Showing papers by "University of Haifa published in 1981"

The forest revisited more on global precedence

Abstract: Several issues pertaining to the notion of global precedence, its testing, and its ecological validity are discussed. Global precedence is presented as a claim that, other things being equal, global structure is available in the percept earlier than local features are. It does not state that local processing starts only after global processing is terminated. Since global precedence is a hypothesis about temporal development of percepts, a natural way to test it is to limit exposure duration. Global precedence predicts that local features will be more sensitive to stimulus duration than global ones. An experiment is reported in which subjects were presented with 150 ms exposures of large letters made up of small ones, and had to discriminate either just the large letters or just the small ones. In addition, they had to respond to the presence of a concurrent tone. Local letters were responded to more slowly than global ones, and were associated with more tone errors. The variation of the global level as well as the consistency between the identities of the levels affected the latency to the local letter, but not vice versa. A single small-letter control-condition was used to rule out an explanation in terms of relative size. The effects, albeit weaker than some previous results, are compatible with the hypothesis tested. The results of this experiment are interpreted in the context of an extensive discussion of findings in the paradigm and the generality of the phenomenon assumed to underly them. Possible mechanisms which may mediate global precedence are evaluated. Among them are relative size, lateral masking, diffuse attention, and spatial uncertainty. The magnitude, or even the presence, of global precedence depends on some factors, most prominent of which are visual angle and retinal position. Ecological considerations suggest that proximal sizes and eccentricities which favor global features may be very frequent. Some further subtleties of, as well as problems with, the logic of compound letters are discussed.

Semantic facilitation in lexical decision as a function of prime-target association

Abstract: Using a lexical decision task, the relationship between magnitude of semantic facilitation and degree of prime-target relatedness was examined as a function of amount of attention allocated to the prime and the prime-target interval. In none of the conditions studied did amount of facilitation vary with prime-target relatedness, a finding which was seen as inconsistent with the spread of activation account of the association effect in lexical decision. Both forward (prime to target) and backward (target to prime) associations were effective in producing semantic facilitation. Backward associates, however, were effective only during earlier stages of the experiment and forward associations only during later stages. The implications of these findings for the processes underlying the association effect was discussed.

Floral mimicry between Orchis israelitica Baumann and Dafni (Orchidaceae) and Bellevalia flexuosa Boiss. (Liliaceae).

Abstract: Orchis israelitica, which has no food reward, was found to share the pollinators of Bellevalia flexuosa: Eucera clypeata, Bombylius sp. and possibly also Anthophora sp. Since both species have a similar coloration pattern, flowering period and habitats — it is suggested that O. israelitica mimics the flowers of B. flexuosa as a deceit syndrome of pollination.

Stability and Centrality: The Nuclear Family in Modern Israel

Abstract: In many modem societies the family is undergoing a serious crisis. This crisis is reflected by objective statistics as well as by a growing devaluation of such basic principles of the familial way of life as heterosexuality, childbearing, and the division of labor by age and gender. Some distinguished students of the family view these symptoms as partial and transitory (Fletcher; Litwak and Szelenyi; Parke and Glick; Parsons and Bates), while others discover, or even recommend, alternative intimate lifestyles (Constantine and Constantine; Elliott; Rainey; Sussman). Against this background it seems worthwhile to examine societies which are modem by economic, political, and cultural criteria, and in which the conventional form of nuclear monogamous family nevertheless retains an impressive degree of centrality and stability. Israel is an example of such a constellation. Israel is an urban society: 90 percent of its Jewish population dwells in cities or townships, 24 percent of its labor force is employed in industry, and 70 percent in services. (All data relate to the Jewish sector of the Israeli population.) The average standard of living does not fall below that of European countries such as France or Italy. Due to her special relationship with the United States, Israel, to a greater extent than comparable countries, tends to adopt American attitudes and social patterns. Fashions, and even fads in clothing, entertainment, art, or research usually appear in Israel shortly after they become established in the U.S. Taking these factors into account, one would expect the Israeli family to change in the same direction as its counterparts in the Western world. It will be shown below, however, that the dominant pattern in the Israeli

Microgeographic edaphic differentiation in allozyme polymorphisms of wild barley (Hordeum spontaneum, Poaceae).

Abstract: Allozymic variation in proteins encoded by 22 loci was analyzed electrophoretically in 278 individual plants of wild barley,Hordeum spontaneum, the progenitor of cultivated barley, in four 100 meter transects, in Israel, each equally subdivided into basalt and terra rossa soil types. Significant differentiation according to soil was found in 9 alleles. Our results suggest that allozyme polymorphisms in wild barley are at least partly adaptive, and differentiate by edaphic natural selection rather than by stochastic processes, and/or neutrality of allozymic variants.

Mercury selection of allozyme genotypes in shrimps

Abstract: The effects of mercury pollution on the allozymic variation of 15 phosphoglucomutase (PGM) genotypes was tested in the Mediterranean shrimpPalaemon elegans in 79 laboratory tests involving 2765 shrimps, with 1560 survivors (767 test and 793 control). Our results indicate differential tolerance of genotypes in variable mercury concentrations, suggesting that they are adaptive. The genetic structure can possibly be explored and potentially be used as a monitoring system for the quality and quantity of marine pollutants.

Leafless autumnal-flowering geophytes in the Mediterranean region--phytogeographical, ecological and evolutionary aspects.

Abstract: Numerous Mediterranean geophytes are hysteranthous, i.e. they flower in a leafless stage during autumn. On the basis of their life cycles and other features two types can be recognized: In the Crocus type flowers with subterranean ovary develop at the start of the new reproductive cycle from an annual storage organ; seed dispersal and germination are delayed to the spring and the next autumn. In the Urginea type, flowers with supraterranean ovary originate from a perennial storage organ at the end of the life cycle; seed dispersal and germination follow flowering immediately. Similar rhythms exist in other seasonal climates. Field observations and some experiments demonstrate flower stimulation by temperature decrease or increase in different geophytes, and relationships between water supply and synanthous versus hysteranthous leaf development. The origin, ecological importance, and horticultural implication of the hysteranthous syndrome is discussed.

Pollination of Serapias vomeracea Briq. (Orchidaceae) by imitation of holes for sleeping solitary male bees (Hymenoptera)

Abstract: SUMMARY In two locations in Israel, bees were found to be sleeping in flowers of Serapias vomeracea Briq. Of these bees. Proposis spp. and Ceratina spp. were too small to be pollinators, whereas Eucera spp., Andrena spp., Osmia spp. and Tetralonia spp., mostly males, pollinated. Pollination occurs when in the afternoon hours the bees waver from flower to flower. The bees finally come to rest on a particular flower and remain there for the duration of the night. In the morning, the bees which slept in the flowers, are warmed up as a result of solar radiation which heats the flowers to 3 ***°C above ambient temperature. Since the males of many Hymenoptera sleep in holes, the hypothesis is that the flowers mimic such holes. The shortness of the flower tube can be held responsible for the observed frequent changes from flower to flower, which is so important for pollination efficiency.

Origin and evolution of ethological isolation in subterranean mole rats.

Abstract: Reproductive isolation is essential for speciation and for the maintenance of species genetic integrity, yet its origin and evolution, particularly of ethological isolation, is still largely controversial and in most cases unknown (Mayr, 1970). The nature, origin and evolution of reproductive isolation may be highlighted particularly in actively evolving species, and thereby contribute to understanding the process of speciation and the evolutionary future of hybrid zones between parapatric species. There are two major classical theories of the origin of isolating mechanisms (Mayr, 1970; Dobzhansky et al., 1977): (a) the allopatric, or incidental origin theory and (b) the sympatric, or reinforcement theory. According to the former, pre-zygotic isolating mechanisms arise as an incidental by-product of genetic divergence in isolated populations (Darwin, 1859; Muller, 1940, 1942; Mayr, 1942, 1970). The latter theory postulates that isolating mechanisms are perfected through direct selection when two incipient species begin to become sympatric, through progressive elimination of hybrids of lower fitness, in the overlapping (sympatric) zones (Wallace, 1889; Fisher, 1930; Dobzhansky, 1940, 1970). It is widely accepted that post-zygotic isolating mechanisms are the incidental result of evolutionary divergence (Moore, 1957; Littlejohn, 1969; Dobzhansky et al., 1977; but see also alternative views in Grant, 1966; Watson and Martin, 1968; Coyne, 1974). The main controversy between the allopatric and sympatric theories concerns the origins of pre-zygotic isolating mechanisms, and is focused on the question of the extent to which direct selection contributes to this acquisition. The problem may be restated as follows: is the pre-zygotic isolation accumulated and perfected strictly as an incidental by-product of divergence in isolated populations-or, do these mechanisms evolve primarily by direct selection in sympatry (Dobzhansky, 1970; Dobzhansky and Pavlovsky, 1971; Ehrman, 1971, 1979). A third alternative combines the two theories suggesting that the principal genetic basis of this isolation was acquired in separate gene pools and then perfected by direct selection in sympatry. The studies and techniques which support the allopatric theory have been extensively reviewed (Grant, 1966, 1977; Littlejohn, 1969, 1980; Mayr, 1970; Brown, 1975), but only in a small number of cases was there clear experimental evidence for this process (e.g., Nevo, 1969b; Capranica et al., 1973). A much larger number of experiments studied the reinforcement process, and results of these studies are generally interpreted as supporting this theory (see the above reviews and also Dobzhansky, 1970; Blair, 1974; Dobzhansky et al., 1977). Yet critical analysis of these studies reveal that only a few of them provide unequivocal evidence for reinforcement in pre-zygotic isolation (see reviews of different taxa in Thielcke, 1973; Walker, 1974; Fouquette, 1975; Loftus-Hills, 1975). Therefore, critical tests of the origin of pre-zygotic isolation are indispensable in as large of array of taxa as possible. Suitable methodologies for such studies are suggested and discussed by Grant (1966), Littlejohn (1969), and Nevo (1969b). Recently, an additional, chiefly stochastic theory of the origin of pre-zygotic isolating mechanisms has been suggested (Carson, 1975, 1978; Kaneshiro, 1976).

The Road to Solving a Combinatorial Problem is Strewn with Pitfalls.

Abstract: In this paper we examine typical difficulties involved in solving a combinatorial problem, and demonstrate them throughout the solution of the “Problem of the misaddressed letters”. We focus on difficulties of two sorts: Those which stem from the fact that a combinatorial problem is usually an infinite set of problems, and others which are involved in finding a systematic approach to their solution.

The distribution of information within letters

Abstract: To study the relative importance of various letter segments for letter recognition, we presented each letter of two alphabets, English and Hebrew, preceded by a brief presentation of an intact or a mutilated version of it. Mutilations were done by eliminating a specific segment. It was reasoned that the more critical the eliminated segment is, the less the mutilated version activates the letter code in memory and, thus, the longer it takes to name the subsequently presented target letter. This procedure was successful in detecting significant differences consistent with our expectations. In further analysis, it was shown that the latency data were highly correlated with the distinctiveness of the mutilated segment, its uniqueness over the alphabet, its impact on the letter global shape, and its topography within the letter and other variables. The dependency of latency on the various factors varied considerably between alphabets. Some correlational analyses were done to evaluate the roles of the various factors.

The flower biology ofCephalanthera longifolia (Orchidaceae)—pollen imitation and facultative floral mimicry

Abstract: Solitary bees (Halictus sp.) were found to be the effective pollinators ofCephalanthera longifolia. In the same foraging flight the bees also visit flowers ofCistus salviifolius which has a similar colour pattern.Cephalanthera offers no reward to its pollinators, but orange papillae on its labellum successfully imitate pollen ofCistus. AsCephalanthera also attracts pollinators in the absence ofCistus, this is regarded as “facultative floral mimicry”.

Papal and Royal Attitudes Toward Jewish Lending in the Thirteenth Century

Abstract: The question of Jewish usury is usually perceived in straightforward terms. The Church unilaterally opposed Jewish lending, and the kings did all they could to promote it. In the long run, however, the utility of Jewish lending diminished, and the forces of the Church were thus able to prevail. The kings, too, soon began to outlaw Jewish lending.

Recent maritime archaeological research in Israel

Abstract: Le Centre d'etudes maritimes de l'Universite de Haifa a depuis trois ans concentre ses travaux sur quatre projets principaux: 1) exploration au sonar du fond de la mer le long de la cote israelienne, avec pour but principal la detection de navires pheniciens naufrages| 2) continuation des fouilles systematiques du port englouti de Cesaree| 3) etude de la topographie ancienne (changements du niveau de la mer, installations portuaires anciennes, etc.)| 4) etude interdisciplinaire de l'industrie de la teinture pourpre ancienne. Principaux resultats: la decouverte d'une ancre romaine composite| de sites prehistoriques immerges| d'un eperon de bronze au large d'Atlit| avancement des travaux dans le port du Cesaree| releve de Doryam (mer et cote).

Drainage area and the variation of channel geometry downstream

Abstract: Recent geomorphological studies tend to deal with small basins. The understanding of small basin dynamics provides important information for the understanding of large basin dynamics assuming that the extrapolation of small basin data to larger basins is valid. This work tests the validity of this extrapolation of data with reference to channel geometry. An analysis of the variation of channel width downstream reveals that the value b =0.5 (W = aQb) is a ‘good’ average. However, the use of a one-line model consisting of a simple power function incurs a loss of a considerable amount of relevant information concerning the channel form and hence the channel processes. It has been shown that the –b– value for small basins and very big basins is lower than the one for the intermediate basins.

Productivity-based financial net income analysis

Abstract: This paper develops the analytical framework for a productivity based financial analysis, which has been successfully introduced by the authors as standard reporting in a major corporation. This analysis is designed to broaden and supplement conventional income statement analysis. It partitions expense and revenue items into their respective price and quantity components and establishes the precise relationship between total factor productivity performance and key aspects of financial performance. The underlying theory is reviewed. Subsequently, an actual case study example is analyzed. Some of the major additional insights into factors affecting the economic health of a productive enterprise and their implications for corrective actions are illustrated and discussed.

Spherically symmetric fields in Rosen's bimetric theories of gravitation

Abstract: By means of bimetric Killing vectors two spherically symmetric fields are investigated: (i) the time-dependent one in Rosen's flat-background bimetric theory; and (ii) the energy-preserving in Rosen's cosmological-background bimetric theory withk = 1 In the first case a wave behavior of the field is present In the second case a time evolution is obtained for fields, created by insular systems of constant energy These phenomena are typical for bimetric theories of gravitation

Genetic variation and climatic selection in the lizard Agama stellio in Israel and Sinai.

Abstract: Allozymic variation in proteins encoded by 25 loci was analyzed electrophoretically in 242 adult specimens representing nine populations of the Levantine lizard, Agama stellio, comprising two subspecies: the Mediterranean A stellio subsp, and the desert-inhabiting A stellio brachydactyla from the Negev and Sinai Likewise, four body traits were measured in the same populations The nine populations were sampled along a general southward transect of increasing aridity Agama stellio is above average in both polymorphism, P, and heterozygosity, H, as compared to other reptiles and vertebrates in general, displaying levels of genetic variation characterizing habitat generalist vertebrates In the populations studied no fixation of alternative alleles was found in any of the 25 loci: rather the commonest allele was either fixed or predominated in 23 of 25 loci examined Eleven loci (44%) were monomorphic in all nine populations However, of the remaining 14 polymorphic loci, eight were strongly polymorphic displaying distinct genetic differentiation between populations Genetic diversity (indexed by P and H) displayed geographic variation and was slightly higher in As brachydactyla than in A stellio subsp Nevertheless, genic similarity between populations was high A statistically significant amount of morphological variation between localities was found for all body characters In general, body size increased southwards and eastwards with aridity

Genetic Diversity in Marine Molluscs: A Test of the Niche‐Width Variation Hypothesis

Abstract: . A test of the niche width variation hypothesis was conducted in the three Mediterranean littoral species of the family Trochidae: Monodonta turbinata, M. turbiformis and Gibbula richardi. Allozymic variation encoded by 26 gene loci was analyzed, and the levels of polymorphism (P), heterozygosity (H) and allele diversity per locus (A) were estimated and appear to support the niche-width variation hypothesis. The broad-niche species, M. turbiformis and G. richardi are more polymorphic and heterozygous than the relatively narrow-niche M. turbinata (P = 0.571; 0.731 and 0.417; H = 0.108; 0.116 and 0.078; A = 2.025; 2.489 and 1.965, respectively).

Mothers' and non-mothers' identification of infant cries.

Abstract: In the very few studies examining adults' ability to recognize the different types of infants' cries, it has usually been concluded that experience is the prime factor which facilitates identification of the various types of cry. The present study explored the specific skill of the mother, irrespective of experience. Thirty six-mothers and 32 non-mothers were asked to identify hunger, pain and pleasure cries of infants. The non-mothers were pregnant women, 14 experienced in child care, 18 inexperienced; among the mothers, 17 had one infant and 29 had one infant and an older child. Mothers responded more accurately than non-mothers, and in comparison with both experienced and inexperienced non-mothers, they proved to have unique skills in dealing with infant cries.

Turnover analysis and prediction from a career developmental point of view

Abstract: Demographic and psychological characteristics of 479 job leavers from two plants were processed, and work stability of 110 previously tested subjects was followed up for up to eight years. The study revealed that job quitting is a career decision depending upon career type, career stage and the characteristics of the organization, from the career development point of view. These variables make it possible to predict leaving decisions by employees, and also job stability.

A geometric condition for an l.c.K. manifold to be Kähler

Abstract: We prove that a necessary and sufficient condition for a locally conformal Kahler manifold(M n , g), n ⩾ 2, to be Kahler is thatM admits through every one of its points a minimal Kahler submanifold of complex dimensionp⩾2.

The Contours of Female Piety in Later Medieval Hagiography

Abstract: The thirteenth century represents a high point in the establishment of female orders, whose ministry was directed largely at an urban population prone to heresy and undergoing the disruptive transition from pastoral feudalism to nascent capitalism. During this period, more than a quarter of the contemporary saints were women; they identified with all of the new movements which animated the church. Some, continuing the already established tradition of princely veneration, were active in evangelization in the recently Christianized regions of Europe's periphery, like Spain and Poland, through the patronage of charitable institutions and religious houses. The canonization trials of Hedwig of Poland, Elizabeth of Thuringia and Margaret of Hungary all reflect a broadly based constituency including rural and urban, lay and clerical, male and female support Others appealed to a narrower social and geographical audience and ministered to the problems of the urban poor: Sperandea of Cingoli's miraculous cures were performed exclusively on married women of the city and of the adjacent countryside. But the largest number of female saints continued to be cloistered women whose chief accomplishment was the establishment or endowment of a new convent or the foundation of a new female order, usually in association with a male order; for while many such orders began independently, the church feared the consequences of independent female piety and sought to ensure orthodoxy by associating the female houses with a corresponding male order. Nevertheless, while contemporary hagiography continued to be patterned after the stereotypical saints of early Christianity, the character of female piety changed to reflect such dynamic changes within the church as the rise of mendicancy, the transition from rural to urban life, the cult of the Virgin, the rise of national states, the war against heresy, the new emphasis on the humanity of Christ and the political struggles of the papacy.

Do Friends Share and Communicate More Than Non-Friends?:

Abstract: Eighty children, kindergarteners and first graders, were assigned to classmate same-sex pairs of friends and non-friends. Each dyad was asked to draw on a single sheet of paper using paints and cuttings. Social communicative behaviors; smiles, looks and verbal activity, and sharing behaviors; exchange of materials and use of space, were observed. Interobserver reliability was 0.80. Results showed that friends unexpectedly exhibited less sharing and less communicative behaviors, while they showed more task activity. An explanatory model is suggested to account for social intimacy among friends; task relevant behaviors are maximized, and other social behaviors minimized among friends. Non-friends minimized task relevant behaviors and maximized social communicative behaviors. Implications for the vicissitudes of intimacy among friends are discussed.

Genetic structure and climatic correlates of desert landsnails.

Abstract: Allozymic variation in proteins encoded by 20 loci was analyzed electrophoretically in 126 adult specimens representing 4 populations and 2 species of the desert landsnail Trochoidea, subgenus Xerocrassa, in a variable desert climatic back-ground of temperature and water factors. In addition, geographic variation in 3 morphological body variables of these snails was also studied. The results indicate that: (i) Most loci (55%) were strongly polymorphic; (ii) A large proportion of the polymorphic loci (55%) displayed fixation of alternative alleles either within or between species; (iii) Most of the variant alleles (75%) were not widespread, indicating sharp local and regional geographic differentiation; (iv) Southward progressive trends were found in genic diversity, some allele frequencies, shell banding and body characters. (v) The mean estimates of genetic indices are: not of alleles per locus, A=1.69; proportion of polymorphism per population P=0.41, and proportion of heterozygosity per individual, H=0.07; (vi) The level of P increases and that of H decreases southward; (vii) The amount of variation in different functional elasses of enzymes follows the Gillespie-Kojima and partly the Johnson hypotheses; (viii) Coefficients of genetic disfance, D, between populations are high, $$\bar D = 0.14$$ , range 0.05–0.26. D's within species may be higher than between species. Likewise, D's from the northernmost population increase progressively southwards; (ix) Significant gametic phase disequilibria occur in several populations in both species; (x) Deviations from Hardy-Weinberg equilibria were found in several loci in some populations in both species; (xi) A statistically significant (P<0.001) amount of morphological variation of all 3 body variables occurs within and between species. Body diameter decreases with evaporation. (xii) P, H, and allozymic variation in several gene loci are significantly correlated with climatic variable, primarily related to some water factors and secondarily to temperature; (xiii) Shell banding was negatively correlated with solar radiation; and (xiv) Few correlations between allozymic and morphological variations were revealed. The pattern of genetic variation of Trochoidea (Xerocrassa) vetzenii and T. (X) erkelii suggests that (a) climatic selection plays a major role in allozymic (and morphological) population structure and differentiation; (b) variation in allozyme and visual polymorphisms may provide the genetic basis for the complex physiological adaptations of landsnails enabling them to survive in hostile, hot and dry deserts, and is therefore partly adaptive rather than neutral.

Morphine-induced anorexia in lateral hypothalamic rats.

Abstract: The anorexic effect of morphine in rats with lateral hypothalamic lesions was examined. Morphine (15 mg/kg) produced an anorectic effect which was greater in lesioned rats than in controls. However, in lesioned rats, morphine anorexia was completely reversed by naloxone (2 mg/kg), while in controls there was mild anorexia. Repeated morphine injections caused decreasing anorectic effects, an effect which developed more rapidly in control than in lesioned subjects. The effects of morphine on food intake in lesioned rats were similar to the effects of fenfluramine, rather than amphetamine, suggesting involvement of serotonergic, rather than catecholaminergic mediation of morphine anorexia.