Showing papers by "University of Haifa published in 2004"
TL;DR: SSRs within genes evolve through mutational processes similar to those for SSRs located in other genomic regions including replication slippage, point mutation, and recombination and may provide a molecular basis for fast adaptation to environmental changes in both prokaryotes and eukaryotes.
Abstract: Recently, increasingly more microsatellites, or simple sequence repeats (SSRs) have been found and characterized within protein-coding genes and their untranslated regions (UTRs). These data provide useful information to study possible SSR functions. Here, we review SSR distributions within expressed sequence tags (ESTs) and genes including protein-coding, 3'-UTRs and 5'-UTRs, and introns; and discuss the consequences of SSR repeat-number changes in those regions of both prokaryotes and eukaryotes. Strong evidence shows that SSRs are nonrandomly distributed across protein-coding regions, UTRs, and introns. Substantial data indicates that SSR expansions and/or contractions in protein-coding regions can lead to a gain or loss of gene function via frameshift mutation or expanded toxic mRNA. SSR variations in 5'-UTRs could regulate gene expression by affecting transcription and translation. The SSR expansions in the 3'-UTRs cause transcription slippage and produce expanded mRNA, which can be accumulated as nuclear foci, and which can disrupt splicing and, possibly, disrupt other cellular function. Intronic SSRs can affect gene transcription, mRNA splicing, or export to cytoplasm. Triplet SSRs located in the UTRs or intron can also induce heterochromatin-mediated-like gene silencing. All these effects caused by SSR expansions or contractions within genes can eventually lead to phenotypic changes. SSRs within genes evolve through mutational processes similar to those for SSRs located in other genomic regions including replication slippage, point mutation, and recombination. These mutational processes generate DNA changes that should be connected by DNA mismatch repair (MMR) system. Mutation that has escaped from the MMR system correction would become new alleles at the SSR loci, and then regulate and/or change gene products, and eventually lead to phenotype changes. Therefore, SSRs within genes should be subjected to stronger selective pressure than other genomic regions because of their functional importance. These SSRs may provide a molecular basis for fast adaptation to environmental changes in both prokaryotes and eukaryotes.
1,039 citations
TL;DR: The relationship between teacher empowerment and teachers' organizational commitment, professional commitment, and organizational citizenship behavior (OCB) was examined in this paper, which examined which subscales of teacher empowerment can best predict these outcomes and found that teachers' perceptions of their level of empowerment are significantly related to their feelings of commitment to the organization and to the profession.
695 citations
TL;DR: This publication contains reprint articles for which IEEE does not hold copyright and which are likely to be copyrighted.
Abstract: Online spaces that enable shared public interpersonal communications are of significant social, organizational, and economic importance. In this paper, a theoretical model and associated unobtrusive method are proposed for researching the relationship between online spaces and the behavior they host. The model focuses on the collective impact that individual information-overload coping strategies have on the dynamics of open, interactive public online group discourse. Empirical research was undertaken to assess the validity of both the method and the model, based on the analysis of over 2.65 million postings to 600 Usenet newsgroups over a 6-month period. Our findings support the assertion that individual strategies for coping with "information overload" have an observable impact on large-scale online group discourse. Evidence was found for the hypotheses that: (1) users are more likely to respond to simpler messages in overloaded mass interaction; (2) users are more likely to end active participation as the overloading of mass interaction increases; and (3) users are more likely to generate simpler responses as the overloading of mass interaction grows.The theoretical model outlined offers insight into aspects of computer-mediated communication tool usability, technology design, and provides a road map for future empirical research.
684 citations
TL;DR: In this article, a review of conceptualisations and empirical evidence in support of emotional intelligence (EI) and its claimed role in the occupational environment is presented, with particular emphasis on personnel selection and placement, job performance, and satisfaction.
Abstract: Cet article est une revue critique des theories et resultats empiriques favorables a l’intelligence emotionelle (I.E.) et a son pretendu role dans l’environnement professionnel. On s’interesse au statut suppose de l’I.E. dans la performance au travail, la satisfaction et l’evaluation de la carriere et des competences (surtout dans la domaine de la selection et de l’orientation). Globalement, cette revue de questions prouve que les recherches recentes ont fait de grands pas dans la comprehension de l’utilite de l’I.E. au travail. Les preuves strictement scientifiques sont cependant insuffisantes, la litterature accordant une confiance excessive aux avis d’experts, aux anecdotes, aux etudes de cas et aux enquetes privees non publiees. On propose, a la fin de l’article, quelques directives pratiques pour favoriser le developpement et l’utilisation de mesures de l’I.E. dans les situations professionnelles.
This paper critically reviews conceptualisations and empirical evidence in support of emotional intelligence (EI) and its claimed role in the occupational environment. Consideration is given to the purported status of EI in occupational and career assessment (with particular emphasis on personnel selection and placement), job performance, and satisfaction. Overall, this review demonstrates that recent research has made important strides towards understanding the usefulness of EI in the workplace. However, the ratio of hyperbole to hard evidence is high, with over-reliance in the literature on expert opinion, anecdote, case studies, and unpublished proprietary surveys. The review concludes by providing a number of practical guidelines for the development and implementation of EI measures within occupational settings.
615 citations
TL;DR: This article examined factors that led nascent organizations to write business plans, following 396 entrepreneurs during a two-year period, and found that institutional variables, such as coercion and mimetic forces, are important predictors influencing the propensity of new organizations to develop business plans.
480 citations
TL;DR: In this paper, the authors describe the development and trial of a bilingual computerized test of vocabulary size, the number of words the learner knows, and strength, a combination of four aspects of knowledge of meaning that are assumed to constitute a hierarchy of difficulty.
Abstract: In this article, we describe the development and trial of a bilingual computerized test of vocabulary size, the number of words the learner knows, and strength, a combination of four aspects of knowledge of meaning that are assumed to constitute a hierarchy of difficulty: passive recognition (easiest), active recognition, passive recall, and active recall (hardest). The participants were 435 learners of English as a second language. We investigated whether the above hierarchy was valid and which strength modality correlated best with classroom language performance. Results showed that the hypothesized hierarchy was present at all word frequency levels, that passive recall was the best predictor of classroom language performance, and that growth in vocabulary knowledge was different for the different strength modalities.
477 citations
The Chinese University of Hong Kong1, City University of Hong Kong2, University of Macau3, Simón Bolívar University4, University of Tokyo5, University of Osnabrück6, California State University, Chico7, University of Vienna8, Katholieke Universiteit Leuven9, University of Alberta10, University of Guelph11, Chinese Academy of Sciences12, Academy of Sciences of the Czech Republic13, Charles University in Prague14, Pedagogical University15, Åbo Akademi University16, University of Lyon17, Tbilisi State University18, International University, Cambodia19, Hong Kong Polytechnic University20, Hungarian Academy of Sciences21, National and Kapodistrian University of Athens22, University of Delhi23, Indian Statistical Institute24, Indian Institute of Management Ahmedabad25, Padjadjaran University26, University of Haifa27, University of Padua28, Seowon University29, University of Latvia30, American University of Beirut31, Universiti Sains Malaysia32, Universiti Malaysia Sabah33, Tilburg University34, Victoria University of Wellington35, University of Lagos36, University of Bergen37, University of Peshawar38, University of the Philippines39, University of Porto40, University of Minho41, Russian Academy of Sciences42, University of Cape Town43, Autonomous University of Madrid44, National Taiwan University45, Assumption University46, Boğaziçi University47, University College London48, University of Greenwich49
TL;DR: Leung et al. as mentioned in this paper revealed a five-dimensional structure of social axioms across individuals from five cultural groups across 41 nations and revealed the culture level factor structure and its correlates across 41 cultures.
Abstract: Leung and colleagues have revealed a five-dimensional structure of social axioms across individuals from five cultural groups. The present research was designed to reveal the culture level factor structure of social axioms and its correlates across 41 nations. An ecological factor analysis on the 60 items of the Social Axioms Survey extracted two factors: Dynamic Externality correlates with value measures tapping collectivism, hierarchy, and conservatism and with national indices indicative of lower social development. Societal Cynicism is less strongly and broadly correlated with previous values measures or other national indices and seems to define a novel cultural syndrome. Its national correlates suggest that it taps the cognitive component of a cultural constellation labeled maleficence, a cultural syndrome associated with a general mistrust of social systems and other people. Discussion focused on the meaning of these national level factors of beliefs and on their relationships with individual level factors of belief derived from the same data set.
443 citations
TL;DR: Alternative accounts for the hot hand fallacy and the gambler’s fallacy are proposed and it is demonstrated that sequence recency influences attributions that human performance or chance generated the sequence.
Abstract: The representativeness heuristic has been invoked to explain two opposing expectations—that random sequences will exhibit positive recency (the hot hand fallacy) and that they will exhibit negative recency (the gambler’s fallacy). We propose alternative accounts for these two expectations: (1) The hot hand fallacy arises from the experience of characteristic positive recency in serial fluctuations in human performance. (2) The gambler’s fallacy results from the experience of characteristic negative recency in sequences of natural events, akin to sampling without replacement. Experiment 1 demonstrates negative recency in subjects’ expectations for random binary outcomes from a roulette game, simultaneously with positive recency in expectations for another statistically identical sequence—the successes and failures of their predictions for the random outcomes. These findings fit our proposal but are problematic for the representativeness account. Experiment 2 demonstrates that sequence recency influences attributions that human performance or chance generated the sequence.
436 citations
TL;DR: In contrast to the findings from less regular orthographies such as English and Dutch, beginning readers of a highly regular orthography (Hebrew) appear to be relatively insensitive to word-specific orthographic detail, reading in a nonlexical "surface" fashion.
420 citations
TL;DR: The earliest direct evidence for human processing of grass seeds, including barley and possibly wheat, in the form of starch grains recovered from a ground stone artefact from the Upper Palaeolithic site of Ohalo II in Israel is reported.
Abstract: Barley (Hordeum vulgare L.) and wheat (Triticum monococcum L. and Triticum turgidum L.) were among the principal 'founder crops' of southwest Asian agriculture. Two issues that were central to the cultural transition from foraging to food production are poorly understood. They are the dates at which human groups began to routinely exploit wild varieties of wheat and barley, and when foragers first utilized technologies to pound and grind the hard, fibrous seeds of these and other plants to turn them into easily digestible foodstuffs. Here we report the earliest direct evidence for human processing of grass seeds, including barley and possibly wheat, in the form of starch grains recovered from a ground stone artefact from the Upper Palaeolithic site of Ohalo II in Israel. Associated evidence for an oven-like hearth was also found at this site, suggesting that dough made from grain flour was baked. Our data indicate that routine processing of a selected group of wild cereals, combined with effective methods of cooking ground seeds, were practiced at least 12,000 years before their domestication in southwest Asia.
405 citations
TL;DR: Under various sparsity assumptions on the optimal predictor there is “asymptotically no harm” in introducing many more explanatory variables than observations, and such practice can be beneficial in comparison with a procedure that screens in advance a small subset of explanatory variables.
Abstract: Let Z i =(Y i,X 1 i,..., X m i), i=1,...,n , be independent and identically distributed random vectors, Z i ∼F,F∈cal F . It is desired to predict Y by ∑ β jX j , where ( β 1,...,β m)∈B n⊆R m , under a prediction loss. Suppose that m =n α, α >1 , that is, there are many more explanatory variables than observations. We consider sets Bn restricted by the maximal number of non-zero coefficients of their members, or by their l1 radius. We study the following asymptotic question: how 'large' may the set Bn be, so that it is still possible to select empirically a predictor whose risk under F is close to that of the best predictor in the set? Sharp bounds for orders of magnitudes are given under various assumptions on cal F . Algorithmic complexity of the ensuing procedures is also studied. The main message of this paper and the implications of the orders derived are that under various sparsity assumptions on the optimal predictor there is 'asymptotically no harm' in introducing many more explanatory variables than observations. Furthermore, such practice can be beneficial in comparison with a procedure that screens in advance a small subset of explanatory variables. Another main result is that 'lasso' procedures, that is, optimization under l1 constraints, could be efficient in finding optimal sparse predictors in high dimensions.
TL;DR: The objective of this article is to describe the way this technology works, to review its assets relative to other VR platforms, and to provide an overview of some of the major studies that have evaluated the use of video capture technologies for rehabilitation.
Abstract: Video capture virtual reality (VR) uses a video camera and software to track movement in a single plane without the need to place markers on specific bodily locations. The user's image is thereby embedded within a simulated environment such that it is possible to interact with animated graphics in a completely natural manner. Although this technology first became available more than 25 years ago, it is only within the past five years that it has been applied in rehabilitation. The objective of this article is to describe the way this technology works, to review its assets relative to other VR platforms, and to provide an overview of some of the major studies that have evaluated the use of video capture technologies for rehabilitation.
TL;DR: This paper examined the relationship between perceived threat posed by an outgroup population and the perceived threat mediates the relations between size of the outgroup and exclusionary attitudes toward the out-group.
TL;DR: The results indicate that Triticum turgidum L. var.
Abstract: One major strategy to increase the level of zinc (Zn) and iron (Fe) in cereal crops, is to exploit the natural genetic variation in seed concentration of these micronutrients. Genotypic variation for Zn and Fe concentration in seeds among cultivated wheat cultivars is relatively narrow and limits the options to breed wheat genotypes with high concentration and bioavailability of Zn and Fe in seed. Alternatively, wild wheat might be an important genetic resource for enhancing micronutrient concentrations in seeds of cultivated wheat. Wild wheat is widespread in diverse environments in Tarkey and other parts of the Fertile Crescent (e.g., Iran, Iraq, Lebanon, Syria, Israel, and Jordan). A large number of accessions of wild wheat and of its wild relatives were collected from the Fertile Crescent and screened for Fe and Zn concentrations as well as other mineral nutrients. Among wild wheat, the collections of wild emmer wheat, Triticum turgidum ssp. dicoccoides (825 accessions) showed impressive vari...
Bradley University1, Pontifical Catholic University of Chile2, University of Tartu3, University of Louisville4, University of Latvia5, University of New Mexico6, Slovak Academy of Sciences7, University of San Carlos8, University of Malta9, Ghent University10, Clemson University11, University of Buenos Aires12, Osaka University13, Illinois State University14, National Autonomous University of Mexico15, University of Brasília16, University of Western Australia17, University of Lima18, Boğaziçi University19, University of Kassel20, University of York21, University of Queensland22, Åbo Akademi University23, Al Akhawayn University24, Indian Institute of Technology Kharagpur25, University of Hawaii at Manoa26, University of Catania27, University of Otago28, University of Dhaka29, Chemnitz University of Technology30, Knox College31, Comenius University in Bratislava32, University of Rijeka33, University of Malaya34, Vilnius University35, American University of Beirut36, Kwangju Health College37, University of Salzburg38, Utrecht University39, National Computerization Agency40, City University of Hong Kong41, University of Idaho42, University of Zimbabwe43, University of Lisbon44, University of Central Lancashire45, Loyola Marymount University46, University of Natal47, University of Granada48, University of Botswana49, University of Jordan50, Babeș-Bolyai University51, University of Cyprus52, University of Belgrade53, KPMG54, University of Montpellier55, University of Zurich56, University of Alabama57, Baylor University58, Queen's University Belfast59, University of Ljubljana60, University of Haifa61, University of La Serena62, Florida Atlantic University63, University of California, Davis64, University of Dar es Salaam65, Ramapo College66, Cyprus College67, Middle East Technical University68, University of the South Pacific69, VU University Amsterdam70, State University of New York System71, University of the Aegean72, Vrije Universiteit Brussel73, University of Lethbridge74, University of Vienna75, University of Hong Kong76, Yuan Ze University77, Charles University in Prague78, Chonnam National University79
TL;DR: In the International Sexuality Description Project, a total of 17,804 participants from 62 cultural regions completed the RelationshipQuestionnaire (RQ), a self-report measure of adult romantic attachment as discussed by the authors.
Abstract: As part of the International Sexuality Description Project, a total of 17,804 participants from 62 cultural regions completedthe RelationshipQuestionnaire(RQ), a self-reportmeasure of adult romanticattachment. Correlational analyses within each culture suggested that the Model of Self and the Model of Other scales of the RQ were psychometrically valid within most cultures. Contrary to expectations, the Model of Self and Model of Other dimensions of the RQ did not underlie the four-category model of attachment in the same way across all cultures. Analyses of specific attachment styles revealed that secure romantic attachment was normative in 79% of cultures and that preoccupied romantic attachment was particularly prevalent in East Asian cultures. Finally, the romantic attachment profiles of individual nations were correlated with sociocultural indicators in ways that supported evolutionary theories of romantic attachment and basic human mating strategies.
TL;DR: Results and others reported suggest that participants can access their knowledge about forgetting but only when theory-based predictions are made, and then only when the notion of forgetting is accentuated either by manipulating retention interval within individuals or by framing recall predictions in terms of forgetting rather than remembering.
Abstract: The authors examined the hypothesis that judgments of learning (JOL), if governed by processing fluency during encoding, should be insensitive to the anticipated retention interval. Indeed, neither item-by-item nor aggregate JOLs exhibited “forgetting” unless participants were asked to estimate recall rates for several different retention intervals, in which case their estimates mimicked closely actual recall rates. These results and others reported suggest that participants can access their knowledge about forgetting but only when theory-based predictions are made, and then only when the notion of forgetting is accentuated either by manipulating retention interval within individuals or by framing recall predictions in terms of forgetting rather than remembering. The authors interpret their findings in terms of the distinction between experience-based and theory-based JOLs.
TL;DR: Results indicate that patients with prefrontal lesions (especially those with lesions involving the orbitoprefrontal and medial regions) were significantly impaired in both cognitive and affective empathy as compared to parietal patients and healthy controls.
Abstract: The present study was designed to examine the degree of impairment in cognitive and affective empathy among patients with focal brain lesions, and the contribution of specific cognitive abilities (such as cognitive flexibility and processing of emotional information), to empathy. The cognitive and affective empathic response of patients with localized prefrontal lesions (n=36) was compared to responses of patients with parietal lesions (n=15) and healthy control subjects (n=19). Results indicate that patients with prefrontal lesions (especially those with lesions involving the orbitoprefrontal and medial regions) were significantly impaired in both cognitive and affective empathy as compared to parietal patients and healthy controls. When the damage was restricted to the prefrontal cortex, either left- or right-hemisphere lesions resulted in impaired empathy. However, when the lesion involved the right hemisphere, patients with parietal lesions were also impaired. The pattern of relationships between cognitive performance and empathy suggested dissociation between the cognitive correlates of affective and cognitive empathy.
TL;DR: In this paper, the authors examine seven myths about emotional intelligence and the prospects for an eventual science of El and identify weaknesses in evidence and evidence that challenge the value of the El construct.
Abstract: Inspired by an influx of academic research, the writ ingof several best-selling trade texts, and frequent me dia exposure, emotional intelligence (El) has emerged recently as one of the most high profile of the psycholog ical constructs (Matthews, Zeidner, & Roberts, 2002). The concept has also prospered due both to cultural trends and orientations that stress the previously ne glected role of the emotions (with some claiming it con stitutes a zeitgeist) and to increasing efforts at standard ized assessment of individual differences in El (Mayer, Salovey & Caruso, 2000a). Common claims suggest that tests for El are predictive of important educational and( occupational criteria, beyond that proportion of variance that general intellectual ability predicts. Thus, the field has increasingly important implications for so ciety, particularly in the impetus to improve emotional fuinctioning in real life. Proponents of El claim that indi v iduals can enjoy happier and more fulfilled lives if they ar-e aware of both their own emotions and those of other people and able to regulate those emotions effectively. Another reason for the widespread, often uncritical, em bracing of the El construct is the suggestion that El gives hope for a more utopian, classless society. This vision for the future stands in contrast to research suggesting a preordained "cognitive elite" (Herrnstein & Murray, 1'994) because El is within anyone's realm to learn and cultivate. Goleman's (1995) widely read book claims that raising El is a panacea for all manner of psychologi cal and social problems. Despite the seeming importance of these claims, scientific investigation of a clearly identified construct of El is sparse. Many of the current propositions pre sented in bo h the populist and specialist literature have littl empirical substance (Matthews, Zeidner et al., 2002). Stripped of scientific trappings, it remains plausible that El is nothing but the latest in a long line of psychological fads. On the other hand, because sys tematic scientific research is just beginning, EI could ind ed mature into a construct that is theoretically me ningful, empirically important, and practically useful. In this article, we examine seven myths about El, that is, st ong, widely believed claims that purport edly give the concept of El scientific credibility. In each case, we identify weaknesses in evidence and ar gument that challenge the value of the El construct. Today's myth could become tomorrow's accepted wisdom, or it could be conclusively falsified. For each claim, we also evaluate the likelihood that it will even tually be substantiated by research. This article focuses on what we see as the key shortcomings of current work on El and the prospects for an eventual science of El. How ver, we also acknowledge the intrinsic inter est of the subject material and the various research ef for s inspired by the concept. Our aim is not to dismiss work on El out of hand, but to examine where the first wave of research on the construct is meeting barriers to progress, and whether those barriers can be overcome.
TL;DR: Two types of RGC2 genes (Type I and Type II) were initially distinguished based on the pattern of sequence identities between their 3′ regions, and the high frequency of sequence exchange and the presence of numerous chimeric R GC2 genes in nature were confirmed.
Abstract: Resistance Gene Candidate2 (RGC2) genes belong to a large, highly duplicated family of nucleotide binding site–leucine rich repeat (NBS-LRR) encoding disease resistance genes located at a single locus in lettuce (Lactuca sativa). To investigate the genetic events occurring during the evolution of this locus, ∼1.5- to 2-kb 3′ fragments of 126 RGC2 genes from seven genotypes were sequenced from three species of Lactuca, and 107 additional RGC2 sequences were obtained from 40 wild accessions of Lactuca spp. The copy number of RGC2 genes varied from 12 to 32 per genome in the seven genotypes studied extensively. LRR number varied from 40 to 47; most of this variation had resulted from 13 events duplicating two to five LRRs because of unequal crossing-over within or between RGC2 genes at one of two recombination hot spots. Two types of RGC2 genes (Type I and Type II) were initially distinguished based on the pattern of sequence identities between their 3′ regions. The existence of two types of RGC2 genes was further supported by intron similarities, the frequency of sequence exchange, and their prevalence in natural populations. Type I genes are extensive chimeras caused by frequent sequence exchanges. Frequent sequence exchanges between Type I genes homogenized intron sequences, but not coding sequences, and obscured allelic/orthologous relationships. Sequencing of Type I genes from additional wild accessions confirmed the high frequency of sequence exchange and the presence of numerous chimeric RGC2 genes in nature. Unlike Type I genes, Type II genes exhibited infrequent sequence exchange between paralogous sequences. Type II genes from different genotype/species within the genus Lactuca showed obvious allelic/orthologous relationships. Trans-specific polymorphism was observed for different groups of orthologs, suggesting balancing selection. Unequal crossover, insertion/deletion, and point mutation events were distributed unequally through the gene. Different evolutionary forces have impacted different parts of the LRR.
TL;DR: Kangaroo care seems to influence state organization and motor system modulation of the newborn infant shortly after delivery, and medical and nursing staff may be well advised to provide this kind of care shortly after birth.
Abstract: Background. The method of skin-to-skin contact (kangaroo care [KC]) has shown physiologic, cognitive, and emotional gains for preterm infants; however, KC has not been studied adequately in term newborns. Aims. To evaluate the effect of KC, used shortly after delivery, on the neurobehavioral responses of the healthy newborn. Study Design. A randomized, controlled trial using a table of random numbers. After consent, the mothers were assigned to 1 of 2 groups: KC shortly after delivery or a no-treatment standard care (control group). Subjects. Included were 47 healthy mother-infant pairs. KC began at 15 to 20 minutes after delivery and lasted for 1 hour. Control infants and KC infants were brought to the nursery 15 to 20 and 75 to 80 minutes after birth, respectively. Results. During a 1-hour-long observation, starting at 4 hours postnatally, the KC infants slept longer, were mostly in a quiet sleep state, exhibited more flexor movements and postures, and showed less extensor movements. Conclusions. KC seems to influence state organization and motor system modulation of the newborn infant shortly after delivery. The significance of our findings for supportive transition from the womb to the extrauterine environment is discussed. Medical and nursing staff may be well advised to provide this kind of care shortly after birth.
TL;DR: Reviewing the role of salt-need both in the expression of liking for salty tastes, and paradoxically, in dissociating need from palatability, indicates that palatable is not a simple reflection of need state, but acts to promote intake through a distinct hedonic system, which has inputs from a variety of other systems, including those regulating need.
Abstract: The traditional view of palatability was that it reflected some underlying nutritional deficit and was part of a homeostatically driven motivational system. However, this idea does not fit with the common observation that palatability can lead to short-term overconsumption. Here, we attempt to re-evaluate the basis of palatability, first by reviewing the role of salt-need both in the expression of liking for salty tastes, and paradoxically, in dissociating need from palatability, and second by examining the role of palatability in short-term control of appetite. Despite the clarity of this system in animals, however, most salt (NaCl) intake in man occurs in a need-free state. Similar conclusions can be drawn in relation to the palatability of food in general. Importantly, the neural systems underlying the hedonic system relating to palatability and homeostatic controls of eating are separate, involving distinct brain structures and neurochemicals. If palatability was a component of homeostatic control, reducing need-state should reduce palatability. However, this is not so, and if anything palatability exerts a stronger stimulatory effect on eating when sated, and over-consumption induced by palatability may contribute to obesity. Differential responsivity to palatability may be a component of the obese phenotype, perhaps through sensitisation of the neural structures related to hedonic aspects of eating. Together, these disparate data clearly indicate that palatability is not a simple reflection of need state, but acts to promote intake through a distinct hedonic system, which has inputs from a variety of other systems, including those regulating need. This conclusion leads to the possibility of novel therapies for obesity based on modulation of hedonic rather than homeostatic controls. Potential developments are discussed.
TL;DR: In this article, the authors explore various reasons that the concept of terrorism has evaded a widely agreed upon definition for so long despite the efforts of so many writers, and they attempt to determine a consensus definition of terrorism by turning to an empirical analysis of how the term has been employed by academics over the years.
Abstract: This analysis begins by exploring various reasons that the concept of terrorism has evaded a widely agreed upon definition for so long despite the efforts of so many writers. Emphasis is placed on the difficulties associated with all “essentially contested concepts.” In addition, the investigation calls attention to such problems as conceptual “stretching” and “traveling.” In an effort to solve the difficulties, the inquiry attempts to determine a consensus definition of terrorism by turning to an empirical analysis of how the term has been employed by academics over the years. Specifically, the well-known definition developed by Alex Schmid, based upon responses to a questionnaire he circulated in 1985, is compared with the way the concept has been employed by contributors to the major journals in the field: Terrorism, Studies in Conflict and Terrorism, and Terrorism and Political Violence. The 22 “definitional elements” of which Schmid's definition is composed are compared to the frequency with which th...
TL;DR: Several new problems motivated by covering arrays applications are raised and algorithms for their solution are discussed.
TL;DR: Oviposition avoidance and mode of detection of the predator have important implications for how to assess the true impact of predators and for the use of commercially produced kairomones for mosquito control.
Abstract: Natural selection should favor females that avoid ovipositing where risk of predation is high for their progeny. Despite the large consequences of such oviposition behavior for individual fitness, population dynamics, and community structure, relatively few studies have tested for this behavior. Moreover, these studies have rarely assessed the mode of detection of predators, compared responses in prey species that vary in vulnerability to predators, or tested for the behavior in natural habitats. In an outdoor artificial pool experiment, we tested the oviposition responses of two dipteran species, Culiseta longiareolata (mosquito) and Chironomus riparius (midge), to the hemipteran predator, Notonecta maculata. Both dipteran species have similar life history characteristics, but Culiseta longiareolata larvae are highly vulnerable to predation by Notonecta, while Chironomus riparius larvae are not. As their vulnerabilities would suggest, Culiseta longiareolata, but not Chironomus riparius, strongly avoided ovipositing in pools containing Notonecta. An experiment in natural rock pools assessing oviposition by Culiseta longiareolata in response to Notonecta maculata yielded an oviposition pattern highly consistent with that of the artificial pool experiment. We also demonstrated that the cue for oviposition avoidance by Culiseta longiareolata was a predator-released chemical: Notonecta water (without Notonecta replenishment) repelled oviposition for 8 days. Oviposition avoidance and mode of detection of the predator have important implications for how to assess the true impact of predators and for the use of commercially produced kairomones for mosquito control.
05 Jan 2004
TL;DR: A novel way of measuring social and cultural capital, situational antecedents of lurking and de-lurking is proposed and some directions towards measuring active participation in virtual communities are provided.
Abstract: The asymmetry of activity in virtual communities is of great interest. While participation in the activities of virtual communities is crucial for a community's survival and development, many people prefer lurking, that is passive attention over active participation. Often, lurkers are the vast majority. There could be many reasons for lurking. Lurking can be measured and perhaps affected by both dispositional and situational variables. This project investigates social and cultural capital, situational antecedents of lurking and de-lurking. We propose a novel way of measuring such capital, lurking, and de-lurking. We try to figure out what are the triggers to active participation. We try to answer this by mathematically defining a social communication network of activities in authenticated discussion forums. Authenticated discussion forums provide exact log information about every participant's activities and allow us to identify lurkers that become first time posters. The proposed social communication network approach (SCN) is an extension of the traditional social network methodology to include, beyond human actors, discussion topics (e.g. Usenet newsgroups threads) and subjects of discussions (e.g. Usenet groups) as well. In addition, the social communication network approach distinguishes between READ and POST link types. These indicate active participation on the part of the human actor. We attempt to validate this model by examining the SCN using data collected in a sample of 82 online forums. By analyzing a graph structure of the network at moments of initial postings we verify several hypotheses about causes of de-lurking and provide some directions towards measuring active participation in virtual communities.
TL;DR: In this paper, the authors describe the development and validation of a test of vocabulary size and strength, which can be used to determine the status of a learner's vocabulary development as well as screening and placement.
Abstract: This article describes the development and validation of a test of vocabulary size and strength. The rst part of the article sets out the theoretical rationale for the test, and describes how the size and strength constructs have been conceptualized and operationalized. The second part of the article focusses on the process of test validation, which involved the testing of the hypotheses implicit in the test design, using both unidimensional and multifaceted Rasch analyses. Possible applications for the test include determining the status of a learner’s vocabulary development as well as screening and placement. A model for administering the test in computer adaptive mode is also proposed. The study has implications both for the design and delivery of this test as well as for theories of vocabulary acquisition.
TL;DR: Prevalence rates of maladaptive vs adaptive responses determined according to a more stringent approach to the concept of inclusion/exclusion criteria (cutoff behavioral criteria—CBC) were assessed in rats exposed to stressors in two different paradigms; exposure to a predator and underwater trauma.
TL;DR: In this article, the authors explored the issue of organizational citizenship behavior (OCB) as a context-related phenomenon, from a multidimensional perspective, and found that organizational learning (structures and learning values) would be positively related to OCB that benefited the organization as a whole (OCBO) and immediately benefited particular individuals (OCBI).
Abstract: The present study explored the issue of organizational citizenship behaviour (OCB) as a context-related phenomenon, from a multidimensional perspective. More specifically, it was hypothesized that organizational learning (structures and learning values) would be positively related to (a) OCB that benefited the organization as a whole (OCBO) and (b) OCB that immediately benefited particular individuals (OCBI). The hypotheses identified the school as the unit of analysis; so all variables were aggregates of individual responses to the organizational level of analysis. Justification for aggregation was provided by a within-group similarity index (r wg ) and a within- and between-entities analysis (WABA). Results from a sample of 31 schools confirmed the main hypotheses, and generally supported the notion that OCB could be treated as a context-related phenomenon. These results should encourage researchers and practitioners to focus more attention on the organizational context and its characteristics as related to OCB.
TL;DR: The reconstruction of the origin and evolutionary history of the triplet code becomes a powerful research tool for molecular evolution studies, especially in its early stages.
Abstract: Temporal order (“chronology”) of appearance of amino acids and their respective codons on evolutionary scene is reconstructed. A consensus chronology of amino acids is built on the basis of 60 different criteria each offering certain temporal order. After several steps of filtering the chronology vectors are averaged resulting in the consensus order: G, A, D, V, P, S, E, (L, T), R, (I, Q, N), H, K, C, F, Y, M, W. It reveals two important features: the amino acids synthesized in imitation experiments of S. Miller appeared first, while the amino acids associated with codon capture events came last. The reconstruction of codon chronology is based on the above consensus temporal order of amino acids, supplemented by the stability and complementarity rules first suggested by M. Eigen and P. Schuster, and on the earlier established processivity rule. At no point in the reconstruction the consensus amino-acid chronology was in conflict with these three rules. The derived genealogy of all 64 codons sugge...
TL;DR: The differential expression of cytoglobin argues against a general respiratory function of this molecule, but rather indicates a connective tissue-specific function and it is hypothesized that cytoglobin may be involved in collagen synthesis.