress.

Greater percentage of colony termination was observed in single‐foundress nests than in multiple‐foundress nests, and the colony termination in single‐foundress colonies increased with the nest density.

Ant predation was the key factor causing the variation of the percentage of colony termination.
Asynchronous pupation of univoltine insects as evolutionarily stable phenology
Authors: Iwasa Yoh
Published: October 2006

Evolutionarily stable seasonal timing of larval feeding stages is studied theoretically for univoltine insects. In the evolutionarily stable (or ESS) population, each individual maximizes its own lifetime reproductive success by choosing the hatching and pupation dates, given the resource availability curve with a peak in the middle of a year, a higher daily mortality in the feeding stages, and the growth rate decreasing with the larval biomass in the population. If growth rate is proportional to the body size, the population at the ESS is composed of a mixture of phenotypes differing in hatching and pupation, but pupation interval over which some popation occur every day is much longer than hatching interval. If growth rate increases with the body size at a speed slower than linearly, large sized larvae should pupate earlier than small ones.