Showing papers by "University of Haifa published in 2001"

Taking stock of naturalistic decision making

Abstract: We review the progress of naturalistic decision making (NDM) in the decade since the first conference on the subject in 1989. After setting out a brief history of NDM we identify its essential characteristics and consider five of its main contributions: recognition-primed decisions, coping with uncertainty, team decision making, decision errors, and methodology. NDM helped identify important areas of inquiry previously neglected (e.g. the use of expertise in sizing up situations and generating options), it introduced new models, conceptualizations, and methods, and recruited applied investigators into the field. Above all, NDM contributed a new perspective on how decisions (broadly defined as committing oneself to a certain course of action) are made. NDM still faces significant challenges, including improvement of the quantity and rigor of its empirical research, and confirming the validity of its prescriptive models. Copyright © 2001 John Wiley & Sons, Ltd.

Some empirical evidence for the involvement load hypothesis in vocabulary acquisition

Abstract: EFL learners in two countries participated in two parallel experiments testing whether retention of vocabulary acquired incidentally is contingent on amount of task-induced involvement. Short- and long-term retention of ten unfamiliar words was investigated in three learning tasks (reading comprehension, comprehension plus filling in target words, and composition-writing with target words) with varying “involvement loads”—various combinations of need, search, and evaluation. Time-on-task, regarded as inherent to a task, differed among all three tasks. As predicted, amount of retention was related to amount of task-induced involvement load: Retention was highest in the composition task, lower in reading plus fill-in, and lowest in the reading. These results are discussed in light of the construct of task-induced involvement.

The Economics of Network Industries

Abstract: This book introduces upper-level undergraduates, graduate students, and researchers to the latest developments in network economics, one of the fastest-growing fields in all industrial organization. Network industries include the Internet, e-mail, telephony, computer hardware and software, music and video players, and service operations in the banking, legal, and airlines industries among many others. The work offers an overview of the subject matter as well as investigations about specific industries. It conveys the essential features of how strategic interactions between firms are affected by network activity, as well as covering social interaction and its influence on consumers' choices of products and services. Virtually no calculus is used in the text, and each chapter ends with a series of exercises and selected references. The text may be used for both one- and two-semester courses.

Critical swimming speed: its ecological relevance.

Abstract: Critical swimming speed (U(crit)) is a standard measurement to assess swimming capabilities of fishes. To conduct this measurement a fish is introduced into a water tunnel in which the current velocity can be controlled by the investigator. At the beginning of the measurement water velocity is low, approximately 1 body length (BL) s(-1), and is then incrementally increased at prescribed intervals. Fishes tend to maintain their position in the water tunnel against the current until fatigue sets in. The time and velocity at which the fish fatigue are used to calculate the critical swimming speed. This procedure is widely used to assess the effects of environmental conditions and pollutants on fish performance. Since the procedure is conducted in conditions that are far from representing most natural environment experienced by fishes, doubts have been raised about its ecological and ecophysiological relevance. Few studies examined correlations between critical swimming speed and traits that seem to be more ecologically relevant. Positive correlations were found between U(crit) and routine activity, metabolic rates and body size of open water, planktivorous fishes, metabolic rates and body size. These data indirectly suggest ecological relevancy of U(crit), but direct measurements relating U(crit) to reproductive success or survival are required to assess such relevancy.

The Economics of Network Industries

Abstract: This book introduces upper-level undergraduates, graduate students, and researchers to the latest developments in network economics, one of the fastest-growing fields in all industrial organization. Network industries include the Internet, e-mail, telephony, computer hardware and software, music and video players, and service operations in the banking, legal, and airlines industries among many others. The work offers an overview of the subject matter as well as investigations about specific industries. It conveys the essential features of how strategic interactions between firms are affected by network activity, as well as covering social interaction and its influence on consumers' choices of products and services. Virtually no calculus is used in the text, and each chapter ends with a series of exercises and selected references. The text may be used for both one- and two-semester courses.

Evolution of genome–phenome diversity under environmental stress

Abstract: The genomic era revolutionized evolutionary biology. The enigma of genotypic-phenotypic diversity and biodiversity evolution of genes, genomes, phenomes, and biomes, reviewed here, was central in the research program of the Institute of Evolution, University of Haifa, since 1975. We explored the following questions. ( i ) How much of the genomic and phenomic diversity in nature is adaptive and processed by natural selection? ( ii ) What is the origin and evolution of adaptation and speciation processes under spatiotemporal variables and stressful macrogeographic and microgeographic environments? We advanced ecological genetics into ecological genomics and analyzed globally ecological, demographic, and life history variables in 1,200 diverse species across life, thousands of populations, and tens of thousands of individuals tested mostly for allozyme and partly for DNA diversity. Likewise, we tested thermal, chemical, climatic, and biotic stresses in several model organisms. Recently, we introduced genetic maps and quantitative trait loci to elucidate the genetic basis of adaptation and speciation. The genome–phenome holistic model was deciphered by the global regressive, progressive, and convergent evolution of subterranean mammals. Our results indicate abundant genotypic and phenotypic diversity in nature. The organization and evolution of molecular and organismal diversity in nature at global, regional, and local scales are nonrandom and structured; display regularities across life; and are positively correlated with, and partly predictable by, abiotic and biotic environmental heterogeneity and stress. Biodiversity evolution, even in small isolated populations, is primarily driven by natural selection, including diversifying, balancing, cyclical, and purifying selective regimes, interacting with, but ultimately overriding, the effects of mutation, migration, and stochasticity.

Attachment security and adjustment to school in middle childhood.

Abstract: The concurrent association between security of attachment and adaptive functioning at school in middle childhood was examined. A sample of 113 children of 4th and 5th grade filled out a selfreport ...

Hurwitz numbers and intersections on moduli spaces of curves

Abstract: 1 Department of Mathematics, University of Stockholm, S-10691, Stockholm, Sweden (e-mail: teke@matematik.su.se) 2 Higher College of Mathematics, Independent University of Moscow and Institute for System Research RAS, Moscow, Russia (e-mail: lando@mccme.ru) 3 Department of Mathematics, Royal Institute of Technology, S-10044, Stockholm, Sweden (e-mail: mshapiro@math.kth.se) 4 Department of Mathematics and Department of Computer Science, University of Haifa, Haifa 31905, Israel (e-mail: alek@mathcs.haifa.ac.il)

Two visual systems and two theories of perception: An attempt to reconcile the constructivist and ecological approaches

Abstract: The two contrasting theoretical approaches to visual perception, the constructivist and the ecological, are briefly presented and illustrated through their analyses of space and size perception. Earlier calls for their reconciliation and unification are reviewed. Neurophysiological, neuropsychological, and psychophysical evidence for the existence of two quite distinct visual systems, the ventral and the dorsal, is presented. These two perceptual systems differ in their functions; the ventral system's central function is that of identification, while the dorsal system is mainly engaged in the visual control of motor behavior. The strong parallels between the ecological approach and the functioning of the dorsal system, and between the constructivist approach and the functioning of the ventral system are noted. It is also shown that the experimental paradigms used by the proponents of these two approaches match the functions of the respective visual systems. A dual-process approach to visual perception emerges from this analysis, with the ecological-dorsal process transpiring mainly without conscious awareness, while the constructivist-ventral process is normally conscious. Some implications of this dual-process approach to visual-perceptual phenomena are presented, with emphasis on space perception.

The relationship between vision strength, leadership style, and context ☆

Abstract: This investigation examined the relationship between leadership style and the content of vision tapes produced in a comprehensive leadership workshop with community leaders. The transformational leadership style of 141 leaders positively predicted the inspirational “strength” of their vision statements, as reflected in the level of optimism expressed in the videotaped presentation of their visions. Organizational size was related to vision strength and moderated the relationship between passive leadership style and vision strength.

Coping with breast cancer: patient, spouse, and dyad models.

Abstract: Objective The objectives of this study were 1) to assess similarities and differences between patients with breast cancer and their spouses in terms of coping strategies and adjustment (psychosocial and psychological) to cancer and 2) to investigate the pattern of relationships between the patients' and spouses' coping strategies and between each of these strategies and the patient's adjustment to the illness using three types of models: patient, spousal, and dyadic coping. Methods Seventy-three patients with breast cancer and their spouses completed questionnaires that measured distress (Brief Symptom Inventory), psychosocial adjustment, and coping strategies. Results The patients' distress was greater than their spouses', but a similar level of psychosocial adjustment was reported. The patients used more strategies involving problem-focused coping than their spouses. The use of emotion-focused coping, which included ventilation and avoidance strategies, was highly related to distress and poor adjustment on the part of the patient. The spouses' emotion-focused coping and distress were related to that of the patients. Dyad emotion-focused coping measures were highly associated with the patients' distress and adjustment. Conclusions Spousal and dyad coping are important factors in a patient's adjustment to breast cancer.

Component averaging: An efficient iterative parallel algorithm for large and sparse unstructured problems

Abstract: Component averaging (CAV) is introduced as a new iterative parallel technique suitable for large and sparse unstructured systems of linear equations. It simultaneously projects the current iterate onto all the system's hyperplanes, and is thus inherently parallel. However, instead of orthogonal projections and scalar weights (as used, for example, in Cimmino's method), it uses oblique projections and diagonal weighting matrices, with weights related to the sparsity of the system matrix. These features provide for a practical convergence rate which approaches that of algebraic reconstruction technique (ART) (Kaczmarz's row-action algorithm) – even on a single processor. Furthermore, the new algorithm also converges in the inconsistent case. A proof of convergence is provided for unit relaxation, and the fast convergence is demonstrated on image reconstruction problems of the Herman head phantom obtained within the SNARK93 image reconstruction software package. Both reconstructed images and convergence plots are presented. The practical consequences of the new technique are far reaching for real-world problems in which iterative algorithms are used for solving large, sparse, unstructured and often inconsistent systems of linear equations.

The Role of Vowels in Reading Semitic Scripts: Data from Arabic and Hebrew.

Abstract: This study investigated the effect of vowels and context on readingaccuracy of skilled adult native Arabic speakers in Arabic and inHebrew, their second language. Their reading comprehension was alsotested in Arabic and Hebrew texts as a function of vowels. Theparticipants (n = 65) read fully vowelized and unvowelized lists ofArabic words, and vowelized and unvowelized paragraphs of Arabic.Further, they, read pointed and unpointed lists of Hebrew words, andpointed and unpointed paragraphs of Hebrew. They were also administeredtwo stories, one in Arabic and one in Hebrew, in two reading conditions,a fully vowelized and unvowelized Arabic story and a pointed andunpointed Hebrew story. The results revealed a significant effect forvowels and for context across all reading conditions in Arabic andHebrew. The surprising result was that the vowelized texts in Arabic andthe pointed and unpointed texts in Hebrew were comprehendedsignificantly better. Further, Pearson correlation procedures andmultiple regression analysis indicated no positive significantrelationship between oral reading accuracy results and silent readingcomprehension results. These findings are explained throughcharacteristics of the Semitic languages Arabic and Hebrew, and thetriliteral/quadriliteral-root model is suggested toexplain reading in unvowelized/unpointed texts in Semitic languages.

The Treaty of Nice and qualified majority voting

Abstract: We analyse and evaluate three decision rules for the Council of Ministers of the EU, which are prescribed by the `definitive form' of the Treaty of Nice. The first will apply from 2005 to the present 15-member EU, if it will not have been enlarged by then. The second or third will apply to an enlarged 27-member EU. We conclude that the first of these is an improvement on the current decision rule; but the other two have extremely undesirable features.

The effect of treadmill training on the ambulation of stroke survivors in the early stages of rehabilitation: a randomized study.

Abstract: The objective of this study was to compare the effects of conventional over-ground gait training with treadmill training on the restoration of gait in people with hemiparesis following a stroke. Twenty-five individuals in the early stages of rehabilitation were alternately assigned to one of two treatment groups. In addition to conventional physical therapy, the experimental group participated in 15 treadmill-training sessions in which a handrail was used for external support. The control group received the same number of equal length sessions of over-ground ambulation. Treatment effects were established by pre- and posttreatment assessment of: 1) functional walking ability, 2) walking speed, 3) stride length, 4) temporal characteristics of gait, and 5) electromyographic activity of calf muscles. Normal values were obtained from eight healthy individuals of approximately the same age as the stroke survivors. The study demonstrates that individuals following a stroke are well able to tolerate treadmill training in the early stage of their rehabilitation process without the use of a weight support apparatus. Furthermore, the findings suggest that treadmill training may be more effective than conventional gait training for improving some gait parameters such as functional ambulation, stride length, percentage of paretic single stance period, and gastrocnemius muscular activity.

Internet pornography: A social psychological perspective on internet sexuality

Abstract: Spectacular growth in availability of sexually explicit material on the Internet challenges sexual science to study antecedents and consequences of experience with such content. The current analysi...

Human resource strategy: formulation, implementation, and impact

Abstract: Introduction The Formulation and Emergence of Human Resource Strategies Models of Human Resource Strategy People Flow Subsystem Appraisal and Reward Subsystem Employee Relations Subsystem The Impact of Human Resource Strategy

An algorithm for approximate tandem repeats.

Abstract: A perfect single tandem repeat is defined as a nonempty string that can be divided into two identical substrings, e.g., abcabc. An approximate single tandem repeat is one in which the substrings are similar, but not identical, e.g., abcdaacd. In this paper we consider two criterions of similarity: the Hamming distance (k mismatches) and the edit distance (k differences). For a string S of length n and an integer k our algorithm reports all locally optimal approximate repeats, r = umacro u, for which the Hamming distance of umacro and u is at most k, in O(nk log (n/k)) time, or all those for which the edit distance of umacro and u is at most k, in O(nk log k log (n/k)) time. This paper concentrates on a more general type of repeat called multiple tandem repeats. A multiple tandem repeat in a sequence S is a (periodic) substring r of S of the form r = u(a)u', where u is a prefix of r and u' is a prefix of u. An approximate multiple tandem repeat is a multiple repeat with errors; the repeated subsequences are similar but not identical. We precisely define approximate multiple repeats, and present an algorithm that finds all repeats that concur with our definition. The time complexity of the algorithm, when searching for repeats with up to k errors in a string S of length n, is O(nka log (n/k)) where a is the maximum number of periods in any reported repeat. We present some experimental results concerning the performance and sensitivity of our algorithm. The problem of finding repeats within a string is a computational problem with important applications in the field of molecular biology. Both exact and inexact repeats occur frequently in the genome, and certain repeats occurring in the genome are known to be related to diseases in the human.

Analysis of the Mediating Effect of Personal-Psychological Variables on the Relationship Between Socioeconomic Status and Political Participation: A Structural Equations Framework

Abstract: The goal of this research was to test whether the relationship between socioeconomic status and political participation is direct or mediated by personal variables such as self-esteem, locus of control, and political efficacy, and to detect how such a mediating process might operate if it exists. Two forms of participation, namely active political participation and the more passive psychological involvement of citizens in the democratic process, were treated as separate but related facets of participation. Four competing models were advanced and tested. The data were collected from 434 citizens in the north of Israel who were interviewed by questionnaire. The analysis was performed by structural equations modeling with LISREL VIII. The findings show that the relationship between socioeconomic status and political participation can be better understood as being mediated by personal variables rather than direct. This is demonstrated by the many nonsignificant paths in the direct model. The findings also reveal that active political participation and psychological involvement are distinct but related constructs, where involvement leads to active participation. In addition, all research variables were related more strongly to psychological involvement than to active political participation. The findings are discussed in terms of their implications for future research on political participation.

Determinants of entrepreneurial intentions: Mexican immigrants in Chicago

Abstract: This paper focuses on Mexican immigrants who are considering to start a business but do not so for various reasons (latent entrepreneurs). The research design is unusual in that it queries the individuals at the very preliminary stages of the process when they are contemplating the alternatives, so it is well suited to learn about the determinants of business ownership. First, the findings demonstrate the potential value of personality measures (e.g., risk disposition) for predicting who will want to start a business. Second, the results underscore that having close family members in business exposes individuals to role models and sources of financial and nonfinancial help that might put business ownership within reach of people with modest resources. Third, economic resources in the household, in the form of financial investments, also affect the wish to start a business because they furnish available capital for the start-up.

A Cross-Age Study of Junior High School Students' Conceptions of Basic Astronomy Concepts.

Abstract: Junior high school students' astronomy conceptions were analysed by means of a written questionnaire presented to them during the beginning of the first semester. The main findings were as follows: almost half of the students indicated that the cause of the day-night cycle is the Earth spinning on its axis; most students chose as their best account for changes in the Moon's phases the Moon moving around the Earth. Despite that, most students thought that the Moon must be in its Full phase for there to be a total solar eclipse; most students underestimated the distances in the Universe and overestimated the Earth's diameter. A great proportion of students indicated that the reason for the different seasons is the tilt of the Earth's axis relative to the plane of its orbit as it revolves around the Sun. But almost the same number of students chose the varying distance between Sun and Earth or between the Earth, Moon and Sun, as a reason for the seasons. Only a third of the students answered correctly that i...

Differential activation of hippocampus and amygdala following spatial learning under stress.

Abstract: We examined the activation of memory-related processes in the hippocampus and the amygdala following spatial learning under stress, in the rat. Animals were trained in a water maze in a massed spatial task under two stress conditions (cold and warm water). In the dorsal CA1, training was accompanied by increased phosphorylation of ERK2 only in animals that have acquired the task (irrespective of whether they were trained in cold or warm water). In the amygdala, significant activation of ERK2 was found only in animals that learned the task well under high levels of stress. Hence, the results suggest that the amygdala and the hippocampus are differentially activated following spatial learning, depending on the level of stress involved.

Social Relationships and Internet Use among Adolescents in Israel

Abstract: Objective. This study examined the relationship between youth leisure activities, peer relations, and prosocial attitudes and the frequency of Internet use among adolescents in Israel. Methods. Hypotheses were tested using data from a face-to-face survey of a representative sample of the Israeli youth population (n = 927) conducted in February 1998. Results. It was found that the lower an individual's level of attachment to close friends and the less prosocial attitudes he/she expressed, the higher was the likelihood of his/her being a frequent Internet user. However, Internet users were more likely than nonusers to participate in social activities such as parties, singers' performances, and sports activities. Conclusions. Contrary to public perceptions it appears that among the adolescent population of Israel, Internet use is not displacing other social activities. However, adolescents who are more socially isolated are more likely to be frequent Internet users. Future research should explore whether for this group, the Internet is being used to overcome individuals' barriers to the formation of social relationships.

Enhanced Efficiency of Quantitative Trait Loci Mapping Analysis Based on Multivariate Complexes of Quantitative Traits

Abstract: An approach to increase the efficiency of mapping quantitative trait loci (QTL) was proposed earlier by the authors on the basis of bivariate analysis of correlated traits. The power of QTL detection using the log-likelihood ratio (LOD scores) grows proportionally to the broad sense heritability. We found that this relationship holds also for correlated traits, so that an increased bivariate heritability implicates a higher LOD score, higher detection power, and better mapping resolution. However, the increased number of parameters to be estimated complicates the application of this approach when a large number of traits are considered simultaneously. Here we present a multivariate generalization of our previous two-trait QTL analysis. The proposed multivariate analogue of QTL contribution to the broad-sense heritability based on interval-specific calculation of eigenvalues and eigenvectors of the residual covariance matrix allows prediction of the expected QTL detection power and mapping resolution for any subset of the initial multivariate trait complex. Permutation technique allows chromosome-wise testing of significance for the whole trait complex and the significance of the contribution of individual traits owing to: (a) their correlation with other traits, (b) dependence on the chromosome in question, and (c) both a and b. An example of application of the proposed method on a real data set of 11 traits from an experiment performed on an F(2)/F(3) mapping population of tetraploid wheat (Triticum durum x T. dicoccoides) is provided.

Prevalence and characteristics of post coronary artery bypass graft surgery pain (PCP).

Abstract: Coronary artery bypass grafting (CABG) is one of the most common surgical procedures performed worldwide. However, its frequent complication, the post-CABG pain (PCP) syndrome, remains poorly documented. This retrospective cohort study was aimed to investigate the prevalence and characteristics of this syndrome. Five hundred and four of 540 subjects, who underwent CABG surgery at our institution between January 1995 and December 1996 and who could be identified, were mailed questionnaires regarding the presence and characteristics of chest wall pain. Eighty of 217 patients, who were defined as having PCP based on these questionnaires, were evaluated in detail. Main outcome measures included a preliminary pain questionnaire, pain localization on a body scheme, a five-point verbal scale and the Visual Analogue Scale (VAS) for measuring pain intensity. Pain qualities, disability and depression were measured by the McGill Pain Questionnaire (MPQ), the Pain Disability Index (PDI), and the Beck Depression Inventory (BDI), respectively. Medical and neurological examinations were also conducted, as well as quantitative thermal testing (QTT) of the chest wall. The preliminary pain questionnaires indicated that 219 of the 387 respondents (56%) reported chest wall pain, which was categorized as PCP. One hundred and forty-two (65%) of the patients with PCP reported pain of at least moderate severity, and 151 (72%) reported that the pain interfered with their daily activities. Eighty PCP patients were available for a detailed evaluation. Left-sided chest wall pain was noted by 53 subjects, midline scar pain by 47, and right-sided pain by nine subjects. Pain intensity (VAS) was 35 +/- 22 (mean +/- SD), MPQ score was 4.9 +/- 3.7, PDI score was 2.0 +/- 0.7, and BDI score was 9.3 +/- 7.3. The neurological examination and the QTT indicated three subcategories of PCP: (1) left-sided chest wall pain often associated with hypoesthesia, mechanical allodynia, and elevated thermal thresholds; (2) midline scar pain accompanied primarily by mechanical allodynia; (3) right-sided, relatively infrequent pain. While the first two subcategories seem to have a neurogenic etiology, this later subcategory of pain is of a mal-defined etiology. This study indicates that PCP is a group of pain syndromes with a high prevalence, and with a negative effect on mood and performance of daily activities. The risk of developing PCP and its potential consequences should therefore be discussed with every patient prior to CABG surgery. These results will need to be confirmed in larger, multi-center studies.

The Impossible Role of Teacher Educators in a Changing World

Abstract: The thesis of this article is that the external demands placed on teacher education at the present time, combined with inherent professional needs of teachers and student teachers, create a nearly impossible situation for teacher educators. The article starts with a brief analysis of some of the external demands and constraints on teacher education: globalization, professionalization, and the call of many experts to teach for understanding. These external demands are exacerbated by teachers’ needs for certainty and control, and the frequent gaps between teachers’ professional self-images and the demands of their teaching contexts also contribute to the complexities of the role of teacher educators. The article concludes with a discussion of the societal implications of the current situation.