Showing papers by "University of Haifa published in 1986"

Interpersonal Influences in Adolescent Drug Use—The Role of Older Siblings, Parents, and Peers

Abstract: Drawing data from the first year of a longitudinal study of 508 families with focal adolescents aged 11 to 13 years and their older siblings (14 to 18 years), the investigators examined the influence of older siblings' drug-using attitudes and behaviors, in comparison with parental and peer drug-using attitudes and behaviors, on focal adolescents' nonuse and use of substances. Older siblings are frequently a source of drugs and use substances with their younger siblings, though peers remain the primary source and the most frequent cousers. For most substances, frequency of use was predicted by older sibling and peer substance use, each after controlling for the other. Parental drug use was found to be minimal in comparison to older siblings and peers. Findings relative to the potentially important role of older siblings in influencing their younger siblings' drug-using behavior are discussed.

Genetic diversity and environmental associations of wild barley,Hordeum spontaneum, in Turkey

Abstract: Genetic variability within and between populations of the wild progenitor of barley was studied electrophoretically Thirty enzyme loci were assayed in 437 individuals representing 11 populations ofH spontaneum in Turkey The results indicated that: (a)H spontaneum in Turkey is genetically rich in allozyme variation, but because of predominant self-pollination the variation is maintained as different homozygotes in the population; (b) genetic differentiation of populations includes clinal, regional, and local patterns, sometimes displaying sharp geographic differentiation over short distances; (c) overall indices of allozymic diversity and some allele frequencies of wild barley are significantly correlated with the environment and are predictable ecologically, chiefly by combinations of temperature and humidity variables; (d) a high percentage of alleles (66%) occur in local areas or are distributed sporadically rather than widespread; (e) Wright Fixation index was very high, F=0995; (f) genetic distance was high (D=011, ranging from 0031 to 0288) between populations, and (g) average relative genetic differentiation was high among populations (Gst=047, ranging from 002 to 066) The spatial patterns and environmental correlates and predictors of genetic variation ofH spontaneum in Turkey, indicated that genetic variation in wild barley populations is not only common, but also at least partly, adaptive Therefore, a much fuller exploitation of these genetic resources by breeding is warranted

Genetic resources of wild barley in the near East: structure, evolution and application in breeding

Abstract: Genetic diversity and structure of populations of the wild progenitor of barley, Hordeum spontaneum, from three countries, Israel, Turkey and Iran, in the Near East Fertile Crescent, are compared and contrasted. The analysis is based on electrophoretically discernible allozymic variation in proteins encoded by 27 shared loci in 2125 individuals representing 52 populations of wild barley. The results indicate that: (a) H. spontaneum in the Near East Fertile Crescent is very variable genetically; (b) genetic differentiation of populations includes some clinal but primarily regional and local patterns often displaying sharp geographic differentiation over short distances; (c) the average relative genetic differentiation (Gst) was 54% within populations, 39% among populations, and 8% between the three countries; (d) allele distribution is characterized by a high proportion of unique alleles (51%), and a high proportion of common alleles that are distributed either locally or sporadically; (e) discriminant analysis by allele frequencies successfully clustered wild barley of each of the three countries (96% correct classification); (f) a substantial portion of the patterns of allozyme variation in the wild gene pool is significantly correlated with the environment and is predictable ecologically, chiefly by a combination of humidity and temperature variables; (g) natural populations of wild barley are, on the average, more variable than two composite crosses and land races of cultivated barley. The spatial patterns and environmental correlates and predictors of genetic variation of H, spontaneum in the Fertile Crescent indicate that genetic variation in wild barley populations is not only rich but at least partly adaptive and predictable by ecology and allozyme markers. Consequently, conservation and utilization programmes should optimize sampling strategies by following the ecological-genetic factors and allozyme markers as effectively predictive guidelines.

Television as a talking picture book: A prop for language-acquisition

Abstract: This study provides longitudinal observations of young children's behaviours while viewing television in their own homes, over a time when the children were actively involved in the process of language acquisition. Sixteen children were observed for a period ranging from 0; 6 to 0;8. At the beginning, their ages ranged from 0; 6.15 to 5.15; at the end, from 1; 2.15 to 3;0. The observations yielded documentation of an overwhelming and consistent occurrence of language-related behaviours among children and parents in the viewing situation. The categories of child and adult talk are reported, with description and examples of each category. The categories are compared with those reported for parent–child interactions outside the viewing experience, – in particular joint book-reading. A model of television as a talking picture book is proposed. It is argued that television has the potential to serve as a facilitator of children's language acquisition.

Zonoids with Minimal Volume-Product

Abstract: Of course, only the "only if" part needs a proof. We give here some preliminaries and notations. First, we make the remark that our approach is based on the analysis of random polytopes made in [7] and we make extensive reference to [7] and [6] in order to avoid repeating calculations that are done there. We use standard geometric terminology as may be found, e.g., in [3] or [4]. The dimension n will be fixed throughout the paper. B is the Euclidean unit ball in ~" , S the unit sphere of ~ " with the relative topology, co is the rotation invariant measure on S, normalized so that

Natural selection of allozyme polymorphisms: a microsite test revealing ecological genetic differentiation in wild barley.

Abstract: Allozymic variation in proteins encoded by 25 loci was analyzed electrophoretically in 1982 and 1983 in 356 individual plants from a dense population of wild barley, Hordeum spontaneum, the progenitor of cultivated barley. The test involved six microniches organized in a mosaic pattern in the open Tabor oak forest at Neve Ya'ar, Israel. The microniches were i) sun-soil, ii) sun-rock, iii) shade-soil, iv) shade-rock, and the contact zones: v) soil periphery of the sun-rock microniche, and vi) soil periphery of the shade-rock microniche. Discriminant analysis indicated significant multilocus allozymic differentiation between the microniches. Our results suggest that allozyme polymorphisms in wild barley are at least partly adaptive and differentiate predominately by microniche ecological selection, rather than by stochastic processes and/or neutrality of allozymic variants.

Genetic diversity and resistance to marine pollution

Abstract: We tested in the laboratory three pairs of species belonging to three genera and families of marine gastropods, Monodonta turbinata, M. turbiformis (Trochidae), Littorina punctata, L. neritoides (Littorinidae), Cerithium scabridum, C. rupestre (Cerithiidae), for resistance to diverse inorganic (heavy metals and NaC1) and organic (detergents and crude oil) pollutants. Each pair consisted of one narrow-niche species with low genetic diversity and one broad-niche species with higher genetic diversity. Evidence is presented that in all three cases the species with a higher level of genetic diversity was more resistant to all pollutants than its counterpart. These results suggest that fitness is positively correlated with heterozygosity and support the niche-width-variation hypothesis in regard to pollutants. The results also have practical implications for the identification of optimum marine species as genetic monitors of pollution.

Adaptive optimal sound for vocal communication in tunnels of a subterranean mammal (Spalax ehrenbergi).

Abstract: The adaptive value of sound signal characteristics for transmission in the underground tunnel ecotope was tested using tunnels of the solitary territorial subterranean mole rats. We analyzed the propagation of synthetic calls with various frequencies through natural tunnels along different distances. Here we present evidence that sound propagation proved efficient only across short distances (a few meters). The least attenuation of sounds occurred at low frequencies. The 440 Hz sound was transmitted better than the lower (220 Hz) or higher (880, 1760, 3520 Hz) tested frequencies. These characteristics matched perfectly with the mole rat features of vocalization and hearing, thus reflecting the operation of natural selection for adaptive vocal communication in the underground tunnel ecotope.

A comparison of the eigenvalue method and the geometric mean procedure for ratio scaling

Abstract: This article evaluates and compares the performance of two ratio scaling methods, the eigenvalue method proposed by Saaty (1977, 1980) and the geometric mean procedure advocated by Williams and Cra...

Age Replacement Policy With Age-Dependent Minimal Repair*

Abstract: The presence of quantity discounts, in general, increases the order quantities (lot size). Other factors such as limited space or limited cash, however, restrict the degree to which the lot sizes c...

The Effect of Hope on Coping with Stress

Abstract: My studies on hope and its effects on coping are still in their initial stages, and, consequently, this presentation will be a highly speculative one. It consists of an attempt to delineate some common foci pertaining to hope that can be found in a variety of stressful situations. These foci are abstractions based on qualitative information obtained in interviews with people under a serious threat, such as awaiting the results of biopsy testing for breast cancer, waiting for surgery, anticipation of a major oral exam, and so forth. Because the purpose of these interviews was hypothesis-generating, rather than testing, some clear notions about the role of hope, the samples are by no means representative, nor were they meant to be.

Genetic diversity and environmental associations of wild barley,Hordeum spontaneum (Poaceae), in Iran

Abstract: Genetic diversity and structure of populations of the wild progenitor of barleyHordeum spontaneum in Iran was studied by electrophoretically discernible allozymic variation in proteins encoded by 30 gene loci in 509 individuals representing 13 populations of wild barley. The results indicate that: a)Hordeum spontaneum in Iran is extremely rich genetically but, because of predominant self-pollination, the variation is carried primarily by different homozygotes in the population. Thus, genetic indices of polymorphismP-1% = 0.375, range = 0.267−0.500, and of genetic diversity,He = 0.134, range = 0.069−0.198, are very high. b) Genetic differentiation of populations includes clinal, regional and local patterns, sometimes displaying sharp geographic differentiation over short distances. The average relative differentiation among populations isGst = 0.28, range = 0.02−0.61. c) A substantial portion of the patterns of allozyme variation in the wild gene pool is significanctly correlated with the environment and is predictable ecologically, chiefly by combinations of temperature and humidity variables. d) The natural populations studied, on the average, are more variable than two composite crosses, and more variable than indigenous land races of cultivated barely,Hordeum vulgare, in Iran. — The spatial patterns and environmental correlates and predictors of genetic variation ofH. spontaneum in Iran indicate that genetic variation in wild barley populations is not only rich but also at least partly adaptive. Therefore, a much fuller exploitation of these genetic resources by breeding for disease resistance and economically important agronomic traits is warranted.

Shifts in reasoning

Abstract: The process of transition from a novice's state to that of an expert, in the constrained domain of decimals, is described in terms of explicit, intermediate, and transitional rules which are consistent, yet erroneous. These rules can be traced to former rules already established in earlier knowledge domains. Empirical data from children at grades 6, 7, 8 and 9 will demonstrate the evolution of an expert's knowledge through an elaborated learning path.

Resistance of wild wheat to stripe rust: Predictive method by ecology and allozyme genotypes

Abstract: From 114 accessions of wild emmer wheat from 11 sites in Israel, known for their allozymic variation (Nevo & al. 1982), individual genotypes were tested for resistance to one isolate of stripe rust both in the seedling stage in a growth chamber and in the adult plant stage in the field. The results indicate that resistance to stripe rust in seedlings and adults are significantly correlated (rs = 0.40, p < 0.001). Genetic polymorphisms of resistance to stripe rust vary geographically and are predictable by climatic, as well as allozymic markers. Three variable combinations of rainfall, evaporation, and temperature explain significantly 0.40–0.53 of the spatial variance in disease resistance to stripe rust, suggesting the operation of natural selection. Several allozyme genotypes are significantly associated with disease resistance. We conclude that natural populations of wild emmer wheat in Israel contain large amounts of disease resistance genes. These populations could be effectively screened and then utilized by the phytopathologist for identifying resistant genotypes and producing new resistant cultivars.

Hematocrit and hemoglobin concentration in four chromosomal species and some isolated populations of actively speciating subterranean mole rats in Israel

Abstract: Hematocrit (HCT) and hemoglobin (Hb) concentration were measured in four chromosomal species and some peripherally semi-isolated and isolated populations of the mole rat superspecies Spalax ehrenbergi in Israel. HCT was 52.0, 51.4, 50.9, and 47.8%, and Hb was 16.0, 16.6, 16.3, and 14.7 g/100 ml for 2n = 52, 58, 54, and 60, respectively. The species 2n = 60, which lives in arid habitats, had lower HCT and Hb than the other three species. HCT decreased as aridity increased between the species and within the species 2n = 60. Changes in HCT probably reflect clinal changes in both soil permeability to gases and ambient temperature.

Aggression patterns in adaptation and speciation of subterranean mole rats

Abstract: The patterns and correlates of aggressionwithin andbetween actively speciating subterranean mole rats of theSpalax ehrenbergi superspecies in Israel were tested in an attempt to approach an evolutionary theory of aggression related to both adaptation and speciation. Laboratory experiments were conducted on 314 adult mole rats (188 males and 126 females) caught in nature, representing 12 populations and comprising four chromosomal species (2n = 52, 54, 58, 60). The present analysis concentrates on “total aggression” comprising four aggressive variables: attacks, bitings, head-ons and sniffing with open mouth, out of 23 recorded variables. The results indicate that (a) aggression is distributed as a multipeak, discontinuous phenotypic parameter, displaying polymorphism within all 12 populations and 4 species tested; (b) the level of aggression was higher in males than in females, in the breeding than in the nonbreeding season, and displayed clinal geographic variation in both sexes across the superspecies range, where “militancy” increased northwards; (c) aggression was significantly correlated with ecological, physiological, genetical and ethological factors. These results support an evolutionary theory of aggression related to the intertwined processes of adaptation and speciation.

Sources of Stress in Academe--The Israeli Case.

Abstract: The effects of stress on the physical and psychological well being of people in different professions and occupations have become, in the last decade, the focal interest of researchers and clinicians. There is a growing body of evidence that stress, adversely affects the performance, productivity, job satisfaction, health and the general quality of life of professionals and people in general (Farber, 1983; Lazarus & Folkman, 1984). Originally, research on stress focused on the “helping professions” and “human services” occupations (Cherniss, 1980; Farber, 1983). More recently, other occupations which involve continuous, intensive interpersonal relationships between people, have been investigated and were found to be a potential source of stress (Holt, 1982). The growing interest in the study of stress and its manifestations resulted among others in newly defined concepts such as: burnout, tedium, wear and tear, deadwoods, midlife crisis, etc. (Maslach and Jackson, 1979; Manuso, 1979; Freudenberger, 1980; Pines, Aronson and Kafry, 1981; Farber, 1983).

Visual accommodation and virtual image displays: target detection and recognition.

Abstract: Twelve subjects performed a complex task, detecting and recognizing small targets presented at infinity, while simultaneously monitoring a virtual image display (VID). The VID was presented at one of four optical distances (2.0, 0.5, 0.0, and-0.5 D). Optical distance was found to affect detection and recognition performance, mainly at the extreme value of 2.0 D. Interactions between optical distance and grouping of subjects according to measures of accommodation indicated that the three other optical distances affect performance differentially. The subjects' resting position of accommodation (RPA) and a combined measure of accommodation range and RPA were significantly correlated with performance (0.58). A narrowing of the functional visual field (complete misses of peripheral targets) was found at the 2.0-D optical distance for all subjects, and at the other optical distances for the subjects with an inferior accommodative mechanism (i.e., a near RPA and/or a narrow accommodation range).

Bronze Age ship's cargo of copper and tin

Abstract: A report on finds from an underwater excavation off the northern coast of israel: a copper ingot, 5 tin ingots, and 4 stone anchors, evidence of a possible bronze age shipwreck. Incisions on the ingots suggest a cypro-minoan inscription. Neutron activation analysis was used to determine the trace elements. The presence of copper and tin ingots in the same cargo may mean that bronze was produced by the crew. References.

Capital Accumulation and Annuities in an Adverse Selection Economy

Abstract: This paper suggests that adverse selection problems in competitive annuity markets can generate quantity constrained equilibria in which some agents whose length of lifetime is uncertain find it advantageous to accumulate capital privately. This occurs despite the higher rates of return on annuities. The welfare properties of these allocations are analyzed. It is shown that the level of capital accumulation is excessive in a Paretian sense. Policies which eliminate this inefficiency are discussed.

The Factorial Structure of the Meaning of Working

Abstract: The structure of the Meaning of Working (MO W) was empirically analyzed through factor analysis. Interviews were conducted with samples from ten occupational groups, as well as a representative sample of the labor force, to determine the dimensions constituting the structure of work meanings. The original 39 variables resulted in 13 interpretable factors which were categorized into the following work domains: centrality of work as a life role, societal norms about working, valued work outcomes, importance of work goals, and work role identification. An unexpected domain, consisting of nonwork areas of life, also emerged as significant.

Two Approaches to Memory

Abstract: The metaphor of memory as a storage place for mental entities is a prevailing one. This metaphor belongs to a substantive approach to the mind. An alternative approach is a relational (or functional) approach in which the mind consists of dispositional and actualized states. Memory in this view is the capacity of the organism to arrive at states similar to its previous states of awareness while knowing about their past origin. Remembering here is an intentional state of awareness directed to events that happened or were learnt in the past. In this approach, the metaphor of internal storage is inadequate since capacities and states are not stored but rather retained. The relational approach to memory has some important implications for other issues in the philosophy of mind.

Laguerre and Minkowski planes produced by dilatations

Abstract: We show that each parabolic curve f in R2 produces a Laguerre plane $$\mathbb{L}(f)$$ if f and all its images under dilatations are cycles. Likewise, two hyperbolic curves f1,f2 produce a Minkowski planeM(f1,f2). We determine for which curves $$\mathbb{L}(f)$$ is miquelian resp. ovoidal, and for which pairs f1,f2,M(f1,f2) is miquelian resp. satisfies the rectangle axiom, thus providing many examples of non-embeddable planes.