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Sample records for assortative female preference

  1. Male mate preference and size-assortative mating in convict cichlids: A role for female aggression?

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    Bloch, A N; Estela, V J; Leese, J M; Itzkowitz, M

    2016-09-01

    Many monogamous species demonstrate size-assortative mating patterns within natural populations. To better understand the role of intersexual selection in this process, we examined the effect of male preference for female body size in the convict cichlid (Amatitlania siquia). We provided males with a choice between females that differed in size, relative to each other and in relation to the focal male. Based on previous work, we expected males to prefer the largest available female mates across all treatments. Surprisingly, males spent more time near the smaller of two available females, but only when the other female was larger than the male. Additionally, males spent little time with either of two potential female mates when both females were larger than the male. We hypothesized that while males might prefer the largest of available females, female behavior might limit males from acting on this preference. To test this, males were force paired with a smaller or larger female. Pair formation only occurred when the female was smaller than the male, and females that were larger than their male counterparts showed significantly more aggression when compared to smaller females. Together, these data suggest that in the absence of intrasexual competition, male mate preference for large females in convict cichlids might be limited by female aggression. PMID:27444247

  2. Female preference for male color is necessary and sufficient for assortative mating in 2 cichlid sister species

    NARCIS (Netherlands)

    Selz, Oliver M.; Pierotti, Michele E. R.; Maan, Martine E.; Schmid, Corinne; Seehausen, Ole

    2014-01-01

    A critical step for speciation in the face of gene flow is the origination of reproductive isolation. The evolution of assortative mating greatly facilitates this process. Assortative mating can be mediated by one or multiple cues across an array of sensory modalities. We here explore possible cues

  3. Characterization of assortative mating in medaka: Mate discrimination cues and factors that bias sexual preference.

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    Utagawa, Umi; Higashi, Shoichi; Kamei, Yasuhiro; Fukamachi, Shoji

    2016-08-01

    Somatolactin alpha (SLα) is a peptide hormone that regulates skin color, and SLα-deficient and SLα-excess strains have been established in medaka (Oryzias latipes). Their skin colors differ conspicuously and males prefer to mate with females from the same strain. Pre-mating sexual isolation in this model vertebrate provides an ideal platform for investigating the molecular mechanisms of mate choice. Thus, we studied the sensory cues utilized by these fish to discriminate the same and different strains. When males were given a choice under monochromatic light, where the skin colors differed only in terms of brightness but not in hue, mating occurred but it was not assortative. This suggests that: (1) a visual cue is essential for mate discrimination rather than odor or acoustic cues; (2) the visual cue is color and not shape, size, or motion; and (3) the color cue needs to be perceived as the relative balance of brightness at multiple wavelengths rather than the brightness at a specific wavelength. In addition, we introduced another skin-color mutation into the SLα-excess strain and found that this new strain and the original SLα-excess strain, which also overexpressed SLα but exhibited distinct skin colors, preferred different colors. This demonstrates that SLα is not a primary determinant of sexual preference. The symmetrically biased sexual preferences of the SLα-deficient and SLα-excess strains may be acquired postnatally depending on their individual skin color or that of tank mates. PMID:27260680

  4. Conservation of multivariate female preference functions and preference mechanisms in three species of trilling field crickets.

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    Blankers, T; Hennig, R M; Gray, D A

    2015-03-01

    Divergence in mate recognition systems among closely related species is an important contributor to assortative mating and reproductive isolation. Here, we examine divergence in male song traits and female preference functions in three cricket species with songs consisting of long trills. The shape of female preference functions appears to be mostly conserved across species and follows the predictions from a recent model for song recognition. Multivariate preference profiles, combining the pulse and trill parameters, demonstrate selectivity for conspecific pulse rates and high trill duty cycles. The rules for integration across pulse and trill timescales were identical for all three species. Generally, we find greater divergence in male song traits than in associated female preferences. For pulse rate, we find a strong match between divergent male traits and female peak preferences. Preference functions for trill parameters and carrier frequency are similar between species and show less congruence between signal and preference. Differences among traits in the degree of trait-preference (mis)match may reflect the strength of preferences and the potential for linkage disequilibrium, selective constraints and alternative selective pressures, but appear unrelated to selection for mate recognition per se. PMID:25661511

  5. Gradient evolution of body colouration in surface- and cave-dwelling Poecilia mexicana and the role of phenotype-assortative female mate choice.

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    Bierbach, David; Penshorn, Marina; Hamfler, Sybille; Herbert, Denise B; Appel, Jessica; Meyer, Philipp; Slattery, Patrick; Charaf, Sarah; Wolf, Raoul; Völker, Johannes; Berger, Elisabeth A M; Dröge, Janis; Wolf, Konstantin; Riesch, Rüdiger; Arias-Rodriguez, Lenin; Indy, Jeanne R; Plath, Martin

    2013-01-01

    Ecological speciation assumes reproductive isolation to be the product of ecologically based divergent selection. Beside natural selection, sexual selection via phenotype-assortative mating is thought to promote reproductive isolation. Using the neotropical fish Poecilia mexicana from a system that has been described to undergo incipient ecological speciation in adjacent, but ecologically divergent habitats characterized by the presence or absence of toxic H2S and darkness in cave habitats, we demonstrate a gradual change in male body colouration along the gradient of light/darkness, including a reduction of ornaments that are under both inter- and intrasexual selection in surface populations. In dichotomous choice tests using video-animated stimuli, we found surface females to prefer males from their own population over the cave phenotype. However, female cave fish, observed on site via infrared techniques, preferred to associate with surface males rather than size-matched cave males, likely reflecting the female preference for better-nourished (in this case: surface) males. Hence, divergent selection on body colouration indeed translates into phenotype-assortative mating in the surface ecotype, by selecting against potential migrant males. Female cave fish, by contrast, do not have a preference for the resident male phenotype, identifying natural selection against migrants imposed by the cave environment as the major driver of the observed reproductive isolation.

  6. Gradient Evolution of Body Colouration in Surface- and Cave-Dwelling Poecilia mexicana and the Role of Phenotype-Assortative Female Mate Choice

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    David Bierbach

    2013-01-01

    Full Text Available Ecological speciation assumes reproductive isolation to be the product of ecologically based divergent selection. Beside natural selection, sexual selection via phenotype-assortative mating is thought to promote reproductive isolation. Using the neotropical fish Poecilia mexicana from a system that has been described to undergo incipient ecological speciation in adjacent, but ecologically divergent habitats characterized by the presence or absence of toxic H2S and darkness in cave habitats, we demonstrate a gradual change in male body colouration along the gradient of light/darkness, including a reduction of ornaments that are under both inter- and intrasexual selection in surface populations. In dichotomous choice tests using video-animated stimuli, we found surface females to prefer males from their own population over the cave phenotype. However, female cave fish, observed on site via infrared techniques, preferred to associate with surface males rather than size-matched cave males, likely reflecting the female preference for better-nourished (in this case: surface males. Hence, divergent selection on body colouration indeed translates into phenotype-assortative mating in the surface ecotype, by selecting against potential migrant males. Female cave fish, by contrast, do not have a preference for the resident male phenotype, identifying natural selection against migrants imposed by the cave environment as the major driver of the observed reproductive isolation.

  7. Linking intra- and interspecific assortative mating: Consequences for asymmetric sexual isolation.

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    Svensson, Erik I; Nordén, Anna; Waller, John T; Runemark, Anna

    2016-06-01

    Assortative mating is of interest because of its role in speciation and the maintenance of species boundaries. However, we know little about how within-species assortment is related to interspecific sexual isolation. Most previous studies of assortative mating have focused on a single trait in males and females, rather than utilizing multivariate trait information. Here, we investigate how intraspecific assortative mating relates to sexual isolation in two sympatric and congeneric damselfly species (genus Calopteryx). We connect intraspecific assortment to interspecific sexual isolation by combining field observations, mate preference experiments, and enforced copulation experiments. Using canonical correlation analysis, we demonstrate multivariate intraspecific assortment for body size and body shape. Males of the smaller species mate more frequently with heterospecific females than males of the larger species, which showed less attraction to small heterospecific females. Field experiments suggest that sexual isolation asymmetry is caused by male preferences for large heterospecific females, rather than by mechanical isolation due to interspecific size differences or female preferences for large males. Male preferences for large females and male-male competition for high quality females can therefore counteract sexual isolation. This sexual isolation asymmetry indicates that sexual selection currently opposes a species boundary. PMID:27151764

  8. Linking intra- and interspecific assortative mating: Consequences for asymmetric sexual isolation.

    Science.gov (United States)

    Svensson, Erik I; Nordén, Anna; Waller, John T; Runemark, Anna

    2016-06-01

    Assortative mating is of interest because of its role in speciation and the maintenance of species boundaries. However, we know little about how within-species assortment is related to interspecific sexual isolation. Most previous studies of assortative mating have focused on a single trait in males and females, rather than utilizing multivariate trait information. Here, we investigate how intraspecific assortative mating relates to sexual isolation in two sympatric and congeneric damselfly species (genus Calopteryx). We connect intraspecific assortment to interspecific sexual isolation by combining field observations, mate preference experiments, and enforced copulation experiments. Using canonical correlation analysis, we demonstrate multivariate intraspecific assortment for body size and body shape. Males of the smaller species mate more frequently with heterospecific females than males of the larger species, which showed less attraction to small heterospecific females. Field experiments suggest that sexual isolation asymmetry is caused by male preferences for large heterospecific females, rather than by mechanical isolation due to interspecific size differences or female preferences for large males. Male preferences for large females and male-male competition for high quality females can therefore counteract sexual isolation. This sexual isolation asymmetry indicates that sexual selection currently opposes a species boundary.

  9. Organizing Products with Complements versus Substitutes: Effects on Store Preferences as a Function of Effort and Assortment Perceptions

    NARCIS (Netherlands)

    Diehl, K.; Herpen, van E.; Lamberton, C.

    2015-01-01

    Retailers often organize at least part of their assortment by displaying complementary products from different product categories together (e.g., a pair of pants with a shirt) rather than grouping items by product type (e.g., a pair of pants with other pants). However, little is known about how reta

  10. Female mate preference for longer fins in medaka.

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    Fujimoto, Shingo; Kawajiri, Maiko; Kitano, Jun; Yamahira, Kazunori

    2014-11-01

    Medaka, Oryzias latipes complex, display sexual dimorphisms in anal- and dorsal-fin lengths that suggest that females may prefer males with longer fins. However, female preference for longer anal and/or dorsal fins has not yet been described for the medaka. One reason that previous studies have not investigated this relationship may be because variations in male fin lengths within a single population are too small to experimentally detect female preference. In this study, we artificially crossed individuals from two wild populations (Aomori and Okinawa) that differed in male anal- and dorsal-fin lengths to increase phenotypic variation. We then tested female mate preference using these hybrid males. The results of the mating experiments and stepwise multiple regression analyses indicate that anal- and/or dorsal-fin lengths of the males contributed to female preference (i.e., males with longer anal and/or dorsal fins were less likely to be rejected by females). Variation in male standard length did not affect female preference. The evolution of female preference for longer fins in the medaka species complex may be explained by the "sexy son" hypothesis or the direct benefit hypothesis. PMID:25366151

  11. Product assortment and individual decision processes.

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    Chernev, Alexander

    2003-07-01

    Research presented in this article examines the impact of product assortment on individuals' decisions. Four experiments report converging evidence that the impact of assortment is moderated by the degree to which individuals have articulated attribute preferences, whereby individuals with an articulated ideal point are more likely to prefer larger assortments than individuals without articulated preferences. The data further show that choices made from large assortments are associated with more selective, alternative-based, and confirmatory processing for individuals with articulated preferences and more comprehensive, attribute-based, and comparative processing for those without articulated preferences.

  12. Mate choice in adult female Bengalese finches: females express consistent preferences for individual males and prefer female-directed song performances.

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    Dunning, Jeffery L; Pant, Santosh; Bass, Aaron; Coburn, Zachary; Prather, Jonathan F

    2014-01-01

    In the process of mate selection by female songbirds, male suitors advertise their quality through reproductive displays in which song plays an important role. Females evaluate the quality of each signal and the associated male, and the results of that evaluation guide expression of selective courtship displays. Some studies reveal broad agreement among females in their preferences for specific signal characteristics, indicating that those features are especially salient in female mate choice. Other studies reveal that females differ in their preference for specific characteristics, indicating that in those cases female evaluation of signal quality is influenced by factors other than simply the physical properties of the signal. Thus, both the physical properties of male signals and specific traits of female signal evaluation can impact female mate choice. Here, we characterized the mate preferences of female Bengalese finches. We found that calls and copulation solicitation displays are equally reliable indicators of female preference. In response to songs from an array of males, each female expressed an individual-specific song preference, and those preferences were consistent across tests spanning many months. Across a population of females, songs of some males were more commonly preferred than others, and females preferred female-directed songs more than undirected songs, suggesting that some song features are broadly attractive. Preferences were indistinguishable for females that did or did not have social experience with the singers, indicating that female preference is strongly directed by song features rather than experiences associated with the singer. Analysis of song properties revealed several candidate parameters that may influence female evaluation. In an initial investigation of those parameters, females could be very selective for one song feature yet not selective for another. Therefore, multiple song parameters are evaluated independently

  13. Mate choice in adult female Bengalese finches: females express consistent preferences for individual males and prefer female-directed song performances.

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    Jeffery L Dunning

    Full Text Available In the process of mate selection by female songbirds, male suitors advertise their quality through reproductive displays in which song plays an important role. Females evaluate the quality of each signal and the associated male, and the results of that evaluation guide expression of selective courtship displays. Some studies reveal broad agreement among females in their preferences for specific signal characteristics, indicating that those features are especially salient in female mate choice. Other studies reveal that females differ in their preference for specific characteristics, indicating that in those cases female evaluation of signal quality is influenced by factors other than simply the physical properties of the signal. Thus, both the physical properties of male signals and specific traits of female signal evaluation can impact female mate choice. Here, we characterized the mate preferences of female Bengalese finches. We found that calls and copulation solicitation displays are equally reliable indicators of female preference. In response to songs from an array of males, each female expressed an individual-specific song preference, and those preferences were consistent across tests spanning many months. Across a population of females, songs of some males were more commonly preferred than others, and females preferred female-directed songs more than undirected songs, suggesting that some song features are broadly attractive. Preferences were indistinguishable for females that did or did not have social experience with the singers, indicating that female preference is strongly directed by song features rather than experiences associated with the singer. Analysis of song properties revealed several candidate parameters that may influence female evaluation. In an initial investigation of those parameters, females could be very selective for one song feature yet not selective for another. Therefore, multiple song parameters are evaluated

  14. A preference for a sexual signal keeps females safe.

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    Tae Won Kim

    Full Text Available Predation is generally thought to constrain sexual selection by female choice and limit the evolution of conspicuous sexual signals. Under high predation risk, females usually become less choosy, because they reduce their exposure to their predators by reducing the extent of their mate searching. However, predation need not weaken sexual selection if, under high predation risk, females exhibit stronger preferences for males that use conspicuous signals that help females avoid their predators. We tested this prediction in the fiddler crab Uca terpsichores by increasing females' perceived predation risk from crab-eating birds and measuring the attractiveness of a courtship signal that females use to find mates. The sexual signal is an arching mound of sand that males build at the openings of their burrows to which they attract females for mating. We found that the greater the risk, the more attractive were males with those structures. The benefits of mate preferences for sexual signals are usually thought to be linked to males' reproductive contributions to females or their young. Our study provides the first evidence that a female preference for a sexual signal can yield direct survival benefits by keeping females safe as they search for mates.

  15. Why do ovigerous females approach courting males? Female preferences and sensory biases in a fiddler crab.

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    Chou, Chun-Chia; Backwell, Patricia R Y

    2016-08-01

    Perceptual biases explain the origin and evolution of female preference in many species. Some responses that mediate mate choice, however, may have never been used in nonmating contexts. In the fiddler crab, Uca mjoebergi, mate-searching females prefer faster wave rates and leading wave; however, it remains unclear whether such responses evolved in a mating context (i.e., the preference has effect on the fitness of the female and her offspring that arise from mating with a particular male) or a nonmating contexts (i.e., a female obtains direct benefits through selecting the male with a more detectable trait). Here, we compared the preferences of mate-searching with those of ovigerous females that are searching for a burrow and do not concern about male "quality." Results showed that as both mate-searching and ovigerous females preferentially approached robotic males with faster wave rates. This suggests that wave rate increases detectability/locatability of males, but the mating preference for this trait is unlikely to evolve in the mating context (although it may currently function in mate choice), as it does not provide fitness-related benefit to females or her offspring. Wave leadership, in contract, was attractive to mate-searching females, but not ovigerous females, suggesting that female preference for leadership evolves because wave leadership conveys information about male quality. We provide not only an empirical evidence of sensory biases (in terms of the preference for faster wave), but the first experimental evidence that mating context can be the only selection force that mediates the evolution of male sexual traits and female preference (in terms of the preference for leading wave). PMID:27551397

  16. You can't always get what you want: size assortative mating by mutual mate choice as a resolution of sexual conflict

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    Thünken Timo

    2009-06-01

    Full Text Available Abstract Background Assortative mating patterns for mate quality traits like body size are often observed in nature. However, the underlying mechanisms that cause assortative mating patterns are less well known. Sexual selection is one important explanation for assortment, suggesting that i one (usually the female or both sexes could show preferences for mates of similar size or ii mutual mate choice could resolve sexual conflict over quality traits into assortment. We tested these hypotheses experimentally in the socially monogamous cichlid fish Pelvicachromis taeniatus, in which mate choice is mutual. Results In mate choice experiments, both sexes preferred large mates irrespective of own body size suggesting mating preferences are not size-assortative. Especially males were highly selective for large females, probably because female body size signals direct fitness benefits. However, when potential mates were able to interact and assess each other mutually they showed size-assortative mating patterns, i.e. the likelihood to mate was higher in pairs with low size differences between mates. Conclusion Due to variation in body size, general preferences for large mating partners result in a sexual conflict: small, lower quality individuals who prefer themselves large partners are unacceptable for larger individuals. Relative size mismatches between mates translate into a lower likelihood to mate, suggesting that the threshold to accept mates depends on own body size. These results suggest that the underlying mechanism of assortment in P. taeniatus is mutual mate choice resolving the sexual conflict over mates, rather than preference for mates of similar size.

  17. Preferred Leadership Behaviours of Male and Female Badminton Players

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    Rajkumar S HARMA

    2015-06-01

    Full Text Available Pr eferences for specific coaching behaviours of male and female Badminton players were measured by the modified and revised Leadership Scale for Sport. Eighty two (Males=61, Females=21 badminton players were selected from amongst the players representing th eir respective university teams in East - zone Inter - university Badminton (Men/Women tournaments held at Bilaspur (CG. The present investigation noted the statistically significant differences among East - zone Inter - university level male as well as female B adminton player’s preferences for specific coaching behaviour. Differences were not observed between male and female badminton players in all the dimensions together of specific coaching behaviours of preferred leadership. It is recommended that coaches a lign their coaching style to meet the needs of their teams.

  18. Infants Prefer Female Body Phenotypes; Infant Girls Prefer They Have an Hourglass Shape.

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    Alexander, Gerianne M; Hawkins, Laura B; Wilcox, Teresa; Hirshkowitz, Amy

    2016-01-01

    Adolescents and adults show preferences for male and female body shapes consistent with evolutionary theories of reproductive fitness and mate selection. However, when these preferences for females with narrow waists (i.e., 0.7 waist-to-hip ratio) and men with broad shoulders (i.e., mesomorphic body shape) emerge during the lifespan is largely unknown. To address this knowledge gap, eye-movements were tracked in 146 infants (3-18 months of age) during computer presentation of three-dimensional human figures varying in body features thought relevant for reproductive success (e.g., secondary sex characteristics, waist-to-hip ratio). When presented with pairs of figures differing in apparent sex, male and female infants looked significantly longer at the female figure compared to the male figure, a new finding that extends previous research showing preferences for female faces in infancy. When presented with same-sex figures differing in characteristics associated with mate value, male and female infants looked longer at a low mate value male (i.e., an endomorphic body type) compared to a high mate value male (i.e., a mesomorphic body type), a finding that replicates the results of previous research. In addition, the novel use of high and low mate value female figures showed a sex difference in visual attention, such that female infants looked longer at the high mate value female figure compared to the low mate female figure whereas male infants showed the opposite pattern of results. In sum, these findings suggest that infants generally do not possess preferences for adult-defined attractive male body shapes. However, infant girls' greater attention to a female figure with an adult-preferred waist-to-hip ratio raises the possibility that evolved preferences for 0.7 waist-to-hip ratio influence girls' later preference for toys representing females with an hourglass shape, perhaps supporting elaboration of adult social behaviors that enhance reproductive success (e

  19. Female rose bitterling prefer MHC-dissimilar males: experimental evidence.

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    Martin Reichard

    Full Text Available The role of genetic benefits in female mate choice remains a controversial aspect of sexual selection theory. In contrast to "good allele" models of sexual selection, "compatible allele" models of mate choice predict that females prefer mates with alleles complementary to their own rather than conferring additive effects. While correlative results suggest complementary genetic effects to be plausible, direct experimental evidence is scarce. A previous study on the Chinese rose bitterling (Rhodeus ocellatus demonstrated a positive correlation between female mate choice, offspring growth and survival, and the functional dissimilarity between the Major Histocompatibility Complex (MHC alleles of males and females. Here we directly tested whether females used cues associated with MHC genes to select genetically compatible males in an experimental framework. By sequentially pairing females with MHC similar and dissimilar males, based on a priori known MHC profiles, we showed that females discriminated between similar and dissimilar males and deposited significantly more eggs with MHC dissimilar males. Notably, the degree of dissimilarity was an important factor for female decision to mate, possibly indicating a potential threshold value of dissimilarity for decision making, or of an indirect effect of the MHC.

  20. Understanding Consumer Reactions to Assortment Unavailability

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    L.M. Sloot (Laurens)

    2006-01-01

    textabstractAny regular grocery shopper will be familiar with the annoying situation in which his or her preferred product is not available at the moment (s) he wants to buy it. Assortment unavailability can be temporary (e.g., out-of-stock) or permanent in nature (e.g., assortment reduction). Shop

  1. Mate preference of female blue tits varies with experimental photoperiod.

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    Laura B Reparaz

    Full Text Available Organisms use environmental cues to time their life-cycles and among these cues, photoperiod is the main trigger of reproductive behaviours such as territory defence or song activity. Whether photoperiod is also important for another behaviour closely associated with reproduction, mate choice, is unknown. In many bird species, mate choice occurs at two different times during the annual cycle that strongly differ in daylength: in late winter when photoperiod is short and social mates are chosen, and again around egg-laying when photoperiod is longer and extra-pair mates are chosen. This duality makes the role that photoperiod plays on mate choice behaviours intriguing. We investigated the effect of photoperiod on mate choice using three experimental photoperiodic treatments (9 L:15 D, 14 L:10 D, 18 L:6 D, using blue tits (Cyanistes caeruleus as a biological model. We show that female choice was stronger under long photoperiods. In addition, female blue tits spent significantly more time near males with long tarsi and long wings. This latter preference was only expressed under long photoperiods, suggesting that some indices of male quality only become significant to females when they are strongly photostimulated, and therefore that females could select their social and extra-pair mates based on different phenotypic traits. These results shed light on the roles that photoperiod may play in stimulating pair-bonding and in refining female selectivity for male traits.

  2. Male size does not correlate with fertilization success in two bufonid toads that show size-assortative mating

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    Xiao-Li FAN, Zhi-Hua LIN, Xiang JI

    2013-12-01

    Full Text Available We examined sexual size dimorphism (SSD, mating pattern, fertilization efficiency and female reproductive traits in two bufonid toads (Bufo gargarizans and Duttaphrynus melanostictus to test the idea that importance of male body size for egg fertilization success depends on the mating pattern. Female-biased SSD was evident only in D. melanostictus. Female B. gargarizans laid fewer larger eggs nearly three months earlier than did female D. melanostictus. Fertilization efficiencies on average were higher in B. gargarizans (95% than in D. melanostictus (91%. Though differing in the degree of SSD, body size, breeding season, clutch size, egg size and fertilization efficiency, the two toads were similar in four aspects: (1 both showed size-assortative mating; (2 females did not tradeoff egg size against egg number; (3 male size, clutch size and clutch dry mass were greater in male-larger than in female-larger pairs after accounting for female snout-vent length (SVL; and (4 the ratio of male to female SVL did not affect fertilization efficiency. Our data show that: (1 a female preference for large males is likely not important in terms of egg fertilization success; (2 a male preference for large females is likely important because larger females are more fecund; and (3 size-assortative mating arises from a male preference for large females. Our study demonstrates that male size is not always important for egg fertilization success in anurans that show size-assortative mating [Current Zoology 59 (6: 740–746, 2013].

  3. Parallel changes in mate-attracting calls and female preferences in autotriploid tree frogs

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    Tucker, Mitch A.; Gerhardt, H. C.

    2011-01-01

    For polyploid species to persist, they must be reproductively isolated from their diploid parental species, which coexist at the same time and place at least initially. In a complex of biparentally reproducing tetraploid and diploid tree frogs in North America, selective phonotaxis—mediated by differences in the pulse-repetition (pulse rate) of their mate-attracting vocalizations—ensures assortative mating. We show that artificially produced autotriploid females of the diploid species (Hyla c...

  4. No evidence for size-assortative mating in the wild despite mutual mate choice in sex-role-reversed pipefishes.

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    Mobley, Kenyon B; Abou Chakra, Maria; Jones, Adam G

    2014-01-01

    Size-assortative mating is a nonrandom association of body size between members of mating pairs and is expected to be common in species with mutual preferences for body size. In this study, we investigated whether there is direct evidence for size-assortative mating in two species of pipefishes, Syngnathus floridae and S. typhle, that share the characteristics of male pregnancy, sex-role reversal, and a polygynandrous mating system. We take advantage of microsatellite-based "genetic-capture" techniques to match wild-caught females with female genotypes reconstructed from broods of pregnant males and use these data to explore patterns of size-assortative mating in these species. We also develop a simulation model to explore how positive, negative, and antagonistic preferences of each sex for body size affect size-assortative mating. Contrary to expectations, we were unable to find any evidence of size-assortative mating in either species at different geographic locations or at different sampling times. Furthermore, two traits that potentially confer a fitness advantage in terms of reproductive success, female mating order and number of eggs transferred per female, do not affect pairing patterns in the wild. Results from model simulations demonstrate that strong mating preferences are unlikely to explain the observed patterns of mating in the studied populations. Our study shows that individual mating preferences, as ascertained by laboratory-based mating trials, can be decoupled from realized patterns of mating in the wild, and therefore, field studies are also necessary to determine actual patterns of mate choice in nature. We conclude that this disconnect between preferences and assortative mating is likely due to ecological constraints and multiple mating that may limit mate choice in natural populations. PMID:24455162

  5. Effect of Female-Biased Sex Ratios on Female Homosexual Behavior in Japanese Macaques: Evidence for the "Bisexual Preference Hypothesis".

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    Leca, Jean-Baptiste; Gunst, Noëlle; Huffman, Michael A; Vasey, Paul L

    2015-11-01

    We aimed to explain the frequent and prevalent female homosexual behavior in the context of female-biased operational sex ratios (OSR) and qualified sex ratios (Q) in a free-ranging group of Japanese macaques (Macaca fuscata) living at Arashiyama-Kyoto, Japan. Our data included the average availability of sexually mature males during females' putative fertile period (OSR), the ratio of sexually mature males to sexually mature females (Q), as well as heterosexual and female homosexual solicitations and consortships collected during 13 mating seasons from 136 females. Our results did not support the "heterosexual deprivation hypothesis," which holds that female homosexual behavior is attributable to a shortage of male mates. Likewise, our results did not support the "lack of opposite-sex sexual competitor hypothesis," which holds that females have more access to female mates when male sexual rivals are scarce. Of the 11 predictions tested, only one yielded statistically significant results: we found that higher ratios of availability of preferred female partners to preferred male partners were associated with female homosexual consortships rather than female heterosexual consortships. This result supported the "bisexual preference hypothesis," which holds that female homosexual behavior is attributable to female preference for certain female mates relative to certain male mates. We conclude that when a female targets another female as a mate, it is an active choice for a female sexual partner over available male alternatives, rather than a by-default situation that occurs because males are not available as sexual partners, or because females are better able to access female sexual partners due to a scarcity of male sexual competitors.

  6. Poeciliid male mate preference is influenced by female size but not by fecundity

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    Luis R. Arriaga

    2013-08-01

    Full Text Available While female mate preference is very well studied, male preference has only recently begun to receive significant attention. Its existence is found in numerous taxa, but empirical research has mostly been limited to a descriptive level and does not fully address the factors influencing its evolution. We attempted to address this issue using preference functions by comparing the strength of male preference for females of different sizes in nine populations of four poeciliid species. Due to environmental constraints (water toxicity and surface versus cave habitat, females from these populations vary in the degree to which their size is correlated to their fecundity. Hence, they vary in how their size signals their quality as mates. Since female size is strongly correlated with fecundity in this subfamily, males were sequentially presented with conspecific females of three different size categories and the strength of their preference for each was measured. Males preferred larger females in all populations, as predicted. However, the degree to which males preferred each size category, as measured by association time, was not correlated with its fecundity. In addition, cave males discriminated against smaller females more than surface males. Assuming that male preference is correlated with female fitness, these results suggest that factors other than fecundity have a strong influence on female fitness in these species.

  7. Heterosexual romantic couples mate assortatively for facial symmetry, but not masculinity.

    Science.gov (United States)

    Burriss, Robert P; Roberts, S Craig; Welling, Lisa L M; Puts, David A; Little, Anthony C

    2011-05-01

    Preferences for partners with symmetric and sex-typical faces are well documented and considered evidence for the good-genes theory of mate choice. However, it is unclear whether preferences for these traits drive the real-world selection of mates. In two samples of young heterosexual couples from the United Kingdom (Study 1) and the United States (Study 2), the authors found assortment for facial symmetry but not for sex typicality or independently rated attractiveness. Within-couple similarity in these traits did not predict relationship duration or quality, although female attractiveness and relationship duration were negatively correlated among couples in which the woman was the more attractive partner. The authors conclude that humans may mate assortatively on facial symmetry, but this remains just one of the many physical and nonphysical traits to which people likely attend when forming romantic partnerships. This is also the first evidence that preferences for symmetry transfer from the laboratory to a real-world setting.

  8. Social preferences based on sexual attractiveness: a female strategy to reduce male sexual attention.

    Science.gov (United States)

    Brask, Josefine B; Croft, Darren P; Thompson, Katharine; Dabelsteen, Torben; Darden, Safi K

    2012-05-01

    Male sexual harassment of females is common across sexually reproducing species and can result in fitness costs to females. We hypothesized that females can reduce unwanted male attention by constructing a social niche where their female associates are more sexually attractive than themselves, thus influencing the decision-making of males to their advantage. We tested this hypothesis in the Trinidadian guppy (Poecilia reticulata), a species with high levels of male sexual harassment. First, we confirmed that non-receptive females were harassed less when they were paired with a more sexually attractive (receptive) female than with another non-receptive female. We then found that, indeed, females exploit this as a strategy to reduce sexual harassment; non-receptive females actively preferred to associate with receptive over non-receptive females. Importantly, when given access only to chemosensory cues, non-receptive females still showed this preference, suggesting that they use information from chemical cues to assess the sexual attractiveness of potential female partners. Receptive females in contrast showed no such preferences. Our results demonstrate that females can decrease male harassment by associating with females that are more sexually attractive than themselves and that they perform active partner choices based on this relative attractiveness. We propose that this strategy is likely to represent an important pathway by which females can construct social niches that influence the decision-making of others to their advantage; in this case, to reduce the sexual harassment they experience. PMID:22158959

  9. Low-quality females prefer low-quality males when choosing a mate

    OpenAIRE

    Holveck, Marie-Jeanne; Riebel, Katharina

    2009-01-01

    Mate choice studies routinely assume female preferences for indicators of high quality in males but rarely consider developmental causes of within-population variation in mating preferences. By contrast, recent mate choice models assume that costs and benefits of searching or competing for high-quality males depend on females' phenotypic quality. A prediction following from these models is that manipulation of female quality should alter her choosiness or even the direction of her mating pref...

  10. Preferred leadership prototypes of male and female leaders in 27 countries

    OpenAIRE

    Lori D Paris; Jon P Howell; Peter W Dorfman; Hanges, Paul J.

    2009-01-01

    Our study shows that preferred leadership prototypes held by female leaders differ from the prototypes held by male leaders, and that these prototype differences vary across countries, cultures, and especially industries. In general, female managers prefer participative, team oriented, and charismatic leadership prototype dimensions more than males. Contrary to popular belief, both males and females valued humane-oriented leadership equally. Gender egalitarianism and industry type were import...

  11. Context‐dependent female preference for multiple ornaments in the bearded reedling

    OpenAIRE

    Griggio, Matteo; Hoi, Herbert; Lukasch, Barbara; Pilastro, Andrea

    2016-01-01

    Abstract While it is well established that females prefer to mate with well‐ornamented males, the influence of perceptive and cognitive processes on the expression of female mate choice is still poorly known. It has been suggested that the female perception of a male's attractiveness is not absolute, but depends on the other males with which he is compared that have been previously encountered (comparative evaluation). We investigated whether mate preference in bearded reedlings ( Panurus bia...

  12. Optimizing Retail Assortments

    NARCIS (Netherlands)

    Rooderkerk, Robert P.; van Heerde, Harald J.; Bijmolt, Tammo H. A.

    2013-01-01

    Retailers face the problem of finding the assortment that maximizes category profit. This is a challenging task because the number. of potential assortments is very large when there are many stock-keeping units (SKUs) to choose from. Moreover, SKIT sales can be cannibalized by other SKUs in the asso

  13. Context-dependent female preference for multiple ornaments in the bearded reedling.

    Science.gov (United States)

    Griggio, Matteo; Hoi, Herbert; Lukasch, Barbara; Pilastro, Andrea

    2016-01-01

    While it is well established that females prefer to mate with well-ornamented males, the influence of perceptive and cognitive processes on the expression of female mate choice is still poorly known. It has been suggested that the female perception of a male's attractiveness is not absolute, but depends on the other males with which he is compared that have been previously encountered (comparative evaluation). We investigated whether mate preference in bearded reedlings (Panurus biarmicus) is dependent on or independent of social context in relation to two different traits: beard and tail lengths. Each female had a choice between two to three males with different modifications of beard and tail. For each female, three different experiments were conducted (one binary and two trinary tests). We found that when females are presented with options that vary antagonistically with respect to two ornaments (binary test), some individuals prefer one trait while others the other trait. This indicates that in our bearded reedlings population exists a mate preference polymorphisms. Moreover, we found that the presence of a third stimulus, irrespective of the initial preference, reduced the strength of the initial preference - what we can call a "preference dilution effect." Our results suggest that the female's choice may be constrained by her cognitive abilities when she is simultaneously presented with several options varying for two uncorrelated traits. PMID:26843933

  14. Low-quality females prefer low-quality males when choosing a mate.

    Science.gov (United States)

    Holveck, Marie-Jeanne; Riebel, Katharina

    2010-01-01

    Mate choice studies routinely assume female preferences for indicators of high quality in males but rarely consider developmental causes of within-population variation in mating preferences. By contrast, recent mate choice models assume that costs and benefits of searching or competing for high-quality males depend on females' phenotypic quality. A prediction following from these models is that manipulation of female quality should alter her choosiness or even the direction of her mating preferences. We here provide (to our knowledge) the first example where an experimental manipulation of female quality induced a mating preference for low-quality males. Zebra finches (Taeniopygia guttata) reared in small or large experimental broods became high- or low-quality adults, respectively. Only high-quality females preferred high-quality males' mate-advertising songs, while all low-quality females preferred low-quality males' song. Subsequent breeding trials confirmed this pattern: latency until egg laying was shortest in quality-matched pairs, indicating that quality-matched birds were accepted faster as partners. Females produced larger eggs when mated with high-quality males, regardless of their own quality, indicating consensus regarding male quality despite the expression of different choices. Our results demonstrate the importance of considering the development of mating preferences to understand their within-population variation and environmentally induced change. PMID:19812084

  15. Preferred Leadership Behaviours of Male and Female Badminton Players

    OpenAIRE

    Rajkumar S HARMA

    2015-01-01

    Pr eferences for specific coaching behaviours of male and female Badminton players were measured by the modified and revised Leadership Scale for Sport. Eighty two (Males=61, Females=21) badminton players were selected from amongst the players representing th eir respective university teams in East - zone Inter - university Badminton (Men/Women) tournaments held at Bilaspur (CG). The present investigation noted ...

  16. Preferences of Male and Female Students for TSA Competitive Events

    Science.gov (United States)

    Mitts, Charles R.; Haynie, W. J., III

    2010-01-01

    Arguably a major issue facing technology education (TE) since its inception has been its failure to attract and keep female students. This article explains one primary reason female students may be avoiding TE courses, presents a research-tested set of tools that TE teachers can use to help fix the problem, and offers a new realizable pathway…

  17. Females prefer the scent of outbred males: good-genes-as-heterozygosity?

    Directory of Open Access Journals (Sweden)

    Thoß Michaela

    2009-05-01

    Full Text Available Abstract Background There is increasing interest to determine the relative importance of non-additive genetic benefits as opposed to additive ones for the evolution of mating preferences and maintenance of genetic variation in sexual ornaments. The 'good-genes-as-heterozygosity' hypothesis predicts that females should prefer to mate with more heterozygous males to gain more heterozygous (and less inbred offspring. Heterozygosity increases males' sexual ornamentation, mating success and reproduction success, yet few experiments have tested whether females are preferentially attracted to heterozygous males, and none have tested whether females' own heterozygosity influences their preferences. Outbred females might have the luxury of being more choosey, but on the other hand, inbred females might have more to gain by mating with heterozygous males. We manipulated heterozygosity in wild-derived house mice (Mus musculus musculus through inbreeding and tested whether the females are more attracted to the scent of outbred versus inbred males, and whether females' own inbreeding status affects their preferences. We also tested whether infecting both inbred and outbred males with Salmonella would magnify females' preferences for outbred males. Results Females showed a significant preference for outbred males, and this preference was more pronounced among inbred females. We found no evidence that Salmonella infection increased the relative attractiveness of outbred versus inbred males; however, we found no evidence that inbreeding affected males' disease resistance in this study. Conclusion Our findings support the idea that females are more attracted to outbred males, and they suggest that such preferences may be stronger among inbred than outbred females, which is consistent with the 'good-genes-as-heterozygosity' hypothesis. It is unclear whether this odour preference reflects females' actual mating preferences, though it suggests that future studies

  18. Coevolution of Male and Female Response Preferences to Sexual Signals in Music Frogs

    Institute of Scientific and Technical Information of China (English)

    Jianguo CUI; Jichao WANG; Guangzhan FANG; Xiaowei SONG; Steven E BRAUTH; Yezhong TANG

    2016-01-01

    Male signaling influences both female choice and male-male competition. Although male signaling characteristics and female preferences have been shown to coevolve in many species, few studies have examined whether male signal characteristics and male receiver responses related to male-male competition also coevolve. The present study tested the hypothesis that male and female signal receiver preferences may coevolve in parallel for frogs in the genus Babina by comparing the acoustic structure of male advertisement calls of four closely related and geographically isolated Babina species. Then we assessed the behavioral responses of both male and female B. daunchina (Emei music frog) to male call playbacks from each of the four species. The results support the hypothesis that male and female signal receiver preferences have coevolved in this species. Specifically, both male and female B. daunchina respond strongly to the heterospecific calls of B. hainanensis, suggesting that preexisting biases exist in both females and males. Both male and female individuals showed a slight response to the calls of B. adenopleura while no response was evoked by the calls of B. lini. The manifestation of similar response profiles in male and female B. daunchina to the calls of the four species support the idea that male and female signal receiver preferences evolved in parallel and that the origin of these receiver biases reflects adaptations dependent on the same neural and cognitive systems in both sexes.

  19. Multivariate models of mixed assortment: phenotypic assortment and social homogamy for education and fluid ability.

    Science.gov (United States)

    Reynolds, C A; Baker, L A; Pedersen, N L

    2000-11-01

    Phenotypic assortment is assumed to be the principal mechanism of spouse similarity in most biometrical studies. Other assortment mechanisms, such as social homogamy, may be plausible. Two models are presented that consider phenotypic assortment and social homogamy simultaneously (i.e., mixed assortment), where selective associations between social background factors (Model I) versus selective associations between total environments (Model II) distinguish the models. A series of illustrative analyses was undertaken for education and fluid ability available on a sample of 116 Swedish twin pairs and their spouses. On the basis of several fit criteria Model I was preferred over Model II. Both social homogamy and phenotypic assortment may contribute to spouse similarity for educational attainment and fluid ability. Furthermore, spouse similarity for fluid ability may arise indirectly from social homogamy and phenotypic assortment for educational attainment. Power analyses indicated greater observed power for Model I than Model II. Additional power analyses indicated that considerably more twin-spouse sets would be needed for Model II than Model I, to resolve social homogamy and phenotypic assortment. Effects of misspecification of mechanisms of spouse similarity are also briefly discussed.

  20. Sexual responsiveness is condition-dependent in female guppies, but preference functions are not

    Directory of Open Access Journals (Sweden)

    Brooks Robert

    2004-04-01

    Full Text Available Abstract Background Variation in mate choice behaviour among females within a population may influence the strength and form of sexual selection, yet the basis for any such variation is still poorly understood. Condition-dependence may be an important source of variation in female sexual responsiveness and in the preference functions for male display traits that she expresses when choosing. We manipulated food intake of female guppies (Poecilia reticulata, and examined the effect on several measures of condition and various components of mate choice behaviour. Results Diet significantly influenced four measures of female condition: standard length, weight, reproductive status and somatic fat reserves. Diet also significantly affected female sexual responsiveness, but not preference functions: females in good and poor condition prefer the same males. Conclusions Variation in female condition within populations is therefore unlikely to influence the direction of sexual selection imposed by female choice. It may, however, influence the strength of sexual selection due to its effects on female responsiveness. The relative importance of female choice as a sexually selective force may also covary with female condition, however, because low responsiveness may result in sneak copulations being relatively more important as a determinant of the paternity of offspring. Differences among populations in mean condition may also influence geographic differences in the strength of sexual selection.

  1. Female preference and filial cannibalism in Aidablennius sphynx (Teleostei, Blenniidae); A combined field and laboratory study

    NARCIS (Netherlands)

    Kraak, SBM

    1996-01-01

    In the fish Aidablennius sphynx, in which males continuously care for up to 7000 eggs throughout the breeding season, females prefer to mate with males that already guard eggs, The present study shows that this preference appears to be adaptive because the probability of eggs being cannibalized decr

  2. FEMALE PREFERENCE FOR NESTS WITH EGGS IS BASED ON THE PRESENCE OF THE EGGS THEMSELVES

    NARCIS (Netherlands)

    KRAAK, SBM; GROOTHUIS, TGG; Kraak, Sarah B.M.; Groothuis, Ton G.G.

    1994-01-01

    In many fish species of which males care for eggs in a nest, including Aidablennius sphynx, females prefer to mate with males that already guard eggs. In this paper we present two aquarium experiments with this Mediterranean blenny to determine whether the females actually use the presence of eggs a

  3. Stimulus qualities of a preferred female partner and sexual behavior of old rhesus males.

    Science.gov (United States)

    Phoenix, C H; Jensen, J N; Chambers, K C

    1986-01-01

    A vaginal lavage from a preferred female sexual partner (donor) with whom old (21-27 yr) rhesus males readily copulated or a distilled water lavage was applied to the perineum of non-preferred females (N = 8) with whom old males rarely copulated. The donor and recipients were ovariectomized and were treated with estradiol benzoate (EB) before being tested. Sexual performance of the males did not differ under the two conditions of testing, but the rate of sexual solicitation by the females was significantly higher when treated with the vaginal lavage. One month later the non-preferred females were again treated with EB and paired with the old males. In these tests the preferred female was present in a cage adjacent to and in view of the test pairs. Sexual behavior was not altered significantly, but whereas these males had never threatened or aggressed their partners in previous tests, there was a significant increase in the rate at which they threatened their partners and aggression occurred for the first time. When paired with the preferred female, males ejaculated in 100% of the tests and the average ejaculation latency was less than 2.5 minutes. PMID:3823182

  4. Women's preference for masculine traits is disrupted by images of male-on-female aggression.

    Directory of Open Access Journals (Sweden)

    Yaoran Li

    Full Text Available Women's preferences for men's masculinized faces and voices were assessed after women (n = 331 were primed with images of male-on-male aggression, male-on-female aggression, pathogens, and neutral scenes. Male-on-male aggression and pathogen primes were associated with increased preference for masculine traits, but the same effect emerged in the neutral condition. We show the increased preference for masculine traits was due to repeated exposure to these traits, not the priming images themselves. Images of male-on-female aggression were an exception; these elicited feelings of disgust and anger appeared to disrupt the preference for masculinized traits. The results suggest women process men's facial and vocal traits as signals of aggressive potential and lose any preference for these traits with cues indicating men might direct this aggression toward them.

  5. Facial features and social attractiveness: preferences of Bosnian female students

    Directory of Open Access Journals (Sweden)

    Nina Bosankić

    2015-09-01

    Full Text Available This research aimed at testing multiple fitness hypothesis of attraction, investigating relationship between male facial characteristic and female students' reported readiness to engage in various social relations. A total of 27 male photos were evaluated on five dimensions on a seven-point Likert-type scale ranging from -3 to 3, by convenient sample of 90 female students of University of Sarajevo. The dimensions were: desirable to date – not desirable to date; desirable to marry – not desirable to marry; desirable to have sex with – not desirable to have sex with; desirable to be a friend – not desirable to be a friend; attractive - not attractive. Facial metric measurements of facial features such as distance between the eyes, smile width and height were performed using AutoCad. The results indicate that only smile width positively correlates with desirability of establishing friendship, whilst none of the other characteristics correlates with any of the other dimensions. This leads to the conclusion that motivation to establish various social relations cannot be reduced to mere physical appearance, mainly facial features, but many other variables yet to be investigated.

  6. Localizing brain regions associated with female mate preference behavior in a swordtail.

    Directory of Open Access Journals (Sweden)

    Ryan Y Wong

    Full Text Available Female mate choice behavior is a critical component of sexual selection, yet identifying the neural basis of this behavior is largely unresolved. Previous studies have implicated sensory processing and hypothalamic brain regions during female mate choice and there is a conserved network of brain regions (Social Behavior Network, SBN that underlies sexual behaviors. However, we are only beginning to understand the role this network has in pre-copulatory female mate choice. Using in situ hybridization, we identify brain regions associated with mate preference in female Xiphophorus nigrensis, a swordtail species with a female choice mating system. We measure gene expression in 10 brain regions (linked to sexual behavior, reward, sensory integration or other processes and find significant correlations between female preference behavior and gene expression in two telencephalic areas associated with reward, learning and multi-sensory processing (medial and lateral zones of the dorsal telencephalon as well as an SBN region traditionally associated with sexual response (preoptic area. Network analysis shows that these brain regions may also be important in mate preference and that correlated patterns of neuroserpin expression between regions co-vary with differential compositions of the mate choice environment. Our results expand the emerging network for female preference from one that focused on sensory processing and midbrain sexual response centers to a more complex coordination involving forebrain areas that integrate primary sensory processing and reward.

  7. Predator-induced changes of female mating preferences: innate and experiential effects

    Directory of Open Access Journals (Sweden)

    Indy Jeane

    2011-07-01

    Full Text Available Abstract Background In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana. Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators. Results In dichotomous choice tests predator-naïve (lab-reared females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus. In contrast, predator experienced (wild-caught females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey. Conclusions Our study highlights that (a predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection, and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators.

  8. Working Mothers and Sons' Preferences Regarding Female Labor: Direct Evidence From Stated Preferences

    OpenAIRE

    Daiji Kawaguchi; Junko Miyazaki

    2005-01-01

    The labor force participation rate of women in Japan has increased in recent decades. To shed light on the mechanism behind this increase, we focus on the explanation that Fernandez, Fogli and Olivetti (QJE (2004)) suggest. They claim that men who are raised by working mothers form a preference that is favorable toward working women and, consequently, they are more likely to have working wives. We test this hypothesis using the Japanese General Social Survey 2000-2002, which consists of repea...

  9. Resource security impacts men's female breast size preferences.

    Directory of Open Access Journals (Sweden)

    Viren Swami

    Full Text Available It has been suggested human female breast size may act as signal of fat reserves, which in turn indicates access to resources. Based on this perspective, two studies were conducted to test the hypothesis that men experiencing relative resource insecurity should perceive larger breast size as more physically attractive than men experiencing resource security. In Study 1, 266 men from three sites in Malaysia varying in relative socioeconomic status (high to low rated a series of animated figures varying in breast size for physical attractiveness. Results showed that men from the low socioeconomic context rated larger breasts as more attractive than did men from the medium socioeconomic context, who in turn perceived larger breasts as attractive than men from a high socioeconomic context. Study 2 compared the breast size judgements of 66 hungry versus 58 satiated men within the same environmental context in Britain. Results showed that hungry men rated larger breasts as significantly more attractive than satiated men. Taken together, these studies provide evidence that resource security impacts upon men's attractiveness ratings based on women's breast size.

  10. [Visually-guided discrimination and preference of sexuality in female macaque monkeys].

    Science.gov (United States)

    Mizuno, M

    1997-04-01

    Visual information about face and body including facial expression and bodily behavioral patterns has been known to play an important role in social and emotional communication in monkeys. Its involvement in sexual activity has also been demonstrated in male monkeys but it is poorly understood in female monkeys. In the present study, visually-guided discrimination and preference of sexuality were investigated in female macaque monkeys performing operant bar-press tasks in an experimental cage which had a transparent panel facing a display. In the sex discrimination task, two rhesus monkeys (Macaca mulatta) were trained to discriminate sex of a monkey shown in a picture which was randomly selected from six photographs (three males and three females) and was presented on the display. The monkey pressed a right or left bar for male or female monkey, respectively, to get water as a reward. Under this discrimination task, the monkeys could discriminate the sexes of monkeys shown in newly presented pictures. When choice bars were reversed, correct responses significantly decreased below chance level. In the sex preference task, three rhesus monkeys and three Japanese monkeys (M. juscata) were used. The monkeys voluntarily pressed the bar to watch the video movie showing either male or female rhesus monkeys. The movies were presented as long as the subject kept pressing the bar. The same movie was continued when the monkey pressed the bar again within 10s after the previous release of the bar, while it was changed to the other when 10s passed after the subject released the bar. The total duration of the responses in daily sessions was measured. In this visual preference task, four out of six monkeys showed sex preference. Three adult Japanese monkeys (6-8 y) pressed the bar to watch the video movie of male monkeys which was taken in breeding season with longer duration than that of female monkeys taken in the same season. The other two adult rhesus monkeys (7 8 y) did not

  11. Female mate preference explains countergradient variation in the sexual coloration of guppies (Poecilia reticulata).

    Science.gov (United States)

    Deere, Kerry A; Grether, Gregory F; Sun, Aida; Sinsheimer, Janet S

    2012-05-01

    We tested the hypothesis that mate choice is responsible for countergradient variation in the sexual coloration of Trinidadian guppies (Poecilia reticulata). The nature of the countergradient pattern is that geographical variation in the carotenoid content of the orange spots of males is counterbalanced by genetic variation in drosopterin production, resulting in a relatively uniform pigment ratio. A female hue preference could produce this pattern, because hue is the axis of colour variation most directly affected by the pigment ratio. To test this hypothesis, we crossed two populations differing in drosopterin production and produced an F(2) generation with variable drosopterin levels. When the carotenoid content of the orange spots was held constant, female guppies preferred males with intermediate drosopterin levels. This shows that females do not simply prefer males with greater orange spot pigment content; instead, the ratio of the pigments also affects male attractiveness. To our knowledge, this is the first direct evidence for a hypothesized agent of countergradient sexual selection.

  12. Piecing together female extra-pair mate choice: females really do prefer more ornamented males.

    Science.gov (United States)

    Wells, Sarah J; Safran, Rebecca J; Dale, James

    2016-08-01

    Evolutionary biologists have long been fascinated by extravagant male traits that abound across the animal kingdom and yet convey no apparent benefits to survival. From isopods to elephants, from armaments to ornaments, researchers have spent decades studying male-male competition and female mate choice in an effort to understand the significance of these secondary sexual characteristics. Among socially monogamous species, a frequently proposed explanation for the existence of male ornaments is that they are indicators of male genetic quality subject to female extra-pair mate choice. However, despite over two decades of extensive research into extra-pair paternity (EPP), the evidence that females actually choose more ornamented extra-pair sires is surprisingly scant. Consequently, whether EPP and female choice have contributed to the evolution of male ornaments in socially monogamous species, and what fitness benefits (if any) they signal to females, remains unclear. Progress in this field has been hampered by the challenge of dissociating clear female choice for ornamentation from confounding factors. In this issue of Molecular Ecology, Whittingham & Dunn (2016) use an experimental approach in a bird species with very high rates of EPP to tease apart these correlative effects. In doing so, they demonstrate clearly that male ornamentation is subject to female extra-pair mate choice. Their findings further suggest that EPP can be adaptive for females, and represent an important step forward in validating the role of EPP as an evolutionary driver of ornamental elaboration in socially monogamous species.

  13. Piecing together female extra-pair mate choice: females really do prefer more ornamented males.

    Science.gov (United States)

    Wells, Sarah J; Safran, Rebecca J; Dale, James

    2016-08-01

    Evolutionary biologists have long been fascinated by extravagant male traits that abound across the animal kingdom and yet convey no apparent benefits to survival. From isopods to elephants, from armaments to ornaments, researchers have spent decades studying male-male competition and female mate choice in an effort to understand the significance of these secondary sexual characteristics. Among socially monogamous species, a frequently proposed explanation for the existence of male ornaments is that they are indicators of male genetic quality subject to female extra-pair mate choice. However, despite over two decades of extensive research into extra-pair paternity (EPP), the evidence that females actually choose more ornamented extra-pair sires is surprisingly scant. Consequently, whether EPP and female choice have contributed to the evolution of male ornaments in socially monogamous species, and what fitness benefits (if any) they signal to females, remains unclear. Progress in this field has been hampered by the challenge of dissociating clear female choice for ornamentation from confounding factors. In this issue of Molecular Ecology, Whittingham & Dunn (2016) use an experimental approach in a bird species with very high rates of EPP to tease apart these correlative effects. In doing so, they demonstrate clearly that male ornamentation is subject to female extra-pair mate choice. Their findings further suggest that EPP can be adaptive for females, and represent an important step forward in validating the role of EPP as an evolutionary driver of ornamental elaboration in socially monogamous species. PMID:27463236

  14. Bigger Is Not Always Better: Females Prefer Males of Mean Body Size in Philautus odontotarsus

    Science.gov (United States)

    Zhu, Bicheng; Wang, Jichao; Zhao, Longhui; Sun, Zhixin; Brauth, Steven E.; Tang, Yezhong; Cui, Jianguo

    2016-01-01

    Most species are believed to evolve larger body sizes over evolutionary time. Previous studies have suggested that sexual selection, through male-male competition and female choice, favors larger males. However, there is little evidence of selection against large size. The female serrate-legged small treefrogs (Philautus odontotarsus) must carry passive males from leks to breeding grounds over relatively long distances after amplexus to find a suitable place to lay eggs. The costs of large male size may therefore decrease mating success due to reduced agility and/or higher energy requirements. Thus, we hypothesized that selection would not favor larger males in P. odontotarsus. Females can assess male body size on the basis of the dominant frequency of male calls in frogs. To assess female P. odontotarsus preferences for a potential mate’s body size, male calls of high, average and low dominant frequency were played back to the females in phonotaxis experiments. Results showed that most females prefer the advertisement call with average dominant frequency. In addition, we compared the body mass distribution of amplectant males with that of single males in nature. The body masses of amplectant males are more narrowly distributed in the intermediate range than that of single males. The phonotaxis results and the data of actual female preferences in the field show that females strongly prefer potential mates of mean body sizes, consistent with the view that, in this species at least, larger males are not always perceived as better by females. In the present study, P. odontotarsus provides an example of an amphibian species in which large size does not have an advantage in mating success for males. Instead, our results provide evidences that stabilizing selection favors the optimal intermediate size of males. PMID:26901766

  15. Sexual behavior of female rats in a multiple-partner preference test.

    Science.gov (United States)

    Ferreira-Nuño, A; Morales-Otal, A; Paredes, Raúl G; Velázquez-Moctezuma, J

    2005-03-01

    In this study, sexually experienced female rats were tested in a multiple-partner preference test (MPPT) in which they were allowed to pace their sexual contacts with four sexually active males. Four cylinders, with a small hole through which only the female could move freely from one cylinder to another, were assembled forming in the center an empty compartment. An intact female was placed in the central compartment and a sexually active male in each cylinder. Female sexual behavior was analyzed throughout the estrus cycle in four consecutive days. Each daily test lasted 15 min. The percentage of exits after intromission or ejaculation was significantly higher than the percentage of exits after each mount. The female spent significantly longer time with one of the males. We designated this male as the preferred male (PM). Although in each of the 4 days studied, females spent significantly longer time with the PM, however, the male selected was not the same throughout the estrus cycle. The number of entries into the compartment of the PM was significantly higher and increased around proestrus. Compared to previous studies, pacing behavior was notably lower in the conditions of the MPPT. No significant differences were observed during the estrous cycle concerning the other parameters recorded. The present results suggest that the MPPT could be a good model to study partner preference in the female rat. PMID:15708757

  16. Effects of vomeronasal organ removal on olfactory sex discrimination and odor preferences of female ferrets.

    Science.gov (United States)

    Woodley, S K; Cloe, A L; Waters, P; Baum, M J

    2004-10-01

    Previous research suggests that body odorants, including anal scents and urinary odors, contribute to sex discrimination and mate identification in European ferrets of both sexes. We assessed the possible role of the vomeronasal organ (VNO) in these functions by surgically removing the organ bilaterally in sexually experienced female ferrets. Lesioned (VNOx) and sham-operated control (VNOi) females reliably discriminated between male- and female-derived anal scent gland as well as fresh urinary odors in habituation/dishabituation tests. However, VNOi females spent significantly more time than VNOx subjects investigating male urinary odors in these tests. Also, VNOi females, but not VNOx subjects, preferred to investigate day-old male versus female urine spots as well as wooden blocks that had previously been soiled by male versus female ferrets. Both groups of female ferrets preferred to approach volatile odors from a breeding male instead of an estrous female in Y-maze tests and both groups showed similar levels of receptive sexual behavior in response to a male's neck grip. The VNO is apparently not required for olfactory sex discrimination or mate recognition in this carnivore, but instead may play a role in promoting continued contact with nonvolatile body odors previously deposited by opposite-sex conspecifics during territorial scent marking. PMID:15466811

  17. Variation in social relationships relates to song preferences and EGR1 expression in a female songbird.

    Science.gov (United States)

    Schubloom, Hannah E; Woolley, Sarah C

    2016-09-01

    Social experiences can profoundly shape social behavior and the underlying neural circuits. Across species, the formation of enduring social relationships is associated with both neural and behavioral changes. However, it remains unclear how longer-term relationships between individuals influence brain and behavior. Here, we investigated how variation in social relationships relates to variation in female preferences for and neural responses to song in a pair-bonding songbird. We assessed variation in the interactions between individuals in male-female zebra finch pairs and found that female preferences for their mate's song were correlated with the degree of affiliation and amount of socially modulated singing, but not with the frequency of aggressive interactions. Moreover, variation in measures of pair quality and preference correlated with variation in the song-induced expression of EGR1, an immediate early gene related to neural activity and plasticity, in brain regions important for auditory processing and social behavior. For example, females with weaker preferences for their mate's song had greater EGR1 expression in the nucleus Taeniae, the avian homologue of the mammalian medial amygdala, in response to playback of their mate's courtship song. Our data indicate that the quality of social interactions within pairs relates to variation in song preferences and neural responses to ethologically relevant stimuli and lend insight into neural circuits sensitive to social information. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1029-1040, 2016. PMID:26713856

  18. Effects of the menstrual cycle on looking preferences for faces in female rhesus monkeys.

    Science.gov (United States)

    Lacreuse, Agnès; Martin-Malivel, Julie; Lange, Henry S; Herndon, James G

    2007-04-01

    Fluctuations of ovarian hormones across the menstrual cycle influence a variety of social and cognitive behaviors in primates. For example, female rhesus monkeys exhibit heightened interest for males and increased agonistic interactions with other females during periods of high estrogen levels. In the present study, we hypothesized that females' preference for males during periods of high estrogen levels is also expressed at the level of face perception. We tested four intact females on two face-tasks involving neutral portraits of male and female rhesus monkeys, chimpanzees and humans. In the visual preference task (VP), monkeys had to touch a button to view a face image. The image remained on the screen as long as the button was touched, and the duration of pressing was taken as an index of the monkey's looking time for the face stimulus. In the Face-Delayed Recognition Span Test (Face-DRST), monkeys were rewarded for touching the new face in an increasing number of serially presented faces. Monkeys were tested 5 days a week across one menstrual cycle. Blood was collected every other day for analysis of estradiol and progesterone. Two of the four females were cycling at the time of testing. We did not find an influence of the cycle on Face-DRST, likely due to a floor effect. In the VP however, the two cycling individuals looked longer at conspecific male faces than female faces during the peri-ovulatory period of the cycle. Such effects were absent for human and chimpanzee faces and for the two noncycling subjects. These data suggest that ovarian hormones may influence females' preferences for specific faces, with heightened preference for male faces during the peri-ovulatory period of the cycle. Heightened interest for stimuli of significant reproductive relevance during periods of high conception risk may help guide social and sexual behavior in the rhesus monkey. PMID:16909232

  19. Mating changes the female dietary preference in the two-spotted cricket, Gryllus bimaculatus

    OpenAIRE

    ShinjiNagata

    2014-01-01

    Most insect species exhibit characteristic behavioral changes after mating. Typical post-mating behaviors in female insects include noticeable increases in food intake, elevated oviposition rates, lowered receptivity to courting males, and enhanced immune response. Although it has been reported that mated females of several insect species including the fruit fly, Drosophila melanogaster increase the amount of food intake and change their dietary preferences, the limited number of comparative ...

  20. Overt female mate competition and preference for central males in a lekking antelope.

    Science.gov (United States)

    Bro-Jørgensen, Jakob

    2002-07-01

    In mammals, there exists only scant evidence of female mate choice in species mating on arenas, so-called leks. This has led to hypotheses of lek evolution that are based on benefits to females from reduced harassment by males, low predation risk, or improved availability of scarce nutrients. Here I report that female topi antelopes (Damaliscus lunatus) compete aggressively for matings with preferred males on central lek territories. Females fight at higher rates and more likely disrupt mating attempts of others in the lek center than elsewhere. Contrary to the predictions of the alternative hypotheses, food resources were insignificant, and harassment levels and estimated predation risk were higher on than off lek. These results clearly demonstrate female competition for mates in a lekking mammal in which a female chooses between males for the sole purpose of mating. The finding suggests that the forces leading to lek evolution in mammals and birds may be more similar than previously acknowledged.

  1. Females of the lekking great snipe do not prefer males with whiter tails.

    Science.gov (United States)

    Saether; Fiske; Kålås; Gjul

    2000-02-01

    A previous experimental study of great snipe, Gallinago media, has reported an effect on male mating success of the amount of white in their tails. That result is one of a very limited set of existing experimental results supporting a female mate preference for a morphological trait in animals. However, a later observational study did not find any correlation between amount of white and male mating success. If females sample a limited number of males, their preferences need not result in strong relationships between mating success and trait values in males, possibly explaining the failure to find the predicted correlation. Yet, females of lekking species are thought to have ample opportunities for mate sampling. To resolve these contrasting results, we present in this paper (1) a larger correlational study (several leks during 10 years) showing no relationship between male mating success and whiteness of tails (measured in several ways), and most importantly (2) evidence that individual females do not mate predominantly with males with very white tails among those males that each female samples. These results show that females do not prefer males with whiter tails as mates, within the contemporary natural variation in the trait. They also show that there is no sexual selection of the trait at present. This does not necessarily imply that white tails are not a sexually selected adaptation in males, but the mechanisms are likely to have been different from direct mate choice of whiter tails per se. Copyright 2000 The Association for the Study of Animal Behaviour.

  2. Males choose to keep their heads: Preference for lower risk females in a praying mantid.

    Science.gov (United States)

    Avigliano, Esteban; Scardamaglia, Romina C; Gabelli, Fabián M; Pompilio, Lorena

    2016-08-01

    Male reproductive success is obviously mate limited, which implies that males should rarely be choosy. One extreme case of a reproductive (or mating) cost is sexual cannibalism. Recent research has proposed that male mantids (Parastagmatoptera tessellata) are choosy and not complicit in cannibalism and that they modify behavior towards females based on the risk imposed by them. Since female cannibalism depends on females' energetic state (i.e. hunger) we investigated whether male mantids are capable of using environmental cues that provide information regarding the energetic state of females to make their mate choices. Under laboratory conditions, males were confronted individually with three options: a female eating a prey, a female without a prey, and a male eating a prey (as a control for the presence of prey). Each subject comprising a choice was harnessed and placed in the corners of a triangular experimental arena at an equidistant distance from the focal male. The prey was a middle size cricket that subjects ate in approximately twenty minutes. The behavior of focal males was recorded for six hours. Females were under the same deprivation regime and, in line with previous studies, consuming one cricket did not significantly increase females' abdomen girth. Male mantids significantly preferred females that were eating a prey. In all cases choices were made after the females consumed the whole prey. This suggests that males did not use the prey as a direct way to avoid being cannibalized by keeping the female busy. The preference for females that had recently fed may have evolved because of the potential reduction in sexual cannibalism. PMID:27298235

  3. Female preferences for spectral call properties in the western genetic lineage of Cope’s gray treefrog (Hyla chrysoscelis)

    OpenAIRE

    Schrode, Katrina M.; Ward, Jessica L; Vélez, Alejandro; Bee, Mark A.

    2012-01-01

    Female frogs discriminate among potential mates based on individual variation in male advertisement calls. While considerable data have accumulated allowing comparisons of female preference functions among species, we still lack fundamental knowledge about how and why the shapes of preference functions for particular call properties vary among populations within all but a few species. Here, we report results from a study aimed at describing female preference functions for spectral call proper...

  4. Multiple mating reveals complex patterns of assortative mating by personality and body size.

    Science.gov (United States)

    Montiglio, Pierre-Olivier; Wey, Tina W; Chang, Ann T; Fogarty, Sean; Sih, Andrew

    2016-01-01

    Understanding patterns of non-random mating is central to predicting the consequences of sexual selection. Most studies quantifying assortative mating focus on testing for correlations among partners' phenotypes in mated pairs. Few studies have distinguished between assortative mating arising from preferences for similar partners (expressed by all or a subset of the population) vs. from phenotypic segregation in the environment. Also, few studies have assessed the robustness of assortative mating against temporal changes in social conditions. We tracked multiple matings by stream water striders (Aquarius remigis) across variable social conditions to investigate mating patterns by both body size and behavioural type (personality). We documented temporal changes in partner availability and used a mixed model approach to analyse individual behaviours and changes in mating status recorded on an hourly basis. We assessed whether all or only a subset of individuals in the population expressed a tendency to mate with similar phenotypes. Our analyses took into account variation in the level of competition and in the phenotypes of available partners. Males and females exhibited significant assortative mating by body size: the largest males and females, and the smallest males and females mated together more often than random. However, individuals of intermediate size were equally likely to mate with small, intermediate or large partners. Individuals also displayed two contrasting patterns of assortative mating by personality (activity level). Individuals generally mated preferentially with partners of similar activity level. However, beyond that general trend, individuals with more extreme personalities tended to exhibit disassortative mating: the most active males mated disproportionately with less active females and the least active males tended to mate with more active females. Our analyses thus revealed multiple, distinct patterns of nonrandom mating. These mating

  5. Evidence for a receiver bias underlying female preference for a male mating pheromone in sea lamprey

    Science.gov (United States)

    Buchinger, Tyler J.; Wang, Huiyong; Li, Weiming; Johnson, Nicholas S.

    2013-01-01

    Receiver bias models suggest that a male sexual signal became exaggerated to match a pre-existing sensory, perceptual or cognitive disposition of the female. Accordingly, these models predict that females of related taxa possessing the ancestral state of signalling evolved preference for the male trait in a non-sexual context. We postulated that female preference for the male-released bile alcohol mating pheromone, 3 keto petromyzonol sulfate (3kPZS), of the sea lamprey (Petromyzon marinus) evolved as a result of a receiver bias. In particular, we propose that migratory silver lamprey (Ichthyomyzon unicuspis), a basal member of the Petromyzontidae, evolved a preference for 3kPZS released by stream-resident larvae as a means of identifying productive habitat for offspring. Larval silver lamprey released 3kPZS at rates sufficient to be detected by migratory lampreys. Females responded to 3kPZS by exhibiting upstream movement behaviours relevant in a migratory context, but did not exhibit proximate behaviours important to mate search and spawning. Male silver lamprey did not release 3kPZS at rates sufficient to be detected by females in natural high-volume stream environments. We infer that female silver lamprey cue onto 3kPZS excreted by stream-resident larvae as a mechanism to locate habitat conducive to offspring survival and that males do not signal with 3kPZS. We suggest that this female preference for a male signal in a non-sexual context represents a bias leading to the sexual signalling observed in sea lamprey.

  6. Preference for Graphic Horror Featuring Male versus Female Victimization: Personality and Past Film Viewing Experiences.

    Science.gov (United States)

    Tamborini, Ron; And Others

    1987-01-01

    Investigates the relationship of personality and past film viewing experiences to preferences for different degrees of graphic horror in film, and for female versus male victimization. Finds that the Machiavellian trait of deceit, past exposure to horror films, and, for male subjects only, the enjoyment of pornography were good predictors. (SR)

  7. Elite Female Business Students in China and Norway: Job-Related Values and Preferences

    Science.gov (United States)

    Nordhaug, Odd; Gooderham, Paul; Zhang, Xian; Liu, Yali; Birkelund, Gunn Elisabeth

    2010-01-01

    The focus of this paper is on the work-related values, preferences, and future expectations among female students at two elite business schools in China and Norway. The paper argues that while gender theory predicts no significant differences between these two groups, both cultural and economic development theory imply fundamental differences. The…

  8. Male Drosophila melanogaster learn to prefer an arbitrary trait associated with female mating status

    DEFF Research Database (Denmark)

    Verzijden, Machteld Nicolette; Abbott, Jessica K.; Philipsborn, Anne von;

    2015-01-01

    are able to learn to associate olfactory and gustatory cues with female receptivity, but the role of more arbitrary, visual cues in mate choice learning has been overlooked to date in this species. We therefore carried out a series of experiments to determine: 1) whether males had a baseline preference...... system for mate choice learning...

  9. Fatal attraction: Male spider mites prefer females killed by the mite-pathogenic fungus Neozygites floridana.

    Science.gov (United States)

    Trandem, Nina; Bhattarai, Upendra Raj; Westrum, Karin; Knudsen, Geir Kjølberg; Klingen, Ingeborg

    2015-06-01

    Exploring prospective mates can be risky. Males of the spider mite Tetranychus urticae approach and guard immobile (quiescent) female nymphs to increase their chances of fathering offspring, this being a first-male sperm priority species. We investigated the behaviour of male T. urticae towards females killed by the mite pathogenic fungus Neozygites floridana, letting them choose between a fungal killed and a healthy quiescent female. The dead female (called cadaver) was in one of three stages: (1) non-sporulating; (2) sporulating with primary conidia (non-infective); (3) surrounded/partly covered by secondary capilliconidia (infective). When the cadaver was in stage 1 or 2, males were significantly more often observed near the cadaver than near the healthy female. When the cadaver was in stage 3 (infective capilliconidia), males preferred the vicinity of healthy females. The frequency of two male behaviours, touching and guarding, was also recorded. Touching the cadaver tended to decrease as cadaver developed, whereas touching the healthy females increased. Guarding of non-sporulating cadavers and healthy females was equally common, while guarding of sporulating cadavers was only observed once (stage 2) or not at all (stage 3). To differentiate between the effect of fungal infection and sex, we also let males choose between a non-sporulating cadaver of each sex. Males then preferred to approach the female cadaver. Touching behaviour followed the same pattern, and guarding of male cadavers was not observed. Our results indicate that T. urticae males are more attracted to non-infective female cadavers than to healthy females, only detecting their mistake when very close. Moreover, males approach and explore cadavers surrounded by infective conidia. Whether the results of host manipulation by the pathogen or just sensory constraints in the host, this inability to detect unsuitable and indeed infective mates promotes transmission of the pathogen.

  10. Direct selection on male attractiveness and female preference fails to produce a response

    Directory of Open Access Journals (Sweden)

    Brooks Robert

    2004-01-01

    Full Text Available Abstract Background Theoretical studies suggest that direct and indirect selection have the potential to cause substantial evolutionary change in female mate choice. Similarly, sexual selection is considered a strong force in the evolution of male attractiveness and the exaggeration of secondary sexual traits. Few studies have, however, directly tested how female mate choice and male attractiveness respond to selection. Here we report the results of a selection experiment in which we selected directly on female mating preference for attractive males and, independently, on male attractiveness in the guppy, Poecilia reticulata. We measured the direct and correlated responses of female mate choice and male attractiveness to selection and the correlated responses of male ornamental traits, female fecundity and adult male and female survival. Results Surprisingly, neither female mate choice nor male attractiveness responded significantly to direct or to indirect selection. Fecundity did differ significantly among lines in a way that suggests a possible sexually-antagonistic cost to male attractiveness. Conclusions The opportunity for evolutionary change in female mate choice and male attractiveness may be much smaller than predicted by current theory, and may thus have important consequences for how we understand the evolution of female mate choice and male attractiveness. We discuss a number of factors that may have constrained the response of female choice and male attractiveness to selection, including low heritabilities, low levels of genetic (covariation in the multivariate direction of selection, sexually-antagonistic constraint on sexual selection and the "environmental covariance hypothesis".

  11. Variation in sexual dimorphism and assortative mating do not predict genetic divergence in the sexually dimorphic Goodeid fish Girardinichthys multiradiatus

    Institute of Scientific and Technical Information of China (English)

    C.MAC(I)AS GARCIA; G SMITH; C.GONZ(A)LEZ ZUARTH; J.A.GRAVES; M.G.RITCHIE

    2012-01-01

    Sexual dimorphism is often used as a proxy for the intensity of sexual selection in comparative studies of sexual selection and diversification.The Mexican Goodeinae are a group of livebearing freshwater fishes with large variation between species in sexual dimorphism in body shape.Previously we found an association between variation in morphological sexual dimorphism between species and the amount of gene flow within populations in the Goodeinae.Here we have examined if morphological differentiation within a single dimorphic species is related to assortative mating or gene flow between populations.In the Amarillo fish Girardinichthys multiradiatus studies have shown that exaggerated male fins are targets of female preferences.We find that populations of the species differ in the level of sexual dimorphism displayed due to faster evolution of differences in male than female morphology.However,this does not predict variation in assortative mating tests in the laboratory; in fact differences in male morphology are negatively correlated with assortative mating.Microsatellite markers reveal significant genetic differences between populations.However,gene flow is not predicted by either morphological differences or assortative mating.Rather,it demonstrates a pattern of isolation by distance with greater differentiation between watersheds.We discuss the caveats of predicting behavioural and genetic divergence from so-called proxies of sexual selection.

  12. Variation in sexual dimorphism and assortative mating do not predict genetic divergence in the sexually dimorphic Goodeid fish Girardinichthys multiradiatus

    Directory of Open Access Journals (Sweden)

    C.MACÍAS GARCIA, G.SMITH, C.GONZÁLEZ ZUARTH, J.A. GRAVES,M.G.RITCHIE

    2012-06-01

    Full Text Available Sexual dimorphism is often used as a proxy for the intensity of sexual selection in comparative studies of sexual selection and diversification. The Mexican Goodeinae are a group of livebearing freshwater fishes with large variation between species in sexual dimorphism in body shape. Previously we found an association between variation in morphological sexual dimorphism between species and the amount of gene flow within populations in the Goodeinae. Here we have examined if morphological differentiation within a single dimorphic species is related to assortative mating or gene flow between populations. In the Amarillo fish Girardinichthys multiradiatus studies have shown that exaggerated male fins are targets of female preferences. We find that populations of the species differ in the level of sexual dimorphism displayed due to faster evolution of differences in male than female morphology. However, this does not predict variation in assortative mating tests in the laboratory; in fact differences in male morphology are negatively correlated with assortative mating. Microsatellite markers reveal significant genetic differences between populations. However, gene flow is not predicted by either morphological differences or assortative mating. Rather, it demonstrates a pattern of isolation by distance with greater differentiation between watersheds. We discuss the caveats of predicting behavioural and genetic divergence from so-called proxies of sexual selection [Current Zoology 58 (3: 437-449, 2012].

  13. Mating changes the female dietary preference in the two-spotted cricket, Gryllus bimaculatus

    Directory of Open Access Journals (Sweden)

    Yusuke eTsukamoto

    2014-03-01

    Full Text Available Most insect species exhibit characteristic behavioral changes after mating. Typical post-mating behaviors in female insects include noticeable increases in food intake, elevated oviposition rates, lowered receptivity to courting males, and enhanced immune response. Although it has been reported that mated females of several insect species including the fruit fly, Drosophila melanogaster increase the amount of food intake and change their dietary preferences, the limited number of comparative studies prevent the formulation of generalities regarding post-mating behaviors in other insects in particular amongst orthopteran species. Here, we investigated whether females of the two-spotted cricket, Gryllus bimaculatus, alter their feeding behavior after mating. Although significant differences in the amount of food intake after mating were not observed, all experimental data indicated a clear trend among crickets towards the ingestion of larger quantities of food. Geometric framework analyses revealed that the mated female crickets preferred food with higher protein content compared to virgin female crickets. This implies that this species required different nutritional demands after mating. These findings further expand our understanding of the behavioral and biological changes that are triggered in female insects post-mating, and highlight the potential for this species in investigating the molecular-based nutritional dependent activities that are linked to post-mating behaviors.

  14. Subadult experience influences adult mate choice in an arthropod: Exposed female wolf spiders prefer males of a familiar phenotype

    OpenAIRE

    Hebets, Eileen A.

    2003-01-01

    Current sexual selection theory proposes several potential mechanisms driving the evolution of female mating preferences, few of which involve social interactions. Although vertebrate examples of socially influenced mating preferences do exist, the invertebrate examples are virtually nonexistent. Here I demonstrate that the mating preferences of female wolf spiders can be acquired through exposure as subadults to unrelated, sexually active adult males. I first conducted exposure trials during...

  15. Outcome and preferences in female-to-male subjects with gender dysphoria: Experience from Eastern India

    OpenAIRE

    Anirban Majumder; Debmalya Sanyal

    2016-01-01

    Context: Awareness of gender dysphoria (GD) and its treatment is increasing. There is paucity of scientific data from India regarding the therapeutic options being used for alleviating GD, which includes psychotherapy, hormone, and surgical treatments. Aim: To study the therapeutic options including psychotherapy, hormone, and surgical treatments used for alleviating GD. Settings and Design: This is a retrospective study of treatment preferences and outcome in 18 female-to-male (FTM) transgen...

  16. Male Syrian Hamsters Demonstrate a Conditioned Place Preference for Sexual Behavior and Female Chemosensory Stimuli

    OpenAIRE

    Bell, Margaret R.; Meerts, Sarah H.; Sisk, Cheryl L.

    2010-01-01

    Sexual behavior is a natural reward for many rodent species, and it often includes chemosensory-directed components. Chemosensory stimuli themselves may also be rewarding. Conditioned place preference (CPP) is one paradigm frequently used to test the rewarding properties of a range of stimuli. Males and females of several rodent species show a CPP for sexual behavior, however, it is currently unknown whether sexual behavior can induce a CPP in male Syrian hamsters. As male Syrian hamsters are...

  17. Patterns of coping preferences for male and female caregivers of frail older adults.

    Science.gov (United States)

    DeVries, H M; Hamilton, D W; Lovett, S; Gallagher-Thompson, D

    1997-06-01

    The similarities and differences in male and female caregivers' preferred strategies for coping and the perceived helpfulness of these strategies in managing caregiving stressors were examined in this study. Respondents were 170 caregivers (139 women and 31 men) who were primary caregivers for an elderly adult relative who was either cognitively impaired or physically frail. Results provide preliminary evidence that gender is related to frequency of use but not to the perceived helpfulness of specific coping strategies. PMID:9189986

  18. Evolution of assortative mating in a population expressing dominance.

    Directory of Open Access Journals (Sweden)

    Kristan A Schneider

    Full Text Available In this article, we study the influence of dominance on the evolution of assortative mating. We perform a population-genetic analysis of a two-locus two-allele model. We consider a quantitative trait that is under a mixture of frequency-independent stabilizing selection and density- and frequency-dependent selection caused by intraspecific competition for a continuum of resources. The trait is determined by a single (ecological locus and expresses intermediate dominance. The second (modifier locus determines the degree of assortative mating, which is expressed in females only. Assortative mating is based on similarities in the quantitative trait ('magic trait' model. Analytical conditions for the invasion of assortment modifiers are derived in the limit of weak selection and weak assortment. For the full model, extensive numerical iterations are performed to study the global dynamics. This allows us to gain a better understanding of the interaction of the different selective forces. Remarkably, depending on the size of modifier effects, dominance can have different effects on the evolution of assortment. We show that dominance hinders the evolution of assortment if modifier effects are small, but promotes it if modifier effects are large. These findings differ from those in previous work based on adaptive dynamics.

  19. Male mice song syntax depends on social contexts and influences female preferences.

    Science.gov (United States)

    Chabout, Jonathan; Sarkar, Abhra; Dunson, David B; Jarvis, Erich D

    2015-01-01

    In 2005, Holy and Guo advanced the idea that male mice produce ultrasonic vocalizations (USV) with some features similar to courtship songs of songbirds. Since then, studies showed that male mice emit USV songs in different contexts (sexual and other) and possess a multisyllabic repertoire. Debate still exists for and against plasticity in their vocalizations. But the use of a multisyllabic repertoire can increase potential flexibility and information, in how elements are organized and recombined, namely syntax. In many bird species, modulating song syntax has ethological relevance for sexual behavior and mate preferences. In this study we exposed adult male mice to different social contexts and developed a new approach of analyzing their USVs based on songbird syntax analysis. We found that male mice modify their syntax, including specific sequences, length of sequence, repertoire composition, and spectral features, according to stimulus and social context. Males emit longer and simpler syllables and sequences when singing to females, but more complex syllables and sequences in response to fresh female urine. Playback experiments show that the females prefer the complex songs over the simpler ones. We propose the complex songs are to lure females in, whereas the directed simpler sequences are used for direct courtship. These results suggest that although mice have a much more limited ability of song modification, they could still be used as animal models for understanding some vocal communication features that songbirds are used for.

  20. Evolution of novel signal traits in the absence of female preferences in Neoconocephalus katydids (Orthoptera, Tettigoniidae.

    Directory of Open Access Journals (Sweden)

    Sarah L Bush

    Full Text Available UNLABELLED: BACKGROUND SIGNIFICANCE: Communication signals that function to bring together the sexes are important for maintaining reproductive isolation in many taxa. Changes in male calls are often attributed to sexual selection, in which female preferences initiate signal divergence. Natural selection can also influence signal traits if calls attract predators or parasitoids, or if calling is energetically costly. Neutral evolution is often neglected in the context of acoustic communication. METHODOLOGY/PRINCIPAL FINDINGS: We describe a signal trait that appears to have evolved in the absence of either sexual or natural selection. In the katydid genus Neoconocephalus, calls with a derived pattern in which pulses are grouped into pairs have evolved five times independently. We have previously shown that in three of these species, females require the double pulse pattern for call recognition, and hence the recognition system of the females is also in a derived state. Here we describe the remaining two species and find that although males produce the derived call pattern, females use the ancestral recognition mechanism in which no pulse pattern is required. Females respond equally well to the single and double pulse calls, indicating that the derived trait is selectively neutral in the context of mate recognition. CONCLUSIONS/SIGNIFICANCE: These results suggest that 1 neutral changes in signal traits could be important in the diversification of communication systems, and 2 males rather than females may be responsible for initiating signal divergence.

  1. Chromosome assortment in Saccharum.

    Science.gov (United States)

    Al-Janabi, S M; Honeycutt, R J; Sobral, B W

    1994-12-01

    Recent work has revealed random chromosome pairing and assortment in Saccharum spontaneum L., the most widely distributed, and morphologically and cytologically variable of the species of Saccharum. This conclusion was based on the analysis of a segregating population from across between S. spontaneum 'SES 208' and a spontaneously-doubled haploid of itself, derived from anther culture. To determine whether polysomic inheritance is common in Saccharum and whether it is observed in a typical biparental cross, we studied chromosome pairing and assortment in 44 progeny of a cross between euploid, meiotically regular, 2n=80 forms of Saccharum officinarum 'LA Purple' and Saccharum robustum ' Mol 5829'. Papuan 2n=80 forms of S. robustum have been suggested as the immediate progenitor species for cultivated sugarcane (S. officinarum). A total of 738 loci in LA Purple and 720 loci in Mol 5829 were amplified and typed in the progeny by arbitrarily primed PCR using 45 primers. Fifty and 33 single-dose polymorphisms were identified in the S. officinarum and S. robustum genomes, respectively (χ 2 at 98%). Linkage analysis of single-dose polymorphisms in both genomes revealed linkages in repulsion and coupling phases. In the S. officinarum genome, a map hypothesis gave 7 linkage groups with 17 linked and 33 unlinked markers. Four of 13 pairwise linkages were in repulsion phase and 9 were in coupling phase. In the S. robustum genome, a map hypothesis gave 5 linkage groups, defined by 12 markers, with 21 markers unlinked, and 2 of 9 pairwise linkages were in repulsion phase. Therefore, complete polysomic inheritance was not observed in either species, suggesting that chromosomal behavior is different from that observed by linkage analysis of over 500 markers in the S. spontaneum map. Implications of this finding for evolution and breeding are discussed.

  2. Asymmetry in cricket song: female preference and proximate mechanism of discrimination.

    Science.gov (United States)

    Hirtenlehner, Stefan; Küng, Saskia; Kainz, Franz; Römer, Heiner

    2013-06-01

    Subtle random deviations from perfect symmetry in bilateral traits are suggested to signal reduced phenotypic and genetic quality of a sender, but little is known about the related receiver mechanisms for discriminating symmetrical from asymmetrical traits. Here, we investigated these mechanisms in behavioural and neurophysiological experiments in the Mediterranean field cricket, Gryllus bimaculatus. A downward frequency modulation at the end of each syllable in the calling song has been suggested to indicate morphological asymmetry in sound radiating structures between left and right forewings. Even under ideal laboratory conditions on a trackball system, female crickets only discriminated between songs of symmetrical and asymmetrical males in two-choice experiments at carrier frequencies of 4.4 kHz and a large modulation depth of 600 and 800 Hz. Under these conditions they preferred the pure-tone calling songs over the modulated (asymmetrical) alternative, whereas no preference was observed at carrier frequencies of 4.9 and 5.2 kHz. These preferences correlate well with the responses of a pair of identified auditory interneurons (AN1), known for their importance in female phonotaxis. The AN1 interneuron is tuned to an average frequency of 4.9 kHz, and the roll-off towards lower and higher frequencies determines the magnitude of responses to pure-tone and frequency-modulated calling songs. The difference in response magnitude between the two neurons appears to drive the decision of females towards the song alternatives. We discuss the relevance of song differences based on asymmetry in the morphology of song-producing structures under natural conditions.

  3. Male Drosophila melanogaster learn to prefer an arbitrary trait associated with female mating status

    DEFF Research Database (Denmark)

    Verzijden, Machteld Nicolette; Abbott, Jessica K.; Philipsborn, Anne von;

    2015-01-01

    are able to learn to associate olfactory and gustatory cues with female receptivity, but the role of more arbitrary, visual cues in mate choice learning has been overlooked to date in this species. We therefore carried out a series of experiments to determine: 1) whether males had a baseline preference...... of the experiment was carried out in darkness.This is, to our knowledge 1) the first evidence that male D. melanogaster can use more arbitrary cues and 2) the first evidence that males use visual cues during mate choice learning. Our findings suggest that that D. melanogaster has untapped potential as a model...... system for mate choice learning...

  4. Reconsidering the heritability of intelligence in adulthood: taking assortative mating and cultural transmission into account.

    Science.gov (United States)

    Vinkhuyzen, Anna A E; van der Sluis, Sophie; Maes, Hermine H M; Posthuma, Danielle

    2012-03-01

    Heritability estimates of general intelligence in adulthood generally range from 75 to 85%, with all heritability due to additive genetic influences, while genetic dominance and shared environmental factors are absent, or too small to be detected. These estimates are derived from studies based on the classical twin design and are based on the assumption of random mating. Yet, considerable positive assortative mating has been reported for general intelligence. Unmodeled assortative mating may lead to biased estimates of the relative magnitude of genetic and environmental factors. To investigate the effects of assortative mating on the estimates of the variance components of intelligence, we employed an extended twin-family design. Psychometric IQ data were available for adult monozygotic and dizygotic twins, their siblings, the partners of the twins and siblings, and either the parents or the adult offspring of the twins and siblings (N = 1314). Two underlying processes of assortment were considered: phenotypic assortment and social homogamy. The phenotypic assortment model was slightly preferred over the social homogamy model, suggesting that assortment for intelligence is mostly due to a selection of mates on similarity in intelligence. Under the preferred phenotypic assortment model, the variance of intelligence in adulthood was not only due to non-shared environmental (18%) and additive genetic factors (44%) but also to non-additive genetic factors (27%) and phenotypic assortment (11%).This non-additive nature of genetic influences on intelligence needs to be accommodated in future GWAS studies for intelligence.

  5. Male foraging efficiency, but not male problem-solving performance, influences female mating preferences in zebra finches.

    Science.gov (United States)

    Chantal, Véronique; Gibelli, Julie; Dubois, Frédérique

    2016-01-01

    Experimental evidence suggests that females would prefer males with better cognitive abilities as mates. However, little is known about the traits reflecting enhanced cognitive skills on which females might base their mate-choice decisions. In particular, it has been suggested that male foraging performance could be used as an indicator of cognitive capacity, but convincing evidence for this hypothesis is still lacking. In the present study, we investigated whether female zebra finches (Taeniopygia guttata) modify their mating preferences after having observed the performance of males on a problem-solving task. Specifically, we measured the females' preferences between two males once before and once after an observation period, during which their initially preferred male was incapable of solving the task contrary to their initially less-preferred male. We also conducted a control treatment to test whether the shift in female preferences was attributable to differences between the two stimulus males in their foraging efficiency. Finally, we assessed each bird's performance in a color associative task to check whether females can discriminate among males based on their learning speed. We found that females significantly increased their preference toward the most efficient male in both treatments. Yet, there was no difference between the two treatments and we found no evidence that females assess male cognitive ability indirectly via morphological traits. Thus, our results suggest that females would not use the males' problem-solving performance as an indicator of general cognitive ability to gain indirect fitness benefits (i.e., good genes) but rather to assess their foraging efficiency and gain direct benefits.

  6. Female house sparrows "count on" male genes: experimental evidence for MHC-dependent mate preference in birds

    Directory of Open Access Journals (Sweden)

    Biard Clotilde

    2011-02-01

    Full Text Available Abstract Background Females can potentially assess the quality of potential mates using their secondary sexual traits, and obtain "good genes" that increase offspring fitness. Another potential indirect benefit from mating preferences is genetic compatibility, which does not require extravagant or viability indicator traits. Several studies with mammals and fish indicate that the genes of the major histocompatibility complex (MHC influence olfactory cues and mating preferences, and such preferences confer genetic benefits to offspring. We investigated whether individual MHC diversity (class I influences mating preferences in house sparrows (Passer domesticus. Results Overall, we found no evidence that females preferred males with high individual MHC diversity. Yet, when we considered individual MHC allelic diversity of the females, we found that females with a low number of alleles were most attracted to males carrying a high number of MHC alleles, which might reflect a mating-up preference by allele counting. Conclusions This is the first experimental evidence for MHC-dependent mating preferences in an avian species to our knowledge. Our findings raise questions about the underlying mechanisms through which birds discriminate individual MHC diversity among conspecifics, and they suggest a novel mechanism through which mating preferences might promote the evolution of MHC polymorphisms and generate positive selection for duplicated MHC loci.

  7. Bilateral coordination and the motor basis of female preference for sexual signals in canary song.

    Science.gov (United States)

    Suthers, Roderick A; Vallet, Eric; Kreutzer, Michel

    2012-09-01

    The preference of female songbirds for particular traits in the songs of courting males has received considerable attention, but the relationship of preferred traits to male quality is poorly understood. Female domestic canaries (Serinus canaria, Linnaeus) preferentially solicit copulation with males that sing special high repetition rate, wide-band, multi-note syllables, called 'sexy' or A-syllables. Syllables are separated by minibreaths but each note is produced by pulsatile expiration, allowing high repetition rates and long duration phrases. The wide bandwidth is achieved by including two notes produced sequentially on opposite sides of the syrinx, in which the left and right sides are specialized for low or high frequencies, respectively. The emphasis of low frequencies is facilitated by a positive relationship between syllable repetition rate and the bandwidth of the fundamental frequency of notes sung by the left syrinx, such that bandwidth increases with increasing syllable repetition rate. The temporal offset between notes prevents cheating by unilaterally singing a note on the left side with a low fundamental frequency and prominent higher harmonics. The syringeal and respiratory motor patterns by which sexy syllables are produced support the hypothesis that these syllables provide a sensitive vocal-auditory indicator of a male's performance limit for the rapid, precisely coordinated interhemispheric switching, which is essential for many sensory and motor processes involving specialized contributions from each cerebral hemisphere. PMID:22875764

  8. Sexual experience modulates partner preference and mPOA nitric oxide synthase in female rats.

    Science.gov (United States)

    Meerts, Sarah H; Park, Jin Hong; Sekhawat, Ria

    2016-10-01

    Sexually experienced female rats return to the male more quickly after intromissions, exhibit shorter interintromission intervals, and spend more time with the male rat during a test of paced mating behavior in comparison to naïve rats. The present study tested whether these changes reflect heightened sexual motivation independent of receipt of vaginocervical stimulation and/or neurochemical changes in the medial preoptic area (mPOA). Ovariectomized, female rats were given estradiol benzoate and progesterone, and then received either 6 paced mating encounters (experienced) or 6 control exposures to an empty paced mating arena (naïve). Experienced and naïve rats received a no-contact partner preference test under oil vehicle and then under hormone on a different day. Hormonal status and sexual experience led to significantly higher preference for the male. Brains were collected 1 hr after both experienced and naïve rats received paced mating to compare mPOA levels of Fos, a marker of neural activity, in response to copulation and nitric oxide synthase (NOS), the enzyme responsible for production of nitric oxide (NO). Expression of NOS was higher in experienced relative to naïve rats, whereas Fos was comparable between the groups. The data are consistent with the idea that both sexual motivation and changes to the mPOA contribute to the shift in paced mating behavior induced by sexual experience. (PsycINFO Database Record PMID:27657310

  9. Implicit out-group preference is associated with eating disorders symptoms amongst Emirati females.

    Science.gov (United States)

    Thomas, Justin; Quadflieg, Susanne; O'Hara, Lily

    2016-04-01

    Studies exploring the relationship between acculturation and eating disorders symptoms have proven equivocal. Socially desirable responding associated with the use of explicit measures may account for these mixed findings. This study explores the relationship between in-group identity, acculturation and eating disorders symptoms using both implicit and explicit assessments. Emirati female college students (N=94) completed an affective priming task (APT) designed to implicitly assess Emirati in-group evaluations. Participants also completed explicit measures, including the Westernization Survey and the Multicomponent In-group Identification Scale. Eating disorders symptoms were assessed using the Eating Attitudes Test. Only implicit in-group evaluations were correlated with eating disorders symptoms. Specifically, increases in in-group preference were associated with lower levels of eating disorders symptomatology. Furthermore, participants with an actual out-group preference had significantly higher levels of eating disorders symptomatology compared with those demonstrating an in-group preference. These findings support the acculturative stress hypothesis, and suggest that the relationship between eating disorders and acculturation may be better understood with reference to implicit rather than explicit in-group evaluations. PMID:26741259

  10. Product Assortment in a Triopoly

    OpenAIRE

    Steven M. Shugan

    1989-01-01

    Producers of super-premium ice cream, such as Häagen-Dazs, offer a smaller assortment of flavors than the producers of lesser quality ice cream. Examples of this phenomenon can be found in other industries as well. In many industries, the producers of higher-quality products offer a smaller assortment of flavors, colors, sizes, patterns, textures, fragrances, tones, styles, models, designs, types or other options. This paper explores when and why producers of super-premium products should fin...

  11. Outcome and preferences in female-to-male subjects with gender dysphoria: Experience from Eastern India

    Directory of Open Access Journals (Sweden)

    Anirban Majumder

    2016-01-01

    Full Text Available Context: Awareness of gender dysphoria (GD and its treatment is increasing. There is paucity of scientific data from India regarding the therapeutic options being used for alleviating GD, which includes psychotherapy, hormone, and surgical treatments. Aim: To study the therapeutic options including psychotherapy, hormone, and surgical treatments used for alleviating GD. Settings and Design: This is a retrospective study of treatment preferences and outcome in 18 female-to-male (FTM transgender subjects who presented to the endocrine clinic. Results: The mean follow-up was 1.6 years and only one subject was lost to follow-up after a single visit. All subjects desiring treatment had regular counseling and medical monitoring. All FTM subjects were cross-dressing. Seventeen (94.4% FTM subjects were receiving cross-sex hormone therapy, in the form of testosterone only (61.1% or gonadotropin-releasing hormone (GnRH agonist in combination with testosterone (11.1% or medroxyprogesterone acetate (MPA depot in combination with testosterone (22.2%. FTM subjects preferred testosterone or testosterone plus MPA; very few could afford GnRH therapy. Testosterone esters injection was preferred by most (72.2% subjects as it was most affordable while 22.2% chose 3 monthly injections of testosterone undecanoate for convenience and better symptomatic improvement, but it was more expensive. None preferred testosterone gels because of cost and availability concerns. About 33.3% of our subjects underwent mastectomy, 38.9% had hysterectomy with bilateral salpingo-oophorectomy, and only one subject underwent phalloplasty. About 16.7% of FTM subjects presented with prior mastectomy depicting a high prevalence of unsupervised or poorly supervised surgeries not following protocol wise approach. Conclusion: Notwithstanding of advances in Standards of Care in the Western world, there is lack of awareness and acceptance in the FTM subjects, about proper and timely protocol

  12. Outcome and preferences in female-to-male subjects with gender dysphoria: Experience from Eastern India

    Science.gov (United States)

    Majumder, Anirban; Sanyal, Debmalya

    2016-01-01

    Context: Awareness of gender dysphoria (GD) and its treatment is increasing. There is paucity of scientific data from India regarding the therapeutic options being used for alleviating GD, which includes psychotherapy, hormone, and surgical treatments. Aim: To study the therapeutic options including psychotherapy, hormone, and surgical treatments used for alleviating GD. Settings and Design: This is a retrospective study of treatment preferences and outcome in 18 female-to-male (FTM) transgender subjects who presented to the endocrine clinic. Results: The mean follow-up was 1.6 years and only one subject was lost to follow-up after a single visit. All subjects desiring treatment had regular counseling and medical monitoring. All FTM subjects were cross-dressing. Seventeen (94.4%) FTM subjects were receiving cross-sex hormone therapy, in the form of testosterone only (61.1%) or gonadotropin-releasing hormone (GnRH) agonist in combination with testosterone (11.1%) or medroxyprogesterone acetate (MPA) depot in combination with testosterone (22.2%). FTM subjects preferred testosterone or testosterone plus MPA; very few could afford GnRH therapy. Testosterone esters injection was preferred by most (72.2%) subjects as it was most affordable while 22.2% chose 3 monthly injections of testosterone undecanoate for convenience and better symptomatic improvement, but it was more expensive. None preferred testosterone gels because of cost and availability concerns. About 33.3% of our subjects underwent mastectomy, 38.9% had hysterectomy with bilateral salpingo-oophorectomy, and only one subject underwent phalloplasty. About 16.7% of FTM subjects presented with prior mastectomy depicting a high prevalence of unsupervised or poorly supervised surgeries not following protocol wise approach. Conclusion: Notwithstanding of advances in Standards of Care in the Western world, there is lack of awareness and acceptance in the FTM subjects, about proper and timely protocol

  13. Effect of Vomeronasal Organ Removal From Male Mice on Their Preference for and Neural Fos Responses to Female Urinary Odors

    OpenAIRE

    Pankevich, Diana E.; Cherry, James A.; Baum, Michael J.

    2006-01-01

    Four experiments were conducted to determine whether vomeronasal organ (VNO) inputs in male mice mediate the rewarding properties of estrous female urinary odors. Sexually naive male mice with either an intact (VNOi) or lesioned (VNOx) VNO preferred to investigate female urine over water in Y-maze tests. Subsequently, VNOi males ran significantly more quickly and remained in nasal contact longer with estrous female urine than with male urine, whereas VNOx males investigated these odors equall...

  14. The developmental inter-relationships between activity, novelty preferences, and delay discounting in male and female rats.

    Science.gov (United States)

    Lukkes, Jodi L; Thompson, Britta S; Freund, Nadja; Andersen, Susan L

    2016-03-01

    Increased locomotion, novelty-seeking, and impulsivity are risk factors associated with substance use. In this study, the inter-relationships between activity, novelty preferences, and delay discounting, a measure of impulsivity, were examined across three stages: juvenile/early adolescence (postnatal Day [P] 15, 19, and 42 for activity, novelty, and impulsivity, respectively), adolescent/late adolescent (P28, 32, 73), and adult (P90, 94, 137) in male and female rats. Our estimates of impulsive choice, where animals were trained to criterion, revealed an age × sex interaction where early adolescent females had the lowest levels of impulsivity. The relationships of activity and novelty to impulsivity significantly changed across age within each sex. Early adolescent males with high activity, but low novelty preferences, were more impulsive; however, low activity and high novelty preferences were related to high impulsivity in adult males. Female activity gradually increased across age, but did not show a strong relationship with impulsivity. Novelty preferences are moderately related to impulsivity into adulthood in females. These data show that males and females have different developmental trajectories for these behaviors. Males show greater sensation-seeking (e.g., activity) and risky behavior (e.g., novelty preferences) earlier in life, whereas these behaviors emerge during adolescence in females. PMID:26419783

  15. Reproductive success and female preference in the amazonian cichlid angel fish, Pterophyllum scalare (Lichtenstein, 1823

    Directory of Open Access Journals (Sweden)

    Maria do Socorro R. F. Cacho

    2006-03-01

    Full Text Available The angel fish, Pterophyllum scalare is a cichlid native to the Amazon Basin of Brazil and is exported as an ornamental fish. In this study the importance of the experience and previous reproductive success of males in mate selection was investigated. In order to investigate reproductive experience, six pairs of males (experienced and inexperienced and six females were used. Males were placed in an aquarium, where one female was released. Mate selection was verified by the time spent by a female near one of the males. To evaluate reproductive success, six pairs of males were tested, each pair consisting of a successful male and an unsuccessful one. Again, time spent with one of the males was considered as an indication of preference by the female. Each female was then paired with an unsuccessful male and their reproductive success was assessed. Females preferred larger, aggressive, territorial and experienced males. Correlations between male aggressiveness, aeration and egg survival were significant. During larval care, male aggressiveness was significantly related to larvae survival. Furthermore, intrabucal care and larval survival showed significant correlations with care provided by the experienced, mated and isolated fish. Survival of offspring resulted from mating with experienced and inexperienced males showed significant differences. Correlations between time spent by females with successful males during reproduction and survival rate of eggs and larvae were significant. Females assess the capacity and willingness of males in investing efforts to raise the offspring through their courtship behavior. Experienced and successful males are preferred by females and thereby achieve greater reproductive success.O acará bandeira, Pterophyllum scalareé um ciclídeo nativo da Bacia Amazônica do Brasil, eé exportado como espécie ornamental. Neste estudo foi investigada a importância da experiência dos machos e do sucesso na reprodu

  16. Global dynamics of a PDE model for aedes aegypti mosquitoe incorporating female sexual preference

    KAUST Repository

    Parshad, Rana

    2011-01-01

    In this paper we study the long time dynamics of a reaction diffusion system, describing the spread of Aedes aegypti mosquitoes, which are the primary cause of dengue infection. The system incorporates a control attempt via the sterile insect technique. The model incorporates female mosquitoes sexual preference for wild males over sterile males. We show global existence of strong solution for the system. We then derive uniform estimates to prove the existence of a global attractor in L-2(Omega), for the system. The attractor is shown to be L-infinity(Omega) regular and posess state of extinction, if the injection of sterile males is large enough. We also provide upper bounds on the Hausdorff and fractal dimensions of the attractor.

  17. Transmission of preferences and beliefs about female labor market participation : direct evidence on the role of mothers

    OpenAIRE

    Mora, Ricardo; Machado, Matilde P.; Carro, Jesús M.

    2014-01-01

    Recently, economists have established that culture—defined as a common set of preferences and beliefs —affects economic outcomes, including the levels of female labor force participation. Although this literature has argued that culture is transmitted from parents to children, it has also recognized the difficulty in empirically disentangling the parental transmission of preferences and/or beliefs from other confounding factors, such as technological change or investment in education. Using c...

  18. A Comparative Study of Learning Style Preferences of Monolingual and Bilingual High School Female Students and the Impact of Such Preferences on Language Learning Achievement

    OpenAIRE

    FAYYAZI, Vida; RAHMANI SANGANI, Hamid; BAHADOR, Hamid

    2015-01-01

    Abstract. Every person has a preferred way of learning that is called learning style. Due to the significant role of learning style in learning achievement, it is an ongoing issue of great importance to educational research. Thus, the present study aimed at investigating and comparing learning styles of monolingual (Persian) and bilingual (Turkish-Persian) high school female students. It also examined the impact of learning styles on language learning achievement. The sample of the study cons...

  19. Peripubertal exposure to male chemosignals accelerates vaginal opening and induces male-directed odor preference in female mice

    Directory of Open Access Journals (Sweden)

    Mélanie eJouhanneau

    2015-03-01

    Full Text Available Reproductive physiology in female mouse is profoundly affected by male odor. A well-known effect of male odor is the acceleration of puberty onset in prepubertal female mice exposed to male urine. Whether peripubertal exposure to male odor also influences female sexual behavior in adulthood is poorly known. Recently, we reported that female mice exposed to male-soiled bedding showed advanced vaginal opening associated with early expression of male-directed odor preference in adulthood. The aim of the present study is to determine whether peripubertal exposure to male urinary chemosignals affects both occurrence of vaginal opening and attraction to male odor at older age in female mice. Therefore, we exposed female mice to (1R, 5S, 7R-3,4-dehydro-exo-brevicomin (DHB, 6-hydroxy-6-methyl-3-heptanone (HMH and (S-2-sec-butyl-4,5-dihydrothiazole (SBT, individually or in mixture, from postnatal day (PD 21 to PD38 and monitored the occurrence of vaginal opening. We measured then the time that the female mice spent sniffing male and female mouse urinary volatiles at PD45. As expected, peripubertal exposure to DHB, HMH or SBT accelerated vaginal opening in female mice. In addition, we showed that exposure to a mixture of these three compounds induced expression of male-directed odor preference at PD45, contrary to the single exposure to each of these molecules. In conclusion, the volatile compounds DHB, HMH and SBT in urine of male mice influence both occurrence of vaginal opening and adult expression of male-directed odor preference in female mice.

  20. More choice is better : Effects of assortment size and composition on assortment evaluations

    NARCIS (Netherlands)

    Koelemeijer, K.; Oppewal, H.

    2005-01-01

    This study focuses on effects of assortment size and composition on assortment evaluation. Data from a choice experiment conducted with members of a large consumer panel suggest that adding any item improves assortment evaluation, regardless of their attributes or the size of the assortment. Althoug

  1. Assortment Variety : Attribute versus Product-Based

    NARCIS (Netherlands)

    van Herpen, H.W.I.; Pieters, R.

    2000-01-01

    Retailers need to decide on the content and structure of their product assortments, and thereby on the degree of variety that they offer to their customers.This paper compares measures of assortment variety and relates them to underlying variety components.We conceptualize assortment variety from a

  2. [An investigation of career choice, plans and expectations and practice preferences of male and female dental students

    NARCIS (Netherlands)

    Daalmans, M.T.; Vissia, M.S.; Kuijpers-Jagtman, A.M.; Lagro-Janssen, A.L.M.

    2004-01-01

    Aim of this study was to get more insight into the career choice, plans and expectations, and practice pattern preferences of male and female dental students in The Netherlands. A structured questionnaire was sent out to all 5th year dental students in The Netherlands in the academic year 2001/2002

  3. Cooperation as a signal of genetic or phenotypic quality in female mate choice? Evidence from preferences across the menstrual cycle.

    Science.gov (United States)

    Farrelly, Daniel

    2011-08-01

    Previous research highlighting the role sexual selection may play in the evolution of human cooperation has yet to distinguish what qualities such behaviours actually signal. The aim here was to examine whether female preferences for male cooperative behaviours are because they signal genetic or indirect phenotypic quality. This was possible by taking into account female participants' stage of menstrual cycle, as much research has shown that females at the most fertile stage show greater preferences specifically for signals of genetic quality than any other stage, particularly for short-term relationships. Therefore, different examples of cooperation (personality, costly signals, heroism) and the mate preferences for altruistic traits self-report scale were used across a series of four experiments to examine females' attitudes towards cooperation in potential mates for different relationship lengths at different stages of the menstrual cycle. The results here consistently show that female fertility had no effect on perceptions of cooperative behaviour, and that such traits were considered more important for long-term relationships. Therefore, this provides strong evidence that cooperative behaviour is important in mate choice as predominantly a signal of phenotypic rather than genetic quality.

  4. Social preferences based on sexual attractiveness: a female strategy to reduce male sexual attention

    OpenAIRE

    Brask, Josefine B.; Croft, Darren P.; Thompson, Katharine; Dabelsteen, Torben; Darden, Safi K.

    2011-01-01

    Male sexual harassment of females is common across sexually reproducing species and can result in fitness costs to females. We hypothesized that females can reduce unwanted male attention by constructing a social niche where their female associates are more sexually attractive than themselves, thus influencing the decision-making of males to their advantage. We tested this hypothesis in the Trinidadian guppy (Poecilia reticulata), a species with high levels of male sexual harassment. First, w...

  5. Learning Style Preferences among Male and Female ESL Students in Universiti-Sains Malaysia

    Science.gov (United States)

    Shuib, Munir; Azizan, Siti Norbaya

    2015-01-01

    Individuals preferentially process information in different ways. This includes the varied learning style preference of the individuals in any study program, including English as a Second Language (ESL). However, one of major concerns is, do the ESL students have different preferred way to learn? Past studies have given mixed results including…

  6. Measuring Clothing Color and Design Symbolism Preferences and Purchase Intentions of Asian Indian Females at Different Levels of Acculturation

    OpenAIRE

    Whitney Upchurch Campassi; Ann Beth Presley

    2013-01-01

    The purpose of this study was to develop a reliable and valid instrument to measure color, design clothing preferences, and purchase intentions of Asian-Indian female consumers; secondarily, to determine if westernized clothes with Asian-Indian ethnic dress elements might be purchased more often than westernized clothing with design attributes primarily symbolic of American culture at different levels of acculturation. The instrument included a modified acculturation scale, limited demographi...

  7. Advertisement-call modification, male competition and female preference in the bird-voiced treefrog Hyla avivoca

    Science.gov (United States)

    Martínez-Rivera, Carlos César; Gerhardt, H. Carl

    2009-01-01

    Senders and receivers influence dynamic characteristics of the signals used for mate attraction over different time scales. On a moment-to-moment basis, interactions among senders competing for a mate influence dynamic characteristics, whereas the preferences of receivers of the opposite gender exert an influence over evolutionary time. We observed and recorded the calling patterns of the bird-voiced treefrog Hyla avivoca, to assess how the dynamic characters of calls vary during interactions among groups of males in a chorus. This question was also addressed using playback experiments with males. Playback experiments with females showed how changes in dynamic call properties are likely to affect male mating success. Frogs calling in pairs, groups, or in response to playbacks produced longer calls than did isolated males. During call overlap, males often increased the duration of the silent interval (gaps) between the pulses of their calls so that the pulses of the calls of two neighbors interdigitated. This change resulted in increased variability of pulse rate, a traditionally static acoustic property; however, males also produced high proportions of non-overlapped calls in which variability in pulse rate was low and had species-typical values. Females preferred long calls to short and average-duration calls, and non-overlapped calls to overlapped calls. Given a choice between pairs of overlapped calls, females preferred pairs in which the proportion of overlap was low and pairs in which the pulses of such calls interdigitated completely. The observed patterns of vocal competition thus reflect the preferences of conspecific females, which have influenced the evolution of the calling behavior of H. avivoca. PMID:19789730

  8. Assortative mating and the reversal of gender inequality in education in europe: an agent-based model.

    Directory of Open Access Journals (Sweden)

    André Grow

    Full Text Available While men have always received more education than women in the past, this gender imbalance in education has turned around in large parts of the world. In many countries, women now excel men in terms of participation and success in higher education. This implies that, for the first time in history, there are more highly educated women than men reaching the reproductive ages and looking for a partner. We develop an agent-based computational model that explicates the mechanisms that may have linked the reversal of gender inequality in education with observed changes in educational assortative mating. Our model builds on the notion that individuals search for spouses in a marriage market and evaluate potential candidates based on preferences. Based on insights from earlier research, we assume that men and women prefer partners with similar educational attainment and high earnings prospects, that women tend to prefer men who are somewhat older than themselves, and that men prefer women who are in their mid-twenties. We also incorporate the insight that the educational system structures meeting opportunities on the marriage market. We assess the explanatory power of our model with systematic computational experiments, in which we simulate marriage market dynamics in 12 European countries among individuals born between 1921 and 2012. In these experiments, we make use of realistic agent populations in terms of educational attainment and earnings prospects and validate model outcomes with data from the European Social Survey. We demonstrate that the observed changes in educational assortative mating can be explained without any change in male or female preferences. We argue that our model provides a useful computational laboratory to explore and quantify the implications of scenarios for the future.

  9. The role of active assortment in spousal similarity.

    Science.gov (United States)

    Watson, David; Beer, Andrew; McDade-Montez, Elizabeth

    2014-04-01

    Previous research has established the existence of active assortment, that is, a preference for similarity in a potential mate. Few studies, however, have directly related mate preferences to dyadic similarity by examining them in the same participants. We collected both similarity and mate preference data in two studies: undergraduate students (N = 519) and newlyweds (N = 335). In both studies, women placed a higher value on desirable personality characteristics (e.g., higher Conscientiousness and Agreeableness, lower Neuroticism) than did men. Nevertheless, our data also provided strong evidence of consensual mate preferences: Men and women both desired partners who were agreeable, conscientious, emotionally stable, intelligent, and physically attractive; furthermore, participants desired partners who were better (e.g., more agreeable and attractive) than they were. In contrast, attitudinal variables such as religiousness and political orientation displayed much weaker consensus but showed significant dyadic similarity in both samples; similarity coefficients for personality tended to be positive, but lower. Finally, analyses revealed a direct link between actual and desired similarity: Couples displayed the strongest similarity on those variables for which participants expressed the strongest preference for similarity. Our findings strongly suggest that active assortment is partly responsible for dyadic similarity.

  10. Effects of Vomeronasal Organ Removal on Olfactory Sex Discrimination and Odor Preferences of Female Ferrets

    OpenAIRE

    Woodley, S.K.; Cloe, A.L.; Waters, P; Baum, M.J.

    2004-01-01

    Previous research suggests that body odorants, including anal scents and urinary odors, contribute to sex discrimination and mate identification in European ferrets of both sexes. We assessed the possible role of the vomeronasal organ (VNO) in these functions by surgically removing the organ bilaterally in sexually experienced female ferrets. Lesioned (VNOx) and sham-operated control (VNOi) females reliably discriminated between male- and female-derived anal scent gland as well as fresh urina...

  11. The relationship between intraspecific assortative mating and reproductive isolation between divergent populations

    Institute of Scientific and Technical Information of China (English)

    Daniel I.BOLNICK; Mark KIRKPATRICK

    2012-01-01

    The term'assortative mating' has been applied to describe two very different phenomena:(1) the tendency for individuals to choose phenotypically similar mates from among conspecifics; or (2) the tendency to prefer conspecific over heterospecific mates (behavioral reproductive isolation).Both forms of assortative mating are widespread in nature,but the relationship between these behaviors remains unclear.Namely,it is plausible that a preference for phenotypically similar conspecifics incidentally reduces the probability of mating with phenotypically divergent heterospecifics.We present a model to calculate how the level of reproductive isolation depends on intraspecific assortative mating and the phenotypic divergence between species.For empirically reasonable levels of intraspecific assortment on a single trait axis,we show that strong reproductive isolation requires very substantial phenotypic divergence.We illustrate this point by applying our model to empirical data from threespine stickleback Gasterosteus aculeatus and Darwin's Finches (Geospiza spp).We conclude that typical levels of intraspecific assortment cannot generally be extrapolated to explain levels of interspecitie reproductive isolation.Instead,reproductive isolation between species likely arises from different mate choice behaviors,or multivariate assortative mating.

  12. MATE CHOICE IN AIDABLENNIUS-SPHYNX (TELEOSTEI, BLENNIIDAE) - FEMALES PREFER NESTS CONTAINING MORE EGGS

    NARCIS (Netherlands)

    KRAAK, SBM; VIDELER, JJ

    1991-01-01

    Criteria for female mate choice were investigated in a natural population of a Mediterranean blenny, Aidablennius sphynx. Removable test tubes in concrete blocks were offered as nests. Each tube was guarded by a male and females laid eggs in the tubes. Nests with larger broods received significantly

  13. The Genetic Basis of Female Mate Preference and Species Isolation in Drosophila

    Directory of Open Access Journals (Sweden)

    Meghan Laturney

    2012-01-01

    Full Text Available The processes that underlie mate choice have long fascinated biologists. With the advent of increasingly refined genetic tools, we are now beginning to understand the genetic basis of how males and females discriminate among potential mates. One aspect of mate discrimination of particular interest is that which isolates one species from another. As behavioral isolation is thought to be the first step in speciation, and females are choosy more often than males in this regard, identifying the genetic variants that influence interspecies female mate choice can enhance our understanding of the process of speciation. Here, we review the literature on female mate choice in the most widely used model system for studies of species isolation Drosophila. Although females appear to use the same traits for both within- and between-species female mate choice, there seems to be a different genetic basis underlying these choices. Interestingly, most genomic regions that cause females to reject heterospecific males fall within areas of low recombination. Likely, candidate genes are those that act within the auditory or olfactory system, or within areas of the brain that process these systems.

  14. Perceptions and evaluations of assortment variety

    NARCIS (Netherlands)

    van Herpen, H.W.I.

    2001-01-01

    Given the explosive growth in the number of products, managing their assortments is a challenging task for retailers. An understanding of consumer responses to changes in assortment size and composition is required. This dissertation examines consumers' perceptions and evaluations of product assortm

  15. An Ideal Assortative Network and Synchronization

    Institute of Scientific and Technical Information of China (English)

    DONG Cheng-Dong; LIU Zeng-Rong

    2007-01-01

    This paper proposes a novel complex network with assortative property based on multi-center networks. The average path length and clustering coefficient of the network are calculated, and the impact on the network topology is investigated. A simple dynamic system established on the proposed network is used to analyze how the assortative property of the network affects synchronization.

  16. Real estate ads in Emei music frog vocalizations: female preference for calls emanating from burrows

    OpenAIRE

    Cui, Jianguo; Tang, Yezhong; Narins, Peter M.

    2011-01-01

    During female mate choice, both the male's phenotype and resources (e.g. his nest) contribute to the chooser's fitness. Animals other than humans are not known to advertise resource characteristics to potential mates through vocal communication; although in some species of anurans and birds, females do evaluate male qualities through vocal communication. Here, we demonstrate that calls of the male Emei music frog (Babina dauchina), vocalizing from male-built nests, reflect nest structure info...

  17. Reproductive success and female preference in the amazonian cichlid angel fish, Pterophyllum scalare (Lichtenstein, 1823)

    OpenAIRE

    Maria do Socorro R.F Cacho; Sathyabama Chellappa; Maria Emília Yamamoto

    2006-01-01

    The angel fish, Pterophyllum scalare is a cichlid native to the Amazon Basin of Brazil and is exported as an ornamental fish. In this study the importance of the experience and previous reproductive success of males in mate selection was investigated. In order to investigate reproductive experience, six pairs of males (experienced and inexperienced) and six females were used. Males were placed in an aquarium, where one female was released. Mate selection was verified by the time spent by a fe...

  18. Revisiting 'mothers and sons' preference formation and the female labor force in Switzerland

    OpenAIRE

    Bütikofer, Aline

    2013-01-01

    This paper analyzes the interrelation between men's gender role attitudes and female labor supply decision. Following Fernández, Fogli, and Olivetti (2004), I argue that the recent increases in the female labor market participation rate are driven by the growing proportion of men who were brought up in a family with a working mother. First, the paper reexamines the results of the cross-section analysis of Fernández, Fogli, and Olivetti (2004) using the Swiss Household Panel 200...

  19. Direct selection on male attractiveness and female preference fails to produce a response.

    OpenAIRE

    Hall, M.; Lindholm, A K; Brooks, R.

    2004-01-01

    Background: Theoretical studies suggest that direct and indirect selection have the potential to cause substantial evolutionary change in female mate choice. Similarly, sexual selection is considered a strong force in the evolution of male attractiveness and the exaggeration of secondary sexual traits. Few studies have, however, directly tested how female mate choice and male attractiveness respond to selection. Here we report the results of a selection experiment in which we selected directl...

  20. Direct selection on male attractiveness and female preference fails to produce a response

    OpenAIRE

    Brooks Robert; Lindholm Anna K; Hall Matthew

    2004-01-01

    Abstract Background Theoretical studies suggest that direct and indirect selection have the potential to cause substantial evolutionary change in female mate choice. Similarly, sexual selection is considered a strong force in the evolution of male attractiveness and the exaggeration of secondary sexual traits. Few studies have, however, directly tested how female mate choice and male attractiveness respond to selection. Here we report the results of a selection experiment in which we selected...

  1. 'Prudent habitat choice': a novel mechanism of size-assortative mating.

    Science.gov (United States)

    Taborsky, B; Guyer, L; Demus, P

    2014-06-01

    Assortative mating, an ubiquitous form of nonrandom mating, strongly impacts Darwinian fitness and can drive biological diversification. Despite its ecological and evolutionary importance, the behavioural processes underlying assortative mating are often unknown, and in particular, mechanisms not involving mate choice have been largely ignored so far. Here, we propose that assortative mating can arise from 'prudent habitat choice', a general mechanism that acts under natural selection, and that it can occur despite a complete mixing of phenotypes. We show that in the cichlid Eretmodus cyanostictus size-assortative mating ensues, because individuals of weaker competitive ability ignore high-quality but strongly competed habitat patches. Previous studies showed that in E. cyanostictus, size-based mate preferences are absent. By field and laboratory experiments, here we showed that (i) habitat quality and body size are correlated in this species; (ii) territories with more stone cover are preferred by both sexes in the absence of competition; and (iii) smaller fish prudently occupy vacant territories of worse quality than do larger fish. Prudent habitat choice is likely to be a widespread mechanism of assortative mating, as both preferences for and dominance-based access to high-quality habitats are generic phenomena in animals.

  2. The Roles of Dopamine and α1-Adrenergic Receptors in Cocaine Preferences in Female and Male Rats.

    Science.gov (United States)

    Perry, Adam N; Westenbroek, Christel; Jagannathan, Lakshmikripa; Becker, Jill B

    2015-11-01

    Cocaine dependence is characterized by compulsive drug taking and reduced involvement in social, occupational, or recreational activities. Unraveling the diverse mechanisms contributing to the loss-of-interest in these 'non-drug' pursuits is essential for understanding the neurobiology of addiction and could provide additional targets for treating addiction. The study objectives were to examine changes in cocaine-induced dopamine (DA) overflow in the nucleus accumbens (NAc) over the course of self-administration and determine the roles of α1- and β-adrenergic receptors (AR) in the loss-of-interest in food rewards following the development of an addicted phenotype in male and female rats. Subjects were given access to cocaine and palatable food pellets in a choice self-administration paradigm to identify 'addicted' cocaine-preferring (CP) individuals and resistant pellet-preferring (PP) individuals based on their patterns of self-administration over 7 weeks. Cocaine-induced DA overflow in the NAc was examined with microdialysis early and late during self-administration (weeks 2 and 7). Subjects were treated in counter-balanced order with propranolol (β-AR antagonist), terazosin (α1-AR antagonist), or vehicle for an additional 3 weeks of self-administration. CP rats displayed increased motivation for cocaine and attenuated motivation for pellets following the development of cocaine preferences. In females, the estrous cycle affected pellet, but not cocaine, self-administration. CP rats displayed attenuated cocaine-induced DA overflow in the NAc. Propranolol enhanced cocaine reinforcement and reduced pellet intake, whereas terazosin enhanced motivation for pellets and reversed preferences in a subset of CP rats. The implications of these results for the treatment of addiction are discussed. PMID:25900120

  3. The Roles of Dopamine and α1-Adrenergic Receptors in Cocaine Preferences in Female and Male Rats.

    Science.gov (United States)

    Perry, Adam N; Westenbroek, Christel; Jagannathan, Lakshmikripa; Becker, Jill B

    2015-11-01

    Cocaine dependence is characterized by compulsive drug taking and reduced involvement in social, occupational, or recreational activities. Unraveling the diverse mechanisms contributing to the loss-of-interest in these 'non-drug' pursuits is essential for understanding the neurobiology of addiction and could provide additional targets for treating addiction. The study objectives were to examine changes in cocaine-induced dopamine (DA) overflow in the nucleus accumbens (NAc) over the course of self-administration and determine the roles of α1- and β-adrenergic receptors (AR) in the loss-of-interest in food rewards following the development of an addicted phenotype in male and female rats. Subjects were given access to cocaine and palatable food pellets in a choice self-administration paradigm to identify 'addicted' cocaine-preferring (CP) individuals and resistant pellet-preferring (PP) individuals based on their patterns of self-administration over 7 weeks. Cocaine-induced DA overflow in the NAc was examined with microdialysis early and late during self-administration (weeks 2 and 7). Subjects were treated in counter-balanced order with propranolol (β-AR antagonist), terazosin (α1-AR antagonist), or vehicle for an additional 3 weeks of self-administration. CP rats displayed increased motivation for cocaine and attenuated motivation for pellets following the development of cocaine preferences. In females, the estrous cycle affected pellet, but not cocaine, self-administration. CP rats displayed attenuated cocaine-induced DA overflow in the NAc. Propranolol enhanced cocaine reinforcement and reduced pellet intake, whereas terazosin enhanced motivation for pellets and reversed preferences in a subset of CP rats. The implications of these results for the treatment of addiction are discussed.

  4. Male genital morphology and its influence on female mating preferences and paternity success in guppies.

    Directory of Open Access Journals (Sweden)

    Clelia Gasparini

    Full Text Available In internally fertilizing species male genitalia often show a higher degree of elaboration than required for simply transferring sperm to females. Among the hypotheses proposed to explain such diversity, sexual selection has received the most empirical support, with studies revealing that genital morphology can be targeted by both pre-and postcopulatory sexual selection. Until now, most studies have focused on these two episodes of selection independently. Here, we take an alternative approach by considering both components simultaneously in the livebearing fish, Poecilia reticulata. We allowed females to mate successively (and cooperatively with two males and determined whether male genital length influenced the female's propensity to mate with a male (precopulatory selection, via female choice and whether male genital size and shape predicted the relative paternity share of subsequent broods (postcopulatory selection, via sperm competition/cryptic female choice. We found no evidence that either episode of sexual selection targets male genital size or shape. These findings, in conjunction with our recent work exposing a role of genital morphology in mediating unsolicited (forced matings in guppies, further supports our prior speculation that sexual conflict may be an important broker of genital evolution in this species.

  5. Real estate ads in Emei music frog vocalizations: female preference for calls emanating from burrows

    Science.gov (United States)

    Cui, Jianguo; Tang, Yezhong; Narins, Peter M.

    2012-01-01

    During female mate choice, both the male's phenotype and resources (e.g. his nest) contribute to the chooser's fitness. Animals other than humans are not known to advertise resource characteristics to potential mates through vocal communication; although in some species of anurans and birds, females do evaluate male qualities through vocal communication. Here, we demonstrate that calls of the male Emei music frog (Babina dauchina), vocalizing from male-built nests, reflect nest structure information that can be recognized by females. Inside-nest calls consisted of notes with energy concentrated at lower frequency ranges and longer note durations when compared with outside-nest calls. Centre frequencies and note durations of the inside calls positively correlate with the area of the burrow entrance and the depth of the burrow, respectively. When given a choice between outside and inside calls played back alternately, more than 70 per cent of the females (33/47) chose inside calls. These results demonstrate that males of this species faithfully advertise whether or not they possess a nest to potential mates by vocal communication, which probably facilitates optimal mate selection by females. These results revealed a novel function of advertisement calls, which is consistent with the wide variation in both call complexity and social behaviour within amphibians. PMID:22158736

  6. Asian infants show preference for own-race but not other-race female faces: The role of infant caregiving arrangements

    Directory of Open Access Journals (Sweden)

    Shaoying eLiu

    2015-05-01

    Full Text Available Previous studies have reported that 3- to 4-month-olds show a visual preference for faces of the same gender as their primary caregiver (e.g., Quinn et al., 2002. In addition, this gender preference has been observed for own-race faces, but not for other-race faces (Quinn et al., 2008 However, most of the studies of face gender preference have focused on infants at 3 to 4 months. Development of gender preference in later infancy is still unclear. Moreover, all of these studies were conducted with Caucasian infants from Western countries. It is thus unknown whether a gender preference that is limited to own-race faces can be generalized to infants from other racial groups and different cultures with distinct caregiving practices. The current study investigated the face gender preferences of Asian infants presented with male versus female face pairs from Asian and Caucasian races at 3, 6, and 9 months and the role of caregiving arrangements in eliciting those preferences. The results showed an own-race female face preference in 3- and 6-month-olds, but not in 9-month-olds. Moreover, the downturn in the female face preference correlated with the cumulative male face experience obtained in caregiving practices. In contrast, no gender preference or correlation between gender preference and face experience was found for other-race Caucasian faces at any age. The data indicate that the face gender preference is not specifically rooted in Western cultural caregiving practices. In addition, the race dependency of the effect previously observed for Caucasian infants reared by Caucasian caregivers looking at Caucasian but not Asian faces extends to Asian infants reared by Asian caregivers looking at Asian but not Caucasian faces. The findings also provide additional support for an experiential basis for the gender preference, and in particular suggest that cumulative male face experience plays a role in inducing a downturn in the preference in older

  7. Life history of female preferences for male faces: a comparison of pubescent girls, nonpregnant and pregnant young women, and middle-aged women.

    Science.gov (United States)

    Kościński, Krzysztof

    2011-12-01

    Although scientific interest in facial attractiveness has developed substantially in recent years, few studies have contributed to our understanding of the ontogeny of facial preferences. In this study, attractiveness of 30 male faces was evaluated by four female groups: girls at puberty, nonpregnant and pregnant young women, and middle-aged women. The main findings are as follows: (1) Preference for sexy-looking faces was strongest in young, nonpregnant women. (2) Biologically more mature girls displayed more adultlike preferences. (3) The intragroup consistency for postmenopausal women was relatively low. (4) In terms of the preference pattern, pregnant women were more similar to perimenopausal women than they were to their nonpregnant peers. (5) Preference for youthful appearance decreased with the age of the women. I argue that the life history of female preferences for male faces is, to a large extent, hormone-driven and underpinned by a set of evolutionary adaptations. PMID:22388946

  8. Female breast cancer incidence and survival in Utah according to religious preference, 1985–1999

    OpenAIRE

    Folsom Jeffrey A; Merrill Ray M

    2005-01-01

    Abstract Background Female breast cancer incidence rates in Utah are among the lowest in the U.S. The influence of the Church of Jesus Christ of Latter-day Saint (LDS or Mormon) religion on these rates, as well as on disease-specific survival, will be explored for individuals diagnosed with breast cancer in Utah from 1985 through 1999. Methods Population-based records for incident female breast cancer patients were linked with membership records from the LDS Church to determine religious affi...

  9. How parasitoid females produce sexy sons: a causal link between oviposition preference, dietary lipids and mate choice in Nasonia.

    Science.gov (United States)

    Blaul, Birgit; Ruther, Joachim

    2011-11-01

    Sexual selection theory predicts that phenotypic traits used to choose a mate should reflect honestly the quality of the sender and thus, are often costly. Physiological costs arise if a signal depends on limited nutritional resources. Hence, the nutritional condition of an organism should determine both its quality as a potential mate and its ability to advertise this quality to the choosing sex. In insects, the quality of the offspring's nutrition is often determined by the ovipositing female. A causal connection, however, between the oviposition decisions of the mother and the mating chances of her offspring has never been shown. Here, we demonstrate that females of the parasitic wasp Nasonia vitripennis prefer those hosts for oviposition that have been experimentally enriched in linoleic acid (LA). We show by (13)C-labelling that LA from the host diet is a precursor of the male sex pheromone. Consequently, males from LA-rich hosts produce and release higher amounts of the pheromone and attract more virgin females than males from LA-poor hosts. Finally, males from LA-rich hosts possess three times as many spermatozoa as those from LA-poor hosts. Hence, females making the right oviposition decisions may increase both the fertility and the sexual attractiveness of their sons. PMID:21429922

  10. Assortment of encounters and evolution of cooperativeness.

    Science.gov (United States)

    Eshel, I; Cavalli-Sforza, L L

    1982-02-01

    The method of evolutionary stable strategies (ESS), in its current form, is confronted with a difficulty when it tries to explain how some social behaviors initiate their evolution. We show that this difficulty may be removed by changing the assumption made tacitly in game theory (and in ESS) of randomness of meetings or encounters. In reality, such randomness seems to be rare in nature. Family, population and social structure, customs, and habits impose various types of deviation from randomness. Introducing nonrandomness of meeting in a way formally similar to assortative mating, we show that the bar to initial increase of inherited cooperative or altruistic behaviors can be removed, provided there is sufficient assortment of meetings. Family structure may cause contacts predominantly between certain types of relatives, and one can reconstruct some results of classical kin selection in terms of evolutionary stable strategy with assortative meetings. Neighbor effects and group selection might be similarly treated. Assortment need not be a passive consequence of population and social structure, but it can also be actively pursued. Behaviors favoring the choice of cooperative companions will have the effect of favoring the evolution of cooperativeness. It can be shown that discrimination in the choice of companions, especially if combined with assortment, can favor the development of cooperativeness, making initial increase of cooperative behavior possible even at levels of assortment passively imposed which would not be adequate, per se, to guarantee the increase of cooperativeness. It is possible that, in some cases, cooperativeness and behavior favoring some type of assortment are coselected.

  11. Modern Sexism and Preference for a Coach among Select National Collegiate Athletic Association Division I Female Athletes: A Quantitative and Qualitative Analysis

    Science.gov (United States)

    Greenawalt, Nancy Jo

    2012-01-01

    The purpose of this explanatory mixed methods research study was to examine the relationship of modern sexism to a female athlete's preference for a coach based on the sex of the coach. Female athletes (N = 155) from one National Collegiate Athletic Association (NCAA) Division I institution in the Northeastern United States participated in…

  12. Same-sex cohabitation under the effects of quinpirole induces a conditioned socio-sexual partner preference in males, but not in female rats.

    Science.gov (United States)

    Triana-Del Rio, Rodrigo; Montero-Domínguez, Felix; Cibrian-Llanderal, Tamara; Tecamachaltzi-Silvaran, Miriam B; Garcia, Luis I; Manzo, Jorge; Hernandez, María Elena; Coria-Avila, Genaro A

    2011-10-01

    The effects of the dopamine D2-type receptor agonist quinpirole (QNP) were examined on the development of conditioned same-sex partner preference induced by cohabitation in rats. In Experiment 1, males received either saline or QNP (1.25mg/kg) and cohabited during three trials with almond-scented stimulus males that were sexually naïve. In Experiment 2, males received six trials, and in Experiment 3 received three trials with sexually expert stimulus males. During a final drug-free preference test, males chose between the familiar or a novel male partner. In Experiments 1, 2 and 3 only QNP-treated males displayed a social preference for the familiar male, observed with more time spent together. In Experiment 3 males also displayed a sexual preference observed with more non-contact erections when were exposed to their male partner. In Experiment 4 we tested the effects on OVX, E+P primed females that received 1 systemic injection of either saline or QNP during three conditioning trials. In Experiment 5, females received 2 injections 12-h apart during each trial. Results indicated that both saline and QNP-treated females failed to develop partner preference. These data demonstrate that enhanced D2-type receptor activity during cohabitation facilitates the development of conditioned same-sex partner preference in males, but not in female rats. We discuss the implications for same-sex partner preferences.

  13. Retail Choice Architecture: The Effects of Benefit- and Attribute-Based Assortment Organization on Consumer Perceptions and Choice

    OpenAIRE

    Cait Poynor Lamberton; Kristin Diehl

    2013-01-01

    This article explores the effects of two distinct retail choice architectures--those that organize assortments by attributes and those that organize items by benefits. Relative to attribute-based organizations, benefit-based organizations lead to more abstract construal and heighten similarity perceptions among items in an assortment. Such changes in similarity perceptions alter consumers' strength of preference among items: when choosing from benefit- as opposed to attribute-based organizati...

  14. No evidence for size-assortative mating in the wild despite mutual mate choice in sex-role-reversed pipefishes

    OpenAIRE

    Mobley, K.; Abou Chakra, M.; Jones, A.

    2014-01-01

    Size-assortative mating is a nonrandom association of body size between members of mating pairs and is expected to be common in species with mutual preferences for body size. In this study, we investigated whether there is direct evidence for size-assortative mating in two species of pipefishes, Syngnathus floridae and S. typhle, that share the characteristics of male pregnancy, sex-role reversal, and a polygynandrous mating system. We take advantage of microsatellite- based “genetic-capture”...

  15. Female breast cancer incidence and survival in Utah according to religious preference, 1985–1999

    Directory of Open Access Journals (Sweden)

    Folsom Jeffrey A

    2005-05-01

    Full Text Available Abstract Background Female breast cancer incidence rates in Utah are among the lowest in the U.S. The influence of the Church of Jesus Christ of Latter-day Saint (LDS or Mormon religion on these rates, as well as on disease-specific survival, will be explored for individuals diagnosed with breast cancer in Utah from 1985 through 1999. Methods Population-based records for incident female breast cancer patients were linked with membership records from the LDS Church to determine religious affiliation and, for LDS Church members, level of religiosity. Incidence rates were age-adjusted to the 2000 U.S. standard population using the direct method. Cox proportional hazards model was used to compare survival among religiously active LDS, less religiously active LDS, and non-LDS with simultaneous adjustment for prognostic factors. Results Age-adjusted breast cancer incidence rates were consistently lower for LDS than non-LDS in Utah from 1985 through 1999. Rates were lower among LDS compared with non-LDS across the age span. In 1995–99, the age-adjusted incidence rates were 107.6 (95% CI: 103.9 – 111.3 for LDS women and 130.5 (123.2 – 137.9 for non-LDS women. If non-LDS women in Utah had the same breast cancer risk profile as LDS women, an estimated 214 (4.8% fewer malignant breast cancer cases would have occurred during 1995–99. With religiously active LDS serving as the reference group, the adjusted death hazard ratio for religiously less active LDS was 1.09 (0.94 – 1.27 and for non-LDS was 0.86 (0.75 – 0.98. Conclusion In Utah, LDS lifestyle is associated with lower incidence rates of female breast cancer. However, LDS experience poorer survivability from breast cancer than their non-LDS counterparts. Parity and breastfeeding, while protective factors against breast cancer, may contribute to poorer prognosis of female breast cancer in LDS women.

  16. Preferences for female body size in Britain and the South Pacific.

    Science.gov (United States)

    Swami, Viren; Knight, Daniel; Tovée, Martin J; Davies, Patrick; Furnham, Adrian

    2007-06-01

    To assess current attitudes to body weight and shape in the South Pacific, a region characterised by relatively high levels of obesity and traditionally positive views of large bodies, 38 high socio-economic status (SES) adolescent males and 38 low SES adolescent males in Independent Samoa were asked to rate a set of images of real women for physical attractiveness. Participants in both SES settings preferred women with a slender figure, as did a comparison group in Britain, suggesting that the traditional veneration of large bodies is no longer apparent in Samoa. However, the results also showed that low SES adolescents were more likely to view overweight figures as attractive, which suggests that the veneration of slim figures may be associated with increasing SES. Implications of this finding are discussed in conclusion. PMID:18089268

  17. Marital assortment and phenotypic convergence: longitudinal evidence.

    Science.gov (United States)

    Caspi, A; Herbener, E S

    1993-01-01

    This study provides a direct test of whether the observed similarity of spouses is due to initial assortment rather than to convergence of phenotypes. With data from three well-known longitudinal studies, phenotypic convergence is examined using both variable- and person-centered analyses. The longitudinal evidence does not support the hypothesis that couples increasingly resemble each other with time. Spouse correlations most likely reflect initial assortment at marriage and not the convergence of phenotypes.

  18. Rate of phenotypic assortment in Tetrahymena thermophila.

    Science.gov (United States)

    Doerder, F P; Deak, J C; Lief, J H

    1992-01-01

    During vegetative, asexual reproduction in heterozygous Tetrahymena thermophila, the macronucleus divides amitotically to produce clonal lineages that express either one or the other allele but not both. Because such phenotypic assortment has been described for every locus studied, its mechanism has important implications concerning the development and structure of the macronucleus. The primary tools to study assortment are Rf, the rate at which subclones come to express a single allele stably, and the output ratio, the ratio of assortee classes. Because Rf is related to the number of assorting units, a constant Rf for all loci suggests that all genes are maintained at the same copy number. Output ratios reflect the input ratio of assorting units, with a 1:1 output ratio implying equal numbers of alleles at the end of macronuclear development. Because different outcomes would suggest a different macronuclear structure, it is crucial that these parameters be accurately measured. Although published Rf values are similar for all loci measured, there has been no commonly accepted form of presentation and analysis. Here we examine the experimental determination of Rf. First, we use computer simulation to describe how the variability inherent in the assortment process affects experimental determination of Rf. Second, we describe a simple method of plotting assortment data that permits the uniform calculation of Rf, and we describe how to measure Rf accurately in instances when it is possible to score only the recessive allele. Using this method to produce truly comparable Rfs for all published data, we find that most, if not all, loci assort at Rfs consistent with approximately 45 assorting units, as has been asserted.

  19. Higher order assortativity in complex networks

    CERN Document Server

    Arcagni, Alberto; Stefani, Silvana; Torriero, Anna

    2016-01-01

    Assortativity was first introduced by Newman and has been extensively studied and applied to many real world networked systems since then. Assortativity is a graph metrics and describes the tendency of high degree nodes to be directly connected to high degree nodes and low degree nodes to low degree nodes. It can be interpreted as a first order measure of the connection between nodes, i.e. the first autocorrelation of the degree-degree vector. Even though assortativity has been used so extensively, to the author's knowledge, no attempt has been made to extend it theoretically. This is the scope of our paper. We will introduce higher order assortativity by extending the Newman index based on a suitable choice of the matrix driving the connections. Higher order assortativity will be defined for paths, shortest paths, random walks of a given time length, connecting any couple of nodes. The Newman assortativity is achieved for each of these measures when the matrix is the adjacency matrix, or, in other words, the...

  20. Identifying context-specific gene profiles of social, reproductive, and mate preference behavior in a fish species with female mate choice.

    Science.gov (United States)

    Ramsey, Mary E; Maginnis, Tara L; Wong, Ryan Y; Brock, Chad; Cummings, Molly E

    2012-01-01

    Sensory and social inputs interact with underlying gene suites to coordinate social behavior. Here we use a naturally complex system in sexual selection studies, the swordtail, to explore how genes associated with mate preference, receptivity, and social affiliation interact in the female brain under specific social conditions. We focused on 11 genes associated with mate preference in this species (neuroserpin, neuroligin-3, NMDA receptor, tPA, stathmin-2, β-1 adrenergic receptor) or with female sociosexual behaviors in other taxa (vasotocin, isotocin, brain aromatase, α-1 adrenergic receptor, tyrosine hydroxylase). We exposed females to four social conditions, including pairings of differing mate choice complexity (large males, large/small males, small males), and a social control (two females). Female mate preference differed significantly by context. Multiple discriminant analysis (MDA) of behaviors revealed a primary axis (explaining 50.2% between-group variance) highlighting differences between groups eliciting high preference behaviors (LL, LS) vs. other contexts, and a secondary axis capturing general measures distinguishing a non-favored group (SS) from other groups. Gene expression MDA revealed a major axis (68.4% between-group variance) that distinguished amongst differential male pairings and was driven by suites of "preference and receptivity genes"; whereas a second axis, distinguishing high affiliation groups (large males, females) from low (small males), was characterized by traditional affiliative-associated genes (isotocin, vasotocin). We found context-specific correlations between behavior and gene MDA, suggesting gene suites covary with behaviors in a socially relevant context. Distinct associations between "affiliative" and "preference" axes suggest mate preference may be mediated by distinct clusters from those of social affiliation. Our results highlight the need to incorporate natural complexity of mating systems into behavioral genomics.

  1. A selective androgen receptor modulator enhances male-directed sexual preference, proceptive behavior, and lordosis behavior in sexually experienced, but not sexually naive, female rats.

    Science.gov (United States)

    Kudwa, A E; López, F J; McGivern, R F; Handa, R J

    2010-06-01

    Androgens influence many aspects of reproductive behavior, including sexual preference of females for males. In oophorectomized women with sexual desire disorder, testosterone patches improve libido, but their use is limited because of adverse side effects. Selective androgen receptor modulators offer an improved safety profile for both sexes: enhancing libido and muscle and bone growth in a manner similar to steroidal androgens but with fewer adverse effects, such as hirsutism, acne, and prostate growth. The current study investigated the action of a novel selective androgen receptor modulator (LGD-3303 [9-chloro-2-ethyl-1-methyl-3-(2,2,2-trifluoroethyl)-3H-pyrrolo-[3,2-f]quinolin-7(6H)-one]) on male-directed sexual preference, proceptivity, and lordosis behavior of female rats. LGD-3303 is a nonsteroidal, nonaromatizable, highly selective ligand for the androgen receptor and effectively crosses the blood-brain barrier. Gonadectomized female rats were treated with LGD-3303 (3-30 mg/kg) or vehicle by daily oral gavage. Results showed that LGD-3303 treatment enhanced sexual preference of females for males but only if females had previous sexual experience. This occurred after 1 or 7 d of treatment. In contrast, preference for males was inhibited by LGD-3303 treatments of sexually naive females. The LGD-3303 increase in male preference was blocked by pretreatment with the androgen receptor antagonist flutamide. LGD-3303 treatment increased lordosis and proceptivity behaviors in ovariectomized females primed with suboptimal doses of estradiol benzoate plus progesterone. These data support the concept that LGD-3303 can stimulate aspects of female sexual behavior and may serve as a potential therapeutic for women with sexual desire disorders.

  2. Female mating preferences and offspring survival: testing hypotheses on the genetic basis of mate choice in a wild lekking bird.

    Science.gov (United States)

    Sardell, Rebecca J; Kempenaers, Bart; Duval, Emily H

    2014-02-01

    Indirect benefits of mate choice result from increased offspring genetic quality and may be important drivers of female behaviour. 'Good-genes-for-viability' models predict that females prefer mates of high additive genetic value, such that offspring survival should correlate with male attractiveness. Mate choice may also vary with genetic diversity (e.g. heterozygosity) or compatibility (e.g. relatedness), where the female's genotype influences choice. The relative importance of these nonexclusive hypotheses remains unclear. Leks offer an excellent opportunity to test their predictions, because lekking males provide no material benefits and choice is relatively unconstrained by social limitations. Using 12 years of data on lekking lance-tailed manakins, Chiroxiphia lanceolata, we tested whether offspring survival correlated with patterns of mate choice. Offspring recruitment weakly increased with father attractiveness (measured as reproductive success, RS), suggesting attractive males provide, if anything, only minor benefits via offspring viability. Both male RS and offspring survival until fledging increased with male heterozygosity. However, despite parent-offspring correlation in heterozygosity, offspring survival was unrelated to its own or maternal heterozygosity or to parental relatedness, suggesting survival was not enhanced by heterozygosity per se. Instead, offspring survival benefits may reflect inheritance of specific alleles or nongenetic effects. Although inbreeding depression in male RS should select for inbreeding avoidance, mates were not less related than expected under random mating. Although mate heterozygosity and relatedness were correlated, selection on mate choice for heterozygosity appeared stronger than that for relatedness and may be the primary mechanism maintaining genetic variation in this system despite directional sexual selection.

  3. Phenotypic assortment in wild primate networks: implications for the dissemination of information.

    Science.gov (United States)

    Carter, Alecia J; Lee, Alexander E G; Marshall, Harry H; Ticó, Miquel Torrents; Cowlishaw, Guy

    2015-05-01

    Individuals' access to social information can depend on their social network. Homophily-a preference to associate with similar phenotypes-may cause assortment within social networks that could preclude information transfer from individuals who generate information to those who would benefit from acquiring it. Thus, understanding phenotypic assortment may lead to a greater understanding of the factors that could limit the transfer of information between individuals. We tested whether there was assortment in wild baboon (Papio ursinus) networks, using data collected from two troops over 6 years for six phenotypic traits-boldness, age, dominance rank, sex and the propensity to generate/exploit information-using two methods for defining a connection between individuals-time spent in proximity and grooming. Our analysis indicated that assortment was more common in grooming than proximity networks. In general, there was homophily for boldness, age, rank and the propensity to both generate and exploit information, but heterophily for sex. However, there was considerable variability both between troops and years. The patterns of homophily we observed for these phenotypes may impede information transfer between them. However, the inconsistency in the strength of assortment between troops and years suggests that the limitations to information flow may be quite variable.

  4. Simple models of assortment through environmental feedback.

    Science.gov (United States)

    Pepper, John W

    2007-01-01

    Social evolution depends critically on assortment, or segregation versus even mixing, between cooperators and noncooperators. Altruistic traits, which reduce the absolute fitness of their bearers, cannot evolve without positive assortment (excess segregation). The question of how positive assortment can arise has been controversial, but most evolutionary biologists believe that common descent is the only effective general mechanism. Here I investigate another recently proposed mechanism for generating nonrandom assortment, termed environmental feedback. This requires only that two forms of a trait affect the quality of the local environment differently in such a way that all individuals are more likely to leave low-quality locales. Experiments with simple computational models confirm that environmental feedback generates significant levels of genetic similarity among non-kin within locales. The mechanism is fairly general, and can under some conditions produce levels of genetic similarity comparable to those resulting from close genealogical relationship. Environmental feedback can also generate the negative assortment necessary for the evolution of spiteful traits. Environmental feedback is expected to create positive frequency-dependent selection, which thus favor any social trait that becomes common in the population. Results from this stylized model suggest that environmental feedback could be important in the evolution of both cooperation and spite, within as well as between species.

  5. A test of genetic association among male nuptial coloration,female mating preference, and male aggression bias within a polymorphic population of cichlid fish

    Institute of Scientific and Technical Information of China (English)

    Inke van der SLUIJS; Peter D.DIJKSTRA; Charlotte M.LINDEYER; Bertanne VISSER; Alan M.SMITH; Ton G.G.GROOTHUIS; Jacques J.M.van ALPHEN

    2013-01-01

    Both inter-and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits.Simultaneous disruptive selection by female mate choice and male-male competition can,in theory,lead to speciation without geographical isolation if both act on the same male trait.Female mate choice can generate discontinuities in gene flow,while male-male competition can generate negative frequency-dependent selection stabilizing the male trait polymorphism.Speciation may be facilitated when mating preference and/or aggression bias are physically linked to the trait they operate on.We tested for genetic associations among female mating preference,male aggression bias and male coloration in the Lake Victoria cichlid Pundamilia.We crossed females from a phenotypically variable population with males from both extreme ends of the phenotype distribution in the same population (blue or red).Male offspring of a red sire were significantly redder than males of a blue sire,indicating that intra-population variation in male coloration is heritable.We tested mating preferences of female offspring and aggression biases of male offspring using binary choice tests.There was no evidence for associations at the family level between female mating preferences and coloration of sires,but dam identity had a significant effect on female mate preference.Sons of the red sire directed significantly more aggression to red than blue males,whereas sons of the blue sire did not show any bias.There was a positive correlation among individuals between male aggression bias and body coloration,possibly due to pleiotropy or physical linkage,which could facilitate the maintenance of color polymorphism.

  6. Trans fat intake across gestation and lactation increases morphine preference in females but not in male rats: Behavioral and biochemical parameters.

    Science.gov (United States)

    Roversi, Karine; Pase, Camila Simonetti; Roversi, Katiane; Vey, Luciana Taschetto; Dias, Verônica Tironi; Metz, Vinícia Garzella; Burger, Marilise Escobar

    2016-10-01

    The abuse of morphine has risen considerably in recent years, mainly due to the increase of its prescription in clinical medicine. Also, increased consumption of processed foods, rich in trans fatty acids (TFA), has caused concerns about human health. Thus, the aim of our study was to determine whether trans fat consumption in the perinatal period may affect preference for morphine in adolescent female and male rats. Dams were orally supplemented with water (C-control) or hydrogenated vegetable fat (HVF-rich in TFA) during gestation and lactation periods. On post-natal day 43, pups were exposed to morphine (4mg/kg i.p., for 4 days) and assessed in the conditioned place preference paradigm. Anxiety-like symptoms were assessed, and oxidative status of the brain was estimated by reactive species (RS) generation. Female rats with HVF supplementation showed increased morphine preference and less anxiety-like symptoms. Additionally, both male and female rats from HVF-supplementation showed increased RS generation in the ventral tegmental area, whose level was similar in morphine-conditioned female rats. RS generation was increased in the hippocampus of morphine-conditioned female rats, regardless of the supplementation of their dams. We may infer that gender is a predictive factor to opioid preference, since adolescent female rats showed more susceptibility to addiction than males. Furthermore, trans fat consumption across the perinatal period is able to modify parameters of opioid preference in female rats, possibly due to TFA incorporation in phospholipid membranes, modifying the endogenous opioid system and the oxidative status in brain areas related to drug addiction.

  7. Male mating preferences pre-date the origin of a female trait polymorphism in an incipient species complex of Lake Victoria cichlids.

    Science.gov (United States)

    Pierotti, M E R; Seehausen, O

    2007-01-01

    Disruptive sexual selection on colour patterns has been suggested as a major cause of diversification in the cichlid species flock of Lake Victoria. In Neochromis omnicaeruleus, a colour and sex determination polymorphism is associated with a polymorphism in male and female mating preferences. Theoretical work on this incipient species complex found conditions for rapid sympatric speciation by selection on sex determination and sexual selection on male and female colour patterns, under restrictive assumptions. Here we test the biological plausibility of a key assumption of such models, namely, the existence of a male preference against a novel female colour morph before its appearance in the population. We show that most males in a population that lacks the colour polymorphism exhibit a strong mating preference against the novel female colour morph and that reinforcement is not a likely explanation for the origin of such male preferences. Our results show that a specific condition required for the combined action of selection on sex determination and sexual selection to drive sympatric speciation is biologically justified. Finally, we suggest that Lake Victoria cichlids might share an ancestral female recognition scheme, predisposing colour monomorphic populations/species to similar evolutionary pathways leading to divergence of colour morphs in sympatry. PMID:17210017

  8. Estimativa do padrão de preferência térmica de matrizes pesadas (frango de corte Thermal preference pattern estimates of female broiler breeders

    Directory of Open Access Journals (Sweden)

    Fábio P. F. Curto

    2007-04-01

    Full Text Available A produtividade de matrizes pesadas (frango de corte está ligada aos princípios de conforto térmico, diretamente relacionados ao microclima da instalação. Neste trabalho objetivou-se o monitoramento do comportamento de matrizes pesadas usando-se a tecnologia de radiofreqüência, identificadores eletrônicos injetáveis e leitores no interior de modelo de galpão de produção em escala reduzida e distorcida. Utilizaram-se no experimento oito aves com identificação eletrônica. Três antenas foram dispostas em três pontos dentro do modelo: no piso do ninho, na passagem entre a parede lateral e o comedouro e sob o bebedouro. Registraram-se continuamente as temperaturas de bulbo seco (TBS, bulbo úmido (TBU e de globo negro (TGN. Os resultados apontam para um padrão de preferência térmica das aves diferenciado frente às situações de ambiente ocorridas no experimento. Três modelos probabilísticos de comportamento foram desenvolvidos a partir dos registros coletados: modelo probabilístico para uso da passagem: FP = 1,10 - 0,244 ln(TBS, modelo probabilístico para uso do bebedouro: FB = 0,398 + 0,00866 tbs, e modelo probabilístico para uso do ninho: FN = 2,22 - 0,272 TBS + 0,011 TBS² - 0,000144 TBS³.Female broiler breeder productivity is based on the principles of thermal comfort that are directly related with the microclimate inside the housing. This research had the objective of monitoring the behavior of female broiler breeders, using the technology of radio-frequency, injectable transponders and readers in different existing microclimates inside a small scale distorted housing model. Eight birds with electronic identification were used. Three readers were used, in three different points inside the model: on the floor of the nest, in the passage besides the lateral wall and below the water facility. Dry bulb (DBT, wet bulb (WBT and black globe (BGT temperature were measured continuously. The results point out a distinct

  9. Assortativity in generalized preferential attachment models

    CERN Document Server

    Krot, Alexander

    2016-01-01

    In this paper, we analyze assortativity of preferential attachment models. We deal with a wide class of preferential attachment models (PA-class). It was previously shown that the degree distribution in all models of the PA-class follows a power law. Also, the global and the average local clustering coefficients were analyzed. We expand these results by analyzing the assortativity property of the PA-class of models. Namely, we analyze the behavior of $d_{nn}(d)$ which is the average degree of a neighbor of a vertex of degree $d$.

  10. Why do males of the spider Pisaura mirabilis wrap their nuptial gifts in silk: Female preference or male control?

    DEFF Research Database (Denmark)

    Andersen, Tina; Bollerup, Kristine; Toft, Søren;

    2008-01-01

    male mating success. Large oblong gifts were difficult for males to handle during copulation, resulting in shorter copulations for oblong vs. round gifts. Thus, round gifts were not preferred by the females but were beneficial to the males. Our results indicate two adaptive benefits to males...

  11. Are high-quality mates always attractive?: State-dependent mate preferences in birds and humans.

    Science.gov (United States)

    Riebel, Katharina; Holveck, Marie-Jeanne; Verhulst, Simon; Fawcett, Tim W

    2010-05-01

    Sexual selection theory posits that females should choose mates in a way that maximizes their reproductive success. But what exactly is the optimal choice? Most empirical research is based on the assumption that females seek a male of the highest possible quality (in terms of the genes or resources he can provide), and hence show directional preferences for indicators of male quality. This implies that attractiveness and quality should be highly correlated. However, females frequently differ in what they find attractive. New theoretical and empirical insights provide mounting evidence that a female's own quality biases her judgement of male attractiveness, such that male quality and attractiveness do not always coincide. A recent experiment in songbirds demonstrated for the first time that manipulation of female condition can lead to divergent female preferences, with low-quality females actively preferring low-quality males over high-quality males. This result is in line with theory on state-dependent mate choice and is reminiscent of assortative mating preferences in humans. Here we discuss the implications of this work for the study of mate preferences. PMID:20714411

  12. Assortative mating by unwed biological parents of adopted children.

    Science.gov (United States)

    Plomin, R; DeFries, J C; Roberts, M K

    1977-04-22

    Analyses of data obtained from 662 unwed couples whose children were relinquished for adoption reveal that biological parents of adopted children mate assortatively. For physical characters, assortative mating of unwed parents was similar to that of wed parents; for behavior characters, however, there was less assortative mating by the unwed parents. Because assortative mating inflates estimates of genetic parameters in adoption studies, future studies should collect information on both biological parents.

  13. Impact of sensory feed additives on feed intake, feed preferences, and growth of female piglets during the early postweaning period.

    Science.gov (United States)

    Clouard, C; Val-Laillet, D

    2014-05-01

    Our study aimed at investigating the effect of feed supplementation, from weaning, with 3 sensory feed additives (FA1, FA2, and FA3) on feed preferences, feed intake, and growth of piglets. The FA1 contained extract of Stevia rebaudiana (10 to 20%), extract of high-saponin plants (5 to 10%), and excipients (70 to 85%), the FA2 was mainly composed of a natural extract of Citrus sinensis (60 to 80%), and the FA3 was made of a blend of extracts of hot-flavored spices (5 to 15%) and excipients (85 to 95%). At weaning (d 1), a total of 32 female piglets housed in individual pens were allocated to 4 treatments (FA1, FA2, FA3, and control [CON]) of equivalent mean weight. The pigs were fed a standard pelleted prestarter diet from weaning (d 1) to d 15 and a starter diet from d 16 to 28. The diets were supplemented with the feed additives (FA) corresponding to their treatment, while the CON treatment was the standard diets with no additive. Feed refusals were weighed daily and piglets were weighed weekly on d 1, 7, 14, 21, and 28. On the day of feed transition (d 16) as well as 7 (d 23) and 10 d (d 26) later, the animals were consecutively subjected to 1- and 22-h double-choice feeding tests to investigate their preferences during a short period and a longer period of time for the CON starter diet and the starter diet added with the FA corresponding to their treatment. No overall effect of the feed additives was observed on ADFI, ADG, G:F, and final BW. No overall preference was highlighted for the FA1 treatment, except for a preference for the FA1 starter diet during the 1-h test on d 23 (78% of total feed intake; P < 0.01). For the FA2 treatment, the pigs consumed the FA2 starter diet more than the CON starter diet during the 22-h tests on d 16 (67% of total feed intake; P < 0.05) and 26 (62% of total feed intake; P < 0.01). For the FA3 treatment, on d 26, the FA3 starter diet was and tended to be consumed more than the CON starter diet during 1- (69% of total intake; P

  14. Anticipated identification costs: Improving assortment evaluation by diagnostic attributes

    NARCIS (Netherlands)

    Herpen, van E.; Pieters, F.G.M.

    2007-01-01

    Abstract Consumers often make quick assessments of product assortments, to determine if these are worthwhile for further investigation. They anticipate how difficult it will be to distinguish the various options in the assortment, which will influence their assortment evaluations. We reason that the

  15. Active phenotypic assortment in mate selection: self-descriptions and sought-for attributes of mates in dating advertisements.

    Science.gov (United States)

    Sakai, D K; Johnson, R C

    1997-01-01

    Assortative mating results both from social homogamy (coming for similar environments) and active phenotypic assortment (seeking a mate with desired attributes). Dating advertisements provide a means of assessing the role of active phenotypic assortment in the absence of social homogamy. The relative frequency of mention of different attributes (given limited advertising space) is informative regarding the salience of these attributes in active phenotypic assortment. Sex differences in self descriptions and in attributes desired in others in dating advertisements provide a means of evaluating sociobiological issues. Data were analyzed from 191 ads placed by females and 253 ads placed by males seeking to meet members of the opposite sex. The most frequently mentioned attributes are age, race, occupation, moral characteristics, and physical attractiveness. While close to 80 per cent of the advertisers provided information concerning their own race/ethnicity, only a minority of those providing such information limited their quest for a partner to members of their own race/ethnicity. There is substantial assortative mating for religion, family background, status, and educational attainment, yet these attributes are rarely (religion and education) or never (family background) mentioned in advertisements, suggesting that assortative mating on these dimensions may be solely a consequence of social homogamy.

  16. When Do Girls Prefer Football to Fashion? An Analysis of Female Underachievement in Relation to "Realistic" Mathematics Context.

    Science.gov (United States)

    Boaler, Jo

    1994-01-01

    Reports on a study of the move away from abstract calculations toward "mathematics in context" among 50 British female secondary school students. Discusses implications of findings in relation to reported female underachievement and disinterest in school mathematics. (CFR)

  17. Assortment and the evolution of generalized reciprocity.

    Science.gov (United States)

    Rankin, Daniel J; Taborsky, Michael

    2009-07-01

    Reciprocity is often invoked to explain cooperation. Reciprocity is cognitively demanding, and both direct and indirect reciprocity require that individuals store information about the propensity of their partners to cooperate. By contrast, generalized reciprocity, wherein individuals help on the condition that they received help previously, only relies on whether an individual received help in a previous encounter. Such anonymous information makes generalized reciprocity hard to evolve in a well-mixed population, as the strategy will lose out to pure defectors. Here we analyze a model for the evolution of generalized reciprocity, incorporating assortment of encounters, to investigate the conditions under which it will evolve. We show that, in a well-mixed population, generalized reciprocity cannot evolve. However, incorporating assortment of encounters can favor the evolution of generalized reciprocity in which indiscriminate cooperation and defection are both unstable. We show that generalized reciprocity can evolve under both the prisoner's dilemma and the snowdrift game.

  18. Assortativity Decreases the Robustness of Interdependent Networks

    CERN Document Server

    Zhou, Di; Scala, Antonio; Stanley, H Eugene

    2012-01-01

    The protection of critical infrastructures is one of the highest priorities in our technological society. It was recently recognized that interdependencies among different networks can play a crucial role in triggering cascading failures and hence system-wide disasters. A recent model shows how pairs of interdependent networks can exhibit an abrupt percolation transition as failures accumulate. We report on the effects of topology on failure propagation for a model system consisting of two interdependent networks. We find that the internal node correlations in each of the two interdependent networks significantly changes the critical density of failures that triggers the total disruption of the two-network system. We find, in particular, that the assortativity within a single network decreases the robustness of the entire system. The results of this study on the influence of assortativity may provide insights into ways of improving the robustness of network architecture, and thus enhance the level of protecti...

  19. Progesterone and prostaglandin F2α induce species-typical female preferences for male sexual displays in Cope's gray treefrog (Hyla chrysoscelis).

    Science.gov (United States)

    Ward, Jessica L; Love, Elliot K; Baugh, Alexander T; Gordon, Noah M; Tanner, Jessie C; Bee, Mark A

    2015-12-01

    Endocrine systems play critical roles in facilitating sexual behavior in seasonally breeding vertebrates. Much of the research exploring this topic has focused on the endocrine correlates of signaling behavior in males and sexual proceptivity in females. What is less understood is how hormones promote the expression of the often complex and highly selective set of stimulus-response behaviors that are observed in naturally breeding animals. In female frogs, phonotaxis is a robust and sensitive bioassay of mate choice and is exhibited by gravid females during the breeding season. In stark contrast, females exhibit low phonotactic responsiveness outside the breeding season, but the administration of hormones can induce sexual proceptivity. Here we test the hypothesis that manipulation of a minimal set of reproductive hormones-progesterone and prostaglandin F2α-are capable of evoking not only proceptive behavior in non-breeding females, but also the patterns of intraspecific selectivity for male sexual displays observed in gravid females tested during the breeding season. Specifically, we investigated whether preferences for faster call rates, longer call durations, and higher call efforts were similar between breeding and hormone-treated females of Cope's gray treefrog (Hyla chrysoscelis). Hormone injections induced patterns of selective phonotaxis in non-breeding females that were remarkably similar to those observed in breeding females. These results suggest that there may be an important contribution of hormonal pleiotropy in regulating this complex, acoustically-guided sexual behavior. Our findings also support the idea that hormonal induction could be used to evaluate hypotheses about selective mate choice, and its underlying mechanisms, using non-breeding females. PMID:26454212

  20. Genetic and socioeconomic study of mate choice in Latinos reveals novel assortment patterns.

    Science.gov (United States)

    Zou, James Y; Park, Danny S; Burchard, Esteban G; Torgerson, Dara G; Pino-Yanes, Maria; Song, Yun S; Sankararaman, Sriram; Halperin, Eran; Zaitlen, Noah

    2015-11-01

    Nonrandom mating in human populations has important implications for genetics and medicine as well as for economics and sociology. In this study, we performed an integrative analysis of a large cohort of Mexican and Puerto Rican couples using detailed socioeconomic attributes and genotypes. We found that in ethnically homogeneous Latino communities, partners are significantly more similar in their genomic ancestries than expected by chance. Consistent with this, we also found that partners are more closely related--equivalent to between third and fourth cousins in Mexicans and Puerto Ricans--than matched random male-female pairs. Our analysis showed that this genomic ancestry similarity cannot be explained by the standard socioeconomic measurables alone. Strikingly, the assortment of genomic ancestry in couples was consistently stronger than even the assortment of education. We found enriched correlation of partners' genotypes at genes known to be involved in facial development. We replicated our results across multiple geographic locations. We discuss the implications of assortment and assortment-specific loci on disease dynamics and disease mapping methods in Latinos.

  1. Phenotypic assortment in Tetrahymena thermophila: assortment kinetics of antibiotic-resistance markers, tsA, death, and the highly amplified rDNA locus.

    Science.gov (United States)

    Merriam, E V; Bruns, P J

    1988-10-01

    Phenotypic assortment in Tetrahymena thermophila results from random distribution of alleles during amitotic division of the macronucleus. The rate of assortment is dependent on input ratio and the number of assorting units. The assortment of the antibiotic resistance markers Chx, Mpr and gal was determined and is consistent for each with the model of 45 assorting chromosomes. The gene tsA (previously ts-1) shows normal assortment, in contrast to previous reports. A mutation in the highly amplified ribosomal locus (rdnA2) assorts as if present at only 45 copies. Death of clones occurred at a rate consistent with assortment for a single gene.

  2. Are human mating preferences with respect to height reflected in actual pairings?

    Directory of Open Access Journals (Sweden)

    Gert Stulp

    Full Text Available Pair formation, acquiring a mate to form a reproductive unit, is a complex process. Mating preferences are a step in this process. However, due to constraining factors such as availability of mates, rival competition, and mutual mate choice, preferred characteristics may not be realised in the actual partner. People value height in their partner and we investigated to what extent preferences for height are realised in actual couples. We used data from the Millennium Cohort Study (UK and compared the distribution of height difference in actual couples to simulations of random mating to test how established mate preferences map on to actual mating patterns. In line with mate preferences, we found evidence for: (i assortative mating (r = .18, (ii the male-taller norm, and, for the first time, (iii for the male-not-too-tall norm. Couples where the male partner was shorter, or over 25 cm taller than the female partner, occurred at lower frequency in actual couples than expected by chance, but the magnitude of these effects was modest. We also investigated another preference rule, namely that short women (and tall men prefer large height differences with their partner, whereas tall women (and short men prefer small height differences. These patterns were also observed in our population, although the strengths of these associations were weaker than previously reported strength of preferences. We conclude that while preferences for partner height generally translate into actual pairing, they do so only modestly.

  3. Acquired Smell? Mature Females of the Common Green Bottle Fly Shift Semiochemical Preferences from Feces Feeding Sites to Carrion Oviposition Sites.

    Science.gov (United States)

    Brodie, Bekka S; Babcock, Tamara; Gries, Regine; Benn, Arlan; Gries, Gerhard

    2016-01-01

    We investigated foraging decisions by adult females of the common green bottle fly, Lucilia sericata, in accordance with their physiological state. When we gave female flies a choice between visually occluded, fresh canine feces (feeding site) and a CO2-euthanized rat (carrion oviposition site), 3-d-old "protein-starved" females responded equally well to feces and carrion, whereas protein-fed gravid females with mature oocytes responded only to carrion, indicating resource preferences based on a fly's physiological state. Dimethyl trisulfide (DMTS) is known to attract gravid L. sericata females to carrion. Therefore, we analyzed headspace from canine feces by gas chromatographic-electroantennographic detection (GC-EAD) and GC/mass spectrometry. In bioassays, of the 17 fecal odorants that elicited GC-EAD responses from fly antennae, a blend of indole and one or more of the alcohols phenol, m-/p-cresol and 1-octen-3-ol proved as attractive to flies as canine feces. Unlike young females, gravid females need to locate carrion for oviposition and distinguish between fresh and aging carrion, the latter possibly detrimental to offspring. Gravid female L. sericata accomplish this task, in part, by responding to trace amounts of DMTS emanating from fresh carrion and by discriminating against carrion as soon it begins to produce appreciable amounts of indole, which is also the second-most abundant semiochemical in fresh canine feces, and apparently serves as an indicator of food rather than oviposition resources. Our results emphasize the importance of studying foraging choices by flies in accordance with their physiological stage. PMID:26637207

  4. Assortative mating for relative weight: genetic implications.

    Science.gov (United States)

    Allison, D B; Neale, M C; Kezis, M I; Alfonso, V C; Heshka, S; Heymsfield, S B

    1996-03-01

    Most work on the genetics of relative weight has not considered the role of assortative mating, i.e., mate selection based on similarity between mates. We investigated the extent to which engaged men and women in an archival longitudinal database were similar to each other in relative body weight prior to marriage and cohabitation. After controlling for age, a small but statistically significant mate correlation was found for relative weight (r=.13, p=.023), indicating some assortative mating. Furthermore, we examined whether mate similarity in relative weight prior to marriage predicts survival of the marriage. No significant effects were found. In sum, these results are consistent with those of other studies in suggesting that there is a small but significant intermate correlation for relative weight. However, they are unique in showing that these results cannot be explained on the basis of (a) cohabitation, (b) age similarity, or (c) selective survival of marriages between couples more similar in relative weight. The implications of these findings for heritability studies, linkage studies, and the estimation of shared environmental effects are discussed. PMID:8639146

  5. Positive network assortativity of influenza vaccination at a high school: implications for outbreak risk and herd immunity.

    Science.gov (United States)

    Barclay, Victoria C; Smieszek, Timo; He, Jianping; Cao, Guohong; Rainey, Jeanette J; Gao, Hongjiang; Uzicanin, Amra; Salathé, Marcel

    2014-01-01

    Schools are known to play a significant role in the spread of influenza. High vaccination coverage can reduce infectious disease spread within schools and the wider community through vaccine-induced immunity in vaccinated individuals and through the indirect effects afforded by herd immunity. In general, herd immunity is greatest when vaccination coverage is highest, but clusters of unvaccinated individuals can reduce herd immunity. Here, we empirically assess the extent of such clustering by measuring whether vaccinated individuals are randomly distributed or demonstrate positive assortativity across a United States high school contact network. Using computational models based on these empirical measurements, we further assess the impact of assortativity on influenza disease dynamics. We found that the contact network was positively assortative with respect to influenza vaccination: unvaccinated individuals tended to be in contact more often with other unvaccinated individuals than with vaccinated individuals, and these effects were most pronounced when we analyzed contact data collected over multiple days. Of note, unvaccinated males contributed substantially more than unvaccinated females towards the measured positive vaccination assortativity. Influenza simulation models using a positively assortative network resulted in larger average outbreak size, and outbreaks were more likely, compared to an otherwise identical network where vaccinated individuals were not clustered. These findings highlight the importance of understanding and addressing heterogeneities in seasonal influenza vaccine uptake for prevention of large, protracted school-based outbreaks of influenza, in addition to continued efforts to increase overall vaccine coverage.

  6. Positive network assortativity of influenza vaccination at a high school: implications for outbreak risk and herd immunity.

    Directory of Open Access Journals (Sweden)

    Victoria C Barclay

    Full Text Available Schools are known to play a significant role in the spread of influenza. High vaccination coverage can reduce infectious disease spread within schools and the wider community through vaccine-induced immunity in vaccinated individuals and through the indirect effects afforded by herd immunity. In general, herd immunity is greatest when vaccination coverage is highest, but clusters of unvaccinated individuals can reduce herd immunity. Here, we empirically assess the extent of such clustering by measuring whether vaccinated individuals are randomly distributed or demonstrate positive assortativity across a United States high school contact network. Using computational models based on these empirical measurements, we further assess the impact of assortativity on influenza disease dynamics. We found that the contact network was positively assortative with respect to influenza vaccination: unvaccinated individuals tended to be in contact more often with other unvaccinated individuals than with vaccinated individuals, and these effects were most pronounced when we analyzed contact data collected over multiple days. Of note, unvaccinated males contributed substantially more than unvaccinated females towards the measured positive vaccination assortativity. Influenza simulation models using a positively assortative network resulted in larger average outbreak size, and outbreaks were more likely, compared to an otherwise identical network where vaccinated individuals were not clustered. These findings highlight the importance of understanding and addressing heterogeneities in seasonal influenza vaccine uptake for prevention of large, protracted school-based outbreaks of influenza, in addition to continued efforts to increase overall vaccine coverage.

  7. Human nonindependent mate choice: is model female attractiveness everything?

    Science.gov (United States)

    Vakirtzis, Antonios; Roberts, S Craig

    2012-05-06

    Following two decades of research on non-human animals, there has recently been increased interest in human nonindependent mate choice, namely the ways in which choosing women incorporate information about a man's past or present romantic partners ('model females') into their own assessment of the male. Experimental studies using static facial images have generally found that men receive higher desirability ratings from female raters when presented with attractive (compared to unattractive) model females. This phenomenon has a straightforward evolutionary explanation: the fact that female mate value is more dependent on physical attractiveness compared to male mate value. Furthermore, due to assortative mating for attractiveness, men who are paired with attractive women are more likely to be of high mate value themselves. Here, we also examine the possible relevance of model female cues other than attractiveness (personality and behavioral traits) by presenting video recordings of model females to a set of female raters. The results confirm that the model female's attractiveness is the primary cue. Contrary to some earlier findings in the human and nonhuman literature, we found no evidence that female raters prefer partners of slightly older model females. We conclude by suggesting some promising variations on the present experimental design.

  8. ASSORTMENT AND PRICE POLICY OF STATE PHARMACIES OF MOSCOW

    Directory of Open Access Journals (Sweden)

    I. V. Voronovich

    2015-01-01

    Full Text Available The most important index which determines the level and quality of pharmaceutical support is the correspondence of assortment to consumers needs. Assortment policy is determined by the functions implemented, and the problems of organization of pharmaceutical support of medicinal organizations within the frameworks of substantiated and reasonable expenditure of budget funds, and affordable pharmaceutical support of the population. The purpose of this research was the study of assortment and price policy of state pharmacies of Moscow. The objects were pharmacy subdivisions of state pharmacy network of Moscow. We have used sociological methods (questionnaire, interviewing, method of marketing, and statistic analysis. We have studied the assortment structure, assortment groups’ distribution on price segments. We have established that the drugs, more than 60% of which are foreign-made occupied more than a half of the assortment. Medicinal drugs in 50 rubles price spectrum occupy the biggest share of pharmacy assortment. Distribution within every assortment group revealed that more than a half of drugs are in average price spectrum from 50 to 500 rubles. Average charge for VED amounts to 21.87%, and for drugs which were not included in VED list – 34.07%. The charge for the goods, the price of which is not regulated, trade charge is more. 

  9. Advertisement-call modification, male competition and female preference in the bird-voiced treefrog Hyla avivoca

    OpenAIRE

    Martínez-Rivera, Carlos César; Gerhardt, H. Carl

    2008-01-01

    Senders and receivers influence dynamic characteristics of the signals used for mate attraction over different time scales. On a moment-to-moment basis, interactions among senders competing for a mate influence dynamic characteristics, whereas the preferences of receivers of the opposite gender exert an influence over evolutionary time. We observed and recorded the calling patterns of the bird-voiced treefrog Hyla avivoca, to assess how the dynamic characters of calls vary during interactions...

  10. Knockout of p11 attenuates the acquisition and reinstatement of cocaine conditioned place preference in male but not in female mice.

    Science.gov (United States)

    Thanos, Panayotis K; Malave, Lauren; Delis, Foteini; Mangine, Paul; Kane, Katie; Grunseich, Adam; Vitale, Melissa; Greengard, Paul; Volkow, Nora D

    2016-07-01

    Cocaine's enhancement of dopamine signaling is crucial for its rewarding effects but its serotonergic effects are also relevant. Here we examined the role of the protein p11, which recruits serotonin 5HT1B and 5HT4 receptors to the cell surface, in cocaine reward. For this purpose we tested wild-type (WT) and p11 knockout (KO) male and female mice for cocaine conditioned place preference (CPP) and its cocaine-induced reinstatement at different abstinence times, after 8 days of extinction and 28 days of being home-caged. All mice showed significant cocaine CPP. Among males, p11KO showed lower CPP than WT; this difference was also evident after 28 days of home-cage abstinence. In contrast, in females there were no CPP differences between p11KO and WT mice at any time point tested. Cocaine priming after the 28-day home-cage abstinence period also resulted in lower cocaine conditioned motor activity in both male and female p11KO mice. These results suggest that cocaine CPP and its persistence during extinction and reinstatement are modulated in a sex-differentiated manner by p11. The lack of protein p11 confers protection from CPP on male, but not female mice, immediately after cocaine conditioning as well as after prolonged abstinence, but not after short-term withdrawal. Synapse 70:293-301, 2016. © 2016 Wiley Periodicals, Inc. PMID:26990537

  11. Assortment structure in beech coppice stands in Boljevac region

    Directory of Open Access Journals (Sweden)

    Danilović Milorad

    2004-01-01

    Full Text Available Assortment structure in beech coppice stands was studied in the area of Boljevac. Assortment structure was evaluated according to the articles of the valid standard (JUS. The assortments represented in the assortment structure, based on the stemwood quality are: Logs for matches, sawlogs I II and III classes, mine timber, technical roundwood, pulpwood, wood for excelsior and fuelwood, I and II classes. The results of the analyses show that the value assortment structure (sum of the values of assortments produced from one tree grows significantly with the increase of tree diameter and this dependence is presented by a degree function. The value percentage of logs for matches, sawlogs of the I and II classes, technical roundwood, mine timber, fuelwood and pulpwood, grows with the increase of the tree diameter. The occurrence of better quality logs (sawlogs in these stands, in contrast to the beech coppice stand in the area of Crni Vrh results from the more favourable diameter structure. There are no statistically significant differences between the value assortment structure on the established sample plot series within the same locality, consequently the data ere united. Because of the differences in stand age, the data are not unified for the localities, although there are no statistically significant differences between value assortment structure for diameter degrees represented in them. False heart (red heart is one of very significant defects of beech wood, and its incidence, inter alia, depends on tree age. The low effect of this defect of wood resulted in a significant percentage of logs for matches. Along with the value assortment structure this paper also presents the percentage of assortments depending on tree diameter.

  12. Differences in larval nutritional requirements and female oviposition preference reflect the order of fruit colonization of Zaprionus indianus and Drosophila simulans.

    Science.gov (United States)

    Matavelli, Cristiane; Carvalho, Maria João A; Martins, Nelson E; Mirth, Christen K

    2015-11-01

    Species coexist using the same nutritional resource by partitioning it either in space or time, but few studies explore how species-specific nutritional requirements allow partitioning. Zaprionus indianus and Drosophila simulans co-exist in figs by invading the fruit at different stages; Z. indianus colonizes ripe figs, whereas D. simulans oviposits in decaying fruit. Larvae feed on yeast growing on the fruit, which serves as their primary protein source. Because yeast populations increase as fruit decays, we find that ripe fruit has lower protein content than rotting fruit. Therefore, we hypothesized that Z. indianus and D. simulans larvae differ in their dietary requirements for protein. We used nutritional geometry to assess the effects of protein and carbohydrate concentration in the larval diet on life history characters in both species. Survival, development time, and ovariole number respond differently to the composition of the larval diet, with Z. indianus generally performing better across a wider range of protein concentrations. Correspondingly, we found that Z. indianus females preferred to lay eggs on low protein foods, while D. simulans females chose higher protein foods for oviposition when competing with Z. indianus. We propose the different nutritional requirements and oviposition preference of these two species allows them to temporally partition their habitat.

  13. Incipient sexual isolation in Laupala cerasina: Females discriminate population-level divergence in acoustic characters

    Institute of Scientific and Technical Information of China (English)

    Jaime L.GRACE; Kerry L.SHAW

    2012-01-01

    Sexual selection by female choice can shape the evolution of male traits within populations,since the most attractive males experience an increase in fitness through elevated mating success.Speciation by sexual selection occurs when evolution in traits and preferences within populations causes differentiation among populations,such that females in alternative populations prefer sexual signals of their own population relative to others.Differentiated traits and preferences thereby play an active role in limiting gene flow between divergent populations.The effectiveness of differentiawel preferences in maintaining differentiated male signals against the homogenizing effects of gene flow across populations will be limited by both the degree to which females can discriminate against non-local males,and the breeding values of traits and preferences.Populations of the Hawaiian cricket Laupala cerasina have diverged in pulse rate,a sexually selected male signal,and female acoustic preference for pulse rate.Gene flow between neighboring populations may be reduced if migrants from sexually diverged populations experience reduced mating success.We show that females discriminate among divergent songs characteristic of neighboring populations,that differences among populations in song and preference breed true in a common environment,and that mean preferences for each population closely match the mean pulse rates.Divergence in preference was observed only between populations that also differed in song.Along with a striking ability to discriminate slight differences in song,correlated evolution of song and preference within populations could be a mechanism that promotes assortative mating among populations,thereby reducing gene flow,and leading to speciation in Laupala.

  14. Incipient sexual isolation in Laupala cerasina: Females discriminate population-level divergence in acoustic characters

    Directory of Open Access Journals (Sweden)

    Jaime L. GRACE, Kerry L. SHAW

    2012-06-01

    Full Text Available Sexual selection by female choice can shape the evolution of male traits within populations, since the most attractive males experience an increase in fitness through elevated mating success. Speciation by sexual selection occurs when evolution in traits and preferences within populations causes differentiation among populations, such that females in alternative populations prefer sexual signals of their own population relative to others. Differentiated traits and preferences thereby play an active role in limiting gene flow between divergent populations. The effectiveness of differentiated preferences in maintaining differentiated male signals against the homogenizing effects of gene flow across populations will be limited by both the degree to which females can discriminate against non-local males, and the breeding values of traits and preferences. Populations of the Hawaiian cricket Laupala cerasina have diverged in pulse rate, a sexually selected male signal, and female acoustic preference for pulse rate. Gene flow between neighboring populations may be reduced if migrants from sexually diverged populations experience reduced mating success. We show that females discriminate among divergent songs characteristic of neighboring populations, that diffe­rences among populations in song and preference breed true in a common environment, and that mean preferences for each population closely match the mean pulse rates. Divergence in preference was observed only between populations that also differed in song. Along with a striking ability to discriminate slight differences in song, correlated evolution of song and preference within populations could be a mechanism that promotes assortative mating among populations, thereby reducing gene flow, and leading to speciation in Laupala [Current Zoology 58 (3: 416-425, 2012].

  15. Recent social environment affects colour-assortative shoaling in juvenile angelfish (Pterophyllum scalare).

    Science.gov (United States)

    Gómez-Laplaza, Luis M

    2009-09-01

    Theory predicts that fish should show colour-assortative shoaling in order to avoid the oddity effect whereby individuals that differ in some feature from the group majority appear to incur increased risk of predation. It has also been shown that early experience plays an important role in affecting social preferences in some fish species. In this study, the importance of colour phenotype in promoting assortative shoaling and the role played by the recent social environment on its expression were investigated in juvenile angelfish, Pterophyllum scalare. Individuals of the uniformly black and golden colour morphs were housed in a group with conspecifics of like and unlike body colour to themselves, as well as in mixed-colour groups for 4 weeks. Subsequently, they were subjected to a binary choice to shoal with a group of conspecifics composed of unfamiliar fish of either a like or unlike colour phenotype to themselves. The response of the individuals to the colour attributes of the shoals was related to their recent social environment. Fish in like- and mixed-colour previous treatments showed a preferential association with like colour conspecifics. In contrast, the shoaling behaviour exhibited by fish previously maintained with a group of unlike-coloured conspecifics (cross-housed treatment) indicated no significant preference for any of the shoals. The results suggest that angelfish use body colouration as an intraspecific shoaling cue and that learning, in the form of recent familiarization with a specific colour phenotype of conspecifics, can affect colour-assortative shoaling preferences in this species. This learning component of the choice need not be restricted to early developmental stages. PMID:19376208

  16. Mate choice for a male carotenoid-based ornament is linked to female dietary carotenoid intake and accumulation

    Directory of Open Access Journals (Sweden)

    Toomey Matthew B

    2012-01-01

    Full Text Available Abstract Background The coevolution of male traits and female mate preferences has led to the elaboration and diversification of sexually selected traits; however the mechanisms that mediate trait-preference coevolution are largely unknown. Carotenoid acquisition and accumulation are key determinants of the expression of male sexually selected carotenoid-based coloration and a primary mechanism maintaining the honest information content of these signals. Carotenoids also influence female health and reproduction in ways that may alter the costs and benefits of mate choice behaviours and thus provide a potential biochemical link between the expression of male traits and female preferences. To test this hypothesis, we manipulated the dietary carotenoid levels of captive female house finches (Carpodacus mexicanus and assessed their mate choice behavior in response to color-manipulated male finches. Results Females preferred to associate with red males, but carotenoid supplementation did not influence the direction or strength of this preference. Females receiving a low-carotenoid diet were less responsive to males in general, and discrimination among the colorful males was positively linked to female plasma carotenoid levels at the beginning of the study when the diet of all birds was carotenoid-limited. Conclusions Although female preference for red males was not influenced by carotenoid intake, changes in mating responsiveness and discrimination linked to female carotenoid status may alter how this preference is translated into choice. The reddest males, with the most carotenoid rich plumage, tend to pair early in the breeding season. If carotenoid-related variations in female choice behaviour shift the timing of pairing, then they have the potential to promote assortative mating by carotenoid status and drive the evolution of carotenoid-based male plumage coloration.

  17. Assortative mating for cultural identification as indicated by language use.

    Science.gov (United States)

    Nagoshi, C T; Johnson, R C; Danko, G P

    1990-01-01

    Persons of Japanese ancestry from Hawaii who marry within their own racial/ethnic group show a significant degree of homogamous assortative mating for "pidgin" and for standard English usage, variables reflective of important cultural differences in Hawaii. Persons of Japanese ancestry who married persons of other racial/ethnic groups had less exposure to pidgin in their parental homes and were less likely to speak this dialect of English. Sibling-spouse analyses suggested that assortment for such language use is entirely due to social homogamy rather than active phenotypic assortment.

  18. Assortative mixing in functional brain networks during epileptic seizures

    CERN Document Server

    Bialonski, Stephan

    2013-01-01

    We investigate assortativity of functional brain networks before, during, and after one-hundred epileptic seizures with different anatomical onset locations. We construct binary functional networks from multi-channel electroencephalographic data recorded from 60 epilepsy patients, and from time-resolved estimates of the assortativity coefficient we conclude that positive degree-degree correlations are inherent to seizure dynamics. While seizures evolve, an increasing assortativity indicates a segregation of the underlying functional network into groups of brain regions that are only sparsely interconnected, if at all. Interestingly, assortativity decreases already prior to seizure end. Together with previous observations of characteristic temporal evolutions of global statistical properties and synchronizability of epileptic brain networks, our findings may help to gain deeper insights into the complicated dynamics underlying generation, propagation, and termination of seizures.

  19. Lower bound of assortativity coefficient in scale-free networks

    CERN Document Server

    Yang, Dan; Zhou, Tao

    2016-01-01

    The degree-degree correlation is important in understanding the structural organization of a network and the dynamics upon a network. Such correlation is usually measured by the assortativity coefficient $r$, with natural bounds $r \\in [-1,1]$. For scale-free networks with power-law degree distribution $p(k) \\sim k^{-\\gamma}$, we analytically obtain the lower bound of assortativity coefficient in the limit of large network size, which is not -1 but dependent on the power-law exponent $\\gamma$. This work challenges the validation of assortativity coefficient in heterogeneous networks, suggesting that one cannot judge whether a network is positively or negatively correlated just by looking at its assortativity coefficient.

  20. Continuous microfluidic assortment of interactive ligands (CMAIL)

    Science.gov (United States)

    Hsiao, Yi-Hsing; Huang, Chao-Yang; Hu, Chih-Yung; Wu, Yen-Yu; Wu, Chung-Hsiun; Hsu, Chia-Hsien; Chen, Chihchen

    2016-08-01

    Finding an interactive ligand-receptor pair is crucial to many applications, including the development of monoclonal antibodies. Biopanning, a commonly used technique for affinity screening, involves a series of washing steps and is lengthy and tedious. Here we present an approach termed continuous microfluidic assortment of interactive ligands, or CMAIL, for the screening and sorting of antigen-binding single-chain variable antibody fragments (scFv) displayed on bacteriophages (phages). Phages carrying native negative charges on their coat proteins were electrophoresed through a hydrogel matrix functionalized with target antigens under two alternating orthogonal electric fields. During the weak horizontal electric field phase, phages were differentially swept laterally depending on their affinity for the antigen, and all phages were electrophoresed down to be collected during the strong vertical electric field phase. Phages of different affinity were spatially separated, allowing the continuous operation. More than 105 CFU (colony forming unit) antigen-interacting phages were isolated with ~100% specificity from a phage library containing 3 × 109 individual members within 40 minutes of sorting using CMAIL. CMAIL is rapid, sensitive, specific, and does not employ washing, elution or magnetic beads. In conclusion, we have developed an efficient and cost-effective method for isolating and sorting affinity reagents involving phage display.

  1. The Algebra of Assortative Encounters and the Evolution of Cooperation

    OpenAIRE

    Bergstrom, Ted

    2001-01-01

    This paper explores the quantitative relation between non random, assortative matching and the maintenance of cooperative behavior under evolutionary dynamics. We consider a population of individuals who are \\hardwired" to play either cooperate or defect. They meet other individuals according to some random process and play their programmed strategy in a game of Prisoners' Dilemma. The type that gets the higher expected payoff reproduces more rapidly. We de¯ne an index of assortativity of en...

  2. Assortative and disassortative mixing investigated using the spectra of graphs

    CERN Document Server

    Jalan, Sarika

    2015-01-01

    We investigate the impact of degree-degree correlations on the spectra of networks. Even though density distributions exhibit drastic changes depending on the (dis)assortative mixing and the network architecture, the short range correlations in eigenvalues exhibit universal RMT predictions. The long range correlations turn out to be a measure of randomness in (dis)assortative networks. The analysis further provides insight in to the origin of high degeneracy at the zero eigenvalue displayed by majority of the biological networks.

  3. Managing assortment in terms of foreign economic activity of the enterprise trade

    Directory of Open Access Journals (Sweden)

    Sergei Udin

    2015-02-01

    Full Text Available Assortment management is the main task of trade enterprises. Assortment is a basic tool in the marketing mix, it affects the sales and distribution costs. Management of assortment is an important issue for interna-tional companies, because they have a high cost of export-import operations, and this fact influences the financial result. The article considers the information technology assortment management aimed at increas-ing turnover and reducing distribution costs by forming a balanced assortment structure.

  4. Size-assortative mating and sexual size dimorphism are predictable from simple mechanics of mate-grasping behavior

    Directory of Open Access Journals (Sweden)

    Jablonski Piotr G

    2010-11-01

    Full Text Available Abstract Background A major challenge in evolutionary biology is to understand the typically complex interactions between diverse counter-balancing factors of Darwinian selection for size assortative mating and sexual size dimorphism. It appears that rarely a simple mechanism could provide a major explanation of these phenomena. Mechanics of behaviors can predict animal morphology, such like adaptations to locomotion in animals from various of taxa, but its potential to predict size-assortative mating and its evolutionary consequences has been less explored. Mate-grasping by males, using specialized adaptive morphologies of their forelegs, midlegs or even antennae wrapped around female body at specific locations, is a general mating strategy of many animals, but the contribution of the mechanics of this wide-spread behavior to the evolution of mating behavior and sexual size dimorphism has been largely ignored. Results Here, we explore the consequences of a simple, and previously ignored, fact that in a grasping posture the position of the male's grasping appendages relative to the female's body is often a function of body size difference between the sexes. Using an approach taken from robot mechanics we model coercive grasping of females by water strider Gerris gracilicornis males during mating initiation struggles. We determine that the male optimal size (relative to the female size, which gives the males the highest grasping force, properly predicts the experimentally measured highest mating success. Through field sampling and simulation modeling of a natural population we determine that the simple mechanical model, which ignores most of the other hypothetical counter-balancing selection pressures on body size, is sufficient to account for size-assortative mating pattern as well as species-specific sexual dimorphism in body size of G. gracilicornis. Conclusion The results indicate how a simple and previously overlooked physical mechanism

  5. An experimental test of condition-dependent male and female mate choice in zebra finches.

    Science.gov (United States)

    Holveck, Marie-Jeanne; Geberzahn, Nicole; Riebel, Katharina

    2011-01-01

    In mating systems with social monogamy and obligatory bi-parental care, such as found in many songbird species, male and female fitness depends on the combined parental investment. Hence, both sexes should gain from choosing mates in high rather than low condition. However, theory also predicts that an individual's phenotypic quality can constrain choice, if low condition individuals cannot afford prolonged search efforts and/or face higher risk of rejection. In systems with mutual mate choice, the interaction between male and female condition should thus be a better predictor of choice than either factor in isolation. To address this prediction experimentally, we manipulated male and female condition and subsequently tested male and female mating preferences in zebra finches Taeniopygia guttata, a songbird species with mutual mate choice and obligatory bi-parental care. We experimentally altered phenotypic quality by manipulating the brood size in which the birds were reared. Patterns of association for high- or low-condition individuals of the opposite sex differed for male and female focal birds when tested in an 8-way choice arena. Females showed repeatable condition-assortative preferences for males matching their own rearing background. Male preferences were also repeatable, but not predicted by their own or females' rearing background. In combination with a brief review of the literature on condition-dependent mate choice in the zebra finch we discuss whether the observed sex differences and between-studies differences arise because males and females differ in context sensitivity (e.g. male-male competition suppressing male mating preferences), sampling strategies or susceptibility to rearing conditions (e.g. sex-specific effect on physiology). While a picture emerges that juvenile and current state indeed affect preferences, the development and context-dependency of mutual state-dependent mate choice warrants further study. PMID:21901147

  6. An experimental test of condition-dependent male and female mate choice in zebra finches.

    Directory of Open Access Journals (Sweden)

    Marie-Jeanne Holveck

    Full Text Available In mating systems with social monogamy and obligatory bi-parental care, such as found in many songbird species, male and female fitness depends on the combined parental investment. Hence, both sexes should gain from choosing mates in high rather than low condition. However, theory also predicts that an individual's phenotypic quality can constrain choice, if low condition individuals cannot afford prolonged search efforts and/or face higher risk of rejection. In systems with mutual mate choice, the interaction between male and female condition should thus be a better predictor of choice than either factor in isolation. To address this prediction experimentally, we manipulated male and female condition and subsequently tested male and female mating preferences in zebra finches Taeniopygia guttata, a songbird species with mutual mate choice and obligatory bi-parental care. We experimentally altered phenotypic quality by manipulating the brood size in which the birds were reared. Patterns of association for high- or low-condition individuals of the opposite sex differed for male and female focal birds when tested in an 8-way choice arena. Females showed repeatable condition-assortative preferences for males matching their own rearing background. Male preferences were also repeatable, but not predicted by their own or females' rearing background. In combination with a brief review of the literature on condition-dependent mate choice in the zebra finch we discuss whether the observed sex differences and between-studies differences arise because males and females differ in context sensitivity (e.g. male-male competition suppressing male mating preferences, sampling strategies or susceptibility to rearing conditions (e.g. sex-specific effect on physiology. While a picture emerges that juvenile and current state indeed affect preferences, the development and context-dependency of mutual state-dependent mate choice warrants further study.

  7. Assortative mating and the maintenance of population structure in a natural hybrid zone.

    Science.gov (United States)

    Culumber, Zachary W; Ochoa, Olivia M; Rosenthal, Gil G

    2014-08-01

    Understanding the factors that give rise to natural hybrid zones and govern their dynamics and structure is important to predicting the evolutionary consequences of hybridization. Here we use a combination of multigenerational population genetic data, mating patterns from a natural population, behavioral assays, and mark-recapture data within clinal hybrid zones of the genus Xiphophorus to test the role of assortative mating in maintaining population structure and the potential for ongoing genetic exchange between heterospecifics. Our data demonstrate that population structure is temporally robust and driven largely by assortative mating stemming from precopulatory isolation between pure species. Furthermore, mark-recapture data revealed that rates of migration within the same stream reach are far below the level needed to support population structure. In contrast to many empirical studies of natural hybrid zones, there appeared to be no hybrid male dysfunction or discrimination against hybrid males by pure parental females, and hybrid females mated and associated with pure species and hybrid males at random. Despite strong isolation between pure parentals, hybrids therefore can act as a conduit for genetic exchange between heterospecifics, which has been shown to increase the tempo of evolutionary change. Additionally, our findings highlight the complexity of natural hybrid zone dynamics, demonstrating that sexual and ecological selection together can give rise to patterns that do not fit classical models of hybrid zone evolution.

  8. Assortative mating and the maintenance of population structure in a natural hybrid zone.

    Science.gov (United States)

    Culumber, Zachary W; Ochoa, Olivia M; Rosenthal, Gil G

    2014-08-01

    Understanding the factors that give rise to natural hybrid zones and govern their dynamics and structure is important to predicting the evolutionary consequences of hybridization. Here we use a combination of multigenerational population genetic data, mating patterns from a natural population, behavioral assays, and mark-recapture data within clinal hybrid zones of the genus Xiphophorus to test the role of assortative mating in maintaining population structure and the potential for ongoing genetic exchange between heterospecifics. Our data demonstrate that population structure is temporally robust and driven largely by assortative mating stemming from precopulatory isolation between pure species. Furthermore, mark-recapture data revealed that rates of migration within the same stream reach are far below the level needed to support population structure. In contrast to many empirical studies of natural hybrid zones, there appeared to be no hybrid male dysfunction or discrimination against hybrid males by pure parental females, and hybrid females mated and associated with pure species and hybrid males at random. Despite strong isolation between pure parentals, hybrids therefore can act as a conduit for genetic exchange between heterospecifics, which has been shown to increase the tempo of evolutionary change. Additionally, our findings highlight the complexity of natural hybrid zone dynamics, demonstrating that sexual and ecological selection together can give rise to patterns that do not fit classical models of hybrid zone evolution. PMID:25058282

  9. Variation in human mate choice: simultaneously investigating heritability, parental influence, sexual imprinting, and assortative mating.

    Science.gov (United States)

    Zietsch, Brendan P; Verweij, Karin J H; Heath, Andrew C; Martin, Nicholas G

    2011-05-01

    Human mate choice is central to individuals' lives and to the evolution of the species, but the basis of variation in mate choice is not well understood. Here we looked at a large community-based sample of twins and their partners and parents ([Formula: see text] individuals) to test for genetic and family environmental influences on mate choice, while controlling for and not controlling for the effects of assortative mating. Key traits were analyzed, including height, body mass index, age, education, income, personality, social attitudes, and religiosity. This revealed near-zero genetic influences on male and female mate choice over all traits and no significant genetic influences on mate choice for any specific trait. A significant family environmental influence was found for the age and income of females' mate choices, possibly reflecting parental influence over mating decisions. We also tested for evidence of sexual imprinting, where individuals acquire mate-choice criteria during development by using their opposite-sex parent as the template of a desirable mate; there was no such effect for any trait. The main discernible pattern of mate choice was assortative mating; we found that partner similarity was due to initial choice rather than convergence and also at least in part to phenotypic matching.

  10. Assortment structure in beech coppice stands in the Crni vrh region

    Directory of Open Access Journals (Sweden)

    Danilović Milorad

    2003-01-01

    Full Text Available Assortment structure in beech coppice stands was studied for the region of Crni vrh. Assortment structure was determined according to the standard (JUS in two ecological units. The study results show that the assortment value structure significantly increases with the increase of tree diameter and that there are no statistically significant differences in assortment structure between the selected ecological units. The dependence of the assortment value structure on tree diameter can be represented by an exponential function. The value percentage of assortments made of stem wood in theoretical crosscutting depending on tree diameter has an increasing tendency, except for the wood for excelsior.

  11. Assortment and packaging of the segmented rotavirus genome.

    Science.gov (United States)

    McDonald, Sarah M; Patton, John T

    2011-03-01

    The rotavirus (RV) genome comprises 11 segments of double-stranded RNA (dsRNA) and is contained within a non-enveloped, icosahedral particle. During assembly, a highly coordinated selective packaging mechanism ensures that progeny RV virions contain one of each genome segment. Cis-acting signals thought to mediate assortment and packaging are associated with putative panhandle structures formed by base-pairing of the ends of RV plus-strand RNAs (+RNAs). Viral polymerases within assembling core particles convert the 11 distinct +RNAs to dsRNA genome segments. It remains unclear whether RV +RNAs are assorted before or during encapsidation, and the functions of viral proteins during these processes are not resolved. However, as reviewed here, recent insights gained from the study of RV and two other segmented RNA viruses, influenza A virus and bacteriophage Φ6, reveal potential mechanisms of RV assortment and packaging.

  12. Shifting Preferences in Pornography Consumption.

    Science.gov (United States)

    Zillmann, Dolf; Bryant, Jennings

    1986-01-01

    Concludes that subjects with considerable prior exposure to common, nonviolent pornography preferred to watch uncommon pornography. Male nonstudents preferred it almost exclusively, as did male students to a lesser extent. Females also exhibited this consumption preference, though it was far less pronounced, especially in female students. (JD)

  13. Geometric Assortative Growth Model for Small-World Networks

    Directory of Open Access Journals (Sweden)

    Yilun Shang

    2014-01-01

    Full Text Available It has been shown that both humanly constructed and natural networks are often characterized by small-world phenomenon and assortative mixing. In this paper, we propose a geometrically growing model for small-world networks. The model displays both tunable small-world phenomenon and tunable assortativity. We obtain analytical solutions of relevant topological properties such as order, size, degree distribution, degree correlation, clustering, transitivity, and diameter. It is also worth noting that the model can be viewed as a generalization for an iterative construction of Farey graphs.

  14. Geometric assortative growth model for small-world networks.

    Science.gov (United States)

    Shang, Yilun

    2014-01-01

    It has been shown that both humanly constructed and natural networks are often characterized by small-world phenomenon and assortative mixing. In this paper, we propose a geometrically growing model for small-world networks. The model displays both tunable small-world phenomenon and tunable assortativity. We obtain analytical solutions of relevant topological properties such as order, size, degree distribution, degree correlation, clustering, transitivity, and diameter. It is also worth noting that the model can be viewed as a generalization for an iterative construction of Farey graphs.

  15. Geography, assortative mating, and the effects of sexual selection on speciation with gene flow.

    Science.gov (United States)

    Servedio, Maria R

    2016-01-01

    Theoretical and empirical research on the evolution of reproductive isolation have both indicated that the effects of sexual selection on speciation with gene flow are quite complex. As part of this special issue on the contributions of women to basic and applied evolutionary biology, I discuss my work on this question in the context of a broader assessment of the patterns of sexual selection that lead to, versus inhibit, the speciation process, as derived from theoretical research. In particular, I focus on how two factors, the geographic context of speciation and the mechanism leading to assortative mating, interact to alter the effect that sexual selection through mate choice has on speciation. I concentrate on two geographic contexts: sympatry and secondary contact between two geographically separated populations that are exchanging migrants and two mechanisms of assortative mating: phenotype matching and separate preferences and traits. I show that both of these factors must be considered for the effects of sexual selection on speciation to be inferred. PMID:27087841

  16. Healthy snacks at the checkout counter: A lab and field study on the impact of shelf arrangement and assortment structure on consumer choices

    Directory of Open Access Journals (Sweden)

    van Kleef Ellen

    2012-12-01

    not impacted by manipulations (no main or interaction effects. Employees preferred shelf displays including a larger healthy snack assortment located at top shelves. Employees also felt more freedom in choice when healthy snacks were displayed at top shelves compared to lower shelves. Conclusions Overall, results suggest that increasing the prominence of healthy snacks by enlarging their availability, while permitting access to unhealthy snacks, is a promising strategy to promote sales. These results point to the importance of nudging strategies to encourage healthier snack patterns.

  17. Lilium: breeding history of the modern cultivated assortment

    NARCIS (Netherlands)

    Tuyl, van J.M.; Arens, P.

    2011-01-01

    During the last 50 years the lily has become worldwide one of the most important flower bulbs and cut flowers. They are mainly cultivated in The Netherlands with bulb production acreage of more than 5000 ha. The assortment of lilies consists of thousands of cultivars which can be classified in diffe

  18. [Influence of seedling assortment on Panax notoginseng growth and yield].

    Science.gov (United States)

    Cui, X; Wang, C; Chen, Z

    1998-02-01

    Making Panax notoginseng seedling assortment according to seedling size before transplanting, the result shows that the influence is better, the yield of root tuber and fruit is higher. Culturing good seedling is the fundamental measure to increase yield of P. notoginseng.

  19. Unusual assortment of segments in 2 rare human rotavirus genomes.

    Science.gov (United States)

    De Grazia, Simona; Giammanco, Giovanni M; Potgieter, Christiaan A; Matthijnssens, Jelle; Banyai, Krisztian; Platia, Maria A; Colomba, Claudia; Martella, Vito

    2010-05-01

    Using full-length genome sequence analysis, we investigated 2 rare G3P[9] human rotavirus strains isolated from children with diarrhea. The genomes were recognized as assortments of genes closely related to rotaviruses originating from cats, ruminants, and humans. Results suggest multiple transmissions of genes from animal to human strains of rotaviruses.

  20. The Variety of An Assortment : An Extension to the Attribute-Based Approach

    NARCIS (Netherlands)

    Herpen, van H.W.I.; Pieters, F.G.M.

    2002-01-01

    In recent years, interest in category management has surged, and as a consequence, large retailers now systematically review their product assortments. Variety is a key property of assortments. Assortment variety can determine consumers' store choice and is only gaining in importance with today's in

  1. Females discriminate against heterospecific sperm in a natural hybrid zone.

    Science.gov (United States)

    Cramer, Emily R A; Ålund, Murielle; McFarlane, S Eryn; Johnsen, Arild; Qvarnström, Anna

    2016-08-01

    When hybridization is maladaptive, species-specific mate preferences are selectively favored, but low mate availability may constrain species-assortative pairing. Females paired to heterospecifics may then benefit by copulating with multiple males and subsequently favoring sperm of conspecifics. Whether such mechanisms for biasing paternity toward conspecifics act as important reproductive barriers in socially monogamous vertebrate species remains to be determined. We use a combination of long-term breeding records from a natural hybrid zone between collared and pied flycatchers (Ficedula albicollis and F. hypoleuca), and an in vitro experiment comparing conspecific and heterospecific sperm performance in female reproductive tract fluid, to evaluate the potential significance of female cryptic choice. We show that the females most at risk of hybridizing (pied flycatchers) frequently copulate with multiple males and are able to inhibit heterospecific sperm performance. The negative effect on heterospecific sperm performance was strongest in pied flycatcher females that were most likely to have been previously exposed to collared flycatcher sperm. We thus demonstrate that a reproductive barrier acts after copulation but before fertilization in a socially monogamous vertebrate. While the evolutionary history of this barrier is unknown, our results imply that there is opportunity for it to be accentuated via a reinforcement-like process. PMID:27312694

  2. Assortativity Effects on Diffusion-like Processes in Scale-free Networks

    CERN Document Server

    D'Agostino, Gregorio; Zlatić, Vinko; Caldarelli, Guido

    2011-01-01

    We study the variation in epidemic thresholds in complex networks with different assortativity properties. We determine the thresholds by applying spectral analysis to the matrices associated to the graphs. In order to produce graphs with a specific assortativity we introduce a procedure to sample the space of all the possible networks with a given degree sequence. Our analysis shows that while disassortative networks have an higher epidemiological threshold, assortative networks have a slower diffusion time for diseases. We also used these networks for evaluating the effects of assortativity in a specific dynamic model of sandpile. We show that immunization procedures give different results according to the assortativity of the network considered.

  3. Chickens prefer beautiful humans

    OpenAIRE

    Ghirlanda, Stefano; Jansson, Liselotte; Enquist, Magnus

    2002-01-01

    We trained chickens to react to an average human female face but not to an average male face (or vice-versa). In a subsequent test, the animals showed preferences for faces consistent with human sexual preferences (obtained from university students). This suggests that human preferences arise from general properties of nervous systems, rather than from face-specific adaptations. We discuss this result in the light of current debate on the meaning of sexual signals, and suggest further tests o...

  4. 女大学生的抽象颜色偏好及其与人格特征的关系%Abstract Color Preference and Characteristics among Its Relationship with Personality Female College Students

    Institute of Scientific and Technical Information of China (English)

    逯平平; 崔小迪; 陈国鹏; 许荻枫

    2012-01-01

    Color preferences can be affected by many factors, such as culture, race, gender, age, personality and so on, in addition, these factors are interacted. Eysenck (1981) stated that extrovert people preferred "arousing" colors to increase inner arousal level, whereas introvert people preferred "clam" colors to decrease it. To better explore relationship between color preference and personality, the study focuses on single gender. So the study is to investigate abstract color preference of female college students and its relationship with personality characteristics. Paired-comparisons method and EPQ were adopted to measure 412 female college students' color preferences and personality characteristics respectively. Participants were females aged 18-25, minored in psychology, and reported no color blindness or color weakness. The study chose red, orange, yellow, green, blue, and purple (see CMYK of each color in table 1) as materials. Each color was printed in the form of square (1.45cm * 1.45cm), and 6 colors were paired each other to generate 30 color pairs. 30 color pairs were counterbalanced and arranged in 3 pieces of matt art paper (210mm * 297mm). Subjects were asked to finish color preference test and EPQ in the form of group test. The results showed that the sequence of subjects' color preference was blue, red, yellow, purple, orange, green (see table 2), and there was significant difference among 6 colors' chosen times, F(5, 1800)=35.603, p=0.000. Color preferences in the study confirmed the result of Eysenck (1941), so time influences people's color preference to some extent, it follows some rules though. Regardless of personality characteristics, subjects liked blue most (see table 3 and table 4). Red, orange, and yellow belong to "warm" colors, in addition, blue, green, and purple belong to "cold" colors, so subjects' preference for "warm" or "cold" colors can be obtained. There was significant difference about preference for "warm" or "cold" colors on

  5. Mate preference in wild and domesticated (game-farm) mallards (Anas platyrhynchos): I. Initial preference

    Science.gov (United States)

    Cheng, K.M.; Shoffner, R.N.; Phillips, R.E.; Lee, F.B.

    1978-01-01

    Wild and game-farm mallards (Anas platyrhynchos) raised in pure strain and mixed groups were tested for initial mate preference in a choice test. Female mallards showed no significant preference but males of either strain raised with females of their own strain significantly preferred female models of their own strain during the test. Males raised with females of the other strain merely showed attenuation of their preference for female models of their own strain and did not show preference for female models of the other strain. Game-farm mallards approached models significantly sooner than wild mallards and there was a significant sex X mate interaction.

  6. Assortative mating among animals of captive and wild origin following experimental conservation releases.

    Science.gov (United States)

    Slade, Brendan; Parrott, Marissa L; Paproth, Aleisha; Magrath, Michael J L; Gillespie, Graeme R; Jessop, Tim S

    2014-11-01

    Captive breeding is a high profile management tool used for conserving threatened species. However, the inevitable consequence of generations in captivity is broad scale and often-rapid phenotypic divergence between captive and wild individuals, through environmental differences and genetic processes. Although poorly understood, mate choice preference is one of the changes that may occur in captivity that could have important implications for the reintroduction success of captive-bred animals. We bred wild-caught house mice for three generations to examine mating patterns and reproductive outcomes when these animals were simultaneously released into multiple outdoor enclosures with wild conspecifics. At release, there were significant differences in phenotypic (e.g. body mass) and genetic measures (e.g. Gst and F) between captive-bred and wild adult mice. Furthermore, 83% of offspring produced post-release were of same source parentage, inferring pronounced assortative mating. Our findings suggest that captive breeding may affect mating preferences, with potentially adverse implications for the success of threatened species reintroduction programmes.

  7. Female social preference for males that have evolved via monogamy: evidence of a trade-off between pre- and post-copulatory sexually selected traits?

    OpenAIRE

    Firman, Renée C.

    2014-01-01

    When females mate with multiple males both pre- and post-copulatory sexual selections occur. It has been suggested that females benefit from polyandry when better-quality males are successful in sperm competition and sire high-quality offspring. Indeed, studies of experimental evolution have confirmed that sperm competition selects for both increased ejaculate quality and elevated offspring viability. Fewer investigations have explored whether these fitness benefits are evident beyond early l...

  8. The Sex and the Uni: Educational Assortative Matching the Over-Education*

    OpenAIRE

    Alessandro Tampieri

    2010-01-01

    Educational assortative matching encourages individuals to acquire education so as to increase the probability of marrying a high-income partner. But since everyone is more educated, the chances of a good match do not change. Hence over education emerges, as in absence of educational assortative matching individuals could reach their optimal level of education by exploiting less educational resources. Over-education is stronger the higher the probability of educational assortative matching, t...

  9. Assortative marriages by body mass index have increased simultaneously with the obesity epidemic

    DEFF Research Database (Denmark)

    Adeltoft, Teresa Ajslev; Ängquist, Lars Henrik; Silventoinen, Karri;

    2012-01-01

    Background: The genetic predisposition to obesity may have contributed to the obesity epidemic through assortative mating. We investigated whether spouses were positively assorted by body mass index (BMI; = kg/m(2)) in late childhood, and whether changes in assorted marriage by upper BMI...... percentile were higher and increased more; from 1.39, 1.10-1.81, to 2.39, 1.85-3.09 (p = 0.004). Interpretation: Spousal correlations by pre-marital BMIs were small and stable during the past 65 years. Yet, there were assorted marriages between spouses with high BMI at age 13 years and the tendency increased...

  10. Modern Love : Comparative insights in online dating preferences and assortative mating

    NARCIS (Netherlands)

    Potarca, Gina

    2014-01-01

    Ondanks de opkomst van dating sites in de afgelopen jaren is er nog weinig bekend over de kenmerken en voorkeuren van mensen die een partner online proberen te vinden en over hoe partnerkeuze beïnvloed wordt door dating sites. Dit onderzoek brengt de profielen van gebruikers van een internet dating

  11. Detecting network communities beyond assortativity-related attributes

    Science.gov (United States)

    Liu, Xin; Murata, Tsuyoshi; Wakita, Ken

    2014-07-01

    In network science, assortativity refers to the tendency of links to exist between nodes with similar attributes. In social networks, for example, links tend to exist between individuals of similar age, nationality, location, race, income, educational level, religious belief, and language. Thus, various attributes jointly affect the network topology. An interesting problem is to detect community structure beyond some specific assortativity-related attributes ρ, i.e., to take out the effect of ρ on network topology and reveal the hidden community structures which are due to other attributes. An approach to this problem is to redefine the null model of the modularity measure, so as to simulate the effect of ρ on network topology. However, a challenge is that we do not know to what extent the network topology is affected by ρ and by other attributes. In this paper, we propose a distance modularity, which allows us to freely choose any suitable function to simulate the effect of ρ. Such freedom can help us probe the effect of ρ and detect the hidden communities which are due to other attributes. We test the effectiveness of distance modularity on synthetic benchmarks and two real-world networks.

  12. Palindromes drive the re-assortment in Influenza A.

    Science.gov (United States)

    Zubaer, Abdullah; Thapa, Simrika

    2011-01-01

    Different subtypes of Influenza A virus are associated with species specific, zoonotic or pandemic Influenza. The cause of its severity underlies in complicated evolution of its segmented RNA genome. Although genetic shift and genetic drift are well known in the evolution of this virus, we reported the significant role of unique RNA palindromes in its evolution. Our computational approach identified the existence of unique palindromes in each subtype of Influenza A virus with its absence in Influenza B relating the fact of virulence and vigorous genetic hitchhiking in Influenza A. The current study focused on the re-assortment event responsible for the emergence of pandemic-2009 H1N1 virus, which is associated with outgrow of new palindrome and in turn, changing its RNA structure. We hypothesize that the change in RNA structure due to the presence of palindrome facilitates the event of re-assortment in Influenza A. Thus the evolutionary process of Influenza A is much more complicated as previously known, and that has been demonstrated in this study.

  13. Explosive Synchronization and Emergence of Assortativity on Adaptive Networks

    Institute of Scientific and Technical Information of China (English)

    JIANG Hui-Jun; WU Hao; HOU Zhong-Huai

    2011-01-01

    @@ We report an explosive transition from incoherence to synchronization of coupled phase oscillators on adaptive networks,following an Achlioptas process based on dynamic clustering information.During each adaptive step of the network topology,a portion of the links is randomly removed and the same amount of new links is generated following the so-called product rules(PRs) applied to the dynamic clusters.Particularly,two types of PRs are considered,namely,the min-PR and max-PR.We demonstrate that the synchronization transition becomes explosive in both cases.Interestingly,we find that the min-PR rule can lead to disassortativity of the network topology,while the max-PR rule leads to assortativity.%We report an explosive transition from incoherence to synchronization of coupled phase oscillators on adaptive networks, following an Achlioptas process based on dynamic clustering information. During each adaptive step of the network topology, a portion of the links is randomly removed and the same amount of new links is generated following the so-called product rules (PRs) applied to the dynamic clusters. Particularly, two types of PRs are considered, namely, the min-PR and max-PR. We demonstrate that the synchronization transition becomes explosive in both cases. Interestingly, we find that the min-PR rule can lead to disassortativity of the network topology, while the max-PR rule leads to assortativity.

  14. A test of genetic association among male nuptial coloration, female mating preference, and male aggression bias within a polymorphic population of cichlid fish

    NARCIS (Netherlands)

    van der Sluijs, Inke; Dijkstra, Peter D.; Lindeyer, Charlotte M.; Visser, Bertanne; Smith, Alan M.; Groothuis, Ton G. G.; van Alphen, Jacques J. M.; Seehausen, Ole

    2013-01-01

    Both inter- and intrasexual selection have been implicated in the origin and maintenance of species-rich taxa with diverse sexual traits. Simultaneous disruptive selection by female mate choice and male-male competition can, in theory, lead to speciation without geographical isolation if both act on

  15. Preferred Dance Tempo

    DEFF Research Database (Denmark)

    Dahl, Sofia; Huron, David; Brod, Garvin;

    2014-01-01

    In two experiments participants tuned a drum machine to their preferred dance tempo. Measurements of height, shoulder width, leg length, and weight were taken for each participant, and their sex recorded. Using a multiple regression analysis, height and leg length combined was found to be the best...... predictors of preferred dance tempo in Experiment 1. A second experiment, where males and females were matched in terms of height, resulted in no significant correlation between sex and preferred dance tempo. In the matched sample, height was found to be the single best predictor but with a relatively small...... effect size. These results are consistent with a biomechanical “resonance” model of dancing....

  16. Over-Education and Assortative Matching in Partnerships: A Theoretical Analysis

    Science.gov (United States)

    Tampieri, Alessandro

    2016-01-01

    This paper argues that assortative matching may explain over-education. Education determines individuals' income and, due to the presence of assortative matching, the quality of partners in personal, social and working life. Thus, an individual acquires education to improve the expected partners' quality. However, since every individual of the…

  17. Innovative approaches to the prices management within the framework of product assortment

    Directory of Open Access Journals (Sweden)

    O.I. Laburtseva

    2011-03-01

    Full Text Available The article is devoted to the development of methodical recommendations on a products prices management with presence of substitution or complementation connections in the product assortment. The variants of product intercommunications in the assortment of enterprise are systematized, the proper methodical approaches to pricing are recommended and the results of business-approbation of recommendations are presented.

  18. Methods of forming and realization of assortment policy of retail business enterprises

    Directory of Open Access Journals (Sweden)

    Kudenko Kiril

    2016-07-01

    Full Text Available Within the framework of the article systematisation of methods of forming and realisation of assortment policy of enterprises of retail business is done. Recommendations concerning the priority of the use of separate methods of forming and realisation of assortment policy with different purposes, taking into account their content, advantages and disadvantages are developed.

  19. Social isolation in adolescence alters behaviors in the forced swim and sucrose preference tests in female but not in male rats

    OpenAIRE

    Hong, Suzie; Flashner, Bess; Chiu, Melissa; Hoeve, Elizabeth ver; Luz, Sandra; Bhatnagar, Seema

    2011-01-01

    Social interactions in rodents are rewarding and motivating and social isolation is aversive. Accumulating evidence suggests that disruption of the social environment in adolescence has long-term effects on social interactions, on anxiety-like behavior and on stress reactivity. In previous work we showed that adolescent isolation produced increased reactivity to acute and to repeated stress in female rats, whereas lower corticosterone responses to acute stress and decreased anxiety-related be...

  20. Colour assortative pairing in a colour polymorphic lizard is independent of population morph diversity

    Science.gov (United States)

    Pérez i de Lanuza, Guillem; Font, Enrique; Carretero, Miguel Ángel

    2016-10-01

    Previous work with a colour polymorphic population of Podarcis muralis (Lacertidae) revealed that lizards pair by ventral colour, favouring the same colour (i.e. homomorphic) pairs. Such assortative pairing, which probably results in colour assortative mating, can have consequences for the genetic structure of the population and potentially promote speciation. The population previously studied, located in the Pyrenees, encompasses white, yellow and orange animals, as well as intermediate white-orange and yellow-orange morphs. However, other Pyrenean populations of P. muralis have less ventral colour morphs. Our aim in this study is to test the generality of the assortative colour pairing system, extending our previous analyses to populations with different morph compositions and frequencies. The results show that the assortative pattern of pairing is similar in all the populations analysed and, hence, independent of morph composition and not restricted to pentamorphic populations. This suggests that assortative pairing by colour is a general phenomenon for colour polymorphic populations of P. muralis.

  1. Predation risk as a driving force for phenotypic assortment: a cross-population comparison.

    Science.gov (United States)

    Croft, D P; Darden, S K; Ruxton, G D

    2009-05-22

    Frequency-dependent predation has been proposed as a general mechanism driving the phenotypic assortment of social groups via the 'oddity effect', which occurs when the presence of odd individuals in a group allows a predator to fixate on a single prey item, increasing the predator's attack-to-kill ratio. However, the generality of the oddity effect has been debated and, previously, there has not been an ecological assessment of the role of predation risk in driving the phenotypic assortment of social groups. Here, we compare the levels of body length assortment of social groups between populations of the Trinidadian guppy (Poecilia reticulata) that experience differences in predation risk. As predicted by the oddity effect hypothesis, we observe phenotypic assortment by body length to be greater under high predation risk. However, we found that a number of low-predation populations were also significantly assorted by body length, suggesting that other mechanisms may have a role to play.

  2. Inducing Self-Organized Criticality in a network toy model by neighborhood assortativity

    CERN Document Server

    Allen-Perkins, Alfonso; Pastor, Juan Manuel

    2016-01-01

    Complex networks are a recent type of frameworks used to study complex systems with many interacting elements, such as Self-Organized Criticality (SOC). The network node's tendency to link to other nodes of similar type is characterized by assortative mixing. Real networks exhibit assortative mixing by vertex degree, however typical random network models, such as Erdos-Renyi or Barabasi-Albert, show no assortative arrangements. In this paper we introduce the neighborhood assortativity notion, as the tendency of a node to belong to a community (its neighborhood) showing an average property similar to its own. Imposing neighborhood assortative mixing by degree in a network toy model, SOC dynamics can be found. The long-range correlations resulting from the criticality have been characterized by means of fluctuation analysis and show an anticorrelation in the node's activity. The model contains only one parameter and its statistics plots for different values of the parameter can be collapsed into a single curve....

  3. Phenotypic robustness and the assortativity signature of human transcription factor networks.

    Directory of Open Access Journals (Sweden)

    Dov A Pechenick

    2014-08-01

    Full Text Available Many developmental, physiological, and behavioral processes depend on the precise expression of genes in space and time. Such spatiotemporal gene expression phenotypes arise from the binding of sequence-specific transcription factors (TFs to DNA, and from the regulation of nearby genes that such binding causes. These nearby genes may themselves encode TFs, giving rise to a transcription factor network (TFN, wherein nodes represent TFs and directed edges denote regulatory interactions between TFs. Computational studies have linked several topological properties of TFNs - such as their degree distribution - with the robustness of a TFN's gene expression phenotype to genetic and environmental perturbation. Another important topological property is assortativity, which measures the tendency of nodes with similar numbers of edges to connect. In directed networks, assortativity comprises four distinct components that collectively form an assortativity signature. We know very little about how a TFN's assortativity signature affects the robustness of its gene expression phenotype to perturbation. While recent theoretical results suggest that increasing one specific component of a TFN's assortativity signature leads to increased phenotypic robustness, the biological context of this finding is currently limited because the assortativity signatures of real-world TFNs have not been characterized. It is therefore unclear whether these earlier theoretical findings are biologically relevant. Moreover, it is not known how the other three components of the assortativity signature contribute to the phenotypic robustness of TFNs. Here, we use publicly available DNaseI-seq data to measure the assortativity signatures of genome-wide TFNs in 41 distinct human cell and tissue types. We find that all TFNs share a common assortativity signature and that this signature confers phenotypic robustness to model TFNs. Lastly, we determine the extent to which each of the four

  4. Phenotypic robustness and the assortativity signature of human transcription factor networks.

    Science.gov (United States)

    Pechenick, Dov A; Payne, Joshua L; Moore, Jason H

    2014-08-01

    Many developmental, physiological, and behavioral processes depend on the precise expression of genes in space and time. Such spatiotemporal gene expression phenotypes arise from the binding of sequence-specific transcription factors (TFs) to DNA, and from the regulation of nearby genes that such binding causes. These nearby genes may themselves encode TFs, giving rise to a transcription factor network (TFN), wherein nodes represent TFs and directed edges denote regulatory interactions between TFs. Computational studies have linked several topological properties of TFNs - such as their degree distribution - with the robustness of a TFN's gene expression phenotype to genetic and environmental perturbation. Another important topological property is assortativity, which measures the tendency of nodes with similar numbers of edges to connect. In directed networks, assortativity comprises four distinct components that collectively form an assortativity signature. We know very little about how a TFN's assortativity signature affects the robustness of its gene expression phenotype to perturbation. While recent theoretical results suggest that increasing one specific component of a TFN's assortativity signature leads to increased phenotypic robustness, the biological context of this finding is currently limited because the assortativity signatures of real-world TFNs have not been characterized. It is therefore unclear whether these earlier theoretical findings are biologically relevant. Moreover, it is not known how the other three components of the assortativity signature contribute to the phenotypic robustness of TFNs. Here, we use publicly available DNaseI-seq data to measure the assortativity signatures of genome-wide TFNs in 41 distinct human cell and tissue types. We find that all TFNs share a common assortativity signature and that this signature confers phenotypic robustness to model TFNs. Lastly, we determine the extent to which each of the four components of the

  5. A framework for analyzing contagion in assortative banking networks

    CERN Document Server

    Hurd, Thomas R; Melnik, Sergey

    2016-01-01

    We introduce a probabilistic framework that represents stylized banking networks with the aim of predicting the size of contagion events. Most previous work on random financial networks assumes independent connections between banks, whereas our framework explicitly allows for (dis)assortative edge probabilities (e.g., a tendency for small banks to link to large banks). We analyze default cascades triggered by shocking the network and find that the cascade can be understood as an explicit iterated mapping on a set of edge probabilities that converges to a fixed point. We derive a cascade condition that characterizes whether or not an infinitesimal shock to the network can grow to a finite size cascade, in analogy to the basic reproduction number $R_0$ in epidemic modelling. The cascade condition provides an easily computed measure of the systemic risk inherent in a given banking network topology. Using the percolation theory for random networks we also derive an analytic formula for the frequency of global cas...

  6. The role of conditioning on heterosexual and homosexual partner preferences in rats.

    Science.gov (United States)

    Coria-Avila, Genaro A

    2012-01-01

    Partner preferences are expressed by many social species, including humans. They are commonly observed as selective contacts with an individual, more time spent together, and directed courtship behavior that leads to selective copulation. This review discusses the effect of conditioning on the development of heterosexual and homosexual partner preferences in rodents. Learned preferences may develop when a conditioned stimulus (CS) is associated in contingency with an unconditioned stimulus (UCS) that functions as a reinforcer. Consequently, an individual may display preference for a partner that bears a CS. Some UCS may be more or less reinforcing, depending on when they are experienced, and may be different for males and females. For example, it could be that, only during periods of early development, that stimuli associated with nurture and juvenile play become conditioned. In adulthood, other stimuli such as sexual reward, cohabitation, mild stress, or even pharmacological manipulations may function as reinforcers to condition partner preferences. Evolutionary biologists and psychologists must take into consideration the idea that an individual's experience with reward (i.e. sexual and pharmacological) can override presumably 'innate' mate choices (e.g. assortativeness and orientation) or mate strategies (e.g. monogamy or polygamy) by means of Pavlovian and operant contingencies. In fact, it is likely as innate to learn about the environment in ways that maximize reward and minimize aversive outcomes, making so-called 'proximate' causes (e.g. pleasure) ultimately more powerful predictors of social behavior and choice than so-called 'ultimate' causes (e.g. genetic or reproductive fitness).

  7. Determination of timber assortments obtainable from coppice chestnut stands (Susa Valley, Northern Italy

    Directory of Open Access Journals (Sweden)

    Nosenzo A

    2007-01-01

    Full Text Available Chestnut (Castanea sativa L. coppice stands currently cover about 195.000 ha of Piedmont (North-Western Italy surface, corresponding to 22.4 % of the overall forested area in the region. Most of these forest stands are usually older than the typical rotation period. As a consequence from these stands timber assortments with a higher value could be obtained. The purpose of this study is to assess the amount of timber assortments and to propose a sorting methodology based on measurements on standing trees within these chestnut stands.Five study areas were selected in the Susa Valley, where forest measurements were realized within sampling plots. Timber assortments obtainable from each coppice shoot were then determined by means of the Bitterlich’s relascope. More than 1.000 timber logs were measured. The data elaboration allowed to assess the timber assortment production of the investigated stands. The proposed methodology makes it possible to better exploit timber assortments. In fact, while usually the whole production from chestnut coppices is directly destined to secondary products, the subdivision into assortments could result in a 20 % of products with higher commercial value. It is important to notice that within these stands no tending operation is currently realized. The definition of qualitative features to classify timber assortments can provide useful suggestions on the main yield targets that could be reached through silvicultural management.

  8. Independent preferences

    DEFF Research Database (Denmark)

    Vind, Karl

    1991-01-01

    A simple mathematical result characterizing a subset of a product set is proved and used to obtain additive representations of preferences. The additivity consequences of independence assumptions are obtained for preferences which are not total or transitive. This means that most of the economic ...... theory based on additive preferences - expected utility, discounted utility - has been generalized to preferences which are not total or transitive. Other economic applications of the theorem are given......A simple mathematical result characterizing a subset of a product set is proved and used to obtain additive representations of preferences. The additivity consequences of independence assumptions are obtained for preferences which are not total or transitive. This means that most of the economic...

  9. Sorting on skills and preferences: Tinbergen meets Sattinger

    OpenAIRE

    Dupuy, A.

    2011-01-01

    This paper proposes an assignment model where sorting occurs on attributes that are simultaneously a skill (Sattinger, 1979) and a preference (Tinbergen, 1956). The key feature of this model is that the wage function admits both jobs'' and workers'' attributes as arguments. Since this function is generically nonlinear (Ekeland et al., 2004), even under positive assortative matching, the correlation between the contribution of workers'' attributes to wages and that of jobs'' attributes can var...

  10. 酒店女性住客消费特征与偏好分析*--以福建为例%Analysis on the Female Hotel Guests’Consumption Feature and Preferences:taking Fuj ian province as an example

    Institute of Scientific and Technical Information of China (English)

    范向丽; 郑向敏

    2014-01-01

    With the arrival of sheconomy,female-friendly floor and guestroom which once disappeared several years ago emerges again today.Therefore,many prominent hotels strive to put forward new strategies to enlarge their female market share,howev-er,some of them fail.The reason is that they don’t know about the female guests’needs and consumption preferences accurately, but only follow ,imitate blindly or create gimmicks.So this paper takes a survey on the female guests in 26 lodging enterprises in Fuj ian province,and does a statistical analysis on the data.The results show that,most of the female guests have a salary about RMB4001~8000,and a college degree or above,and business and leisure are their main motive.80% female consider price as the first issue when they choose the hotel.Nearly 70% female make reservation by internet or telephone,and about 90% female guests stay in the hotel less than 3 days.But only 1/3 female guests are satisfied with the hotel service.Based on the result above ,this paper puts forward some targeted measures in market positioning,product designing and marketing.%“她世纪”的到来使得酒店业界一度消失的女性楼层、女性客房悄然重生,一些新锐酒店也纷纷各出新招来扩大自己的女性市场份额。然而,由于一些酒店没有对酒店女性住客的需求特征、消费偏好等进行透彻地分析和调查,而只是出于盲目跟风、简单贴标签或制造噱头等原因,导致其推出女性酒店产品却面临叫好不叫座,甚至无以为继的境地。基于此,本文对福建省内的26家住宿企业的女性住客进行调查访谈,并对调查结果进行了统计分析。分析结果表明:酒店女性住客多为月收入在4001-8000元之间、学历在大专以上的中青年职业女性,出游动机主要为商务、休闲两大类,在选择酒店时,80%女性将价格作为首要考虑因素,近70%女性住客通过网络、电话预定酒店,近90%的女性

  11. Initial Findings Using an Alternative Assessment of Body Shape Preferences.

    Science.gov (United States)

    Ryujin, Donald H.; And Others

    Due to concerns that body shape preferences contribute to eating disorders among women, a new method to assess observer preferences for female body shapes was devised. In prior studies women have preferred thin models, but men have preferred models of average weight. In Experiment 1, an underweight female model was photographed in a white top and…

  12. Perceptual Characteristics of Female Voices.

    Science.gov (United States)

    Batstone, Susan; Tuomi, Seppo K.

    1981-01-01

    Male and females listeners rated 21 young female voices on seven scales representing unique vocal features. Voices were described as "passive", or traditionally female, and "active," characterized as "lively,""colorful," and "sexy." Females found active characteristics more salient; males preferred the passive characteristics. Implications for…

  13. 76 FR 14115 - Culturally Significant Objects Imported for Exhibition Determinations: “Assorted Greek and Roman...

    Science.gov (United States)

    2011-03-15

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition Determinations: ``Assorted Greek and Roman Objects... Greek and Roman Objects'' imported from abroad for temporary exhibition within the United States, are...

  14. Actuality of assortment policy in the modern management of retail business enterprise

    Directory of Open Access Journals (Sweden)

    Yefimova Yevheniia

    2016-07-01

    Full Text Available In the result of research it has been found, that the assortment policy defines the course of actions for managing a point-of-sale assortment which foresees clarification and specification of strategic purpose and current tasks; development and grounding of facilities, methods and forms of activity for their achievement; determination of the real resources providing the realization of the plan. The constituents of assortment policy of enterprise of retail business are identified. It is well-proved that with the help of assortment policy achievement of ultimate goals of an enterprise is provided, the constituents of commercial strategy associate together and the possibility of the most effective usage of resources has arrived.

  15. Assortativity and leadership emergence from anti-preferential attachment in heterogeneous networks

    CERN Document Server

    Sendiña-Nadal, I; Wang, Z; Havlin, S; Boccaletti, S

    2015-01-01

    Many real-world networks exhibit degree-assortativity, with nodes of similar degree more likely to link to one another. Particularly in social networks, the contribution to the total assortativity varies with degree, featuring a distinctive peak slightly past the average degree. The way traditional models imprint assortativity on top of pre-defined topologies is via degree-preserving link permutations, which however destroy the particular graph's hierarchical traits of clustering. Here, we propose the first generative model which creates heterogeneous networks with scale-free-like properties and tunable realistic assortativity. In our approach, two distinct populations of nodes are added to an initial network seed: one (the followers) that abides by usual preferential rules, and one (the potential leaders) connecting via anti-preferential attachments, i.e. selecting lower degree nodes for their initial links. The latter nodes come to develop a higher average degree, and convert eventually into the final hubs....

  16. Understanding the Impact of Brand Delistings on Assortment Evaluations and Store Switching and Complaining Intentions

    NARCIS (Netherlands)

    L.M. Sloot (Laurens); P.C. Verhoef (Peter)

    2004-01-01

    textabstractRecently, retailers have begun considering which brands they can delist without reducing customer satisfaction, losing category sales, or increasing store switching behavior. Although several studies have considered assortment reductions, none has explicitly investigated the impact of to

  17. Recombination and assortment in the macronucleus of Tetrahymena thermophila: a theoretical study by computer simulation.

    Science.gov (United States)

    Doerder, F P; Diblasi, S L

    1984-12-01

    The compound nature of the macronucleus of Tetrahymena thermophila presents multiple opportunities for recombination between genes on the same macronuclear chromosome. Such recombinants should be detectable through their assortment at subsequent amitotic macronuclear divisions. Thus, a macronucleus that is initially AB/ab should produce recombinant assortees of the genotypes Ab/aB. Computer simulation shows that, when the recombination frequency is two or fewer times per cell cycle, recombinant assortees are produced at experimentally measurable frequencies of less than 40%. At higher recombination frequencies, linked genes appear to assort independently. The simulations also show that recombination during macronuclear development can be distinguished from recombination in subsequent cell cycles only if the first appearance of recombinant assortees is 100 or more fissions after conjugation. The use of macronuclear recombination and assortment as a means of mapping macronuclear genes is severely constrained by the large variances in assortment outcomes; with experimentally small sample sizes, such mapping is impossible.

  18. A mechanism for the evolution of altruism among nonkin: positive assortment through environmental feedback.

    Science.gov (United States)

    Pepper, John W; Smuts, Barbara B

    2002-08-01

    The evolution of altruism often requires genetic similarity among interactors. For structured populations in which a social trait affects all group members, this entails positive assortment, meaning that cooperators and noncooperators tend to be segregated into different groups. Several authors have claimed that mechanisms other than common descent can produce positive assortment, but this claim has not been generally accepted. Here, we describe one such mechanism. The process of "environmental feedback" requires only that the cooperative trait affects the quality of the local environment and that individuals are more likely to leave low-quality than high-quality environments. We illustrate this dynamic using an agent-based spatial model of feeding restraint. Depending on parameter settings, results included both positive assortment (required for the evolution of altruism) and negative assortment (required for the evolution of spite). The mechanism of environmental feedback appears to be a general one that could play a role in the evolution of many forms of cooperation.

  19. Educational assortative mating and economic inequality: a comparative analysis of three Latin American countries.

    Science.gov (United States)

    Torche, Florencia

    2010-05-01

    Educational assortative mating and economic inequality are likely to be endogenously determined, but very little research exists on their empirical association. Using census data and log-linear and log-multiplicative methods, I compare the patterns of educational assortative mating in Brazil, Chile, and Mexico, and explore the association between marital sorting and earnings inequality across countries. The analysis finds substantial variation in the strength of specific barriers to educational intermarriage between countries, and a close association between these barriers and the earnings gaps across educational categories within countries. This finding suggests an isomorphism between assortative mating and economic inequality. Furthermore, educational marital sorting is remarkably symmetric across gender in spite of the different resources that men and women bring to the union. This study highlights the limitations of using single aggregate measures of spousal educational resemblance (such as the correlation coefficient between spouses' schooling) to capture variation in assortative mating and its relationship with socioeconomic inequality.

  20. An institutional mechanism for assortment in an ecology of games.

    Science.gov (United States)

    Smaldino, Paul E; Lubell, Mark

    2011-01-01

    Recent research has revived Long's "ecology of games" model to analyze how social actors cooperate in the context of multiple political and social games. However, there is still a paucity of theoretical work that considers the mechanisms by which large-scale cooperation can be promoted in a dynamic institutional landscape, in which actors can join new games and leave old ones. This paper develops an agent-based model of an ecology of games where agents participate in multiple public goods games. In addition to contribution decisions, the agents can leave and join different games, and these processes are de-coupled. We show that the payoff for cooperation is greater than for defection when limits to the number of actors per game ("capacity constraints") structure the population in ways that allow cooperators to cluster, independent of any complex individual-level mechanisms such as reputation or punishment. Our model suggests that capacity constraints are one effective mechanism for producing positive assortment and increasing cooperation in an ecology of games. The results suggest an important trade-off between the inclusiveness of policy processes and cooperation: Fully inclusive policy processes reduce the chances of cooperation.

  1. Reconsidering the Heritability of Intelligence in Adulthood: Taking Assortative Mating and Cultural Transmission into Account

    OpenAIRE

    Vinkhuyzen, Anna A E; van der Sluis, Sophie; Maes, Hermine H. M.; Posthuma, Danielle

    2011-01-01

    Heritability estimates of general intelligence in adulthood generally range from 75 to 85%, with all heritability due to additive genetic influences, while genetic dominance and shared environmental factors are absent, or too small to be detected. These estimates are derived from studies based on the classical twin design and are based on the assumption of random mating. Yet, considerable positive assortative mating has been reported for general intelligence. Unmodeled assortative mating may ...

  2. Assortment structure in poplar plantation Populus x euramerjcana I-214 based on European standard

    Directory of Open Access Journals (Sweden)

    Danilović Milorad

    2005-01-01

    Full Text Available Assortment structure in poplar plantation Populus x euramericana I-214 was obtained by European standard for round wood. Based on the data of theoretical cutting, the correlation between total volume of assortments and tree diameter at breast height was established. Model of the function representing the relation between total volume of assortments of superior quality and tree diameter is reciprocal. The relation between total volumes of normal-quality assortments can be represented by a logarithm model of the function, and the relation between total volume of assortments which cannot be classified into any quality class and tree diameter is best represented by a degree model. Knots up to the height of 6 m had a significant effect on the percentage of classes of superior quality. If the lower branches were pruned from standing trees up to the height of 6 m, the percentage of this class would increase averagely by 22.07%. This shows that pruning of lower branches is a very significant plantation tending measure and that it should be performed in time. Sweep also caused the decrease of percentage of superior assortments, but not to the expected degree, because the plantation is situated along the river Sava.

  3. Preference Learning

    CERN Document Server

    Furnkranz, Johannes

    2011-01-01

    The topic of preferences is a new branch of machine learning and data mining, and it has attracted considerable attention in artificial intelligence research in previous years. It involves learning from observations that reveal information about the preferences of an individual or a class of individuals. Representing and processing knowledge in terms of preferences is appealing as it allows one to specify desires in a declarative way, to combine qualitative and quantitative modes of reasoning, and to deal with inconsistencies and exceptions in a flexible manner. And, generalizing beyond traini

  4. Testing the niche apportionment hypothesis with parasite communities: is random assortment always the rule?

    Science.gov (United States)

    Muñoz, G; Mouillot, D; Poulin, R

    2006-05-01

    Niche apportionment models have only been applied once to parasite communities. Only the random assortment model (RA), which indicates that species abundances are independent from each other and that interspecific competition is unimportant, provided a good fit to 3 out of 6 parasite communities investigated. The generality of this result needs to be validated, however. In this study we apply 5 niche apportionment models to the parasite communities of 14 fish species from the Great Barrier Reef. We determined which model fitted the data when using either numerical abundance or biomass as an estimate of parasite abundance, and whether the fit of niche apportionment models depends on how the parasite community is defined (e.g. ecto, endoparasites or all parasites considered together). The RA model provided a good fit for the whole community of parasites in 7 fish species when using biovolume (as a surrogate of biomass) as a measure of species abundance. The RA model also fitted observed data when ecto- and endoparasites were considered separately, using abundance or biovolume, but less frequently. Variation in fish sizes among species was not associated with the probability of a model fitting the data. Total numerical abundance and biovolume of parasites were not related across host species, suggesting that they capture different aspects of abundance. Biovolume is not only a better measurement to use with niche-orientated models, it should also be the preferred descriptor to analyse parasite community structure in other contexts. Most of the biological assumptions behind the RA model, i.e. randomness in apportioning niche space, lack of interspecific competition, independence of abundance among different species, and species with variable niches in changeable environments, are in accordance with some previous findings on parasite communities. Thus, parasite communities may generally be unsaturated with species, with empty niches, and interspecific interactions may

  5. Genome assortment, not serogroup, defines Vibrio cholerae pandemic strains

    Energy Technology Data Exchange (ETDEWEB)

    Brettin, Thomas S [Los Alamos National Laboratory; Bruce, David C [Los Alamos National Laboratory; Challacombe, Jean F [Los Alamos National Laboratory; Detter, John C [Los Alamos National Laboratory; Han, Cliff S [Los Alamos National Laboratory; Munik, A C [Los Alamos National Laboratory; Chertkov, Olga [Los Alamos National Laboratory; Meincke, Linda [Los Alamos National Laboratory; Saunders, Elizabeth [Los Alamos National Laboratory; Choi, Seon Y [SEOUL NATL. UNIV.; Haley, Bradd J [U. MARYLAND; Taviani, Elisa [U. MARYLAND; Jeon, Yoon - Seong [INTL. VACCINE INST. SEOUL; Kim, Dong Wook [INTL. VACCINE INST. SEOUL; Lee, Jae - Hak [SEOUL NATL. UNIV.; Walters, Ronald A [PNNL; Hug, Anwar [NATL. INST. CHOLERIC ENTERIC DIS.; Colwell, Rita R [U. MARYLAND

    2009-01-01

    Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the 6th and the current 7th pandemics, respectively. Cholera researchers continually face newly emerging and re-emerging pathogenic clones carrying combinations of new serogroups as well as of phenotypic and genotypic properties. These genotype and phenotype changes have hampered control of the disease. Here we compare the complete genome sequences of 23 strains of V. cholerae isolated from a variety of sources and geographical locations over the past 98 years in an effort to elucidate the evolutionary mechanisms governing genetic diversity and genesis of new pathogenic clones. The genome-based phylogeny revealed 12 distinct V. cholerae phyletic lineages, of which one, designated the V. cholerae core genome (CG), comprises both O1 classical and EI Tor biotypes. All 7th pandemic clones share nearly identical gene content, i.e., the same genome backbone. The transition from 6th to 7th pandemic strains is defined here as a 'shift' between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages within the CG clade. In contrast, transition among clones during the present 7th pandemic period can be characterized as a 'drift' between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V.cholerae serogroup O139 and V.cholerae O1 El Tor hybrid clones that produce cholera toxin of classical biotype. Based on the comprehensive comparative genomics presented in this study it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to

  6. Intra- and trans-generational costs of reduced female body size caused by food limitation early in life in mites.

    Directory of Open Access Journals (Sweden)

    Andreas Walzer

    Full Text Available Food limitation early in life may be compensated for by developmental plasticity resulting in accelerated development enhancing survival at the expense of small adult body size. However and especially for females in non-matching maternal and offspring environments, being smaller than the standard may incur considerable intra- and trans-generational costs.Here, we evaluated the costs of small female body size induced by food limitation early in life in the sexually size-dimorphic predatory mite Phytoseiulus persimilis. Females are larger than males. These predators are adapted to exploit ephemeral spider mite prey patches. The intra- and trans-generational effects of small maternal body size manifested in lower maternal survival probabilities, decreased attractiveness for males, and a reduced number and size of eggs compared to standard-sized females. The trans-generational effects of small maternal body size were sex-specific with small mothers producing small daughters but standard-sized sons.Small female body size apparently intensified the well-known costs of sexual activity because mortality of small but not standard-sized females mainly occurred shortly after mating. The disadvantages of small females in mating and egg production may be generally explained by size-associated morphological and physiological constraints. Additionally, size-assortative mate preferences of standard-sized mates may have rendered small females disproportionally unattractive mating partners. We argue that the sex-specific trans-generational effects were due to sexual size dimorphism - females are the larger sex and thus more strongly affected by maternal stress than the smaller males - and to sexually selected lower plasticity of male body size.

  7. Assortative social learning and its implications for human (and animal?) societies.

    Science.gov (United States)

    Katsnelson, Edith; Lotem, Arnon; Feldman, Marcus W

    2014-07-01

    Choosing from whom to learn is an important element of social learning. It affects learner success and the profile of behaviors in the population. Because individuals often differ in their traits and capabilities, their benefits from different behaviors may also vary. Homophily, or assortment, the tendency of individuals to interact with other individuals with similar traits, is known to affect the spread of behaviors in humans. We introduce models to study the evolution of assortative social learning (ASL), where assorting on a trait acts as an individual-specific mechanism for filtering relevant models from which to learn when that trait varies. We show that when the trait is polymorphic, ASL may maintain a stable behavioral polymorphism within a population (independently of coexistence with individual learning in a population). We explore the evolution of ASL when assortment is based on a nonheritable or partially heritable trait, and when ASL competes with different non-ASL strategies: oblique (learning from the parental generation) and vertical (learning from the parent). We suggest that the tendency to assort may be advantageous in the context of social learning, and that ASL might be an important concept for the evolutionary theory of social learning.

  8. METHODOLOGY OF KNOWLEDGE RESOURCES AUDIT FOR FORMATION OF PHARMACY ORGANIZATION ASSORTMENT

    Directory of Open Access Journals (Sweden)

    I. M. Razdorskaya

    2015-01-01

    Full Text Available The timeliness of this subject is conditioned by the increase of a role of knowledge in pharmacy organizations (PO management, significance increase of non-material assets in a competition on the pharmaceutical market. The development and substantiation of methodology of knowledge resources audit significance on the example of drug assortment formation for allergic rhinitis treatment. We have used sociological, statistic, expert methods of a study. Close attention was paid to the method of target management, construction of target tree. The construction of the target tree of the knowledge resources audit was based on the main target establishment, targets of the first level, and eight subtargets. We have offered new special positions of assortment formation. “Formation of consumers’ loyalty” is the target of the first level, subtargets “Analysis of clients preferences”, “Transformation of clients preferences”, “Positioning of consumers by the compliance degree”. We have determined the relevance significance by the main target achievement – rational assortment formation. We have shown that the achievement of the first level target “Formation of consumers’  loyalty” conduce the achievement of the main target by 40%. The analysis of the current assortment and a process of assortment upgrading guarantee the achievement of the target by 30% each. The methodology is prospective for knowledge resources audit by the principal business processes of pharmacy organizations.  

  9. Using Social Network Methods to Test for Assortment of Prosociality among Korean High School Students.

    Science.gov (United States)

    Kim, Jun-Hong; Holman, Darryl J; Goodreau, Steven M

    2015-01-01

    Assortative interaction among altruistic individuals is a necessary condition for the evolution of cooperation. The requirement for assortment holds regardless of whether a meta-population is subdivided into distinct and isolated subgroups or has ephemeral boundaries with a high migration rate. The assumption, however, is rarely tested directly. In this paper, we develop a method to test for assortment of prosociality in network-structured data. The method is applied to a friendship network collected from 238 Korean students attending the same high school. A mixing matrix was used to explore the presence of assortative friendship among more prosocial individuals. An exponential random graph model of network structure that accounts for additional observed relational propensities (higher-than-expected number of people nominating no friends) and sampling constraints (upper bound on friendship nominations) found that individual prosociality predicted friendship propensity, and that individuals with higher prosocial scores had a higher probability of befriending other more prosocial individuals. The results reveal that a considerable level of assortment of prosociality characterizes this population.

  10. Is there an own-race preference in attractiveness?

    Science.gov (United States)

    Burke, Darren; Nolan, Caroline; Hayward, William Gordon; Russell, Robert; Sulikowski, Danielle

    2013-08-15

    Even in multicultural nations interracial relationships and marriages are quite rare, one reflection of assortative mating. A relatively unexplored factor that could explain part of this effect is that people may find members of their own racial group more attractive than members of other groups. We tested whether there is an own-race preference in attractiveness judgments, and also examined the effect of familiarity by comparing the attractiveness ratings given by participants of different ancestral and geographic origins to faces of European, East Asian and African origin. We did not find a strong own-race bias in attractiveness judgments, but neither were the data consistent with familiarity, suggesting an important role for other factors determining the patterns of assortative mating observed.

  11. Moral Preferences

    OpenAIRE

    Bortolotti, Lisa; Jefferson, Anneli

    2016-01-01

    In this brief response to Etzioni’s paper we argue that satisfying one’s preferences and seeking to live up to one’s moral standards are not incompatible ways of living one’s life, and that choosing to act morally need not involve self-sacrifice.

  12. Robustness and assortativity for diffusion-like processes in scale-free networks

    Science.gov (United States)

    D'Agostino, G.; Scala, A.; Zlatić, V.; Caldarelli, G.

    2012-03-01

    By analysing the diffusive dynamics of epidemics and of distress in complex networks, we study the effect of the assortativity on the robustness of the networks. We first determine by spectral analysis the thresholds above which epidemics/failures can spread; we then calculate the slowest diffusional times. Our results shows that disassortative networks exhibit a higher epidemiological threshold and are therefore easier to immunize, while in assortative networks there is a longer time for intervention before epidemic/failure spreads. Moreover, we study by computer simulations the sandpile cascade model, a diffusive model of distress propagation (financial contagion). We show that, while assortative networks are more prone to the propagation of epidemic/failures, degree-targeted immunization policies increases their resilience to systemic risk.

  13. THE IMPROVING OF ASSORTMENT BY «BUMFA GROUP» IN CHERKESSK

    Directory of Open Access Journals (Sweden)

    Gayduk V. I.

    2015-09-01

    Full Text Available The article presents and analyzes the assortment of "Bumfa Group" with the methods of ABC analysis, XYZ-analysis. It gives the description of the goods offered by the organization, its customers and its main competitors. The profile of competitive advantages and disadvantages is compiled. It presents the results of marketing research of consumers acquiring products offered by LLC "Bumfa Group" - the goods in terms of popularity, the factors influencing the decision to purchase, customers’ satisfaction in price, packaging and product quality, the results of customers’choice of new products to update the assortment, customers’ satisfaction in volume of incoming advertising information about the products of "Bumfa Group." The necessity to optimize the assortment of the organization is founded. To achieve this aim we developed a project to introduce new products in the range of goods - wet wipes for office equipment. The characteristics of the new product, the production plan and performance indicators of the project are supplied

  14. Manufacturer and retailer brands in food retail assortments: Notes from a shopping trip across Europe

    DEFF Research Database (Denmark)

    Esbjerg, Lars; Grunert, Klaus G.; Bech-Larsen, Tino;

    retailer branded products in an attempt to differentiate themselves by offering goods only available in their stores. Despite the importance of branding to retailers, the branding literature has focused on how manufacturers develop and maintain strong brands. Relatively little work has been done...... food retailers focus on whether they offer the "right" assort-ment to consumers. Under headings such as efficient consumer response (ECR) and cate-gory management (CM), retailers have been readjusting their assortments, delisting many brands that were deemed to be under-performing and including...... of 'retailer brand archi-tecture', we use this concept to investigate the brand architecture of a number of European food retailers in order to determine similarities and differences in brand architecture strategies. The paper is structured as follows: firstly, the concept of brand archi-tecture is presented...

  15. Geographically selective assortment of cycles in pandemics: meta-analysis of data collected by Chizhevsky.

    Science.gov (United States)

    Gumarova, L; Cornélissen, G; Hillman, D; Halberg, F

    2013-10-01

    In the incidence patterns of cholera, diphtheria and croup during the past when they were of epidemic proportions, we document a set of cycles (periods), one of which was reported and discussed by A. L. Chizhevsky in the same data with emphasis on the mirroring in human disease of the ~11-year sunspot cycle. The data in this study are based on Chizhevsky’s book The Terrestrial Echo of Solar Storms and on records from the World Health Organization. For meta-analysis, we used the extended linear and nonlinear cosinor. We found a geographically selective assortment of various cycles characterizing the epidemiology of infections, which is the documented novel topic of this paper, complementing the earlier finding in the 21st century or shortly before, of a geographically selective assortment of cycles characterizing human sudden cardiac death. Solar effects, if any, interact with geophysical processes in contributing to this assortment.

  16. Co-assortment in integron-associated gene cassette assemblages in environmental DNA samples

    Directory of Open Access Journals (Sweden)

    Michael Carolyn A

    2010-08-01

    Full Text Available Abstract Background It has been shown that integron-associated gene cassettes exist largely in tandem arrays of variable size, ranging from antibiotic resistance arrays of three to five cassettes up to arrays of more than 100 cassettes associated with the vibrios. Further, the ecology of the integron/gene cassette system has been investigated by showing that very many different cassettes are present in even small environmental samples. In this study, we seek to extend the ecological perspective on the integron/gene cassette system by investigating the way in which this diverse cassette metagenome is apportioned amongst prokaryote lineages in a natural environment. Results We used a combination of PCR-based techniques applied to environmental DNA samples and ecological analytical techniques to establish co-assortment within cassette populations, then establishing the relationship between this co-assortment and genomic structures. We then assessed the distribution of gene cassettes within the environment and found that the majority of gene cassettes existed in large co-assorting groups. Conclusions Our results suggested that the gene cassette diversity of a relatively pristine sampling environment was structured into co-assorting groups, predominantly containing large numbers of cassettes per group. These co-assorting groups consisted of different gene cassettes in stoichiometric relationship. Conservatively, we then attributed co-assorting cassettes to the gene cassette complements of single prokaryote lineages and by implication, to large integron-associated arrays. The prevalence of large arrays in the environment raises new questions about the assembly, maintenance and utility of large cassette arrays in prokaryote populations.

  17. From sparse to dense and from assortative to disassortative in online social networks

    CERN Document Server

    Li, Menghui; Gong, Xiaofeng; Li, Kun; Wu, Jinshan; Di, Zengru; Lai, Choy-Heng

    2013-01-01

    In this paper, inspired by the analysis on several empirical online social networks, we propose a simple reaction-diffusion-like coevolving model, in which individuals are activated to create links based on their states influenced by local dynamics and their own intension. It is shown that the model can reproduce the remarkable properties observed in empirical online social networks, particularly, that the assortative coefficients are neural or negative and the power law exponents are smaller than 2. Moreover, we demonstrate that, under feasible conditions, the modeling networks naturally convert from assortative to disassortative, and from sparse to dense. Our model is helpful for understanding the formation and evolution of online social networks.

  18. Effect of assortative mixing in the second-order Kuramoto model

    CERN Document Server

    Peron, Thomas K DM; Rodrigues, Francisco A; Kurths, Jürgen

    2015-01-01

    In this paper we analyze the second-order Kuramoto model presenting a positive correlation between the heterogeneity of the connections and the natural frequencies in scale-free networks. We numerically show that discontinuous transitions emerge not just in disassortative but also in assortative networks, in contrast with the first-order model. We also find that the effect of assortativity on network synchronization can be compensated by adjusting the phase damping. Our results show that it is possible to control collective behavior of damped Kuramoto oscillators by tuning the network structure or by adjusting the dissipation related to the phases movement.

  19. Social preferences

    DEFF Research Database (Denmark)

    Gulløv, Eva

    2014-01-01

    The focus of this article is social divisions among preschool children in daycare centers. Based on ethnographic fieldwork in three daycare centers in Denmark, the analysis concerns young children’s social preferences. The ethnographic material shows that despite an explicit political ambition...... of daycares as means for social and cultural integration, lines of division do exist amongst the children. Such divisions are established in the daily interactions of the daycare, but they also reflect those of the broader society. With a focus on children’s interactions and social preferences, the material...... indicates that children’s choices of playmates run along lines of ethnic and class divisions. The article will address this pattern and analyze its causes in order to understand why such lines of divisions are to be found in an institutional context designed to overcome social inequality and prevent social...

  20. Leveling the Playing Field: Longer Acquaintance Predicts Reduced Assortative Mating on Attractiveness.

    Science.gov (United States)

    Hunt, Lucy L; Eastwick, Paul W; Finkel, Eli J

    2015-07-01

    Clear empirical demonstrations of the theoretical principles underlying assortative mating remain elusive. This article examines a moderator of assortative mating--how well couple members knew each other before dating--suggested by recent findings related to market-based (i.e., competition) theories. Specifically, competition is pervasive to the extent that people achieve consensus about who possesses desirable qualities (e.g., attractiveness) and who does not. Because consensus is stronger earlier in the acquaintance process, assortative mating based on attractiveness should be stronger among couples who formed a relationship after a short period rather than a long period of acquaintance. A study of 167 couples included measures of how long partners had known each other before dating and whether they had been friends before dating, as well as coders' ratings of physical attractiveness. As predicted, couples revealed stronger evidence of assortative mating to the extent that they knew each other for a short time and were not friends before initiating a romantic relationship. PMID:26068893

  1. Assortativity and leadership emerge from anti-preferential attachment in heterogeneous networks

    Science.gov (United States)

    Sendiña-Nadal, I.; Danziger, M. M.; Wang, Z.; Havlin, S.; Boccaletti, S.

    2016-02-01

    Real-world networks have distinct topologies, with marked deviations from purely random networks. Many of them exhibit degree-assortativity, with nodes of similar degree more likely to link to one another. Though microscopic mechanisms have been suggested for the emergence of other topological features, assortativity has proven elusive. Assortativity can be artificially implanted in a network via degree-preserving link permutations, however this destroys the graph’s hierarchical clustering and does not correspond to any microscopic mechanism. Here, we propose the first generative model which creates heterogeneous networks with scale-free-like properties in degree and clustering distributions and tunable realistic assortativity. Two distinct populations of nodes are incrementally added to an initial network by selecting a subgraph to connect to at random. One population (the followers) follows preferential attachment, while the other population (the potential leaders) connects via anti-preferential attachment: they link to lower degree nodes when added to the network. By selecting the lower degree nodes, the potential leader nodes maintain high visibility during the growth process, eventually growing into hubs. The evolution of links in Facebook empirically validates the connection between the initial anti-preferential attachment and long term high degree. In this way, our work sheds new light on the structure and evolution of social networks.

  2. The genetic correlation between height and IQ: shared genes or assortative mating?

    Directory of Open Access Journals (Sweden)

    Matthew C Keller

    2013-04-01

    Full Text Available Traits that are attractive to the opposite sex are often positively correlated when scaled such that scores increase with attractiveness, and this correlation typically has a genetic component. Such traits can be genetically correlated due to genes that affect both traits ("pleiotropy" and/or because assortative mating causes statistical correlations to develop between selected alleles across the traits ("gametic phase disequilibrium". In this study, we modeled the covariation between monozygotic and dizygotic twins, their siblings, and their parents (total N = 7,905 to elucidate the nature of the correlation between two potentially sexually selected traits in humans: height and IQ. Unlike previous designs used to investigate the nature of the height-IQ correlation, the present design accounts for the effects of assortative mating and provides much less biased estimates of additive genetic, non-additive genetic, and shared environmental influences. Both traits were highly heritable, although there was greater evidence for non-additive genetic effects in males. After accounting for assortative mating, the correlation between height and IQ was found to be almost entirely genetic in nature. Model fits indicate that both pleiotropy and assortative mating contribute significantly and about equally to this genetic correlation.

  3. The Genetic Correlation between Height and IQ: Shared Genes or Assortative Mating?

    Science.gov (United States)

    Keller, Matthew C.; Garver-Apgar, Christine E.; Wright, Margaret J.; Martin, Nicholas G.; Corley, Robin P.; Stallings, Michael C.; Hewitt, John K.; Zietsch, Brendan P.

    2013-01-01

    Traits that are attractive to the opposite sex are often positively correlated when scaled such that scores increase with attractiveness, and this correlation typically has a genetic component. Such traits can be genetically correlated due to genes that affect both traits (“pleiotropy”) and/or because assortative mating causes statistical correlations to develop between selected alleles across the traits (“gametic phase disequilibrium”). In this study, we modeled the covariation between monozygotic and dizygotic twins, their siblings, and their parents (total N = 7,905) to elucidate the nature of the correlation between two potentially sexually selected traits in humans: height and IQ. Unlike previous designs used to investigate the nature of the height–IQ correlation, the present design accounts for the effects of assortative mating and provides much less biased estimates of additive genetic, non-additive genetic, and shared environmental influences. Both traits were highly heritable, although there was greater evidence for non-additive genetic effects in males. After accounting for assortative mating, the correlation between height and IQ was found to be almost entirely genetic in nature. Model fits indicate that both pleiotropy and assortative mating contribute significantly and about equally to this genetic correlation. PMID:23593038

  4. VA-Index: Quantifying Assortativity Patterns in Networks with Multidimensional Nodal Attributes.

    Directory of Open Access Journals (Sweden)

    Konstantinos Pelechrinis

    Full Text Available Network connections have been shown to be correlated with structural or external attributes of the network vertices in a variety of cases. Given the prevalence of this phenomenon network scientists have developed metrics to quantify its extent. In particular, the assortativity coefficient is used to capture the level of correlation between a single-dimensional attribute (categorical or scalar of the network nodes and the observed connections, i.e., the edges. Nevertheless, in many cases a multi-dimensional, i.e., vector feature of the nodes is of interest. Similar attributes can describe complex behavioral patterns (e.g., mobility of the network entities. To date little attention has been given to this setting and there has not been a general and formal treatment of this problem. In this study we develop a metric, the vector assortativity index (VA-index for short, based on network randomization and (empirical statistical hypothesis testing that is able to quantify the assortativity patterns of a network with respect to a vector attribute. Our extensive experimental results on synthetic network data show that the VA-index outperforms a baseline extension of the assortativity coefficient, which has been used in the literature to cope with similar cases. Furthermore, the VA-index can be calibrated (in terms of parameters fairly easy, while its benefits increase with the (co-variance of the vector elements, where the baseline systematically over(underestimate the true mixing patterns of the network.

  5. VA-Index: Quantifying Assortativity Patterns in Networks with Multidimensional Nodal Attributes.

    Science.gov (United States)

    Pelechrinis, Konstantinos; Wei, Dong

    2016-01-01

    Network connections have been shown to be correlated with structural or external attributes of the network vertices in a variety of cases. Given the prevalence of this phenomenon network scientists have developed metrics to quantify its extent. In particular, the assortativity coefficient is used to capture the level of correlation between a single-dimensional attribute (categorical or scalar) of the network nodes and the observed connections, i.e., the edges. Nevertheless, in many cases a multi-dimensional, i.e., vector feature of the nodes is of interest. Similar attributes can describe complex behavioral patterns (e.g., mobility) of the network entities. To date little attention has been given to this setting and there has not been a general and formal treatment of this problem. In this study we develop a metric, the vector assortativity index (VA-index for short), based on network randomization and (empirical) statistical hypothesis testing that is able to quantify the assortativity patterns of a network with respect to a vector attribute. Our extensive experimental results on synthetic network data show that the VA-index outperforms a baseline extension of the assortativity coefficient, which has been used in the literature to cope with similar cases. Furthermore, the VA-index can be calibrated (in terms of parameters) fairly easy, while its benefits increase with the (co-)variance of the vector elements, where the baseline systematically over(under)estimate the true mixing patterns of the network. PMID:26816262

  6. The short- and long-term impact of an assortment reduction on category sales

    NARCIS (Netherlands)

    Sloot, Laurens M.; Fok, Dennis; Verhoef, Peter C.

    2006-01-01

    In a collaborative study with a major Dutch retailer, the authors assess the short- and long-term effects of a 25% item reduction on-category sales. On an aggregate level, a major assortment reduction can lead to substantive short-term category sales losses but only a weak negative long-term categor

  7. Spotting altruistic dictator game players and mingling with them : the elective assortation of classmates

    NARCIS (Netherlands)

    Pradel, Julia; Euler, Harald A.; Fetchenhauer, Detlef

    2009-01-01

    Altruism can evolve through assortation if the selfish advantage of egoistic individuals is outcompeted by the benefits of mutual cooperation between altruists. This selection process is possible if (a) individuals can distinguish altruists from egoists and (b) altruists cooperate electively with ot

  8. The small world phenomenon and assortative mixing in Polish corporate board and director networks

    Science.gov (United States)

    Sankowska, Anna; Siudak, Dariusz

    2016-02-01

    This paper investigates the corporate board and director networks in the Polish capital market in 2014. We examined real board and director networks in comparison with networks that were randomly constructed. Through empirical analyses, we demonstrated that the real networks have the characteristics of small-world networks. In addition, the networks are assortative and highly clustered, which imposes certain behaviors on them.

  9. Sympatric speciation: perfume preferences of orchid bee lineages.

    Science.gov (United States)

    Jackson, Duncan E

    2008-12-01

    Female attraction to an environmentally derived mating signal released by male orchid bees may be tightly linked to shared olfactory preferences of both sexes. A change in perfume preference may have led to divergence of two morphologically distinct lineages.

  10. Assortative mating and gene flow generate clinal phenological variation in trees

    Directory of Open Access Journals (Sweden)

    Soularue Jean-Paul

    2012-06-01

    Full Text Available Abstract Background On-going climate change is shifting the timing of bud burst (TBB of broad leaf and conifer trees in temperate areas, raising concerns about the abilities of natural populations to respond to these shifts. The level of expected evolutionary change depends on the level and distribution of genetic variation of TBB. While numerous experimental studies have highlighted the role of divergent selection in promoting clinal TBB differentiation, we explored whether the observed patterns of variation could be generated by the joint effects of assortative mating for TBB and gene flow among natural populations. We tested this hypothesis using an in silico approach based on quantitative genetic models. Results Our simulations showed that genetic clines can develop even without divergent selection. Assortative mating in association with environmental gradients substantially shifted the mean genetic values of populations. Owing to assortative mating, immigrant alleles were screened for proximal or distant populations depending on the strength of the environmental cline. Furthermore, we confirmed that assortative mating increases the additive genetic variance within populations. However, we observed also a rapid decline of the additive genetic variance caused by restricted gene flow between neighboring populations resulting from preferential matings between phenologically-matching phenotypes. Conclusions We provided evidence that the patterns of genetic variation of phenological traits observed in forest trees can be generated solely by the effects of assortative mating and gene flow. We anticipate that predicted temperature increases due to climate change will further enhance genetic differentiation across the landscape. These trends are likely to be reinforced or counteracted by natural selection if phenological traits are correlated to fitness.

  11. Specialty Preferences of Physicians and Medical Students

    Science.gov (United States)

    Gough, Harrison G.

    1975-01-01

    Family and internal medicine were rated high by the groups studied. Neurological and colon-rectal surgery were rated low. Males gave higher ratings to surgical specialities, whereas females express stronger preferences for obstetrics and gynecology. (Author/KE)

  12. Pedigrees, assortative mating and speciation in Darwin's finches.

    Science.gov (United States)

    Grant, Peter R; Grant, B Rosemary

    2008-03-22

    Pedigree analysis is a useful tool in the study of speciation. It can reveal trans-generational influences on the choice of mates. We examined mating patterns in a population of Darwin's medium ground finches (Geospiza fortis) on Daphne Major Island to improve our understanding of how a barrier to the exchange of genes between populations arises in evolution. Body sizes of mates were weakly correlated. In one year, the smallest females were paired non-randomly with the males of similar size, and in another year the largest males were paired with the largest females. An influence of parental morphology on the choice of mates, as expected from sexual imprinting theory, was found; the body size of mates was predicted by the body sizes of both parents, and especially strongly by the father's. These associations imply that the seeds of reproductive isolation between species are present within a single variable population. The implication was subject to a natural test: two exceptionally large birds of the study species, apparently immigrants, bred with each other, as did their offspring, and not with the members of the resident population. The intense inbreeding represents incipient speciation. It parallels a similar phenomenon when another species, the large ground finch, immigrated to Daphne and established a new population without interbreeding with the resident medium ground finches.

  13. Coaching preferences of athletes.

    Science.gov (United States)

    Terry, P C; Howe, B L

    1984-12-01

    The study examined the coaching preferences of 80 male and 80 female athletes, as measured by the Leadership Scale for Sports (Chelladurai and Saleh, 1978, 1980). In addition, it attempted to assess the applicability to sport of the Life-cycle and Path-goal theories of leadership. Comparisons between groups were made on the basis of sex, age, and type of sport. A MANOVA indicated that athletes in independent sports preferred more democratic behaviour (p less than .001) and less autocratic behaviour (p = .028) than athletes in interdependent sports. No differences in coaching preferences were found which could be attributed to the age or sex of the athlete, or the variability of the sports task. These results partially supported the Path-goal theory, but did not support the Life-cycle theory. Athletes of all groups tended to favour coaches who displayed training behaviour and rewarding behaviour "often", democratic behaviour and social support behaviour "occasionally", and autocratic behaviour "seldom". This consistency may be a useful finding for those organizations and institutions interested in preparing coaches.

  14. Extraversion and risk preference in portfolio theory.

    Science.gov (United States)

    Vestewig, R E

    1977-11-01

    One hundred seventy-eight male and female undergraduates completed the Eysenck Personality Inventory and indicated their risk preference assessed under the assumptions of Coombs' portfolio theory. Extraverts preferred higher risk significantly more than did introverts, and also showed significantly greater risk preference change as expected value increased. It was suggested that a theoretically defensible selection of both personality variables and a risk assessment model may lead to greater personality-risk predictability.

  15. Coevolutionary, coexisting learning and teaching agents model for prisoner’s dilemma games enhancing cooperation with assortative heterogeneous networks

    Science.gov (United States)

    Tanimoto, Jun

    2013-07-01

    Unlike other natural network systems, assortativity can be observed in most human social networks, although it has been reported that a social dilemma situation represented by the prisoner’s dilemma favors dissortativity to enhance cooperation. We established a new coevolutionary model for both agents’ strategy and network topology, where teaching and learning agents coexist. Remarkably, this model enables agents’ enhancing cooperation more than a learners-only model on a time-frozen scale-free network and produces an underlying assortative network with a fair degree of power-law distribution. The model may imply how and why assortative networks are adaptive in human society.

  16. From sparse to dense and from assortative to disassortative in online social networks.

    Science.gov (United States)

    Li, Menghui; Guan, Shuguang; Wu, Chensheng; Gong, Xiaofeng; Li, Kun; Wu, Jinshan; Di, Zengru; Lai, Choy-Heng

    2014-01-01

    Inspired by the analysis of several empirical online social networks, we propose a simple reaction-diffusion-like coevolving model, in which individuals are activated to create links based on their states, influenced by local dynamics and their own intention. It is shown that the model can reproduce the remarkable properties observed in empirical online social networks; in particular, the assortative coefficients are neutral or negative, and the power law exponents γ are smaller than 2. Moreover, we demonstrate that, under appropriate conditions, the model network naturally makes transition(s) from assortative to disassortative, and from sparse to dense in their characteristics. The model is useful in understanding the formation and evolution of online social networks.

  17. New Assortment of Sizing Adhesive%浆纱粘着剂新品种

    Institute of Scientific and Technical Information of China (English)

    刘海文; 何新勇; 张秀敏; 贾立霞; 王联军

    2001-01-01

    The general property , special property and major t echnical index of new assortment of sizing adhesive such as modified starch, mod ified polyvinyl alcohol, acrylic,polyester etc.the four assortments 21 kind products which are in initial use in practice at home and abroad have been intr oduced.%介绍了国内外生产实践中初见使用的一些浆纱粘着剂新品种,例变性淀粉类、变性 聚乙烯醇类、丙烯酸类、聚酯类等4大类21种产品的共性、特性和主要技术指标。

  18. Interactive computer program for learning genetic principles of segregation and independent assortment through meiosis.

    Science.gov (United States)

    Yang, Xiaoli; Ge, Rong; Yang, Yufei; Shen, Hao; Li, Yingjie; Tseng, Charles C

    2009-01-01

    Teaching fundamental principles of genetics such as segregation and independent assortment of genes could be challenging for high school and college biology instructors. Students without thorough knowledge in meiosis often end up of frustration and failure in genetics courses. Although all textbooks and laboratory manuals have excellent graphic demonstrations and photographs of meiotic process, students may not always master the concept due to the lack of hands-on exercise. In response to the need for an effective lab exercise to understand the segregation of allelic genes and the independent assortment of the unlinked genes, we developed an interactive program for students to manually manipulate chromosome models and visualize each major step of meiosis so that these two genetic principles can be thoroughly understood.

  19. Relative importance of social synergy, assortation and networks in the evolution of social cooperation

    CERN Document Server

    Montoreano, Claudia

    2013-01-01

    We compare the likelihood of different socially relevant features to allow the evolutionary emergence and maintenance of cooperation in a generalized variant of the iterated Prisoners Dilemma game. Results show that the average costs/benefit balance of cooperation is the primary constraint for its establishment and maintenance. Behavior increasing inclusive fitness such as assortation, homophily, kin-selection and tagging of individuals, is second in importance. Networks characteristics were the least important in favoring the establishment and maintenance of cooperation, despite being the most popular in recent research on the subject. Results suggest that inclusive fitness theory with its expansions to include assortative and economic considerations is more general, powerful and relevant in analyzing social phenomena than kin selection theory with its emphasis on genetic relatedness. Merging economics with evolutionary theory will be necessary to reveal more about the nature of social dynamics.

  20. Cytological evidence for assortment mitosis leading to loss of heterozygosity in rice.

    Science.gov (United States)

    Wang, Richard R-C; Li, Xiaomei; Chatterton, N Jerry

    2006-05-01

    In the root meristem cells of the rice line AMR, which causes loss of heterozygosity in its hybrids, both normal and assortment mitoses were observed. During normal mitosis, chromosomes did not form homologous pairs at metaphase; all chromosomes lined up at the equatorial plate and 2 chromatids of each chromosome disjoined at the centromere and moved toward opposite poles. During assortment mitosis, varying numbers of paired homologues were observed at mitotic metaphase. Two groups of 12 chromosomes separated and moved towards the opposite poles of daughter cells with few chromosomes having their chromatids separated at anaphase. These observations support the proposed mechanism that is responsible for early genotype fixation in rice hybrids involving AMR.

  1. Effect of genetic heterogeneity and assortative mating on linkage analysis: a simulation study.

    OpenAIRE

    Falk, C T

    1997-01-01

    Linkage studies of complex genetic traits raise questions about the effects of genetic heterogeneity and assortative mating on linkage analysis. To further understand these problems, I have simulated and analyzed family data for a complex genetic disease in which disease phenotype is determined by two unlinked disease loci. Two models were studied, a two-locus threshold model and a two-locus heterogeneity model. Information was generated for a marker locus linked to one of the disease-definin...

  2. The gender divide in urban China: Singlehood and assortative mating by age and education

    OpenAIRE

    Yue Qian; Zhenchao Qian

    2014-01-01

    Objective: Chinese media labels highly educated, urban women who are still single in their late 20s as "leftover ladies". We investigate whether indeed highly educated women are less likely to marry than their less-educated counterparts, and how assortative mating patterns by age and education play a role in singleness. Methods: We use data from the urban samples of the Chinese General Social Surveys in the 2000s. In the analysis we calculate marriage rates to examine the likelihood of ent...

  3. Assortative marriages by body mass index have increased simultaneously with the obesity epidemic

    Directory of Open Access Journals (Sweden)

    Teresa Adeltoft Ajslev

    2012-07-01

    Full Text Available Background: The genetic predisposition to obesity may have contributed to the obesity epidemic through assortative mating. We investigated whether spouses were positively assorted by body mass index (BMI; =kg/m2 in late childhood, and whether changes in assorted marriage by upper BMI-percentiles occurred during the obesity epidemic. Methods: In the Copenhagen School Health Records Register boys and girls with measures of BMI at age 13 years later became 37 792 spousal-pairs who married from 1945–2010. Trends in the spousal BMI correlations using sex-, age- and birth cohort-specific BMI z-scores across time were investigated. Odds ratios (ORs of marriage among spouses both with BMI z-scores >90th or >95th percentile compared with marriage among spouses ≤90th percentile were analysed for marriages entered during the years prior to (1945–1970, and during the obesity epidemic (1971–2010.Findings: Spousal BMI correlations were small and stayed similar across time. ORs of marriage among spouses with BMIs >90th percentile at age 13 were 1.21, 1.05–1.39, in 1945–1970, and increased to 1.63, 1.40–1.91, in 1971–2010 (p=0.006. ORs of marriage among spouses both >95th BMI percentile were higher and increased more; from 1.39, 1.10–1.81, to 2.39, 1.85–3.09 (p=0.004.Interpretation: Spousal correlations by pre-marital BMIs were stable during the past 65 years. Yet, assorted marriages between spouses with BMIs in the upper percentiles were observed and increased significantly across the two marriage periods, and this may possibly influence the following generations’ susceptibility to obesity.

  4. Why Does Spousal Education Matter for Earnings? Assortative Mating or Cross-productivity

    OpenAIRE

    Chong Huang; Hongbin Li; Pak Wai Liu; Junsen Zhang

    2006-01-01

    In interpreting the positive relationship between spousal education and one's earnings, economists have two major hypotheses: cross-productivity between couples and assortative mating. However, no prior empirical study has been able to separate the two effects. This paper empirically disentangles the two effects by using twins data that we collected from urban China. We have two major innovations: we use twins data to control for the unobserved mating effect in our estimations, and we estimat...

  5. Marketing Strategy Development Directions of Web Assortment in the Republic of Serbia

    OpenAIRE

    Jelena Končar; Zita Petrović-Katai; Goran Vukmirović

    2010-01-01

    Electronic commerce is a contemporary way of doing trade activities based on the use of information and communication technologies. In contemporary business conditions, trade faces numerous changes, which are mostly, before all, the result of market globalization, as well as information technology development. The Web assortment in electronic commerce is the key marketing instrument in a trade organization. The basic task of Serbian companies understands the need of tracking all the changes i...

  6. Growth and yield models, assortment type and analysis of deadwood in chestnut coppice

    Directory of Open Access Journals (Sweden)

    Marziliano PA

    2013-02-01

    Full Text Available Chestnut (Castanea sativa MILL. is one of the most important forest tree species in Europe, and it is considered a symbol of the natural vegetation in southern Europe. In Calabria (southern Italy chestnut forest covers an area of approximately 87000 hectares, most of which (about 80% managed as coppice. In this study a growth and yield table has been elaborated. Thurthermore, assortment type and quantity of deadwood have been evaluated according to age of coppice and forest fire prevention, respectively. The study site is located in the “Presila of Catanzaro” and the research was carried out in 15 plots; the age of the examined stands ranged from 2 to 50 years old. More than 30000 shoots per hectare were recorded in the first two years after coppicing. As opposed, about 2300 and 1000 shoots per hectare were observed 15 and 50 years after coppicing, respectively. The culmination of the mean annual increment of the forest standing volume (16 m3 ha-1 year-1 was highlighted 25 years after coppicing, while the current annual increment culmination (21 m3 ha-1 year-1 was observed at 15 years. Fifteen years after coppicing, most of the wood production was constituted by small dimension assortments. Twenty five years after coppicing small and large poles were the prevailing assortments while telegraph poles and timber beams increased after 50 years. The amount of deadwood in forest ranged between 11.9 and 68.7 m3 ha-1. The largest component was represented by standing dead shoots. The results show that coppice management can be adopted even if the main purpose of the chestnut stand is the production of large size assortments. In chestnut coppice, highly vulnerable to fire, the reduction of stand density with silvicultural practices (thinning and displacement is the main way to promote the efficiency of forest and a higher strength and resiliency against forest fire.

  7. VA-Index: Quantifying Assortativity Patterns in Networks with Multidimensional Nodal Attributes

    OpenAIRE

    Konstantinos Pelechrinis; Dong Wei

    2016-01-01

    Network connections have been shown to be correlated with structural or external attributes of the network vertices in a variety of cases. Given the prevalence of this phenomenon network scientists have developed metrics to quantify its extent. In particular, the assortativity coefficient is used to capture the level of correlation between a single-dimensional attribute (categorical or scalar) of the network nodes and the observed connections, i.e., the edges. Nevertheless, in many cases a mu...

  8. Quantifying the risk of pandemic influenza virus evolution by mutation and re-assortment.

    Science.gov (United States)

    Reperant, Leslie A; Grenfell, Bryan T; Osterhaus, Albert D M E

    2015-12-01

    Large outbreaks of zoonotic influenza A virus (IAV) infections may presage an influenza pandemic. However, the likelihood that an airborne-transmissible variant evolves upon zoonotic infection or co-infection with zoonotic and seasonal IAVs remains poorly understood, as does the relative importance of accumulating mutations versus re-assortment in this process. Using discrete-time probabilistic models, we determined quantitative probability ranges that transmissible variants with 1-5 mutations and transmissible re-assortants evolve after a given number of zoonotic IAV infections. The systematic exploration of a large population of model parameter values was designed to account for uncertainty and variability in influenza virus infection, epidemiological and evolutionary processes. The models suggested that immunocompromised individuals are at high risk of generating IAV variants with pandemic potential by accumulation of mutations. Yet, both immunocompetent and immunocompromised individuals could generate high viral loads of single and double mutants, which may facilitate their onward transmission and the subsequent accumulation of additional 1-2 mutations in newly-infected individuals. This may result in the evolution of a full transmissible genotype along short chains of contact transmission. Although co-infection with zoonotic and seasonal IAVs was shown to be a rare event, it consistently resulted in high viral loads of re-assortants, which may facilitate their onward transmission among humans. The prevention or limitation of zoonotic IAV infection in immunocompromised and contact individuals, including health care workers, as well as vaccination against seasonal IAVs-limiting the risk of co-infection-should be considered fundamental tools to thwart the evolution of a novel pandemic IAV by accumulation of mutations and re-assortment.

  9. Prices and the assortment offer of the mineral fertilizers in the farmers’ opinion

    OpenAIRE

    Arkadiusz Piwowar

    2011-01-01

    The mineral fertilizers are the basic means of production used by agriculturalists in order to improve the size and quality of the cultivated plants. The retail prices of the most popular mineral fertilizers have risen in the last years. The paper discusses the research results concerning the agriculturalists' opinion about the mineral fertilizers’ prices and assortment in the market. The research revealed that the high prices and their disadvantageous relation to the fruits' of the earth pri...

  10. From Assortative to Ashortative Coupling: Men's Height, Height Heterogamy, and Relationship Dynamics in the United States

    OpenAIRE

    Abigail Weitzman; Dalton Conley

    2014-01-01

    Studies of online dating suggest that physical attraction is a key factor in early relationship formation, but say little about the role of attractiveness in longer-term relationships. Meanwhile, assortative coupling and exchange models widely employed in demographic research overlook the powerful sorting function of initial and sustained physical attraction. This article observes the effects of one physical characteristic of men--height--on various relationship outcomes in longer-term relati...

  11. Review: Game theory of public goods in one-shot social dilemmas without assortment.

    Science.gov (United States)

    Archetti, Marco; Scheuring, István

    2012-04-21

    We review the theory of public goods in biology. In the N-person prisoner's dilemma, where the public good is a linear function of the individual contributions, cooperation requires some form of assortment, for example due to kin discrimination, population viscosity or repeated interactions. In most social species ranging from bacteria to humans, however, public goods are usually a non-linear function of the contributions, which makes cooperation possible without assortment. More specifically, a polymorphic state can be stable in which cooperators and non-cooperators coexist. The existence of mixed equilibria in public goods games is a fundamental result in the study of cooperation that has been overlooked so far, because of the disproportionate attention given to the two- and N-person prisoner's dilemma. Methods and results from games with pairwise interactions or linear benefits cannot, in general, be extended to the analysis of public goods. Game theory helps explain the production of public goods in one-shot, N-person interactions without assortment, it leads to predictions that can be easily tested and allows a prescriptive approach to cooperation.

  12. Assessment of the effect of quality factors on the assortment structure in poplar plantations

    Directory of Open Access Journals (Sweden)

    Danilović Milorad

    2008-01-01

    Full Text Available Quality factors affecting the assortment quality structure in poplar plantations were researched on nine temporary sample plots in the period 1997-2004, from the aspect of the implementation of roundwood standards. Sample plots were selected depending on the factors, the effect of which was studied. The following factors were researched: clonal species, planting pattern, flood risk, pruning of branches, plantation position and age. The study was performed by the original methodology. Based on the study results, it is concluded that knots have the highest effect on the assortment quality structure in poplar plantations, regardless of the site and stand conditions. Their effect rises significantly with the increase of tree diameter. Also, the analyses show that the number of large and rotten knots on the tree trunk increases considerably with the older age. In the flooded area, the sweep of the lower part of the stem is more intensive and multiple curvatures are frequent on the trees growing immediately along the river, whereas curvature decreases with the distance from the river bank. Based on the study results, it is concluded that the percentage of best quality assortments is considerably reduced by the above wood defects.

  13. Povezave med kakovostjo bukovih dreves in iz njih izdelanih sortimentov: Links between beech tree quality and assortments made of them:

    OpenAIRE

    Marenče, Jurij; Šega, Bogdan

    2015-01-01

    In our research we dealt with the standing tree, estimation of the standing tree, evaluation of its quality and evaluation of quality of assortments made of it. Thereby we critically discussed diverse criteria, currently used in the practice - the five-grade scale for standing tree evaluation, used on permanent sampling plots, and current standards for evaluating the quality of the produced assortments. On the basis of a small analyzed sample of the evaluated and afterwards felled trees we we...

  14. The strength of assortative mating for flowering date and its basis in individual variation in flowering schedule.

    Science.gov (United States)

    Weis, A E; Nardone, E; Fox, G A

    2014-10-01

    Although it has been widely asserted that plants mate assortatively by flowering time, there is virtually no published information on the strength or causes of phenological assortment in natural populations. When strong, assortative mating can accelerate the evolution of plant reproductive phenology through its inflationary effect on genetic variance. We estimated potential assortative mating for flowering date in 31 old-field species in Ontario, Canada. For each species, we constructed a matrix of pairwise mating probabilities from the individual flowering schedules, that is the number of flower deployed on successive dates. The matrix was used to estimate the phenotypic correlation between mates, ρ, for flowering date. We also developed a measure of flowering synchrony within species, S, based upon the eigenstructure of the mating matrix. The mean correlation between pollen recipients and potential donors for flowering date was ρ=0.31 (range: 0.05-0.63). A strong potential for assortative mating was found among species with high variance in flowering date, flowering schedules of short duration and skew towards early flower deployment. Flowering synchrony, S, was negatively correlated with potential assortment (r= -0.49), but we go on to show that although low synchrony is a necessary condition for phenological assortative mating, it may not be sufficient to induce assortment for a given phenological trait. The potential correlation between mates showed no seasonal trend; thus, as climate change imposes selection on phenology through longer growing seasons, spring-flowering species are no more likely to experience an accelerated evolutionary response than summer species.

  15. Expressing Preferences using Preference Set Constraint Atoms

    CERN Document Server

    Brik, Alex

    2012-01-01

    This paper introduces an extension of Answer Set Programming called Preference Set Constraint Programming which is a convenient and general formalism to reason with preferences. PSC programming extends Set Constraint Programming introduced by Marek and Remmel (Marek and Remmel 2004) by introducing two types of preference set constraint atoms, measure preference set constraint atoms and pre-ordered preference set constraint atoms, which are extensions of set constraint atoms. We show that the question of whether a PSC program has a preferred stable model is CoNP-complete. We give examples of the uses of the preference set constraint atoms and show that Answer Set Optimization (Brewka, Niemel\\"a, and Truszczynski 2003) and General Preference (Son and Pontelli 2006) can be expressed using preference set constraint atoms.

  16. Why do males choose heterospecific females in the red spider mite?

    Science.gov (United States)

    Sato, Yukie; Staudacher, Heike; Sabelis, Maurice W

    2016-01-01

    In some species, males readily show courtship behaviour towards heterospecific females and even prefer them to females of their own species. This behaviour is generally explained by indiscriminate mating to acquire more mates, but may partly be explained by male mate preference mechanisms that have developed to choose among conspecific females, as male preference for larger females causes mating with larger heterospecific females. Recently, we found that males of the red spider mite, Tetranychus evansi collected from Spain (invasive population), prefer to mate with females of the two-spotted spider mite, T. urticae rather than with conspecific females. In spider mites, mate preference for non-kin individuals has been observed. Here, we investigated if T. evansi males collected from the area of its origin (Brazil) also show preference for heterospecific females. Secondly, we investigated if mate preference of T. evansi males for heterospecific females is affected by their relatedness to conspecific females which are offered together with heterospecific females. We found that mate preference for heterospecific females exists in Brazilian T. evansi, suggesting that the preference for heterospecific females is not a lack of evolved premating isolation with an allopatric species. We found that T. evansi males showed lower propensity to mate with heterospecific females when alternative females were non-kin in the two iso-female lines collected from Brazil. However, the effect of relatedness on male mate preference was not significant. We discuss alternative hypotheses explaining why T. evansi males prefer to mate with T. urticae females. PMID:26530994

  17. Why do males choose heterospecific females in the red spider mite?

    Science.gov (United States)

    Sato, Yukie; Staudacher, Heike; Sabelis, Maurice W

    2016-01-01

    In some species, males readily show courtship behaviour towards heterospecific females and even prefer them to females of their own species. This behaviour is generally explained by indiscriminate mating to acquire more mates, but may partly be explained by male mate preference mechanisms that have developed to choose among conspecific females, as male preference for larger females causes mating with larger heterospecific females. Recently, we found that males of the red spider mite, Tetranychus evansi collected from Spain (invasive population), prefer to mate with females of the two-spotted spider mite, T. urticae rather than with conspecific females. In spider mites, mate preference for non-kin individuals has been observed. Here, we investigated if T. evansi males collected from the area of its origin (Brazil) also show preference for heterospecific females. Secondly, we investigated if mate preference of T. evansi males for heterospecific females is affected by their relatedness to conspecific females which are offered together with heterospecific females. We found that mate preference for heterospecific females exists in Brazilian T. evansi, suggesting that the preference for heterospecific females is not a lack of evolved premating isolation with an allopatric species. We found that T. evansi males showed lower propensity to mate with heterospecific females when alternative females were non-kin in the two iso-female lines collected from Brazil. However, the effect of relatedness on male mate preference was not significant. We discuss alternative hypotheses explaining why T. evansi males prefer to mate with T. urticae females.

  18. Assortative mating and differential male mating success in an ash hybrid zone population

    Directory of Open Access Journals (Sweden)

    Frascaria-Lacoste Nathalie

    2006-11-01

    Full Text Available Abstract Background The structure and evolution of hybrid zones depend mainly on the relative importance of dispersal and local adaptation, and on the strength of assortative mating. Here, we study the influence of dispersal, temporal isolation, variability in phenotypic traits and parasite attacks on the male mating success of two parental species and hybrids by real-time pollen flow analysis. We focus on a hybrid zone population between the two closely related ash species Fraxinus excelsior L. (common ash and F. angustifolia Vahl (narrow-leaved ash, which is composed of individuals of the two species and several hybrid types. This population is structured by flowering time: the F. excelsior individuals flower later than the F. angustifolia individuals, and the hybrid types flower in-between. Hybrids are scattered throughout the population, suggesting favorable conditions for their local adaptation. We estimate jointly the best-fitting dispersal kernel, the differences in male fecundity due to variation in phenotypic traits and level of parasite attack, and the strength of assortative mating due to differences in flowering phenology. In addition, we assess the effect of accounting for genotyping error on these estimations. Results We detected a very high pollen immigration rate and a fat-tailed dispersal kernel, counter-balanced by slight phenological assortative mating and short-distance pollen dispersal. Early intermediate flowering hybrids, which had the highest male mating success, showed optimal sex allocation and increased selfing rates. We detected asymmetry of gene flow, with early flowering trees participating more as pollen donors than late flowering trees. Conclusion This study provides striking evidence that long-distance gene flow alone is not sufficient to counter-act the effects of assortative mating and selfing. Phenological assortative mating and short-distance dispersal can create temporal and spatial structuring that appears

  19. Women's Stereotypes and Consumer Preferences

    Directory of Open Access Journals (Sweden)

    Andrea Velandia Morales

    2011-01-01

    Full Text Available According to The Ambivalent Sexism Theory (Glick y Fiske, 1996 there are distinct stereotypes of women that men express different attitudes. Among them, the housewife, sexy women and executive women are the clearest ones. One hundred people participated in the present study in order to test the relationship between the female stereotypes, their level of influence and prestige and the level of preference for a commercial product (described in female and male terms. The results showed that sexy women is more associated with the masculine description, whereas the executive women is more associated to the feminine product description, and in both cases the housewife is the least associated with the two different descriptions. It was also found that the influence and the women prestige mediated the relationship between the stereotypes and the preference shown for the product described in feminine terms

  20. Algorithms for Learning Preferences for Sets of Objects

    Science.gov (United States)

    Wagstaff, Kiri L.; desJardins, Marie; Eaton, Eric

    2010-01-01

    A method is being developed that provides for an artificial-intelligence system to learn a user's preferences for sets of objects and to thereafter automatically select subsets of objects according to those preferences. The method was originally intended to enable automated selection, from among large sets of images acquired by instruments aboard spacecraft, of image subsets considered to be scientifically valuable enough to justify use of limited communication resources for transmission to Earth. The method is also applicable to other sets of objects: examples of sets of objects considered in the development of the method include food menus, radio-station music playlists, and assortments of colored blocks for creating mosaics. The method does not require the user to perform the often-difficult task of quantitatively specifying preferences; instead, the user provides examples of preferred sets of objects. This method goes beyond related prior artificial-intelligence methods for learning which individual items are preferred by the user: this method supports a concept of setbased preferences, which include not only preferences for individual items but also preferences regarding types and degrees of diversity of items in a set. Consideration of diversity in this method involves recognition that members of a set may interact with each other in the sense that when considered together, they may be regarded as being complementary, redundant, or incompatible to various degrees. The effects of such interactions are loosely summarized in the term portfolio effect. The learning method relies on a preference representation language, denoted DD-PREF, to express set-based preferences. In DD-PREF, a preference is represented by a tuple that includes quality (depth) functions to estimate how desired a specific value is, weights for each feature preference, the desired diversity of feature values, and the relative importance of diversity versus depth. The system applies statistical

  1. A Study on the Relationships between Digital Game Preference and Game Preference Reason with Gender, Class Level and Learning Styles

    Directory of Open Access Journals (Sweden)

    Ferhat Kadir PALA

    2011-06-01

    Full Text Available This study examined for to determine the relationships between digital game preferences and the game preferences reasons with gender, class levels and learning styles of university students. Study group consisted of students of Computer Education and Instructional Technology Department. Game preferences and preference reasons data were gathered by an open ended 16 items questionnaire. Kolb’s Learning Style Inventory was used for collecting learning styles data. As a result, significant relationships were found game preferences with respect to gender. While males preferred to play real time and full time game, females preferred to play real time games more than full time games. However, class levels and leaning styles had no significant effect to game preferences and game preference reasons. In addition to these findings, we decided that students did reasonable selections between game preferences and game preference reasons when distributions were analyzed.

  2. Genre and Gender in the Structure of Music Preferences.

    Science.gov (United States)

    Christenson, Peter G.

    1988-01-01

    Analyzes the music preference structure of college students based on responses to a variety of music use and preference measures. Finds that the underlying structure of music preference is multivariate and that there are crucial differences between males and females in terms of their "mapping" of music types. (MS)

  3. Broaden Students' Music Preferences.

    Science.gov (United States)

    Le Blanc, Albert

    1983-01-01

    A model of music preference theory suggests ways that teachers can broaden their students' musical preferences. Teachers can change preferences by changing something in the listener, the social environment, the music, or the ways that the listener processes information. (AM)

  4. Mate preference in wild and domesticated (game-farm) mallards: II. Pairing success

    Science.gov (United States)

    Cheng, K.M.; Shoffner, R.N.; Phillips, R.E.; Lee, F.B.

    1979-01-01

    Experiments were designed to determine whether assortative mating occurs in wild and game-farm mallard strains (Anas platyrhynchos). Mallard males of either strain raised with females of their own strain courted females of their own strain more than females of the opposite strain, and these males were only successful in pairing with females of their own strain. Males raised with females of the opposite strain courted wild and game-farm females with equal intensity. They were successful in pairing with females of either strain. While this study does not settle the question of possible gene flow between these two mallard populations, it does indicate that there is a potential barrier to panmixia.

  5. PHYLLOXERA-RESISTANT HYBRID FORM OF GRAPES OF TECHNICAL SORTS FOR IMPROVING THE ASSORTMENT

    OpenAIRE

    Larkina M. D.; Nikulushkina G. E.

    2015-01-01

    Many old varieties of grapes do not meet modern requirements, so there is a need for improved assortment of new high-quality varieties. The translation of the vineyards of the black sea coast of the Krasnodar region on inoculated culture is not fully decided the fate of the viticulture of the area. Weak resistance of American rootstocks to increased content of calcium and salts in the soil, caused the weakening of the bushes, reducing the vigor of the shoots, their maturation and yield of gra...

  6. Marketing Strategy Development Directions of Web Assortment in the Republic of Serbia

    Directory of Open Access Journals (Sweden)

    Jelena Končar

    2010-06-01

    Full Text Available Electronic commerce is a contemporary way of doing trade activities based on the use of information and communication technologies. In contemporary business conditions, trade faces numerous changes, which are mostly, before all, the result of market globalization, as well as information technology development. The Web assortment in electronic commerce is the key marketing instrument in a trade organization. The basic task of Serbian companies understands the need of tracking all the changes in the business environment on the global market with a view of meeting consumers requirements and needs. Business success of an e-commerce trader, besides other factors, greatly depends on the adequate choice of sales programs.

  7. [The marketing analysis of assortment of market of pharmaceuticals applied in treatment of psoriasis in Ukraine].

    Science.gov (United States)

    Kotvitskaya, A A; Karlo, V V

    2013-01-01

    The analysis of assortment of pharmaceuticals for treatment of psoriasis recommended by Minzdrav of Ukraine and present at the national pharmaceutical market is made. The characteristics of distribution of national and foreign producers of antihistamine and anti-psoriatic pharmaceuticals are established The availability of particular medicinal forms of various producers is analyzed too. The characteristics and tendencies in consumption of these groups of pharmaceuticals in natural and monetary units are analyzed including dynamics of changes of mean wholesale prices during the analyzed period.

  8. Assortment of Deep Mantle Fluids and Their Products in Kimberlites from China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Lei; HAO Jinhua; DING Yifei; LIU Yulong

    2004-01-01

    Based on studies of petrography, mineralogy and mineral chemistry, deep mantle fluids and their products in kimberlites and diamonds can be assorted into the ultradeep fluid-transmitted minerals with an oxygen-free feature, the deep fluid metasomatized-minerals characterized by enrichment in TiO2, K2O, BaO, REE and Fe3+, and the deep fluidreformed minerals. The three types show a successive descent in fluid origin depth and metasomatism strength, and they have brought forth a series of corresponding metasomatic products.

  9. 糖和维生素对淡色库蚊及白纹伊蚊产卵选择的影响%The influence of sugars and vitamins on the oviposition preference of gravid female Culex pipiens pallens and Aedes albopictus

    Institute of Scientific and Technical Information of China (English)

    邓天福; 莫建初

    2011-01-01

    Objective To evaluate the influence of diiferent sugars and vitamins on the oviposition behavior of gravid female Culex pipiens pallens and Aedes albopictus in laboratory, providing theoretical support for the development of a highly effective ovitrap. Methods The oviposition preference of gravid female Cx. pipiens pallens and Ae. albopictus to different concentrations of sugar and vitamin solutions was determined in laboratory. Results It was found that the gravid female Cx.pipiens pallens preferred to lay eggs in glucose solutions of 100 mg/L and of 1000 mg/L and sucrose solution of 1000 mg/L, with no obvious oviposition preference of the gravid female Ae. albopictus to the sugar solutions tested found, compared with the control tap water. Vitamin B1 solutions of 100 mg/L and 10 mg/L and VC solution of 100 mg/L could produce a significant oviposition preference for Cx. pipiens pallens and so could VB1 solution of 10 mg/L for Ae. albopictus. Conclusion Gravid Cx. pipiens pallens and Ae. albopictus have a high oviposition preference for VB1 with gravid Cx. pipiens pallens attracted to glucose as well in terms of the preference.%目的 评价不同营养物质对淡色库蚊和白纹伊蚊雌蚊产卵选择的影响,为新型诱卵器的研制提供理论支持.方法 在室内测定淡色库蚊和白纹伊蚊对不同种类糖和维生素溶液的产卵趋性.结果 淡色库蚊怀卵雌蚊偏好在1000 mg/L和100mg/L浓度的葡萄糖溶液及1000mg/L浓度的蔗糖溶液中产卵,而白纹伊蚊则对供试的各种糖液没有明显的产卵选择偏好;浓度为100mg/L的盐酸硫胺(VB1)溶液和抗坏血酸(VC)溶液、10mg/L的VB1溶液能显著引诱淡色库蚊产卵,10mg/L的VB1溶液还能显著引诱白纹伊蚊产卵.结论 葡萄糖对淡色库蚊、VB1对淡色库蚊和白纹伊蚊在室内有较好的产卵引诱效果.

  10. Transitivity of Preferences

    Science.gov (United States)

    Regenwetter, Michel; Dana, Jason; Davis-Stober, Clintin P.

    2011-01-01

    Transitivity of preferences is a fundamental principle shared by most major contemporary rational, prescriptive, and descriptive models of decision making. To have transitive preferences, a person, group, or society that prefers choice option "x" to "y" and "y" to "z" must prefer "x" to "z". Any claim of empirical violations of transitivity by…

  11. Social transmission of face preferences among humans

    OpenAIRE

    Jones, Benedict C.; DeBruine, Lisa M; Little, Anthony C.; Burriss, Robert P.; Feinberg, David R

    2007-01-01

    Previous studies demonstrating mate choice copying effects among females in non-human species have led many researchers to propose that social transmission of mate preferences may influence sexual selection for male traits. Although it has been suggested that social transmission may also influence mate preferences in humans, there is little empirical support for such effects. Here, we show that observing other women with smiling (i.e. positive) expressions looking at male faces increased wome...

  12. Working with Preferences

    CERN Document Server

    Kaci, Souhila

    2011-01-01

    Preferences are useful in many real-life problems, guiding human decision making from early childhood up to complex professional and organizational decisions. In artificial intelligence specifically, preferences is a relatively new topic of relevance to nonmonotonic reasoning, multiagent systems, constraint satisfaction, decision making, social choice theory and decision-theoretic planning. The first part of this book deals with preference representation, with specific chapters dedicated to representation languages, nonmonotonic logics of preferences, conditional preference networks, positive

  13. Brief report on the effect of providing single versus assorted brand name condoms to hospital patients: a descriptive study

    Directory of Open Access Journals (Sweden)

    Cagle Henry H

    2001-06-01

    Full Text Available Abstract Objectives This study examined condom acquisition by persons in a hospital setting when single versus assorted brand name condoms were provided. Methods Condom receptacles were placed in exam rooms of two clinics. During Phase 1, a single brand name was provided; for Phase 2, assorted brand names were added. Number of condoms taken was recorded for each phase. Results For one clinic there was nearly a two-fold increase in number of condoms taken (Phase 1 to Phase 2; for the second clinic there was negligible difference in number of condoms taken. Conclusions The provision of assorted brand name condoms, over a single brand name, can serve to increase condom acquisition. Locations of condoms and target population characteristics are related factors.

  14. Extended inclusive fitness theory: synergy and assortment drives the evolutionary dynamics in biology and economics.

    Science.gov (United States)

    Jaffe, Klaus

    2016-01-01

    W.D. Hamilton's Inclusive Fitness Theory explains the conditions that favor the emergence and maintenance of social cooperation. Today we know that these include direct and indirect benefits an agent obtains by its actions, and through interactions with kin and with genetically unrelated individuals. That is, in addition to kin-selection, assortation or homophily, and social synergies drive the evolution of cooperation. An Extended Inclusive Fitness Theory (EIFT) synthesizes the natural selection forces acting on biological evolution and on human economic interactions by assuming that natural selection driven by inclusive fitness produces agents with utility functions that exploit assortation and synergistic opportunities. This formulation allows to estimate sustainable cost/benefit threshold ratios of cooperation among organisms and/or economic agents, using existent analytical tools, illuminating our understanding of the dynamic nature of society, the evolution of cooperation among kin and non-kin, inter-specific cooperation, co-evolution, symbioses, division of labor and social synergies. EIFT helps to promote an interdisciplinary cross fertilization of the understanding of synergy by, for example, allowing to describe the role for division of labor in the emergence of social synergies, providing an integrated framework for the study of both, biological evolution of social behavior and economic market dynamics. Another example is a bio-economic understanding of the motivations of terrorists, which identifies different forms of terrorism. PMID:27468393

  15. The gender divide in urban China: Singlehood and assortative mating by age and education

    Directory of Open Access Journals (Sweden)

    Yue Qian

    2014-12-01

    Full Text Available Objective: Chinese media labels highly educated, urban women who are still single in their late 20s as "leftover ladies". We investigate whether indeed highly educated women are less likely to marry than their less-educated counterparts, and how assortative mating patterns by age and education play a role in singleness. Methods: We use data from the urban samples of the Chinese General Social Surveys in the 2000s. In the analysis we calculate marriage rates to examine the likelihood of entry into marriage, and then apply log-linear models to investigate the assortative mating patterns by age and education. Results: We find that as education increases, the likelihood of marriage increases among men but decreases among women, especially among those over age 30. The results from log-linear models reveal that more marriages involve better-educated, older men and less-educated, younger women. Conclusions: We argue that persistent traditional gender roles, accompanied by the rapid rise in women's education, contribute to low marriage rates among older, highly educated women.

  16. Evidence that avian reovirus σNS is an RNA chaperone: implications for genome segment assortment.

    Science.gov (United States)

    Borodavka, Alexander; Ault, James; Stockley, Peter G; Tuma, Roman

    2015-08-18

    Reoviruses are important human, animal and plant pathogens having 10-12 segments of double-stranded genomic RNA. The mechanisms controlling the assortment and packaging of genomic segments in these viruses, remain poorly understood. RNA-protein and RNA-RNA interactions between viral genomic segment precursors have been implicated in the process. While non-structural viral RNA-binding proteins, such as avian reovirus σNS, are essential for virus replication, the mechanism by which they assist packaging is unclear. Here we demonstrate that σNS assembles into stable elongated hexamers in vitro, which bind single-stranded nucleic acids with high affinity, but little sequence specificity. Using ensemble and single molecule fluorescence spectroscopy, we show that σNS also binds to a partially double-stranded RNA, resulting in gradual helix unwinding. The hexamer can bind multiple RNA molecules and exhibits strand-annealing activity, thus mediating conversion of metastable, intramolecular stem-loops into more stable heteroduplexes. We demonstrate that the ARV σNS acts as an RNA chaperone facilitating specific RNA-RNA interactions between genomic precursors during segment assortment and packaging.

  17. Extended inclusive fitness theory: synergy and assortment drives the evolutionary dynamics in biology and economics.

    Science.gov (United States)

    Jaffe, Klaus

    2016-01-01

    W.D. Hamilton's Inclusive Fitness Theory explains the conditions that favor the emergence and maintenance of social cooperation. Today we know that these include direct and indirect benefits an agent obtains by its actions, and through interactions with kin and with genetically unrelated individuals. That is, in addition to kin-selection, assortation or homophily, and social synergies drive the evolution of cooperation. An Extended Inclusive Fitness Theory (EIFT) synthesizes the natural selection forces acting on biological evolution and on human economic interactions by assuming that natural selection driven by inclusive fitness produces agents with utility functions that exploit assortation and synergistic opportunities. This formulation allows to estimate sustainable cost/benefit threshold ratios of cooperation among organisms and/or economic agents, using existent analytical tools, illuminating our understanding of the dynamic nature of society, the evolution of cooperation among kin and non-kin, inter-specific cooperation, co-evolution, symbioses, division of labor and social synergies. EIFT helps to promote an interdisciplinary cross fertilization of the understanding of synergy by, for example, allowing to describe the role for division of labor in the emergence of social synergies, providing an integrated framework for the study of both, biological evolution of social behavior and economic market dynamics. Another example is a bio-economic understanding of the motivations of terrorists, which identifies different forms of terrorism.

  18. Assortment Planning Considering Consumers' Two-stage Choice Behavior%考虑消费者两阶段选择行为的品类规划研究

    Institute of Scientific and Technical Information of China (English)

    赵藜; 田澎; 李相勇

    2013-01-01

    This paper studies the assortment planning problem considering consumers' two-stage choice behavior in the context of network revenue management. A two-stage choice model based on consumer preferences is proposed, and a dynamic programming model for assortment planning is developed. The choice deterministic linear programming method (CDLP) is used to approximate the optimal offer sets. Finally,through numerical examples,the effects of consumers' two-stage choice behavior on firm's average expected revenues are discussed.%在网络收益管理框架下,研究了考虑消费者两阶段选择行为的品类规划问题.提出了基于消费者产品偏好的两阶段选择行为模型,并建立了品类规划问题的动态规划模型.利用选择确定性线性规划方法对模型进行了近似求解,推导了最优的产品组合.最后通过数值算例讨论了消费者两阶段选择行为对厂商平均期望收益与产品组合选择的影响.

  19. The effects of rearing conditions on sexual traits and preferences in zebra finches

    NARCIS (Netherlands)

    Holveck, Marie-Jeanne

    2008-01-01

    Although theory predicts that females should prefer the highest quality male, female mating preferences within populations often show pronounced variation. What causes and maintains this variation remains poorly understood. This thesis addresses the influence of rearing conditions both on female mat

  20. Rotational preference in gymnastics.

    Science.gov (United States)

    Heinen, Thomas; Jeraj, Damian; Vinken, Pia M; Velentzas, Konstantinos

    2012-06-01

    In gymnastics, most skills incorporate rotations about one or more body axes. At present, the question remains open if factors such as lateral preference and/or vestibulo-spinal asymmetry are related to gymnast's rotational preference. Therefore, we sought to explore relationships in gymnast's rotation direction between different gymnastic skills. Furthermore, we sought to explore relationships between rotational preference, lateral preference, and vestibulo-spinal asymmetry. In the experiment n = 30 non-experts, n = 30 near-experts and n = 30 experts completed a rotational preference questionnaire, a lateral preference inventory, and the Unterberger-Fukuda Stepping Test. The results revealed, that near-experts and experts more often rotate rightward in the straight jump with a full turn when rotating leftward in the round-off and vice versa. The same relationship was found for experts when relating the rotation preference in the handstand with a full turn to the rotation preference in the straight jump with a full turn. Lateral preference was positively related to rotational preference in non-expert gymnasts, and vestibulo-spinal asymmetry was positively related to rotational preference in experts. We suggest, that gymnasts should explore their individual rotational preference by systematically practicing different skills with a different rotation direction, bearing in mind that a clearly developed structure in rotational preference between different skills may be appropriate to develop more complex skills in gymnastics. PMID:23486362

  1. Body shape preferences: associations with rater body shape and sociosexuality.

    Science.gov (United States)

    Price, Michael E; Pound, Nicholas; Dunn, James; Hopkins, Sian; Kang, Jinsheng

    2013-01-01

    There is accumulating evidence of condition-dependent mate choice in many species, that is, individual preferences varying in strength according to the condition of the chooser. In humans, for example, people with more attractive faces/bodies, and who are higher in sociosexuality, exhibit stronger preferences for attractive traits in opposite-sex faces/bodies. However, previous studies have tended to use only relatively simple, isolated measures of rater attractiveness. Here we use 3D body scanning technology to examine associations between strength of rater preferences for attractive traits in opposite-sex bodies, and raters' body shape, self-perceived attractiveness, and sociosexuality. For 118 raters and 80 stimuli models, we used a 3D scanner to extract body measurements associated with attractiveness (male waist-chest ratio [WCR], female waist-hip ratio [WHR], and volume-height index [VHI] in both sexes) and also measured rater self-perceived attractiveness and sociosexuality. As expected, WHR and VHI were important predictors of female body attractiveness, while WCR and VHI were important predictors of male body attractiveness. Results indicated that male rater sociosexuality scores were positively associated with strength of preference for attractive (low) VHI and attractive (low) WHR in female bodies. Moreover, male rater self-perceived attractiveness was positively associated with strength of preference for low VHI in female bodies. The only evidence of condition-dependent preferences in females was a positive association between attractive VHI in female raters and preferences for attractive (low) WCR in male bodies. No other significant associations were observed in either sex between aspects of rater body shape and strength of preferences for attractive opposite-sex body traits. These results suggest that among male raters, rater self-perceived attractiveness and sociosexuality are important predictors of preference strength for attractive opposite

  2. Body shape preferences: associations with rater body shape and sociosexuality.

    Directory of Open Access Journals (Sweden)

    Michael E Price

    Full Text Available There is accumulating evidence of condition-dependent mate choice in many species, that is, individual preferences varying in strength according to the condition of the chooser. In humans, for example, people with more attractive faces/bodies, and who are higher in sociosexuality, exhibit stronger preferences for attractive traits in opposite-sex faces/bodies. However, previous studies have tended to use only relatively simple, isolated measures of rater attractiveness. Here we use 3D body scanning technology to examine associations between strength of rater preferences for attractive traits in opposite-sex bodies, and raters' body shape, self-perceived attractiveness, and sociosexuality. For 118 raters and 80 stimuli models, we used a 3D scanner to extract body measurements associated with attractiveness (male waist-chest ratio [WCR], female waist-hip ratio [WHR], and volume-height index [VHI] in both sexes and also measured rater self-perceived attractiveness and sociosexuality. As expected, WHR and VHI were important predictors of female body attractiveness, while WCR and VHI were important predictors of male body attractiveness. Results indicated that male rater sociosexuality scores were positively associated with strength of preference for attractive (low VHI and attractive (low WHR in female bodies. Moreover, male rater self-perceived attractiveness was positively associated with strength of preference for low VHI in female bodies. The only evidence of condition-dependent preferences in females was a positive association between attractive VHI in female raters and preferences for attractive (low WCR in male bodies. No other significant associations were observed in either sex between aspects of rater body shape and strength of preferences for attractive opposite-sex body traits. These results suggest that among male raters, rater self-perceived attractiveness and sociosexuality are important predictors of preference strength for

  3. A preference for migration

    OpenAIRE

    Stark, Oded

    2007-01-01

    At least to some extent migration behavior is the outcome of a preference for migration. The pattern of migration as an outcome of a preference for migration depends on two key factors: imitation technology and migration feasibility. We show that these factors jointly determine the outcome of a preference for migration and we provide examples that illustrate how the prevalence and transmission of a migration-forming preference yield distinct migration patterns. In particular, the imitation of...

  4. Examining Office Type Preference

    OpenAIRE

    Rolfö, Linda; Eklund, Jörgen

    2015-01-01

    Office types and their environmental features influence performance and job satisfaction. Yet employees’ opinions are seldom considered when choosing office type. This paper suggests a method that investigates employees’ office type preferences and motives behind the preferences. The method proved to be quick and simple and provided a flow of current to preferred office type. A majority preferred the quiet cell office for its privacy while the open office was considered having a noisy and dis...

  5. Heterogeneous Social Preferences

    OpenAIRE

    Erlei, Mathias

    2003-01-01

    Recent research has shown the usefulness of social preferences for explaining behavior in laboratory experiments. This paper demonstrates that models of social preferences are particularly powerful in explaining behavior if they are embedded in a setting of heteroge-neous actors with heterogeneous (social) preferences. For this purpose a simple model is in-troduced that combines the basic ideas of inequity aversion, social welfare preferences, recip-rocity and heterogeneity. This model is app...

  6. Imposing Nonlinear Constraints When Estimating Genetic and Cultural Transmission Under Assortative Mating: A Simulation Study Using Mx and BUGS

    NARCIS (Netherlands)

    Berg, van den Stephanie M.

    2009-01-01

    Modeling both genetic and cultural transmission in parent-offspring data in the presence of phenotypic assortment requires the imposition of nonlinear constraints. This article reports a simulation study that determined how well the structural equation modeling software package Mx and the Bayesian-o

  7. Accuracy in estimation of timber assortments and stem distribution - A comparison of airborne and terrestrial laser scanning techniques

    Science.gov (United States)

    Kankare, Ville; Vauhkonen, Jari; Tanhuanpää, Topi; Holopainen, Markus; Vastaranta, Mikko; Joensuu, Marianna; Krooks, Anssi; Hyyppä, Juha; Hyyppä, Hannu; Alho, Petteri; Viitala, Risto

    2014-11-01

    Detailed information about timber assortments and diameter distributions is required in forest management. Forest owners can make better decisions concerning the timing of timber sales and forest companies can utilize more detailed information to optimize their wood supply chain from forest to factory. The objective here was to compare the accuracies of high-density laser scanning techniques for the estimation of tree-level diameter distribution and timber assortments. We also introduce a method that utilizes a combination of airborne and terrestrial laser scanning in timber assortment estimation. The study was conducted in Evo, Finland. Harvester measurements were used as a reference for 144 trees within a single clear-cut stand. The results showed that accurate tree-level timber assortments and diameter distributions can be obtained, using terrestrial laser scanning (TLS) or a combination of TLS and airborne laser scanning (ALS). Saw log volumes were estimated with higher accuracy than pulpwood volumes. The saw log volumes were estimated with relative root-mean-squared errors of 17.5% and 16.8% with TLS and a combination of TLS and ALS, respectively. The respective accuracies for pulpwood were 60.1% and 59.3%. The differences in the bucking method used also caused some large errors. In addition, tree quality factors highly affected the bucking accuracy, especially with pulpwood volume.

  8. A phylogenetic analysis of body size evolution in the Anolis roquet group (Sauria: Iguanidae): character displacement or size assortment?

    Science.gov (United States)

    Giannasi, N; Thorpe, R S; Malhotra, A

    2000-02-01

    The important role that competition plays in structuring communities is well documented; however, the role of competition in an evolutionary context remains unclear. Evolutionary investigations into the role of competition have often focused on the process of character displacement, and a good example of this is the evolution of body size in the Anolis lizards of the Caribbean islands. Previous work on the A. roquet species group has taken a phylogenetic approach and concluded that patterns of body size differences are not caused by character displacement but are a result of size assortment. Using a phylogenetic reconstruction based on the sequence of the cytochrome b gene (cyt-b) and ancestral character-state reconstruction methods, we investigated the roles of character displacement and size assortment. Our results indicated that size assortment alone was insufficient to explain the observed patterns of body size differences. Furthermore, we found that change in body size was associated with a change in allopatry/sympatry, thus supporting the character-displacement hypothesis. We conclude that patterns of body size differences in the A. roquet species group appear to be the result of a combination of character displacement and size assortment because character displacement was only found to be possible on three occasions.

  9. Parasite-stress promotes in-group assortative sociality: the cases of strong family ties and heightened religiosity.

    Science.gov (United States)

    Fincher, Corey L; Thornhill, Randy

    2012-04-01

    Throughout the world people differ in the magnitude with which they value strong family ties or heightened religiosity. We propose that this cross-cultural variation is a result of a contingent psychological adaptation that facilitates in-group assortative sociality in the face of high levels of parasite-stress while devaluing in-group assortative sociality in areas with low levels of parasite-stress. This is because in-group assortative sociality is more important for the avoidance of infection from novel parasites and for the management of infection in regions with high levels of parasite-stress compared with regions of low infectious disease stress. We examined this hypothesis by testing the predictions that there would be a positive association between parasite-stress and strength of family ties or religiosity. We conducted this study by comparing among nations and among states in the United States of America. We found for both the international and the interstate analyses that in-group assortative sociality was positively associated with parasite-stress. This was true when controlling for potentially confounding factors such as human freedom and economic development. The findings support the parasite-stress theory of sociality, that is, the proposal that parasite-stress is central to the evolution of social life in humans and other animals.

  10. Uranium recovery from assorted laboratory organic waste solutions using centrifugal contractors

    International Nuclear Information System (INIS)

    Countercurrent extraction runs, carried out in our laboratory for the evaluation studies of N,N-dihexyloctanamide (DHOA) as an alternative of tributyl phosphate (TBP) for spent fuel reprocessing, have led to generation of large volumes of organic wastes containing varying amounts of uranium. It was desirable to recover uranium from such waste solutions prior to the disposal of organic waste solutions. Even though, batch stripping can be used for this purpose, it may take several days to achieve the desired goal. In this context, the centrifugal contactors appear attractive due to high liquid through-put, which may simplify the uranium recovery process. Uranium recovery studies from assorted organic waste solutions were therefore carried out using centrifugal contactors

  11. MODERNIZATION OF ASSORTMENT OF TABLE GRAPES FOR FARMERS AND CROFT VITICULTURE

    Directory of Open Access Journals (Sweden)

    Troshin L. P.

    2014-01-01

    Full Text Available The article highlights the issues of improving the assortment of table grape plantations for use in the farms and croft forms of management. Brief presentation of results of the five-year study of 12 table grape varieties in industrial environments for their cultivation: in the OAO AF of "Juznaja", OOO "Phanagoria-Agro" training field "Kuban" and branches of the Department of Viticulture Kuban State Agricultural University: Citrine, Helios, Bogatyanovsky, Anthracite, Dolgogdanij, Preobragenije, Academic K, Rochefort K, Libya K, Kubattik, Nizina and Chrysolite. These varieties are the basis of modern conveyor of table varieties and are recommended for introduction in the State register of breeding achievements of the Russian Federation in all regions of our country

  12. Intergenerational income mobility – top incomes and assortative mating in Denmark

    DEFF Research Database (Denmark)

    Hussain, M. Azhar; Bonke, Jens; Munk, Martin D.

    2011-01-01

    , in particular, when including capital income in the total income. Also we find the marriage match has a stronger impact on the family-to-family income transfer in the top of the income distribution where the daughter marries a man more like her father than herself. The highest persistence, however, is between......This article investigates intergenerational income mobility among top-income people in Denmark focusing on the impact of assortative mating. Earnings and capital income are the variables of interest included in the analyzes testing the hypothesis that both wealth and social heritage are transferred...... from rich parents to their children. Using administrative registers allow us to look at small fractions of the populations, i.e. dynasties, and to distinguish between sons and daughters and to observe their eventual spouses’ incomes. We find that intergenerational mobility is lower in the top...

  13. The Analysis Of The Correlations And Regressions Between Some Characters On A Wheat Isogenic Varities Assortment

    Science.gov (United States)

    Păniţă, Ovidiu

    2015-09-01

    In the years 2012-2014 on Banu-Maracine DRS there were tested an assortment of 25 isogenic lines of wheat (Triticum aestivum ssp.vulgare), the analyzed characters being the number of seeds/spike, seeds weight/spike (g), no. of spikes/m2, weight of a thousand seeds (WTS) (g) and no. of emerged plants/m2. Based on recorded data and statistical processing of those, they were identified a numbers of links between these characters. Also available regression models were identified between some of the studied characters. Based on component analysis, no. of seeds/spike and seeds weight/spike are components that influence in excess of 88% variance analysis, a total of seven genotypes with positive scores for both factors.

  14. Knocking out multigene redundancies via cycles of sexual assortment and fluorescence selection.

    Science.gov (United States)

    Suzuki, Yo; St Onge, Robert P; Mani, Ramamurthy; King, Oliver D; Heilbut, Adrian; Labunskyy, Vyacheslav M; Chen, Weidong; Pham, Linda; Zhang, Lan V; Tong, Amy H Y; Nislow, Corey; Giaever, Guri; Gladyshev, Vadim N; Vidal, Marc; Schow, Peter; Lehár, Joseph; Roth, Frederick P

    2011-02-01

    Phenotypes that might otherwise reveal a gene's function can be obscured by genes with overlapping function. This phenomenon is best known within gene families, in which an important shared function may only be revealed by mutating all family members. Here we describe the 'green monster' technology that enables precise deletion of many genes. In this method, a population of deletion strains with each deletion marked by an inducible green fluorescent protein reporter gene, is subjected to repeated rounds of mating, meiosis and flow-cytometric enrichment. This results in the aggregation of multiple deletion loci in single cells. The green monster strategy is potentially applicable to assembling other engineered alterations in any species with sex or alternative means of allelic assortment. To test the technology, we generated a single broadly drug-sensitive strain of Saccharomyces cerevisiae bearing precise deletions of all 16 ATP-binding cassette transporters within clades associated with multidrug resistance.

  15. Perceived stimulus complexity and food preference development

    NARCIS (Netherlands)

    Levy, C.M.; MacRae, A.; Köster, E.P.

    2006-01-01

    The importance of perceived complexity, a 'collative property' as defined by [Berlyne, D. E. (1967). Arousal and reinforcement. In Nebraska symposium on motivation (pp. 1-110). University of Nebraska Press], to the dynamic development of preference was investigated. Eighty-six female and 82 male sub

  16. 女性的教育成就與大學畢業後初期位置之關係 Female College Students’ Preference for Fields of Study and Their First-year Jobs

    Directory of Open Access Journals (Sweden)

    陳建州 Jian-Jhou Chen

    2011-09-01

    Full Text Available 女性偏好的教育種類(學類)雖未能帶給她們與男性相當的職業地位,但是長期以來,女性投入某些學類的傾向卻維持著穩定性。本研究認為,如果這些學類能連結女性偏好的職業,便可補充說明女性教育選擇傾向穩定的現象。在考量女性就業需求之後,本研究依據滿足女性就業需求的程度差異,將勞動市場劃分成數組區隔的部門,其中,屬於女性的「好工作」是公部門與非營利機構。本研究採用2006 年「臺灣高等教育資料庫」中大學畢業後一年之女性為樣本,以多元邏輯迴歸分析估計家庭背景、學校類型、學類、證照等變項,針對大學畢業後一年的狀態,描繪女性的教育成就與勞動市場的連結情形。研究發現:(一)升研究所階段的教育轉換具有社經階層差異。(二)公立大學畢業者取得公部門與非營利機構工作的勝算最高,私立技職院校畢業者的勝算最低。(三)女性偏好的學類連結至公部門與非營利機構的機率,高於男性投入較高的學類,此種連結關係可能穩定了女性的教育選擇傾向。(四)除了通過公職考試或國家專業技術考試較有利於取得好工作,其他專業證照或認證並無助益。 This research explores the characteristics of women’s employment and their desire for rewards in different labor market sectors, analyzes the effects of the types of university, fields of study, and professional certifications on higher educated women’s early jobs, and explains the stable distribution of female college students in different fields of study. Using data retrieved from the “Taiwan Higher Education Data System,” the entire analysis includes 7,547 higher educated women who had graduated from universities one year ago. The results of the multinomial logit regression suggest 1 women from upper socio-economic status were more

  17. The structure of a food product assortment modulates the effect of providing choice on food intake.

    Science.gov (United States)

    Parizel, Odile; Sulmont-Rossé, Claire; Fromentin, Gilles; Delarue, Julien; Labouré, Hélène; Benamouzig, Robert; Marsset-Baglieri, Agnès

    2016-09-01

    Several authors showed that providing choice may increase food liking and food intake. However, the impact of choice may be modulated by assortment's characteristics, such as the number of alternatives or their dissimilarity. The present study compared the impact of choice on food liking and intake under the two following conditions: (1) when choosing a product to consume from among similar products versus dissimilar products; and (2) when choosing a product to consume from among pleasant products versus unpleasant products. Two experiments were carried out using the same design: the "apple puree" experiment (n = 80), where the volunteers choose from among similar products (apple purees varying in texture) and the "dessert" experiment (n = 80), where the volunteers choose from among dissimilar products (fruit dessert, dairy dessert, custard, pudding). During the first session, participants rated their liking for 12 products (apples purees or desserts). Then the participants were divided into a "pleasant" group (n = 40) in which volunteers were assigned three pleasant products, and an "unpleasant" group (n = 40) in which volunteers were assigned three unpleasant products. Finally, all of the volunteers participated in a choice session - volunteers were presented with their three assigned products and asked to choose one of the products, and a no-choice session - volunteers were served with one product that was randomly selected from among their three assigned products. Providing choice led to an increase in food liking in both experiments and an increase in food intake only for the desserts, namely only when the volunteers chose the product to consume from among "not too similar" alternatives. No effect of assortment's pleasantness was observed. PMID:26606886

  18. Association between autozygosity and major depression: stratification due to religious assortment.

    Science.gov (United States)

    Abdellaoui, Abdel; Hottenga, Jouke-Jan; Xiao, Xiangjun; Scheet, Paul; Ehli, Erik A; Davies, Gareth E; Hudziak, James J; Smit, Dirk J A; Bartels, Meike; Willemsen, Gonneke; Brooks, Andrew; Sullivan, Patrick F; Smit, Johannes H; de Geus, Eco J; Penninx, Brenda W J H; Boomsma, Dorret I

    2013-11-01

    The effects of inbreeding on the health of offspring can be studied by measuring genome-wide autozygosity as the proportion of the genome in runs of homozygosity (F roh) and relate F roh to outcomes such as psychiatric phenotypes. To successfully conduct these studies, the main patterns of variation for genome-wide autozygosity between and within populations should be well understood and accounted for. Within population variation was investigated in the Dutch population by comparing autozygosity between religious and non-religious groups. The Netherlands have a history of societal segregation and assortment based on religious affiliation, which may have increased parental relatedness within religious groups. Religion has been associated with several psychiatric phenotypes, such as major depressive disorder (MDD). We investigated whether there is an association between autozygosity and MDD, and the extent to which this association can be explained by religious affiliation. All F roh analyses included adjustment for ancestry-informative principal components (PCs) and geographic factors. Religious affiliation was significantly associated with autozygosity, showing that F roh has the ability to capture within population differences that are not captured by ancestry-informative PCs or geographic factors. The non-religious group had significantly lower F roh values and significantly more MDD cases, leading to a nominally significant negative association between autozygosity and depression. After accounting for religious affiliation, MDD was not associated with F roh, indicating that the relation between MDD and inbreeding was due to stratification. This study shows how past religious assortment and recent secularization can have genetic consequences in a relatively small country. This warrants accounting for the historical social context and its effects on genetic variation in association studies on psychiatric and other related traits.

  19. The structure of a food product assortment modulates the effect of providing choice on food intake.

    Science.gov (United States)

    Parizel, Odile; Sulmont-Rossé, Claire; Fromentin, Gilles; Delarue, Julien; Labouré, Hélène; Benamouzig, Robert; Marsset-Baglieri, Agnès

    2016-09-01

    Several authors showed that providing choice may increase food liking and food intake. However, the impact of choice may be modulated by assortment's characteristics, such as the number of alternatives or their dissimilarity. The present study compared the impact of choice on food liking and intake under the two following conditions: (1) when choosing a product to consume from among similar products versus dissimilar products; and (2) when choosing a product to consume from among pleasant products versus unpleasant products. Two experiments were carried out using the same design: the "apple puree" experiment (n = 80), where the volunteers choose from among similar products (apple purees varying in texture) and the "dessert" experiment (n = 80), where the volunteers choose from among dissimilar products (fruit dessert, dairy dessert, custard, pudding). During the first session, participants rated their liking for 12 products (apples purees or desserts). Then the participants were divided into a "pleasant" group (n = 40) in which volunteers were assigned three pleasant products, and an "unpleasant" group (n = 40) in which volunteers were assigned three unpleasant products. Finally, all of the volunteers participated in a choice session - volunteers were presented with their three assigned products and asked to choose one of the products, and a no-choice session - volunteers were served with one product that was randomly selected from among their three assigned products. Providing choice led to an increase in food liking in both experiments and an increase in food intake only for the desserts, namely only when the volunteers chose the product to consume from among "not too similar" alternatives. No effect of assortment's pleasantness was observed.

  20. Do dogs (Canis lupus familiaris) prefer family?

    Science.gov (United States)

    Hamilton, Jennifer; Vonk, Jennifer

    2015-10-01

    Kin recognition requires the ability to discriminate between one's own genetic relatives and non-relatives. There are two mechanisms that aid in kin discrimination: phenotype matching and familiarity. Dogs may be a good model for assessing these mechanisms as dogs are a promiscuous social species with a keen sense of smell. Domestic dogs of both sexes were presented with two scents (close kin, distant-kin) and preference was assessed through three measures (latency to approach, number of visits, time spent). Experiment 1 explored the possibility of phenotype matching as subjects had no contact with sires, whose scent was presented alongside a control male's scent. Experiment 2 explored recognition of siblings raised with the subjects and then separated at seven weeks of age. Whereas female dogs in this experiment did not show a statistically significant preference, male dogs showed a preference for distant-kin when presented with sire and female sibling samples.

  1. Preferences over Social Risk

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Lau, Morten; Rutström, E. Elisabet;

    2013-01-01

    the methodological issues extend to larger groups that form endogenously (e.g., families, committees, communities). Preferences over social risk can be closely approximated by individual risk attitudes when subjects have no information about the risk preferences of other group members. We find no evidence......We elicit individual preferences over social risk. We identify the extent to which these preferences are correlated with preferences over individual risk and the well-being of others. We examine these preferences in the context of laboratory experiments over small, anonymous groups, although...... that subjects systematically reveal different risk attitudes in a social setting with no prior knowledge about the risk preferences of others compared to when they solely bear the consequences of the decision. However, we also find that subjects are significantly more risk averse when they know the risk...

  2. The effects of rearing conditions on sexual traits and preferences in zebra finches

    OpenAIRE

    Holveck, Marie-Jeanne

    2008-01-01

    Although theory predicts that females should prefer the highest quality male, female mating preferences within populations often show pronounced variation. What causes and maintains this variation remains poorly understood. This thesis addresses the influence of rearing conditions both on female mating preferences and male advertising signals in the zebra finch Taeniopygia guttata. It reconciles earlier apparently contradicting findings on the relative importance of visual versus acoustic sig...

  3. Female Infertility

    Science.gov (United States)

    Infertility means not being able to get pregnant after at least one year of trying (or 6 ... woman keeps having miscarriages, it is also called infertility. Female infertility can result from age, physical problems, ...

  4. Facial aesthetics: babies prefer attractiveness to symmetry.

    Science.gov (United States)

    Samuels, Curtis A; Butterworth, George; Roberts, Tony; Graupner, Lida; Hole, Graham

    2013-01-01

    The visual preferences of human infants for faces that varied in their attractiveness and in their symmetry about the midline were explored. The aim was to establish whether infants' visual preference for attractive faces may be mediated by the vertical symmetry of the face. Chimeric faces, made from photographs of attractive and unattractive female faces, were produced by computer graphics. Babies looked longer at normal and at chimeric attractive faces than at normal and at chimeric unattractive faces. There were no developmental differences between the younger and older infants: all preferred to look at the attractive faces. Infants as young as 4 months showed similarity with adults in the 'aesthetic perception' of attractiveness and this preference was not based on the vertical symmetry of the face.

  5. Decision Styles in Coaching: Preferences of Basketball Players.

    Science.gov (United States)

    Chelladurai, P.; Arnott, M.

    1985-01-01

    This study investigated basketball players' preferences for different decision making styles in varying situations. While females were more oriented toward participation than males were, preferences of both groups were more influenced by main effects of coach's information and the interaction of quality requirement with problem complexity.…

  6. Learning to speciate: The biased learning of mate preferences promotes adaptive radiation.

    Science.gov (United States)

    Gilman, R Tucker; Kozak, Genevieve M

    2015-11-01

    Bursts of rapid repeated speciation called adaptive radiations have generated much of Earth's biodiversity and fascinated biologists since Darwin, but we still do not know why some lineages radiate and others do not. Understanding what causes assortative mating to evolve rapidly and repeatedly in the same lineage is key to understanding adaptive radiation. Many species that have undergone adaptive radiations exhibit mate preference learning, where individuals acquire mate preferences by observing the phenotypes of other members of their populations. Mate preference learning can be biased if individuals also learn phenotypes to avoid in mates, and shift their preferences away from these avoided phenotypes. We used individual-based computational simulations to study whether biased and unbiased mate preference learning promotes ecological speciation and adaptive radiation. We found that ecological speciation can be rapid and repeated when mate preferences are biased, but is inhibited when mate preferences are learned without bias. Our results suggest that biased mate preference learning may play an important role in generating animal biodiversity through adaptive radiation.

  7. 条纹短攀鲈的雄性个体大小、雌性偏好以及雄性之间的竞争%Male body size,female preference and male-male competition in croaking gouramis Trichopsis vittata

    Institute of Scientific and Technical Information of China (English)

    Supanee LIENGPORNPAN; Mullica JAROENSUTASINEE; Krisanadej JAROENSUTASINEE

    2007-01-01

    本研究考察了条纹短攀鲈(Trichopsis vittata)雄性个体的身体大小对雌性个体性偏好的影响以及对雄性之间竞争的影响.本研究设立了两种处理来研究雌性个体的性偏好以及雄性之间的竞争.在一种处理中,放入同样大小的雄性个体,而在另一种处理中,放入大小不同的雄性个体.结果表明,雄性个体的大小不影响雌性条纹短攀鲈的性偏好.在对雄性之间竞争的研究中,发现个体较大的个体获胜的次数比较多.在个体大小相同的处理中,雄性之间打斗的持续时间比另一种处理中的打斗持续时间长.对这两种处理中不同对抗行为的比较表明,个体大小相同处理组中的发声、咬、以及总体对抗行为发生得更为频繁.对个体大小不同处理组中的大、小个体的进一步观察也揭示出体型大的个体比体型小的个体有更多的追逐行为和更少的逃脱行为.这些结果表明,在雄性个体比雌性个体大的物种中,体型的性两型可能与雄性之间的竞争有关,而不是与雌性偏好有关.[动物学报 53(2):233-240,2007].%This study examined the role of the male body size in the female sexual preference and male-male competition among croaking gouramis (Trichopsis vittata Cuvier,1831).Two studies were conducted; in the first males were matched in size,and in the second males of different sizes were placed together.The results showed that male body size did not affect sexual preference among female croaking gouramis.Regarding the male-male competition study,large males won more fights than small ones.Fighting durations between size-matched fish were longer than those between size-mismatched fish.A comparison of different agonistic behaviours of the fish under both treatments showed that sound producing,biting and total agonistic behaviours were found more frequently among the size-matched fish.Further observations of the large and small fish in the size-mismatched group

  8. Theoretical studies on the molecular structure, conformational preferences, topological and vibrational analysis of allicin

    Science.gov (United States)

    Durlak, Piotr; Berski, Sławomir; Latajka, Zdzisław

    2016-01-01

    The molecular structure, conformational preferences, topological and vibrational analysis of allicin has been investigated at two different approaches. Calculations have been carried out on static (DFT and MP2) levels with an assortment of Dunning's basis sets and dynamic CPMD simulations. In this both case within the isolated molecule approximation. The results point out that at least twenty different conformers coexist on the PES as confirmed by the flexible character of this molecule. The topological analysis of ELF showed very similar nature of the Ssbnd S and Ssbnd O bonds. The infrared spectrum has been calculated, and a comparative vibrational analysis has been performed.

  9. Learning Style Preferences of Iranian EFL High School Students

    OpenAIRE

    Reza Vaseghi; Hamed Barjesteh; Sedigheh Shakib

    2013-01-01

    The current study examined the learning style preferences of 75 Iranian students at Marefat high school in Kuala Lumpur of which, 41 are females and 34 are males. As there are very few researches in which the learning style preferences of Iranian high school students investigated, this study attempts to fulfil this gap. To this end, in order to identify the students’ preferred learning styles (Visual, Auditory, Kinesthetic, Tactile, Group, and Individual) Reid’s Perceptual Learning Style Pref...

  10. Gender differences in ethanol preference and ingestion in rats. The role of the gonadal steroid environment.

    OpenAIRE

    Almeida, O F; Shoaib, M.; Deicke, J; Fischer, D.; Darwish, M H; Patchev, V K

    1998-01-01

    An ethanol oral self administration paradigm showed the existence of gender differences in alcohol preference in rats: whereas males and females initiated alcohol drinking at similar rates, females maintained their preference for ethanol over a longer duration. Neonatal estrogenization of females, which effectively confers a male phenotype on a genetically female brain, resulted in patterns of drinking that were similar to those displayed by intact male rats, indicating that gender difference...

  11. Assortment of the plants in the Medieval diet in Czech countries (based on archaeobotanical finds).

    Science.gov (United States)

    Culíková, V

    2000-01-01

    The finds of remains of useful plants in archaeological objects were drawing attention already in the last century. However, it was not until after the World War II, in relation with renovation of historical cores of the towns, when a separate branch of the botany--archaeobotany constituted. In the Czech Republic it was E. Opravil who was the first to become engaged in a systematic archaeobotanical research at the beginning of the 60's. All the vegetal remains--fruits and seeds on the first place as well as pollen grains from prehistoric times to the post-medieval period, are the subjects of archaeobotany. The medieval waste pits are the richest sources of the vegetal remains. They contain a lot of diasporas of cultural as well as wild plants. The remains of useful plants are an authentic document of the vegetal component of diet. Even though some vegetal species, such as for example garlic, onion or stalk-plants, about whose cultivation we are informed from literature, occur only seldom, there appeared also the species not mentioned in literature. All the basic cereals have been known in our country already since the early Middle Ages. Wheat (Triticum aestivum) and rye (Secale cereale), as well as millet (Panicum miliaceum) that, along with buckwheat (Fagopyrum esculentum), were replaced by potatoes in the modern times were the most important. Also leguminous plants were of great importance in the diet even though their charred seeds seldom preserved. Remains of oil plants such as hemp (Cannabis sativa), flax (Linum usitatissimum) and poppy (Papaver somniferum) preserved well. It was successfully proved that cucumber (Cucumis sativus), among other numerous kinds of vegetables, was introduced by the Slavs already in the 8th century in Moravia and in the 9th century in Bohemia. The assortment of fruit was rich--especially the assortment of cultivated fruit. Among the imported kinds of fruit the first place occupied figs (Ficus carica), from the numerous finds it can

  12. Assortment of the plants in the Medieval diet in Czech countries (based on archaeobotanical finds).

    Science.gov (United States)

    Culíková, V

    2000-01-01

    The finds of remains of useful plants in archaeological objects were drawing attention already in the last century. However, it was not until after the World War II, in relation with renovation of historical cores of the towns, when a separate branch of the botany--archaeobotany constituted. In the Czech Republic it was E. Opravil who was the first to become engaged in a systematic archaeobotanical research at the beginning of the 60's. All the vegetal remains--fruits and seeds on the first place as well as pollen grains from prehistoric times to the post-medieval period, are the subjects of archaeobotany. The medieval waste pits are the richest sources of the vegetal remains. They contain a lot of diasporas of cultural as well as wild plants. The remains of useful plants are an authentic document of the vegetal component of diet. Even though some vegetal species, such as for example garlic, onion or stalk-plants, about whose cultivation we are informed from literature, occur only seldom, there appeared also the species not mentioned in literature. All the basic cereals have been known in our country already since the early Middle Ages. Wheat (Triticum aestivum) and rye (Secale cereale), as well as millet (Panicum miliaceum) that, along with buckwheat (Fagopyrum esculentum), were replaced by potatoes in the modern times were the most important. Also leguminous plants were of great importance in the diet even though their charred seeds seldom preserved. Remains of oil plants such as hemp (Cannabis sativa), flax (Linum usitatissimum) and poppy (Papaver somniferum) preserved well. It was successfully proved that cucumber (Cucumis sativus), among other numerous kinds of vegetables, was introduced by the Slavs already in the 8th century in Moravia and in the 9th century in Bohemia. The assortment of fruit was rich--especially the assortment of cultivated fruit. Among the imported kinds of fruit the first place occupied figs (Ficus carica), from the numerous finds it can

  13. Gender bias in specialty preferences among Danish medical students

    DEFF Research Database (Denmark)

    Pedersen, Laura Erna Toftegaard; Skytte, Nanna Hasle Bak; Dissing, Agnete Skovlund;

    2011-01-01

    Female medical students tend to prefer person-oriented specialties characterized by close doctor-patient contact and aspects of care. Conversely, male medical students tend to seek towards specialties with elements of autonomy, technology and "action" . Furthermore, female doctors will outnumber ...

  14. Learning Style Preferences of Iranian EFL High School Students

    Directory of Open Access Journals (Sweden)

    Reza Vaseghi

    2013-07-01

    Full Text Available The current study examined the learning style preferences of 75 Iranian students at Marefat high school in Kuala Lumpur of which, 41 are females and 34 are males. As there are very few researches in which the learning style preferences of Iranian high school students investigated, this study attempts to fulfil this gap. To this end, in order to identify the students’ preferred learning styles (Visual, Auditory, Kinesthetic, Tactile, Group, and Individual Reid’s Perceptual Learning Style Preferences Questionnaire was used. Results indicated that the six learning style preferences considered in the questionnaire were positively preferred. Overall, kinesthetic and tactile learning were major learning styles. Auditory, group, visual, and individual were minor. Keywords: Learning Style Preferences, High School Students, EFL

  15. Estimating exponential scheduling preferences

    DEFF Research Database (Denmark)

    Hjorth, Katrine; Börjesson, Maria; Engelson, Leonid;

    2015-01-01

    Different assumptions about travelers' scheduling preferences yield different measures of the cost of travel time variability. Only few forms of scheduling preferences provide non-trivial measures which are additive over links in transport networks where link travel times are arbitrarily distribu...

  16. A computer model allowing maintenance of large amounts of genetic variability in Mendelian populations. II. The balance of forces between linkage and random assortment.

    Science.gov (United States)

    Wills, C; Miller, C

    1976-02-01

    It is shown, through theory and computer simulations of outbreeding Mendelian populations, that there may be conditions under which a balance is struck between two facotrs. The first is the advantage of random assortment, which will, when multilocus selection is for intermediate equilibrium values, lead to higher average heterozygosity than when linkage is introduced. There is some indication that random assortment is also advantageous when selection is toward a uniform distribution of equilibrium values. The second factor is the advantage of linkage between loci having positive epistatic interactions. When multilocus selection is for a bimodal distribution of equilibrium values an early advantage of random assortment is replaced by a later disadvantage. Linkage disequilibrium, which in finite populations is increased only by random or selective sampling, may hinder the movement of alleles to their selective equilibria, thus leading to the advantage of random assortment.-Some consequences of this approach to the structure of natural populations are discussed.

  17. Assortative mating and differential fertility by phenotype and genotype across the 20th century.

    Science.gov (United States)

    Conley, Dalton; Laidley, Thomas; Belsky, Daniel W; Fletcher, Jason M; Boardman, Jason D; Domingue, Benjamin W

    2016-06-14

    This study asks two related questions about the shifting landscape of marriage and reproduction in US society over the course of the last century with respect to a range of health and behavioral phenotypes and their associated genetic architecture: (i) Has assortment on measured genetic factors influencing reproductive and social fitness traits changed over the course of the 20th century? (ii) Has the genetic covariance between fitness (as measured by total fertility) and other traits changed over time? The answers to these questions inform our understanding of how the genetic landscape of American society has changed over the past century and have implications for population trends. We show that husbands and wives carry similar loadings for genetic factors related to education and height. However, the magnitude of this similarity is modest and has been fairly consistent over the course of the 20th century. This consistency is particularly notable in the case of education, for which phenotypic similarity among spouses has increased in recent years. Likewise, changing patterns of the number of children ever born by phenotype are not matched by shifts in genotype-fertility relationships over time. Taken together, these trends provide no evidence that social sorting is becoming increasingly genetic in nature or that dysgenic dynamics have accelerated. PMID:27247411

  18. Intelligent, net or wireless enabled fluorosensors for high throughput monitoring of assorted crops

    International Nuclear Information System (INIS)

    Phenotypic characterization of assorted crops of different genotypes requires large data sets of diverse types for statistical reliability. Temporal monitoring of plant fluorescence is able to capture the dynamics of the photosynthesis process that is summarized in a number of parameters for which the genotypic heritability can be calculated. In this paper, an intelligent sensor system is presented that is capable of high-throughput production of baseline-corrected temporal fluorescence curves with many feature points. These are obtained by integrating several (direct and modulated) measurement methods applied at different wavelengths. Simultaneously, temporal change of the sample's emission and the ambient reference temperatures are recorded. Multiple sensors can be deployed easily in large span greenhouse environments with centralized data collection over wired or wireless infrastructure. The unique features of the sensors are a compact, embedded signal guiding fibre optic system, instrument-standard variable tubular detector and source modules, net or wireless enabling for remote control and fast, quasi real-time data collection. Along with the instrumentation, some representative phenotyping data are also presented that were taken on a subset of pepper recombinant inbred line population. It is also demonstrated that transient fluorescence feature points yield high heritability, offering a high confidence level for distinguishing the pepper genotypes. (paper)

  19. Collaboration in sensor network research: an in-depth longitudinal analysis of assortative mixing patterns.

    Science.gov (United States)

    Pepe, Alberto; Rodriguez, Marko A

    2010-09-01

    Many investigations of scientific collaboration are based on statistical analyses of large networks constructed from bibliographic repositories. These investigations often rely on a wealth of bibliographic data, but very little or no other information about the individuals in the network, and thus, fail to illustrate the broader social and academic landscape in which collaboration takes place. In this article, we perform an in-depth longitudinal analysis of a relatively small network of scientific collaboration (N = 291) constructed from the bibliographic record of a research centerin the development and application of wireless and sensor network technologies. We perform a preliminary analysis of selected structural properties of the network, computing its range, configuration and topology. We then support our preliminary statistical analysis with an in-depth temporal investigation of the assortative mixing of selected node characteristics, unveiling the researchers' propensity to collaborate preferentially with others with a similar academic profile. Our qualitative analysis of mixing patterns offers clues as to the nature of the scientific community being modeled in relation to its organizational, disciplinary, institutional, and international arrangements of collaboration.

  20. ABC & XYZ – ANALYSIS OF ASSORTMENT OF ENTERPRISES OF BAKERY INDUSTRIES OF CONSUMER COOPERATIVES

    Directory of Open Access Journals (Sweden)

    Baranovskaya T. P.

    2015-12-01

    Full Text Available To develop detailed and effective business model of bakery enterprises of consumer cooperation it is necessary to have knowledge on strategic goods displayed on a busy segment of the market, not only in volumetric terms, but in the parameters that characterize the stability of sales or consumption. The particular relevance of this study reveals in modern conditions of functioning. The outcome of the baking enterprises of consumer cooperatives is more than 760 tons per day, distributed between 41 baking enterprise producing more than 300 kinds of products. Of course, the information on quantitative and qualitative characteristics of the strategic positions of the range will be a key in making managerial decisions about the production of the program, resourcing, turnover, etc. To solve the problem we have chosen the method of ABC - and XYZ-analysis of assortment of production, based on the criteria of ease of use and breadth of the resulting information. As a result of the application of the methods of ABC and XYZ-analysis and combining the obtained results, we present a classification of the range of the baking enterprises of consumer cooperation product based on the criteria of the contribution of commodity positions in revenue and stability of sales

  1. PHYLLOXERA-RESISTANT HYBRID FORM OF GRAPES OF TECHNICAL SORTS FOR IMPROVING THE ASSORTMENT

    Directory of Open Access Journals (Sweden)

    Larkina M. D.

    2015-10-01

    Full Text Available Many old varieties of grapes do not meet modern requirements, so there is a need for improved assortment of new high-quality varieties. The translation of the vineyards of the black sea coast of the Krasnodar region on inoculated culture is not fully decided the fate of the viticulture of the area. Weak resistance of American rootstocks to increased content of calcium and salts in the soil, caused the weakening of the bushes, reducing the vigor of the shoots, their maturation and yield of grape plantations in some areas of the district while reducing their quality indicators. In this regard, the development of new high-yielding varieties suitable for own-rooted viticulture remains the most urgent task for breeders. The article shows the potential of many years of breeding work and study of grapes of technical varieties in Anapa Zone Station, tolerant to phylloxera and resistant to fungal diseases and frost, with high quality products and gives a brief description of some prominent grape varieties

  2. 分类觅食人工鱼群算法%Assorted foraging artificial fish swarm algorithm

    Institute of Scientific and Technical Information of China (English)

    李辉

    2016-01-01

    针对人工鱼群算法搜索速度和搜索精度不高,且对高维问题寻优能力较差等缺点,提出了一种改进的人工鱼群算法——分类觅食人工鱼群算法(Assorted Foraging Artificial Fish Swarm Algorithm-AFAFSA).该算法对执行觅食行为的个体分类进行更新,既保持种群的多样性又通过觅食行为加快算法的搜索速度,同时加入禁忌的思想帮助算法跳出局部最优,提高算法的性能.通过一系列的测试试验,发现改进算法在收敛速度和精度方面都有了明显的提高,对于高维问题有也具有较好的寻优能力.

  3. Strong assortative mating by diet, color, size, and morphology but limited progress toward sympatric speciation in a classic example: Cameroon crater lake cichlids.

    Science.gov (United States)

    Martin, Christopher H

    2013-07-01

    Models predict that sympatric speciation depends on restrictive parameter ranges, such as sufficiently strong disruptive selection and assortative mating, but compelling examples in nature have rarely been used to test these predictions. I measured the strength of assortative mating within a species complex of Tilapia in Lake Ejagham, Cameroon, a celebrated example of incipient sympatric adaptive radiation. This species complex is in the earliest stages of speciation: morphological and ecological divergence are incomplete, species differ primarily in breeding coloration, and introgression is common. I captured 27 mated pairs in situ and measured the diet, color, size, and morphology of each individual. I found strong assortative mating by color, size, head depth, and dietary source of benthic or pelagic prey along two independent dimensions of assortment. Thus, Ejagham Tilapia showed strong assortative mating most conducive to sympatric speciation. Nonetheless, in contrast to a morphologically bimodal Sarotherodon cichlid species pair in the lake, Ejagham Tilapia show more limited progress toward speciation, likely due to insufficient strength of disruptive selection on morphology estimated in a previous study (γ = 0.16). This supports the predicted dependence of sympatric speciation on strong assortment and strong disruptive selection by examining a potentially stalled example in nature. PMID:23815664

  4. Female sexuality.

    Science.gov (United States)

    Rao, T S Sathyanarana; Nagaraj, Anil Kumar M

    2015-07-01

    Sex is a motive force bringing a man and a woman into intimate contact. Sexuality is a central aspect of being human throughout life and encompasses sex, gender identities and roles, sexual orientation, eroticism, pleasure, intimacy, and reproduction. Sexuality is experienced and expressed in thoughts, fantasies, desires, beliefs, attitudes, values, behaviors, practices, roles and relationships. Though generally, women are sexually active during adolescence, they reach their peak orgasmic frequency in their 30 s, and have a constant level of sexual capacity up to the age of 55 with little evidence that aging affects it in later life. Desire, arousal, and orgasm are the three principle stages of the sexual response cycle. Each stage is associated with unique physiological changes. Females are commonly affected by various disorders in relation to this sexual response cycle. The prevalence is generally as high as 35-40%. There are a wide range of etiological factors like age, relationship with a partner, psychiatric and medical disorders, psychotropic and other medication. Counseling to overcome stigma and enhance awareness on sexuality is an essential step in management. There are several effective psychological and pharmacological therapeutic approaches to treat female sexual disorders. This article is a review of female sexuality. PMID:26330647

  5. Female infertility

    International Nuclear Information System (INIS)

    Infertility, defined as 1 year of unprotected intercourse without conception, is becoming of increasingly important medical concern. Fertility in both the male and the female is at its peak in the twenties. Many couples today have postponed marriage and/or childbearing into their 30s until careers are established, but at that point fertility may be diminished. The current epidemic of venereal disease has been associated with an increasing incidence of tubal scarring. In addition, the use of intrauterine devices (IUDs) and birth control pills for contraception have let to later problems with pelvic inflammatory disease (PID) and ovulation disturbances. The problem of infertility intensifies as the number of babies available for adoption decreases. Therefore, it is estimated that approximately 10-20% of couples will eventually seek medical attention for an infertility-related problem. Fortunately, marked improvements in the results of tubal surgery are concurrently occurring secondary to refinements in microsurgical techniques, and many medical alternatives to induce ovulation are being developed. The male factor causes infertility in 30-40 % of couples, and the female factor is responsible in approximately 50% of couples. No cause is found in 10-20% of couples. This chapter discusses the role of coordinated imaging in the diagnosis and therapy of infertility in the female

  6. Chinese Consumers' Preferences for Livestock Products

    OpenAIRE

    Peng, Xuehua; Marchant, Mary A.; Qin, Xiang Dong; Zhuang, Jun

    2005-01-01

    This research surveyed over 784 Chinese consumers in Shanghai and Nanjing in 2001 and 2002, evaluating their preferences for livestock product attributes using ordered-probit models and factor analyses. Empirical results confirm the heterogeneity of Chinese livestock retail markets and suggest that livestock distributors should focus on Chinese female consumers and young consumers considering cooking convenience as a key attribute. Chinese consumers with higher incomes placed less importance ...

  7. Experience restores innate female preference for male ultrasonic vocalizations

    OpenAIRE

    Shepard, Kathryn N.; Liu, Robert C.

    2011-01-01

    Mouse models are increasingly contributing to our understanding of the neural genetics of sensory processing and memory. For example, strain differences have helped elucidate basic mechanisms of age-related hearing loss and auditory fear conditioning. Assessing sensory differences arising in acoustic communication contexts is also important for understanding natural audition. While this topic has not been well studied, it is currently being addressed through auditory neuroethological studies ...

  8. Preferred axis in cosmology

    CERN Document Server

    Zhao, Wen

    2016-01-01

    The foundation of modern cosmology relies on the so-called cosmological principle which states an homogeneous and isotropic distribution of matter in the universe on large scales. However, recent observations, such as the temperature anisotropy of the cosmic microwave background (CMB) radiation, the motion of galaxies in the universe, the polarization of quasars and the acceleration of the cosmic expansion, indicate preferred directions in the sky. If these directions have a cosmological origin, the cosmological principle would be violated, and modern cosmology should be reconsidered. In this paper, by considering the preferred axis in the CMB parity violation, we find that it coincides with the preferred axes in CMB quadrupole and CMB octopole, and they all align with the direction of the CMB kinematic dipole. In addition, the preferred directions in the velocity flows, quasar alignment, anisotropy of the cosmic acceleration, the handedness of spiral galaxies, and the angular distribution of the fine-structu...

  9. Poverty Prefers Company

    OpenAIRE

    Eriksson, Kimmo; Simpson, B

    2014-01-01

    In three web-based experiments, we show that both actual poverty and experimentally induced (imagined) poverty create a preference for greater inequality. Study 1, a cross-national comparison between Americans and Swedes, showed that respondents who were actually poor and those who were experimentally induced to imagine that they were poor tended to express a heightened preference for greater inequality, and for a higher proportion of poor citizens. Study 2 replicated the effects using differ...

  10. Essays on Social Preference

    OpenAIRE

    Jeon, Joo Young

    2014-01-01

    This thesis consists of six essays related to experimental investigation of social preference. We investigate the effects of a pure income effect on social preference in the first essay. In the second essay we explore the effects of gender in altruism and the corresponding anticipation behavior. The third essay discusses the effects of different type of rebate schemes on altruistic behavior. We study the effects of a real and a minimal identity on initiation and escalation of conflict i...

  11. Preference for newspaper size.

    Science.gov (United States)

    Tsang, Steve N H; Hoffmann, Errol R; Chan, Alan H S

    2014-05-01

    The past few years has seen a change in the size of newspapers, with publishers moving to a smaller size format. Five 'standard' newspaper sizes are used in different countries: Broadsheet, Rhensch, Tabloid, Tall Tabloid and Berliner. These papers vary in both width and height of pages and hence there are implications for human reading comfort, which may be dependent on reading location such as on a lounge chair or on a train. Experiments were carried out to determine preferences for the different sizes and to relate these preferences to the geometric characteristics of the newspapers. For both comfortable and cramped/uncomfortable reading conditions, the rank order of preference for paper types was, from least to most-preferred, Broadsheet, Rhensch, Berliner, Tall Tabloid and Tabloid. Preferences were much stronger when determined in cramped/uncomfortable reading conditions, where most comparisons were significantly different. There was good correlation between participant ratings on several scales and preference, where most factors were related to comfort of holding and controlling the paper. PMID:23987982

  12. Preference for newspaper size.

    Science.gov (United States)

    Tsang, Steve N H; Hoffmann, Errol R; Chan, Alan H S

    2014-05-01

    The past few years has seen a change in the size of newspapers, with publishers moving to a smaller size format. Five 'standard' newspaper sizes are used in different countries: Broadsheet, Rhensch, Tabloid, Tall Tabloid and Berliner. These papers vary in both width and height of pages and hence there are implications for human reading comfort, which may be dependent on reading location such as on a lounge chair or on a train. Experiments were carried out to determine preferences for the different sizes and to relate these preferences to the geometric characteristics of the newspapers. For both comfortable and cramped/uncomfortable reading conditions, the rank order of preference for paper types was, from least to most-preferred, Broadsheet, Rhensch, Berliner, Tall Tabloid and Tabloid. Preferences were much stronger when determined in cramped/uncomfortable reading conditions, where most comparisons were significantly different. There was good correlation between participant ratings on several scales and preference, where most factors were related to comfort of holding and controlling the paper.

  13. The impact of attitudes and work preferences on Dutch mothers' employment patterns

    NARCIS (Netherlands)

    J. Ruitenberg; P. de Beer

    2012-01-01

    In the last decades, preference theory has gained significance in the academic literature on the determinants of female employment patterns. Mostly, within these studies gender and work attitudes and work preferences (the number of hours a woman prefers to work) are treated as one concept. However,

  14. Multi-locus assortment (MLA for transgene dispersal and elimination in mosquito populations.

    Directory of Open Access Journals (Sweden)

    Jason L Rasgon

    Full Text Available BACKGROUND: Replacement of wild-type mosquito populations with genetically modified versions is being explored as a potential strategy to control vector-borne diseases. Due to lower expected relative fitness of transgenic individuals, transgenes must be driven into populations for these scenarios to be successful. Several gene drive mechanisms exist in a theoretical sense but none are currently workable in mosquitoes. Even if strategies were workable, it would be very difficult to recall released transgenes in the event of unforeseen consequences. What is needed is a way to test transgenes in the field for feasibility, efficacy and safety prior to releasing an active drive mechanism. METHODOLOGY/PRINCIPAL FINDINGS: We outline a method, termed Multi-locus assortment (MLA, to spread transgenes into vector populations by the release of genetically-modified mosquitoes carrying multiple stable transgene inserts. Simulations indicate that [1] insects do not have to carry transgenes at more than 4 loci, [2] transgenes can be maintained at high levels by sequential small releases, the frequency of which depends on the construct fitness cost, and [3] in the case of unforeseen negative non-target effects, transgenes can be eliminated from the population by halting transgenic releases and/or mass releases of wild-type insects. We also discuss potential methods to create MLA mosquito strains in the laboratory. CONCLUSIONS/SIGNIFICANCE: While not as efficient as active drive mechanisms, MLA has other advantages: [1] MLA strains can be constructed for some mosquito species with currently-available technology, [2] MLA will allow the ecological components of transgenic mosquito releases to be tested before actual gene drive mechanisms are ready to be deployed, [3] since MLA is not self-propagating, the risk of an accidental premature release into nature is minimized, and [4] in the case that active gene drive mechanisms prove impossible to develop, the MLA

  15. Molecular Assortment of Lens Species with Different Adaptations to Drought Conditions Using SSR Markers.

    Science.gov (United States)

    Singh, Dharmendra; Singh, Chandan Kumar; Tomar, Ram Sewak Singh; Taunk, Jyoti; Singh, Ranjeet; Maurya, Sadhana; Chaturvedi, Ashish Kumar; Pal, Madan; Singh, Rajendra; Dubey, Sarawan Kumar

    2016-01-01

    The success of drought tolerance breeding programs can be enhanced through molecular assortment of germplasm. This study was designed to characterize molecular diversity within and between Lens species with different adaptations to drought stress conditions using SSR markers. Drought stress was applied at seedling stage to study the effects on morpho-physiological traits under controlled condition, where tolerant cultivars and wilds showed 12.8-27.6% and 9.5-23.2% reduction in seed yield per plant respectively. When juxtaposed to field conditions, the tolerant cultivars (PDL-1 and PDL-2) and wild (ILWL-314 and ILWL-436) accessions showed 10.5-26.5% and 7.5%-15.6% reduction in seed yield per plant, respectively under rain-fed conditions. The reductions in seed yield in the two tolerant cultivars and wilds under severe drought condition were 48-49% and 30.5-45.3% respectively. A set of 258 alleles were identified among 278 genotypes using 35 SSR markers. Genetic diversity and polymorphism information contents varied between 0.321-0.854 and 0.299-0.836, with mean value of 0.682 and 0.643, respectively. All the genotypes were clustered into 11 groups based on SSR markers. Tolerant genotypes were grouped in cluster 6 while sensitive ones were mainly grouped into cluster 7. Wild accessions were separated from cultivars on the basis of both population structure and cluster analysis. Cluster analysis has further grouped the wild accessions on the basis of species and sub-species into 5 clusters. Physiological and morphological characters under drought stress were significantly (P = 0.05) different among microsatellite clusters. These findings suggest that drought adaptation is variable among wild and cultivated genotypes. Also, genotypes from contrasting clusters can be selected for hybridization which could help in evolution of better segregants for improving drought tolerance in lentil. PMID:26808306

  16. Molecular Assortment of Lens Species with Different Adaptations to Drought Conditions Using SSR Markers.

    Directory of Open Access Journals (Sweden)

    Dharmendra Singh

    Full Text Available The success of drought tolerance breeding programs can be enhanced through molecular assortment of germplasm. This study was designed to characterize molecular diversity within and between Lens species with different adaptations to drought stress conditions using SSR markers. Drought stress was applied at seedling stage to study the effects on morpho-physiological traits under controlled condition, where tolerant cultivars and wilds showed 12.8-27.6% and 9.5-23.2% reduction in seed yield per plant respectively. When juxtaposed to field conditions, the tolerant cultivars (PDL-1 and PDL-2 and wild (ILWL-314 and ILWL-436 accessions showed 10.5-26.5% and 7.5%-15.6% reduction in seed yield per plant, respectively under rain-fed conditions. The reductions in seed yield in the two tolerant cultivars and wilds under severe drought condition were 48-49% and 30.5-45.3% respectively. A set of 258 alleles were identified among 278 genotypes using 35 SSR markers. Genetic diversity and polymorphism information contents varied between 0.321-0.854 and 0.299-0.836, with mean value of 0.682 and 0.643, respectively. All the genotypes were clustered into 11 groups based on SSR markers. Tolerant genotypes were grouped in cluster 6 while sensitive ones were mainly grouped into cluster 7. Wild accessions were separated from cultivars on the basis of both population structure and cluster analysis. Cluster analysis has further grouped the wild accessions on the basis of species and sub-species into 5 clusters. Physiological and morphological characters under drought stress were significantly (P = 0.05 different among microsatellite clusters. These findings suggest that drought adaptation is variable among wild and cultivated genotypes. Also, genotypes from contrasting clusters can be selected for hybridization which could help in evolution of better segregants for improving drought tolerance in lentil.

  17. Molecular Assortment of Lens Species with Different Adaptations to Drought Conditions Using SSR Markers.

    Science.gov (United States)

    Singh, Dharmendra; Singh, Chandan Kumar; Tomar, Ram Sewak Singh; Taunk, Jyoti; Singh, Ranjeet; Maurya, Sadhana; Chaturvedi, Ashish Kumar; Pal, Madan; Singh, Rajendra; Dubey, Sarawan Kumar

    2016-01-01

    The success of drought tolerance breeding programs can be enhanced through molecular assortment of germplasm. This study was designed to characterize molecular diversity within and between Lens species with different adaptations to drought stress conditions using SSR markers. Drought stress was applied at seedling stage to study the effects on morpho-physiological traits under controlled condition, where tolerant cultivars and wilds showed 12.8-27.6% and 9.5-23.2% reduction in seed yield per plant respectively. When juxtaposed to field conditions, the tolerant cultivars (PDL-1 and PDL-2) and wild (ILWL-314 and ILWL-436) accessions showed 10.5-26.5% and 7.5%-15.6% reduction in seed yield per plant, respectively under rain-fed conditions. The reductions in seed yield in the two tolerant cultivars and wilds under severe drought condition were 48-49% and 30.5-45.3% respectively. A set of 258 alleles were identified among 278 genotypes using 35 SSR markers. Genetic diversity and polymorphism information contents varied between 0.321-0.854 and 0.299-0.836, with mean value of 0.682 and 0.643, respectively. All the genotypes were clustered into 11 groups based on SSR markers. Tolerant genotypes were grouped in cluster 6 while sensitive ones were mainly grouped into cluster 7. Wild accessions were separated from cultivars on the basis of both population structure and cluster analysis. Cluster analysis has further grouped the wild accessions on the basis of species and sub-species into 5 clusters. Physiological and morphological characters under drought stress were significantly (P = 0.05) different among microsatellite clusters. These findings suggest that drought adaptation is variable among wild and cultivated genotypes. Also, genotypes from contrasting clusters can be selected for hybridization which could help in evolution of better segregants for improving drought tolerance in lentil.

  18. Educational attainment influences levels of homozygosity through migration and assortative mating.

    Directory of Open Access Journals (Sweden)

    Abdel Abdellaoui

    Full Text Available Individuals with a higher education are more likely to migrate, increasing the chance of meeting a spouse with a different ancestral background. In this context, the presence of strong educational assortment can result in greater ancestry differences within more educated spouse pairs, while less educated individuals are more likely to mate with someone with whom they share more ancestry. We examined the association between educational attainment and F roh (= the proportion of the genome consisting of runs of homozygosity [ROHs] in ~2,000 subjects of Dutch ancestry. The subjects' own educational attainment showed a nominally significant negative association with F roh (p = .045, while the contribution of parental education to offspring F roh was highly significant (father: p < 10(-5; mother: p = 9 × 10(-5, with more educated parents having offspring with fewer ROHs. This association was significantly and fully mediated by the physical distance between parental birthplaces (paternal education: pmediation = 2.4 × 10(-4; maternal education: pmediation = 2.3 × 10(-4, which itself was also significantly associated with F roh (p = 9 × 10(-5. Ancestry-informative principal components from the offspring showed a significantly decreasing association with geography as parental education increased, consistent with the significantly higher migration rates among more educated parents. Parental education also showed a high spouse correlation (Spearman's ρ = .66, p = 3 × 10(-262. We show that less educated parents are less likely to mate with the more mobile parents with a higher education, creating systematic differences in homozygosity due to ancestry differences not directly captured by ancestry-informative principal components (PCs. Understanding how behaviors influence the genomic structure of a population is highly valuable for studies on the genetic etiology of behavioral, cognitive, and social traits.

  19. An Exploratory Study of the Language-learning Style Preferences of Iranian EFL High School Students

    Directory of Open Access Journals (Sweden)

    Afsaneh Effatdokht Ramezani

    2015-04-01

    Full Text Available This study explored the learning style preferences of 40 Iranian students at Marefat Iranian high school in Kuala Lumpur of which, 20 are females and 20 are males. To this end, this study used structured interview to elicit in-depth information from the students. The results of the study showed that learning style preferences of Iranian students were different according to their gender. Female students preferred auditory learning as their major learning style, while male students preferred kinesthetic more. Moreover, the findings revealed that Kinesthetic learning was the least preferred learning style of the most female students, whereas the least preferred learning style of male students was tactile learning. Keywords:  Learning Style Preferences, High School Students, Gender, EFL 

  20. Mate choice and human stature: homogamy as a unified framework for understanding mating preferences.

    Science.gov (United States)

    Courtiol, Alexandre; Raymond, Michel; Godelle, Bernard; Ferdy, Jean-Baptiste

    2010-08-01

    Assortative mating for human height has long attracted interest in evolutionary biology, and the phenomenon has been demonstrated in numerous human populations. It is often argued that mating preferences generate this pattern, but other processes can also induce trait correlations between mates. Here, we present a methodology tailored to quantify continuous preferences based on choice experiments between pairs of stimuli. In particular, it is possible to explore determinants of interindividual variations in preferences, such as the height of the chooser. We collected data from a sample of 200 individuals from France. Measurements obtained show that the perception of attractiveness depends on both the height of the stimuli and the stature of the individual who judged them. Therefore, this study demonstrates that homogamy is present at the level of preferences for both sexes. We also show that measurements of the function describing this homogamy are concordant with several distinct mating rules proposed in the literature. In addition, the quantitative approach introduced here fulfills metrics that can be used to compare groups of individuals. In particular, our results reveal an important disagreement between sexes regarding height preferences in the context of mutual mate choice. Finally, both women and men prefer individuals who are significantly taller than average. All major findings are confirmed by a reanalysis of previously published data.

  1. Brain serotonin signaling does not determine sexual preference in male mice.

    Directory of Open Access Journals (Sweden)

    Mariana Angoa-Pérez

    Full Text Available It was reported recently that male mice lacking brain serotonin (5-HT lose their preference for females (Liu et al., 2011, Nature, 472, 95-100, suggesting a role for 5-HT signaling in sexual preference. Regulation of sex preference by 5-HT lies outside of the well established roles in this behavior established for the vomeronasal organ (VNO and the main olfactory epithelium (MOE. Presently, mice with a null mutation in the gene for tryptophan hydroxylase 2 (TPH2, which are depleted of brain 5-HT, were tested for sexual preference. When presented with inanimate (urine scents from male or estrous female or animate (male or female mouse in estrus sexual stimuli, TPH2-/- males show a clear preference for female over male stimuli. When a TPH2-/- male is offered the simultaneous choice between an estrous female and a male mouse, no sexual preference is expressed. However, when confounding behaviors that are seen among 3 mice in the same cage are controlled, TPH2-/- mice, like their TPH2+/+ counterparts, express a clear preference for female mice. Female TPH2-/- mice are preferred by males over TPH2+/+ females but this does not lead to increased pregnancy success. In fact, if one or both partners in a mating pair are TPH2-/- in genotype, pregnancy success rates are significantly decreased. Finally, expression of the VNO-specific cation channel TRPC2 and of CNGA2 in the MOE of TPH2-/- mice is normal, consistent with behavioral findings that sexual preference of TPH2-/- males for females is intact. In conclusion, 5-HT signaling in brain does not determine sexual preference in male mice. The use of pharmacological agents that are non-selective for the 5-HT neuronal system and that have serious adverse effects may have contributed historically to the stance that 5-HT regulates sexual behavior, including sex partner preference.

  2. Brain serotonin signaling does not determine sexual preference in male mice.

    Science.gov (United States)

    Angoa-Pérez, Mariana; Herrera-Mundo, Nieves; Kane, Michael J; Sykes, Catherine E; Anneken, John H; Francescutti, Dina M; Kuhn, Donald M

    2015-01-01

    It was reported recently that male mice lacking brain serotonin (5-HT) lose their preference for females (Liu et al., 2011, Nature, 472, 95-100), suggesting a role for 5-HT signaling in sexual preference. Regulation of sex preference by 5-HT lies outside of the well established roles in this behavior established for the vomeronasal organ (VNO) and the main olfactory epithelium (MOE). Presently, mice with a null mutation in the gene for tryptophan hydroxylase 2 (TPH2), which are depleted of brain 5-HT, were tested for sexual preference. When presented with inanimate (urine scents from male or estrous female) or animate (male or female mouse in estrus) sexual stimuli, TPH2-/- males show a clear preference for female over male stimuli. When a TPH2-/- male is offered the simultaneous choice between an estrous female and a male mouse, no sexual preference is expressed. However, when confounding behaviors that are seen among 3 mice in the same cage are controlled, TPH2-/- mice, like their TPH2+/+ counterparts, express a clear preference for female mice. Female TPH2-/- mice are preferred by males over TPH2+/+ females but this does not lead to increased pregnancy success. In fact, if one or both partners in a mating pair are TPH2-/- in genotype, pregnancy success rates are significantly decreased. Finally, expression of the VNO-specific cation channel TRPC2 and of CNGA2 in the MOE of TPH2-/- mice is normal, consistent with behavioral findings that sexual preference of TPH2-/- males for females is intact. In conclusion, 5-HT signaling in brain does not determine sexual preference in male mice. The use of pharmacological agents that are non-selective for the 5-HT neuronal system and that have serious adverse effects may have contributed historically to the stance that 5-HT regulates sexual behavior, including sex partner preference. PMID:25706994

  3. FEMALE PSEUDOHERMAPHRODITISM

    Directory of Open Access Journals (Sweden)

    AL. Bulotta

    2012-01-01

    Full Text Available Introduction. 21α-hydroxylase deficiency is the most frequent cause of virilization in patients with female karyotype due to exposure of a female fetus to excess of androgen. We report anatomical and cosmetic results of feminizing genital reconstruction of two related patients (second cousin with XX karyotype born with urogenital sinus anomalies (UGS and not treated at birth. Materials and Metods. Patient 1 is 6-years old with ambiguous genitalia graded as Prader V and never undergone therapy or surgery. Patient 2 is 10-years old, graded as Prader IV and subjected to hormonal therapy and clitoral amputation at the age of 6. Mobilization of urogenital sinus, pull-through of vagina and tubulization of urethra was performed in both after placement of Foley chateters in vagina and bladder by cisto-vaginoscopy. Genitoplasty involved refashioning the tissues to create minora and majora labia and, after removal of corpora, partial clitorectomy was carried in patient 1 and clitoridal reconstruction in patient 2. Result. Vaginal introitus was positioned in the vestibule region below urethral meatus. Foley chateters was removed after two weeks in narcosis and the cosmetic and anatomic result was good. Conclusion. Goals of feminizing genitoplasty are to restore, soon as possible, anatomy achieving a more feminine appareance with a vagina for menstruation, to preserve reproductive capacity and to prevent urological sequelae but it’s also important to contribute in a development of a more stable gender identity. This procedure in two stage, based on an accurate diagnosis, is good to create feminine genital appareance in children with female pseudohermaphroditism expecially if not treated at birth.

  4. Animal Personality and Mate Preference in American Mink

    DEFF Research Database (Denmark)

    Noer, Christina Lehmkuhl

    to assess mate quality before making their mate choice, and then introduce these cues and signals from different males to the female prior to introduction of a mate. Females have the ability to determine the male to which they are genetically better matched among available options and studies...... of the outcomes of mate choice suggest that choosy females benefit from increased fecundity, litter size, and offspring survival. Thus, providing females with the opportunity to choose from several males might improve the sustainability of captive populations. The main objective of this thesis is to develop...... and test a method to assess female preference using selected male signals and cues and to investigate whether this preference translates into a mate choice. Due to their biological relevance, and because research has proved their importance in other species’ mate assessment, I focus on three signals...

  5. Measuring children's food preferences

    DEFF Research Database (Denmark)

    Olsen, Annemarie; Kildegaard, Heidi; Gabrielsen, Gorm;

    2012-01-01

    The aim of this study is to investigate if children’s food preferences can be reliable measured by using pictures of foods presented on a computer screen in a conjoint layout.We investigate reproducibility (test–retest) and infer validity by comparison with traditional hedonic evaluations...... juices (tangible products), chosen to span the preference spectrum, were hedonically evaluated for appearance and taste. Finally, an actual product choice was performed by having the children choose between two buns and two juices.Results showed that the computer evaluationswith pictures of foods...... provided reproducible information about the children’s visual food preferences, which were in concordance with both hedonic measures and products choices, and can thus be considered valid....

  6. Open-nucleus breeding strategies compared with population-wide positive assortative mating: I. Equal distribution of testing efforts.

    Science.gov (United States)

    Lstibůrek, M; Mullin, T J; Lindgren, D; Rosvall, O

    2004-10-01

    Positive assortative mating (PAM) can enhance the additive genetic variance in a breeding population(BP). This increases the potential for gains in the production population (PP, selected subset of the BP) for recurrent selection programs in forest trees. The assortment of mates can be either: (1) by individual tree rank across the whole BP (PAM), or (2) trees of similar rank can be merged into larger hierarchical groups and then mated randomly within group ("open"-nucleus breeding,NB). The objective of this study was to compare PAM and NB in quantitative terms. The NB simulation model assumed two tiers (nucleus, main) with unrestricted migration between the tiers. Clonal tests were used to predict breeding values and test resources per mate were kept constant for all mates. Both gain and diversity were combined into a single selection criterion, "group-merit selection." Alternatives were compared over five breeding cycles by considering genetic gain and diversity in a selected PP established in a seed orchard. The assortment of mates in both alternatives enhanced additive variance and increased the additive effect in the BP, leading to additional gain in the PP. Gains generated under PAM always exceeded gains under NB. Thus, the main message from this study is that PAM in both the short- and long-term results in more gain at any target level of diversity in the PP (the breeder's target) than is achieved by the NB alternative. The optimum size of the nucleus varies with the desired level of seed orchard diversity. At lower target diversity, smaller nucleus sizes are favorable, while larger sizes result in more gain when seed orchard diversity is considered more important.

  7. Revealed smooth nontransitive preferences

    DEFF Research Database (Denmark)

    Keiding, Hans; Tvede, Mich

    2013-01-01

    consumption bundle, all strictly preferred bundles are more expensive than the observed bundle. Our main result is that data sets can be rationalized by a smooth nontransitive preference relation if and only if prices can normalized such that the law of demand is satisfied. Market data sets consist of finitely...... many observations of price vectors, lists of individual incomes and aggregate demands. We apply our main result to characterize market data sets consistent with equilibrium behaviour of pure-exchange economies with smooth nontransitive consumers....

  8. Highly Competitive Reindeer Males Control Female Behavior during the Rut

    OpenAIRE

    Guillaume Body; Robert B. Weladji; Øystein Holand; Mauri Nieminen

    2014-01-01

    During the rut, female ungulates move among harems or territories, either to sample mates or to avoid harassment. Females may be herded by a male, may stay with a preferred male, or aggregate near a dominant male to avoid harassment from other males. In fission-fusion group dynamics, female movement is best described by the group's fission probability, instead of inter-harem movement. In this study, we tested whether male herding ability, female mate choice or harassment avoidance influence f...

  9. EXERCISE PREFERENCES OF PATIENTS IN SUBSTANCE ABUSE TREATMENT

    OpenAIRE

    Abrantes, Ana M.; Battle, Cynthia L.; Strong, David R.; Ing, Eileen; Dubreuil, Mary Ella; Gordon, Alan; Brown, Richard A.

    2011-01-01

    While emerging studies have demonstrated the benefit of exercise in early recovery from substance use disorders, recruitment and adherence to exercise interventions have been challenging. Tailoring interventions based on patient exercise preferences may address these concerns. Ninety-seven (N=97; age=41.6 years; 44% female) patients were recruited from an intensive substance abuse outpatient program and filled out questionnaires about their exercise preferences. Most (71%) patients were not c...

  10. Learning style preferences among pre-clinical medical students

    Directory of Open Access Journals (Sweden)

    Aye Aye Mon

    2014-02-01

    Full Text Available Generally, different students employ different learning styles dur-ing their studies and medical students are exposed to diverse methods of teaching. Therefore, understanding students’ learning style preference is an important consideration for a high quality and effective teaching and learning process.The aim of the study was to study the variation of learning styles among pre-clinical medical students of SEGi University, Malaysia. A cross-sectional study was performed by using VARK (Visual, Audio, Reading and Kinaesthetic questionnaire version 7.2 to assess the learning style preference of 98 (n=98 pre-clinical medical students in SEGi University. The questionnaire consists of 16 items which identify four different learning styles: visual, aural, reading/writing and kin-esthetic. Descriptive statistics were used to identify the learning styles of students. 61 students preferred multimodal as their learning style, out of which 43 (70% of them were female stu-dents and 18 (30% were male students. 37 students preferred unimodal as their learning style out of which 22 (59% of them were female students and 15 (41% were male students. In addi-tion, female students had more diverse preferences than male students by having 10 out of the other 11 possible combinations in multimodal learning style of preference, whereas the male stu-dents only had 5 out of the 11 combinations. In this study, there was no significant gender difference in the percentages of males and female students who preferred unimodal and multimodal styles of information presentation (P= 0.263; α=0.05. To con-clude, the majority of students of both genders had chosen quad-modal as their learning style preference. The results of this study can provide useful information for improving the quality of the teaching and learning experiences of students.

  11. Economy of referential preferences

    OpenAIRE

    Goucha, T

    2012-01-01

    In this paper we introduce basic notions of new economic model where preference relations on commodities set are represented by a group action on Euclidean space instead of utility function. Conditions that ensure the existence of individual demand functions and a general equilibrium in the setting of exchange economy are examined.

  12. FUZZY PREFERENCES IN CONFLICTS

    Institute of Scientific and Technical Information of China (English)

    Mubarak S. AL-MUTAIRI; Keith W. HIPEL; Mohamed S. KAMEL

    2008-01-01

    A systematic fuzzy approach is developed to model fuzziness and uncertainties in the preferences of decision makers involved in a conflict. This unique fuzzy preference formulation is used within the paradigm of the Graph Model for Conflict Resolution in which a given dispute is modeled in terms of decision makers, each decision maker's courses of actions or options, and each decision maker's preferences concerning the states or outcomes which could take place. In order to be able to determine the stability of each state for each decision maker and the possible equilibria or resolutions, a range of solution concepts describing potential human behavior under conflict are defined for use with fuzzy preferences. More specifically, strong and weak definitions of stability are provided for the solution concepts called Nash, general metarational, symmetric metarational, and sequential stability. To illustrate how these solution concepts can be conveniently used in practice, they are applied to a dispute over the contamination of an aquifer by a chemical company located in Elmira, Ontario, Canada.

  13. Arm chair perspective preferences

    NARCIS (Netherlands)

    Koenderink, Jan; van Doorn, A.J.; Pinna, Baingio; Pepperell, Robert

    2016-01-01

    Do generic observers in their free-style viewing of postcard-size pictures have a preference for specific modes of perspective rendering? This most likely depends upon the phrasing of the question. Here we consider the feeling of ‘presence’: does the observer experience a sense of being ‘immersed in

  14. Facial preferences in early adolescent girls: pubertal maturity predicts preferences maturity.

    Science.gov (United States)

    Kościński, Krzysztof

    2013-09-01

    Despite numerous studies on perception of facial attractiveness in adults, preferences in adolescents remain poorly recognized. The aim of present study was to explore facial preferences in girls at early adolescence (11-14 years old) and compare them with preferences of women. All females evaluated the same 30 male faces, which were also assessed by independent judges for several perceived features. Regardless of age, girls assessed attractiveness much the same as women, and the strengths of their preferences for specific facial features were similar to those of women. Except for the youngest girls, pubertal maturity (measured as the time elapsed since the menarche and breast development) correlated positively with the similarity of the girls' attractiveness evaluations to those of adult women and with strength of preference for cues to good biological quality (skin healthiness and sexy appearance). This remained true even after controlling for age and psychosexual development, suggesting thus that sex hormones are involved in development of facial preferences in pubescent girls. PMID:24308210

  15. Personality and music preferences: the influence of personality traits on preferences regarding musical elements.

    Science.gov (United States)

    Kopacz, Malgorzata

    2005-01-01

    The purpose of this scientific study was to determine how personality traits, as classified by Cattell, influence preferences regarding musical elements. The subject group consisted of 145 students, male and female, chosen at random from different Polish universities. For the purpose of determining their personality traits the participants completed the 16PF Questionnaire (Cattell, Saunders, & Stice, 1957; Russel & Karol, 1993), in its Polish adaptation by Choynowski (Nowakowska, 1970). The participants' musical preferences were determined by their completing a Questionnaire of Musical Preferences (specifically created for the purposes of this research), in which respondents indicated their favorite piece of music. Next, on the basis of the Questionnaire of Musical Preferences, a list of the works of music chosen by the participants was compiled. All pieces were collected on CDs and analyzed to separate out their basic musical elements. The statistical analysis shows that some personality traits: Liveliness (Factor F), Social Boldness (Factor H), Vigilance (Factor L), Openness to Change (Factor Q1), Extraversion (a general factor) have an influence on preferences regarding musical elements. Important in the subjects' musical preferences were found to be those musical elements having stimulative value and the ability to regulate the need for stimulation. These are: tempo, rhythm in relation to metrical basis, number of melodic themes, sound voluminosity, and meter. PMID:16086606

  16. Personality and music preferences: the influence of personality traits on preferences regarding musical elements.

    Science.gov (United States)

    Kopacz, Malgorzata

    2005-01-01

    The purpose of this scientific study was to determine how personality traits, as classified by Cattell, influence preferences regarding musical elements. The subject group consisted of 145 students, male and female, chosen at random from different Polish universities. For the purpose of determining their personality traits the participants completed the 16PF Questionnaire (Cattell, Saunders, & Stice, 1957; Russel & Karol, 1993), in its Polish adaptation by Choynowski (Nowakowska, 1970). The participants' musical preferences were determined by their completing a Questionnaire of Musical Preferences (specifically created for the purposes of this research), in which respondents indicated their favorite piece of music. Next, on the basis of the Questionnaire of Musical Preferences, a list of the works of music chosen by the participants was compiled. All pieces were collected on CDs and analyzed to separate out their basic musical elements. The statistical analysis shows that some personality traits: Liveliness (Factor F), Social Boldness (Factor H), Vigilance (Factor L), Openness to Change (Factor Q1), Extraversion (a general factor) have an influence on preferences regarding musical elements. Important in the subjects' musical preferences were found to be those musical elements having stimulative value and the ability to regulate the need for stimulation. These are: tempo, rhythm in relation to metrical basis, number of melodic themes, sound voluminosity, and meter.

  17. How packaging designs of cosmetics affect female consumers' purchasing behavior?

    OpenAIRE

    Liu, Yinuo

    2011-01-01

    The topic of the thesis is “How packaging designs of cosmetics affect female consumers’ purchasing behavior?” Its aim is to identify whether female consumers are attracted by packaging designs of cosmetics, and how packaging designs of cosmetics affect different female consumer groups. Research question is: “If packaging of cosmetics affects which cosmetics females prefer when they buy cosmetics? And if so, is this preferences related to age and income?” To answer this question, the author us...

  18. Male chimpanzees' grooming rates vary by female age, parity, and fertility status

    DEFF Research Database (Denmark)

    Proctor, Darby P; Lambeth, Susan P; Schapiro, Steve;

    2011-01-01

    , should show little or no preference when choosing mating partners (e.g. should mate indiscriminately). To determine if the preferences indicated by copulations appear in other contexts as well as how they interact, we examined how male chimpanzees' grooming patterns varied amongst females. We found...... that males' preferences were based on interactions among females' fertility status, age, and parity. First, grooming increased with increasing female parity. We further found an effect of the estrous cycle on grooming; when females were at the lowest point of their cycle, males preferentially groomed parous...... females at peak reproductive age, but during maximal tumescence, males preferred the oldest multiparous females. Nulliparous females received relatively little grooming regardless of age or fertility. Thus, male chimpanzees apparently chose grooming partners based on both female's experience and fertility...

  19. Female Reproductive System

    Science.gov (United States)

    ... Things to Know About Zika & Pregnancy Female Reproductive System KidsHealth > For Parents > Female Reproductive System Print A ... or sperm. continue Components of the Female Reproductive System Unlike the male, the human female has a ...

  20. Incestuous sisters: mate preference for brothers over unrelated males in Drosophila melanogaster.

    Directory of Open Access Journals (Sweden)

    Adeline Loyau

    Full Text Available The literature is full of examples of inbreeding avoidance, while recent mathematical models predict that inbreeding tolerance or even inbreeding preference should be expected under several realistic conditions like e.g. polygyny. We investigated male and female mate preferences with respect to relatedness in the fruit fly D. melanogaster. Experiments offered the choice between a first order relative (full-sibling or parent and an unrelated individual with the same age and mating history. We found that females significantly preferred mating with their brothers, thus supporting inbreeding preference. Moreover, females did not avoid mating with their fathers, and males did not avoid mating with their sisters, thus supporting inbreeding tolerance. Our experiments therefore add empirical evidence for inbreeding preference, which strengthens the prediction that inbreeding tolerance and preference can evolve under specific circumstances through the positive effects on inclusive fitness.

  1. Does gender influence learning style preferences of first-year medical students?

    Science.gov (United States)

    Slater, Jill A; Lujan, Heidi L; DiCarlo, Stephen E

    2007-12-01

    Students have specific learning style preferences, and these preferences may be different between male and female students. Understanding a student's learning style preference is an important consideration when designing classroom instruction. Therefore, we administered the visual, auditory, reading/writing, kinesthetic (VARK) learning preferences questionnaire to our first-year medical students; 38.8% (97 of 250 students) of the students returned the completed questionnaire. Both male (56.1%) and female (56.7%) students preferred multiple modes of information presentation, and the numbers and types of modality combinations were not significantly different between genders. Although not significantly different, the female student population tended to be more diverse than the male population, encompassing a broader range of sensory modality combinations within their preference profiles. Instructors need to be cognizant of these differences and broaden their range of presentation styles accordingly.

  2. FISH detection of ribosomal cistrons and assortment-distortion for X and B chromosomes in Dichroplus pratensis (Acrididae).

    Science.gov (United States)

    Bidau, C J; Rosato, M; Martí, D A

    2004-01-01

    Assortment-distortion with respect to the X and NOR activity of a rare mitotically stable B chromosome (B(N)), was examined in 16 males of Dichroplus pratensis (Acrididae: Melanoplinae) from Argentine populations. In 1B individuals, the X and B associate preferentially during prophase I reaching a maximum level of association at zygotene. Frequency of X/B association remains relatively high up to diplotene-diakinesis and decreases steeply towards metaphase I. The percent X/B association at each stage is positively influenced by association at the previous stage, and interindividual variability in X/B association decreases as the frequency of association increases. Both chromosomes tended to preferentially orientate toward the same pole at MI (mean ratio of 16 individuals, 1.50:1) which determined an excess of XB and 00 second spermatocytes over X0 and 0B ones (1.39:1). No significant differences occurred between the MI, AI and MII assortment ratios. Fluorescent in situ hybridisation (FISH) confirmed that the B chromosome carries ribosomal genes and helped to establish that, during spermiogenesis, both the B and the normal NOR-bearing chromosome (S8) are clustered near the centriole adjunct region of spermatids. However, FISH failed to reveal the existence of inactive ribosomal cistrons in the X chromosome, as previously suggested, thus providing no support to a simple origin of the B from the X.

  3. 基于HVI检验数据的配棉方法%Cotton assorting based on HVI data

    Institute of Scientific and Technical Information of China (English)

    石洋; 张得昆; 徐玫

    2011-01-01

    利用公检棉花的HVI数据对棉纺企业配棉方法进行指导,达到优棉优用、稳定质量、节约资源、降低成本的目的.通过分析公检棉花各项数据指标和棉纺企业配棉指标的关系,以公检棉花的HVI数据为基础,根据配棉原理建立配棉数学模型,把配棉数学模型转化为标准的线性方程组,利用计算机求解方程组,完成对配棉模型的求解.通过对配棉方案进行优化,使棉纺企业更加合理地利用棉花资源.%The relationship between the objective fair detection data and cotton assorting indicators is analyzed. Taking HVI data as the basis,the mathematical model of cotton assorting is set up,then it is changed to standard system of linear equations,finally,the system of linear equations is solved by computer. The optimized cotton as-soring plan provides a reasonable way for cotton bales management and processing.

  4. Do mate preferences influence actual mating decisions? Evidence from computer simulations and three studies of mated couples.

    Science.gov (United States)

    Conroy-Beam, Daniel; Buss, David M

    2016-07-01

    Evolutionary research continues to discover new features of human mate preferences, but the downstream consequences of these preferences for mate selection have been insufficiently explored. Some have inferred that stated preferences have few behavioral consequences given seemingly weak effects of preferences in predicting mating outcomes. Here we test this inference with data from simulated mating markets as well as from real-world couples. We generate a series of agent-based models in which preferences either do or do not drive mate selection. We compare these simulations with 3 empirical studies of real-world couples (Study 1, n = 214; Study 2, n = 259; Study 3, n = 294). Preference-driven agent based models produce several effects that emerge in real couples, but not within random simulations. These include low-magnitude correlations between stated preferences and the individual traits of chosen partners; the novel finding that people with high mate value leverage that value into securing partners with more desirable traits; and the finding that couples assort based on overall mate value. Moreover, real-world mate choices correspond strongly with preference-driven simulations, but not to simulations in which mate selection is random with respect to preferences. Finally, we provide evidence that these effects are due to the causal role of stated preferences, and are not better explained by people updating their mate preferences to match chosen mates. These results provide new evidence that stated mate preferences guide actual mate selections under real mating-market constraints. (PsycINFO Database Record PMID:27337140

  5. Cotton Assorting Optimized Model Based on HVI Data and Its Application%基于HVI数据的配棉优选模型及应用研究

    Institute of Scientific and Technical Information of China (English)

    邱兆宝

    2012-01-01

    研究基于HVI数据的配棉方案优选模型的创建方法及应用效果.以HVI数据为基础,配棉技术标准为依据,运用系统工程的思想和方法,遵循配棉原则,利用较少的定量信息使决策的思维过程数学化,从而为多目标、多准则的配棉问题提供比较简便的决策方法.模型的求解采用隐枚举法,有效地解决了非线性目标整数规划配棉问题.认为:配棉方案优选模型与配棉方案的评价方法,可作为棉纺质量工艺专家指导系统的组成部分.%Establish method and application effect of cotton assorting optimized model based on HVI data were researched. HVI data were taken as base, technology standard of cotton assorting were selected as foundation, ideas and method of system engineering was used. Principle of cotton assorting should be followed. Decision-making process of thinking could be mathematical by using less quantitative information, so decision method of cotton assorting problems with multi-objective and multi criteria can be provided. Implicit enumeration was used for model solve,cotton assorting problems of nonlinear objective integer programming can be solved effectively. It is considered that the cotton assorting optimization model and evaluation methods could be the part of cotton spinning processing expert guide system.

  6. Preference for sons: past and present.

    Science.gov (United States)

    Li, D

    1997-10-01

    This brief article discusses the present and past preference for sons in China. The preference for sons is rooted in feudal views that men are superior to women. Preference for sons dates back to the Warring States Period, in about 500 B.C. Clan brotherhoods of men have existed for centuries. Historical records mention the practice of female infanticide. Patriarchal families believed that women were economically dependent on men and thus became their subjects. Daughters married, lived in their husband's home, and did not carry the responsibility of caring for their own parents. Couples with only daughters would seek a son-in-law to support them in old age. Rural families with no sons were looked down upon. Sons were expected to carry on the family lineage, increase the reputation of the family, and protect the family's interests. The lack of sons was a sign of humiliation and a curse. The founding of the People's Republic of China brought changes to son preference. The government attempted to increase women's status. In rural areas, women were given equal access to the land. Job opportunities were created for women during the industrialization drive. The Chinese government encouraged the repudiation of the negative impacts of the doctrines of Confucius and Mencius. Efforts were made to give men and women equal pay for equal work. Legislation was passed prohibiting arranged marriage, polygyny, and early marriage. A side effect of fertility decline is the renewed preference for sons. In Huangyan and Haining in Zhejiang, a developed province, the sex ratio at birth is normal. Sexual division of labor reinforces son preference.

  7. Assortative mating among Dutch married and cohabiting same-sex and different-sex couples

    NARCIS (Netherlands)

    E. Verbakel; M. Kalmijn

    2014-01-01

    The authors compared male and female same-sex and different-sex couples in the Netherlands with respect to age and educational homogamy. Because many same-sex couples in the Netherlands are married, differences between married and cohabiting couples were analyzed for all 3 groups. Analyses of data f

  8. Estimating exponential scheduling preferences

    DEFF Research Database (Denmark)

    Hjorth, Katrine; Börjesson, Maria; Engelson, Leonid;

    the travel time is random, Noland and Small (1995) suggested using expected utility theory to derive the reduced form of expected travel time cost that includes the cost of TTV. For the α-β-γ formulation of scheduling preferences and exponential or uniform distribution of travel time, Noland and Small (1995......, and consider how it should be normalised across individuals. The resulting discrete choice model is thus a combined model for mode and departure time choice. We use it to estimate the preference parameters of H and W and to compare the goodness-of-fit of the constant-exponential and constant...... convergence problems. However, the signs of the obtained parameter estimates are consistent with theory. We have no problems estimating the simpler constant-affine specification, where all parameter estimates have signs consistent with theory and low standard errors. Whether the models with the additivity...

  9. PREFERENCE, PRINCIPLE AND PRACTICE

    DEFF Research Database (Denmark)

    Skovsgaard, Morten; Bro, Peter

    2011-01-01

    journalists justify themselves and their work. This article introduces an analytical framework for understanding legitimacy in a journalistic context. A framework based on a review of material ranging from historical accounts to research articles, and book-length studies. The framework comprises three...... distinct, but interconnected categories*preference, principle, and practice. Through this framework, historical attempts to justify journalism and journalists are described and discussed in the light of the present challenges for the profession....

  10. Perspectives on Preference Aggregation.

    Science.gov (United States)

    Regenwetter, Michel

    2009-07-01

    For centuries, the mathematical aggregation of preferences by groups, organizations, or society itself has received keen interdisciplinary attention. Extensive theoretical work in economics and political science throughout the second half of the 20th century has highlighted the idea that competing notions of rational social choice intrinsically contradict each other. This has led some researchers to consider coherent democratic decision making to be a mathematical impossibility. Recent empirical work in psychology qualifies that view. This nontechnical review sketches a quantitative research paradigm for the behavioral investigation of mathematical social choice rules on real ballots, experimental choices, or attitudinal survey data. The article poses a series of open questions. Some classical work sometimes makes assumptions about voter preferences that are descriptively invalid. Do such technical assumptions lead the theory astray? How can empirical work inform the formulation of meaningful theoretical primitives? Classical "impossibility results" leverage the fact that certain desirable mathematical properties logically cannot hold in all conceivable electorates. Do these properties nonetheless hold true in empirical distributions of preferences? Will future behavioral analyses continue to contradict the expectations of established theory? Under what conditions do competing consensus methods yield identical outcomes and why do they do so? PMID:26158988

  11. A study of postgraduate students' endogamous preference in mate selection.

    Science.gov (United States)

    Saroja, K; Surendra, H S

    1991-01-01

    Researchers distributed questionnaires to 395 21-28 year old postgraduate students at the University of Agricultural Sciences and Dharwad and Karnataka University both in Dharwad, India, to determine their endogamous preferences in selecting a mate and to examine the relationship between these preferences and their sex, desired type of marriage, and discipline of postgraduate studies. 64.3% preferred limited mate selection within their caste. Specifically, 32.4% favored subcaste endogamy, 19.5% caste endogamy, and 12.4% kinship endogamy. 24.1% wanted to marry someone from another caste but someone of the same religion. 11.6% wished to marry someone of another religion. Female students were more likely to prefer caste endogamy than male students (76.0% vs. 53.5%; p .01): kinship endogamy (14.8% vs. 10.3%), subcaste endogamy (38.5% vs. 27.2%), and caste endogamy (23.6% vs. 16%) than male students. Male students were more likely to prefer a mate from either the same or different religion than female students (29.6% vs. 17.6% and 16.9% vs. 5.5%, respectively; p .01). Even though most students (58%) preferred arranged marriages, a considerable percentage (42%) preferred to marry for love. 41.6% of those who preferred love marriages wanted to marry someone from another caste compared with only 11.4% of those who preferred arranged marriage (p .01). Students who wanted to marry for love were 3 times more likely to want to marry someone from another religion than were those who preferred arranged marriage (18.6% vs. 6.5%; p .01). 45.4% of students who preferred arranged marriage wanted to choose their mate from the same subcaste compared with only 14.5% of those who wanted a love marriage (p .01). 41.2% of applied science students preferred to marry someone of the same religion compared with 21.7% for basic science students and 16.3% for humanities students (p .01). 50% of applied science students, 75.2% of basic science students, and 66.3% of humanities students preferred

  12. A study of postgraduate students' endogamous preference in mate selection.

    Science.gov (United States)

    Saroja, K; Surendra, H S

    1991-01-01

    Researchers distributed questionnaires to 395 21-28 year old postgraduate students at the University of Agricultural Sciences and Dharwad and Karnataka University both in Dharwad, India, to determine their endogamous preferences in selecting a mate and to examine the relationship between these preferences and their sex, desired type of marriage, and discipline of postgraduate studies. 64.3% preferred limited mate selection within their caste. Specifically, 32.4% favored subcaste endogamy, 19.5% caste endogamy, and 12.4% kinship endogamy. 24.1% wanted to marry someone from another caste but someone of the same religion. 11.6% wished to marry someone of another religion. Female students were more likely to prefer caste endogamy than male students (76.0% vs. 53.5%; p .01): kinship endogamy (14.8% vs. 10.3%), subcaste endogamy (38.5% vs. 27.2%), and caste endogamy (23.6% vs. 16%) than male students. Male students were more likely to prefer a mate from either the same or different religion than female students (29.6% vs. 17.6% and 16.9% vs. 5.5%, respectively; p .01). Even though most students (58%) preferred arranged marriages, a considerable percentage (42%) preferred to marry for love. 41.6% of those who preferred love marriages wanted to marry someone from another caste compared with only 11.4% of those who preferred arranged marriage (p .01). Students who wanted to marry for love were 3 times more likely to want to marry someone from another religion than were those who preferred arranged marriage (18.6% vs. 6.5%; p .01). 45.4% of students who preferred arranged marriage wanted to choose their mate from the same subcaste compared with only 14.5% of those who wanted a love marriage (p .01). 41.2% of applied science students preferred to marry someone of the same religion compared with 21.7% for basic science students and 16.3% for humanities students (p .01). 50% of applied science students, 75.2% of basic science students, and 66.3% of humanities students preferred

  13. Neuropeptides Modulate Female Chemosensory Processing upon Mating in Drosophila.

    OpenAIRE

    Ashiq Hussain; Üçpunar, Habibe K.; Mo Zhang; Loschek, Laura F.; Grunwald Kadow, Ilona C.

    2016-01-01

    Author Summary Food choices often correlate with nutritional needs or physiological states of an animal. For instance, during pregnancy, women frequently report that their food preferences change—sometimes dramatically. In part, this change in preference is brought about by a change in the perception of smells and tastes. Research has shown that female insects also change their food and egg-laying site preferences depending on their reproductive state. However, the mechanisms that trigger the...

  14. STD patients’ preferences for HIV prevention strategies

    Directory of Open Access Journals (Sweden)

    Castro JG

    2014-12-01

    Full Text Available Jose G Castro,1 Deborah L Jones,2 Stephen M Weiss2 1Infectious Diseases, Department of Medicine, 2Department of Psychiatry and Behavioral Sciences, University of Miami, Miami, FL, USA Abstract: The objective of this pilot study was to explore the knowledge of and preferences regarding effective biomedical interventions among high risk individuals attending a sexually transmitted diseases clinic, and to examine the effect of a brief information intervention on preference. Participants completed a baseline assessment, attended a presentation on human immunodeficiency virus (HIV prevention methods, and completed a postintervention assessment. Outcome measures included: demographics and sexual risk factors, self-perceived HIV risk, and knowledge and attitudes regarding new biomedical methods of HIV prevention. After the baseline evaluation, participants were provided with information on new biomedical prevention strategies. Participants were given the option to review the information by reading a pamphlet or by viewing a brief video containing the same information. Participants (n=97 were female (n=51 and male (n=46. At baseline, only a small minority of participants were aware of the newer biomedical strategies to prevent HIV infection. Postintervention, 40% endorsed having heard about the use of HIV medications to prevent HIV infection; 72% had heard that male circumcision can decrease the risk of acquiring HIV infection in men; and 73% endorsed knowledge of the potential role of microbicides in decreasing the risk of acquiring HIV. Following the intervention, the most preferred prevention method was male condoms, followed by preexposure prophylaxis, and microbicides. The least preferred methods were male circumcision and female condoms. This study provides preliminary information on knowledge and attitudes regarding newer biomedical interventions to protect against HIV infection. Keywords: STD clinic, biomedical HIV prevention, PrEP, male

  15. Puerto Rico Revealed Preference data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Revealed preference models provide insights into recreational angler behavior and the economic value of recreational fishing trips. Revealed preference data is...

  16. Human preference for air movement

    DEFF Research Database (Denmark)

    Toftum, Jørn; Melikov, Arsen Krikor; Tynel, A.;

    2002-01-01

    Human preference for air movement was studied at slightly cool, neutral, and slightly warm overall thermal sensations and at temperatures ranging from 18 deg.C to 28 deg.C. Air movement preference depended on both thermal sensation and temperature, but large inter-individual differences existed...... between subjects. Preference for less air movement was linearly correlated with draught discomfort, but the percentage of subjects who felt draught was lower than the percentage who preferred less air movement....

  17. Is mate choice copying or aggregation responsible for skewed distributions of females on leks?

    Science.gov (United States)

    McComb, K; Clutton-Brock, T

    1994-01-22

    In several lek-breeding populations of birds and mammals, females arriving on leks tend to join males that already have females in their territories. This might occur either because females have an evolved preference for mating with males that are attractive to other females, or because they join groups of other females to obtain greater safety from predation or dangerous harassment by males. We have previously used controlled experiments to show that oestrous fallow deer females join males with established harems because they are attracted to female groups rather than to the males themselves. Here we demonstrate that the preference for males with females over males without females is specific to oestrous females and weak or absent in anoestrous ones, and that it is not associated with a preference for mating with males that have previously been seen to mate with other females. Furthermore, oestrous females given the choice between males that do not already have females with them show no significant preference for antlered over deantlered males or for older males over younger ones. We conclude that female attraction to other females on the lek is likely to be an adaptation to avoiding harassment in mixed-sex herds. In this situation, a male's ability to maintain the cohesion of his harem may be the principal cause of variation in mating success between males.

  18. Immigrants' location preferences

    DEFF Research Database (Denmark)

    Damm, Anna Piil

    This paper exploits a spatial dispersal policy for refugee immigrants to estimate the importance of local and regional factors for refugees' location preferences. The main results of a mixed proportional hazard competing risks model are that placed refugees react to high regional unemployment and...... lack of a local immigrant population by migrating to large municipalities. Lack of local fellow countrymen, however, increases the exit rate to medium-sized as well as large municipalities. This finding is likely to be a result of the dispersal policy. Finally, refugees react strongly to assignment to...

  19. Conversion/Preference Games

    OpenAIRE

    Le Roux, Stéphane; Lescanne, Pierre; Vestergaard, René

    2008-01-01

    We introduce the concept of Conversion/Preference Games, or CP games for short. CP games generalize the standard notion of strategic games. First we exemplify the use of CP games. Second we formally introduce and define the CP-games formalism. Then we sketch two `real-life' applications, namely a connection between CP games and gene regulation networks, and the use of CP games to formalize implied information in Chinese Wall security. We end with a study of a particular fixed-point constructi...

  20. Concordance in mate choice in female mound-building mice.

    Science.gov (United States)

    Beigneux, Emilie; Féron, Christophe; Gouat, Patrick

    2012-03-01

    Females must evaluate male quality to perform mate choice. Since females generally base their selection on different male features, individual females may differ in their choice. In this study, we show that concordance between females in mate choice decisions may arise without any experimental maximization of a particular attractive trait. Choice tests were performed in mound-building mice, Mus spicilegus, a monogamous species. Body odours of two male donors were presented to 12 female subjects individually. To determine female choice, the same pair of males was presented three times to a female. Four different pairs of male body odours were used. Male donors, not related to females, were selected at random in our polymorphic breeding stock. Using this two-way choice design, female mice displayed a clear choice and had a similar preference for particular males.

  1. Focused grooming networks and stress alleviation in wild female baboons.

    Science.gov (United States)

    Wittig, Roman M; Crockford, Catherine; Lehmann, Julia; Whitten, Patricia L; Seyfarth, Robert M; Cheney, Dorothy L

    2008-06-01

    We examine the relationship between glucocorticoid (GC) levels and grooming behavior in wild female baboons during a period of instability in the alpha male rank position. All females' GC levels rose significantly at the onset of the unstable period, though levels in females who were at lower risk of infanticide began to decrease sooner in the following weeks. Three factors suggest that females relied on a focused grooming network as a coping mechanism to alleviate stress. First, all females' grooming networks became less diverse in the weeks following the initial upheaval. Second, females whose grooming had already focused on a few predictable partners showed a less dramatic rise in GC levels than females whose grooming network had been more diverse. Third, females who contracted their grooming network the most experienced a greater decrease in GC levels in the following week. We conclude that close bonds with a few preferred partners allow female baboons to alleviate the stress associated with social instability.

  2. Mate Selection Preferences among African American College Students.

    Science.gov (United States)

    Ross, Louie E.

    1997-01-01

    Examines the attitudes and preferences of African American college students toward physical characteristics, social status, and related variables regarding dating and future mate selection. Findings mostly confirmed that females would differ from males on social status variables (willing to date persons from lower social status), and males would…

  3. Mothers matter too: benefits of temperature oviposition preferences in newts.

    Directory of Open Access Journals (Sweden)

    Vendula Kurdíková

    Full Text Available The maternal manipulation hypothesis states that ectothermic females modify thermal conditions during embryonic development to benefit their offspring (anticipatory maternal effect. However, the recent theory suggests that the ultimate currency of an adaptive maternal effect is female fitness that can be maximized also by decreasing mean fitness of individual offspring. We evaluated benefits of temperature oviposition preferences in Alpine newts (Ichthyosaura [formerly Triturus] alpestris by comparing the thermal sensitivity of maternal and offspring traits across a range of preferred oviposition temperatures (12, 17, and 22°C and by manipulating the egg-predation risk during oviposition in a laboratory thermal gradient (12-22°C. All traits showed varying responses to oviposition temperatures. Embryonic developmental rates increased with oviposition temperature, whereas hatchling size and swimming capacity showed the opposite pattern. Maternal oviposition and egg-predation rates were highest at the intermediate temperature. In the thermal gradient, females oviposited at the same temperature despite the presence of caged egg-predators, water beetles (Agabus bipustulatus. We conclude that female newts prefer a particular temperature for egg-deposition to maximize their oviposition performance rather than offspring fitness. The evolution of advanced reproductive modes, such as prolonged egg-retention and viviparity, may require, among others, the transition from selfish temperature preferences for ovipositon to the anticipatory maternal effect.

  4. Parental monitoring, sensitivity toward parents, and a child's mate preferences

    NARCIS (Netherlands)

    Dubbs, Shelli L.; Buunk, Abraham P.; Li, Jessica

    2012-01-01

    This study investigated gender differences in parental monitoring and sensitivity toward parents and the extent to which these measures can influence children's mate preferences. In 2 samples (the United States and the Netherlands), females reported experiencing higher levels of parental monitoring

  5. Computer Technology and Student Preferences in a Nutrition Course

    Science.gov (United States)

    Temple, Norman J.; Kemp, Wendy C.; Benson, Wendy A.

    2006-01-01

    This study assessed learner preferences for using computer-based technology in a distance education course. A questionnaire was posted to students who had taken an undergraduate nutrition course at Athabasca University, Canada. The response rate was 57.1% (176 returned out of 308). Subjects were predominately female (93.7%) and nursing students…

  6. CVCC Student Performance on the Holland Vocational Preference Inventory.

    Science.gov (United States)

    Reed, M. Douglas

    In the fall of 1968, 269 males and 167 females at Central Virginia Community College were administered the Holland Vocational Preference Inventory. Statistical comparisons were made scale-for-scale between these students and national normative group average scores. The comparisons of means and standard deviations were analyzed by "t" tests; the…

  7. Patients Prefer Boarding in Inpatient Hallways: Correlation with the National Emergency Department Overcrowding Score

    Directory of Open Access Journals (Sweden)

    John R. Richards

    2011-01-01

    Full Text Available Objective. The boarding of patients in Emergency Department (ED hallways when no inpatient beds are available is a major cause of ED crowding. One solution is to board admitted patients in an inpatient rather than ED hallway. We surveyed patients to determine their preference and correlated their responses to real-time National Emergency Department Overcrowding Score (NEDOCS. Methods. This was a survey of admitted patients in the ED of an urban university level I trauma center serving a community of 5 million about their personal preferences regarding boarding. Real-time NEDOCS was calculated at the time each survey was conducted. Results. 99 total surveys were completed during October 2010, 42 (42% patients preferred to be boarded in an inpatient hallway, 33 (33% preferred the ED hallway, and 24 (24% had no preference. Mean (±SD NEDOCS (range 0–200 was 136±46 for patients preferring inpatient boarding, 112±39 for ED boarding, and 119±43 without preference. Male patients preferred inpatient hallway boarding significantly more than females. Preference for inpatient boarding was associated with a significantly higher NEDOCS. Conclusions. In this survey study, patients prefer inpatient hallway boarding when the hospital is at or above capacity. Males prefer inpatient hallway boarding more than females. The preference for inpatient hallway boarding increases as the ED becomes more crowded.

  8. Complex networks generated by the Penna bit-string model: Emergence of small-world and assortative mixing

    Science.gov (United States)

    Li, Chunguang; Maini, Philip K.

    2005-10-01

    The Penna bit-string model successfully encompasses many phenomena of population evolution, including inheritance, mutation, evolution, and aging. If we consider social interactions among individuals in the Penna model, the population will form a complex network. In this paper, we first modify the Verhulst factor to control only the birth rate, and introduce activity-based preferential reproduction of offspring in the Penna model. The social interactions among individuals are generated by both inheritance and activity-based preferential increase. Then we study the properties of the complex network generated by the modified Penna model. We find that the resulting complex network has a small-world effect and the assortative mixing property.

  9. Left or right? Sources of political orientation: the roles of genetic factors, cultural transmission, assortative mating, and personality.

    Science.gov (United States)

    Kandler, Christian; Bleidorn, Wiebke; Riemann, Rainer

    2012-03-01

    In this study, we used an extended twin family design to investigate the influences of genetic and cultural transmission as well as different sources of nonrandom mating on 2 core aspects of political orientation: acceptance of inequality and rejecting system change. In addition, we studied the sources of phenotypic links between Big Five personality traits and political beliefs using self- and other reports. Data of 1,992 individuals (224 monozygotic and 166 dizygotic twin pairs, 92 unmatched twins, 530 spouses of twins, 268 fathers, and 322 mothers) were analyzed. Genetically informative analyses showed that political attitudes are genetically but not environmentally transmitted from parents to offspring and that a substantial proportion of this genetic variance can be accounted for by genetic variance in personality traits. Beyond genetic effects and genotypic assortative mating, generation-specific environmental sources act to increase twins' and spouses' resemblance in political beliefs. The results suggest multiple sources of political orientations in a modern democracy.

  10. Processing technology of assorted spiced rabbit meat%卤味兔肉加工工艺

    Institute of Scientific and Technical Information of China (English)

    陈兴; 盛本国; 王军锋; 李海龙; 严文慧

    2012-01-01

    阐述了卤味兔肉的加工工艺、操作关键点及质量要求,此加工工艺简化了传统的酱卤工艺,且卤香味与兔肉的结合,既去除了兔肉的腥膻味,也赋予了兔肉特色的卤香味。%The assorted spiced rabbit meat processing technology, operating key points and quality requirements were elaborated; using this processing technology could simplify the traditional sauce halogen and halogen technology, and combine the fragrance with rabbit meat, which not only removed fishy and sheepy smell of rabbit meat, but also gave the meat characteristic bittern flavor.

  11. Left or right? Sources of political orientation: the roles of genetic factors, cultural transmission, assortative mating, and personality.

    Science.gov (United States)

    Kandler, Christian; Bleidorn, Wiebke; Riemann, Rainer

    2012-03-01

    In this study, we used an extended twin family design to investigate the influences of genetic and cultural transmission as well as different sources of nonrandom mating on 2 core aspects of political orientation: acceptance of inequality and rejecting system change. In addition, we studied the sources of phenotypic links between Big Five personality traits and political beliefs using self- and other reports. Data of 1,992 individuals (224 monozygotic and 166 dizygotic twin pairs, 92 unmatched twins, 530 spouses of twins, 268 fathers, and 322 mothers) were analyzed. Genetically informative analyses showed that political attitudes are genetically but not environmentally transmitted from parents to offspring and that a substantial proportion of this genetic variance can be accounted for by genetic variance in personality traits. Beyond genetic effects and genotypic assortative mating, generation-specific environmental sources act to increase twins' and spouses' resemblance in political beliefs. The results suggest multiple sources of political orientations in a modern democracy. PMID:21988277

  12. Random length assortment of human and mouse T cell receptor for antigen alpha and beta chain CDR3.

    Science.gov (United States)

    Johnson, G; Wu, T T

    1999-10-01

    In view of the recently determined three-dimensional structures of complexes formed by the T cell receptor for antigen (TCR), the processed peptide and the MHC class I molecule, it is expected that the combined configuration formed by the third complementarity determining regions (CDR3) of TCR alpha and beta chains will be very restricted in size and shape due to the limited length variations of the processed peptides. Thus, the combined TCR alpha and beta chain CDR3 lengths should have a fairly narrow distribution. This feature can be due to the selective association of long alpha chain CDR3 with short beta chain CDR3 and vice versa or due to random assortment of alpha and beta chain CDR3 of even narrower length distribution. Based on existing translated amino acid sequence data, it has been found that the latter mechanism is responsible.

  13. Son preference in rural China: patrilineal families and socioeconomic change.

    Science.gov (United States)

    Murphy, Rachel; Tao, Ran; Lu, Xi

    2011-01-01

    This article draws on a survey conducted in six provinces in summer 2008 to investigate the determinants of son preference in rural China. The analysis confirms the conventional wisdom that son preference is embedded within patrilineal family structures and practices. We extend our analysis by exploring specific aspects of variation within patrilineal family culture. We find that the patrilineal group (clan) composition of villages and family participation in practices such as building ancestral halls and updating genealogies significantly influence son preference. Yet even though son preference is embedded within patrilineal family culture, our analysis suggests that over time the attenuation of son preference is likely. This is because determinants associated with socioeconomic change—for instance, higher levels of education, direct exposure to official policy education materials, higher income (a proxy for rural industrialization), and agricultural mechanization—all attenuate son preference. Being younger and female are also associated with weaker son preference, and both characteristics are likely to interact with education and industrialization to further dilute son preference in the longer term. Nevertheless, our findings suggest that concerted efforts are needed to ameliorate institutional discrimination against rural people in welfare provisioning and in labor markets, and to promote multiple dimensions of gender equality, including in land rights, wage rates, and education.

  14. Negative Average Preference Utilitarianism

    Directory of Open Access Journals (Sweden)

    Roger Chao

    2012-03-01

    Full Text Available For many philosophers working in the area of Population Ethics, it seems that either they have to confront the Repugnant Conclusion (where they are forced to the conclusion of creating massive amounts of lives barely worth living, or they have to confront the Non-Identity Problem (where no one is seemingly harmed as their existence is dependent on the “harmful” event that took place. To them it seems there is no escape, they either have to face one problem or the other. However, there is a way around this, allowing us to escape the Repugnant Conclusion, by using what I will call Negative Average Preference Utilitarianism (NAPU – which though similar to anti-frustrationism, has some important differences in practice. Current “positive” forms of utilitarianism have struggled to deal with the Repugnant Conclusion, as their theory actually entails this conclusion; however, it seems that a form of Negative Average Preference Utilitarianism (NAPU easily escapes this dilemma (it never even arises within it.

  15. Why Languages Prefer Prohibitives

    Institute of Scientific and Technical Information of China (English)

    Johan van der Auwera

    2006-01-01

    This paper deals with prohibitive markers, i.e., negative markers that are more or less dedicated to the expression of a prohibition. It documents the variety in the formal make-up of these markers and it confims the earlier claims that they are frequent everywhere, with at least one exception, viz., Western Europe. Four origins are discussed:prohibitive markers may derive from predicative constructions, they may appear as a side product of Jespersen's cycle,they may derive from a univerbation of imperative and negative markers, and they may be borrowed. As explanation is offered as to why languages prefer to have prohibitive markers. It is argued that attempts to explain this preference in terms of morphosyntax are misguided. Instead a frequency-based semantic explanation is offered. The most frequent use of negatives are declarative, thereby inviting a static ‘it is not the case that' paraphrase. It is important, however, to mark clearly that prohibitives are instances of a dynamic ‘let it be the case that' appeal. The paper ends on a discussion of languages that do not employ prohibitive markers.

  16. Normal Female Reproductive Anatomy

    Science.gov (United States)

    ... historical Searches are case-insensitive Reproductive System, Female, Anatomy Add to My Pictures View /Download : Small: 720x756 ... Large: 3000x3150 View Download Title: Reproductive System, Female, Anatomy Description: Anatomy of the female reproductive system; drawing ...

  17. Presenting the female condom to men: a dyadic analysis of effect of the woman's approach.

    Science.gov (United States)

    Penman-Aguilar, Ana; Hall, Jeffrey; Artz, Lynn; Crawford, Myra A; Peacock, Nadine; van Olphen, Juliana; Parker, Lutissa; Macaluso, Maurizio

    2002-01-01

    Although male partner resistance to female condom use has been reported, little is understood about circumstances under which partners will agree to female condom use. This study documents the experiences of couples who have worked together to achieve female condom use. As part of a prospective female condom efficacy study, female participants (age 18-34) received a behavioral intervention and an assortment of take-home items. Selected women and their partners were recruited for a qualitative interview focusing on their experience with the female condom. Interviews were transcribed, double-coded, and verified using a standard retrieval coding system. Twenty-six pairs of linked interviews were analyzed dyadically: 9 couples who used the female condom "consistently," 12 "experimenters," and 5 "non-users." Women who successfully promoted the female condom to their partners used multiple presentation strategies. Initial male partner reaction did not predict continued use beyond the first trial. In conclusion, employment of multiple strategies facilitates successful introduction of the female condom into a sexual partnership.

  18. Does hunger influence judgments of female physical attractiveness?

    Science.gov (United States)

    Swami, Viren; Tovée, Martin J

    2006-08-01

    To account for male preferences for female body weight following a consistent socio-economic pattern, Nelson and Morrison (2005) proposed a social-cognitive model based on the individual experience of resource scarcity. We replicated their studies showing that calorific dissatisfaction can influence preference for female body weight using a different dependent variable, namely photographic stimuli of women with known body weight and shape. Using this revised methodology, we found that operationalized intra-individual resource scarcity affects preferences for body weight: 30 hungry male participants preferred figures with a higher body weight and rated as more attractive heavier figures than 31 satiated male participants. Hungrier men were also less likely to be influenced by cues for body shape, supporting extant cross-cultural studies on female physical attractiveness. These findings corroborate those of Nelson and Morrison (2005) and are discussed in terms of how cultural contexts shape individual psychological experience as predicted by the theory of mutual constitution. PMID:16848948

  19. Analysis of skin conductance response during evaluation of preferences for cosmetic products

    Science.gov (United States)

    Ohira, Hideki; Hirao, Naoyasu

    2015-01-01

    We analyzed skin conductance response (SCR) as a psychophysiological index to evaluate affective aspects of consumer preferences for cosmetic products. To examine the test-retest reliability of association between preferences and SCR, we asked 33 female volunteers to complete two experimental sessions approximately 1 year apart. The participants indicated their preferences in a typical paired comparison task by choosing the better option from a combination of two products among four products. We measured anticipatory SCR prior to expressions of the preferences. We found that the mean amplitude of the SCR elicited by the preferred products was significantly larger than that elicited by the non-preferred products. The participants' preferences and corresponding SCR patterns were well preserved at the second session 1 year later. Our results supported cumulating findings that SCR is a useful index of consumer preferences that has future potential, both in laboratory and marketing settings. PMID:25709593

  20. Brow archetype preferred by Korean women.

    Science.gov (United States)

    Kim, Seong Kee; Cha, Seung Hyun; Hwang, Kun; Hwang, Se Won; Kim, Young Suk

    2014-07-01

    The aim of this study is to see which brow archetype is preferred by Korean women. The archetypes were chosen from a literature search, which contain detailed, replicable methods and have diagrams (Westmore, Lamas, Anastasia, Schreiber, and Hwang). A survey was conducted on 300 subjects (group A, 100 female medical students; group B, 100 women who had visited a plastic surgery clinic for periorbital rejuvenation; and group C, 100 women who visited the brow bar). They were asked whether they think there might be a method that yields an ideal brow archetype. In the cases where they said yes, they were asked to choose 1 of the illustrated 5 brow archetypes that they think is ideal. Among the 300 respondents, 232 (77.3%) thought there might be a method to yield an ideal brow archetype, whereas 68 (22.7%) answered they did not. The preference for the brow archetypes was different among the 5 archetypes (P = 0.0001, χ2). Anastasia was the most preferred (44.8%, brow starts on a perpendicular line drawn from the middle of the nostril, arches on a line drawn from the center of the nose through the center of the pupil, and ends on a line drawn from the edge of the corresponding nasal ala through the outer edge of the eye). Anastasia was followed by Lamas (22.0%). In group A, Anastasia (55.7%) was the most preferred, followed by Lamas (26.2%) and Westmore (13.1%). In group B, Anastasia (34.8%) was the most preferred, followed by Lamas (30.3%) and Westmore and Schreiber (both 13.5%). In group C, Anastasia (47.6%) was the most preferred, followed by Hwang (25.5%) and Westmore (11.0%). There was a significant difference (P archetype and occupation (P = 0.0033). However, no significant differences were noted for the preference of brow archetype between the age groups of younger than 30 years and older than 30 years (P = 0.1374), level of education (P = 0.3403), marital status (P = 0.541), or monthly income (P = 0.1696, χ2). The result of this study might be useful in facial

  1. Rapid Evolution of Assortative Fertilization between Recently Allopatric Species of Drosophila

    Directory of Open Access Journals (Sweden)

    Yasir H. Ahmed-Braimah

    2012-01-01

    Full Text Available The virilis group of Drosophila represents a relatively unexplored but potentially useful model to investigate the genetics of speciation. Good resolution of phylogenetic relationships and the ability to obtain fertile hybrid offspring make the group especially promising for analysis of genetic changes underlying reproductive isolation separate from hybrid sterility and inviability. Phylogenetic analyses reveal a close relationship between the sister species, Drosophila americana and D. novamexicana, yet excepting their contemporary allopatric distributions, factors that contribute to reproductive isolation between this species pair remain uncharacterized. A previous report has shown reduced progeny numbers in laboratory crosses between the two species, especially when female D. novamexicana are crossed with male D. americana. We show that the hatch rate of eggs produced from heterospecific matings is reduced relative to conspecific matings. Failure of eggs to hatch, and consequent reduction in hybrid progeny number, is caused by low fertilization success of heterospecific sperm, thus representing a postmating, prezygotic incompatibility. Following insemination, storage and motility of heterospecific sperm is visibly compromised in female D. novamexicana. Our results provide evidence for a mechanism of reproductive isolation that is seldom reported for Drosophila species, and indicate the rapid evolution of postmating, prezygotic reproductive barriers in allopatry.

  2. A spider that feeds indirectly on vertebrate blood by choosing female mosquitoes as prey

    OpenAIRE

    Robert R. Jackson; Nelson, Ximena J.; Sune, Godfrey O.

    2005-01-01

    Spiders do not feed directly on vertebrate blood, but a small East African jumping spider (Salticidae), Evarcha culicivora, feeds indirectly on vertebrate blood by choosing as preferred prey female mosquitoes that have had recent blood meals. Experiments show that this spider can identify its preferred prey by sight alone and by odor alone. When presented with two types of size-matched motionless lures, E. culicivora consistently chose blood-fed female mosquitoes in preference to nonmosquito ...

  3. Speciality preferences in Dutch medical students influenced by their anticipation on family responsibilities

    NARCIS (Netherlands)

    Alers, M.; Pepping, T.; Bor, H.; Verdonk, P.; Hamberg, K.; Lagro-Janssen, A.

    2014-01-01

    Physician gender is associated with differences in the male-to-female ratio between specialities and with preferred working hours. We explored how graduating students' sex or full-time or part-time preference influences their speciality choice, taking work-life issues into account. Graduating medica

  4. Effect of Vocal Vibrato and Performer's Sex on Children's Music Preference.

    Science.gov (United States)

    LeBlanc, Albert; Sherrill, Carolyn

    1986-01-01

    Part of an ongoing series of studies designed to develop formal theory of development of individual music listening preference, this study investigated effect of low and high levels of vocal vibrato, employed by male and female performers, on self-reported music listening preferences of upper elementary school children. Results showed significant…

  5. Mates of Competitive Females: The Relationships between Female Aggression, Mate Quality, and Parental Care

    Directory of Open Access Journals (Sweden)

    Kristal E. Cain

    2014-01-01

    Full Text Available Though rarely mate-limited, females in a wide variety of species express traits commonly associated with mate competition in males. Recent research has shown that these competitive traits (ornaments, armaments, and intense aggression often function in the context of female-female competition for nonsexual reproductive resources and are often positively related to reproductive success. Increased success could occur because competitive females acquire limited ecological resources (nest sites, territories, etc. or because they pair with high quality males, that is, older, more ornamented, or more parental males. Further, males paired with aggressive/low care females may compensate by increasing their paternal efforts. Here, I examined patterns of social pairing and parental care in free-living dark-eyed juncos (Junco hyemalis, a biparental songbird. I found no detectable relationship between female competitive behavior (aggression and male quality (age, size, or ornamentation or male provisioning. Thus, neither of the mate choice hypotheses (females compete for males or males prefer aggressive females was supported. Instead, these results suggest that females compete for nonsexual resources and mate quality is a secondary consideration. I also found a negative relationship between male and female provisioning rates, suggesting that partners adjust their level of parental effort in response to their partner’s efforts.

  6. 基于灰色局势决策的备件品种级别配置%Application of Grey Situation Decision Approach to Determining the Assortment of Spares and Level of Repair

    Institute of Scientific and Technical Information of China (English)

    李云锋; 王瑞林; 贾云非; 长建宇

    2011-01-01

    Analyzes the significant factors which have influence on spares assortment. This paper introduce a new method of quantizing spares assortment that is grey situation decision approach. It accounts for spares assortment basis on level of repair.%分析了影响备件品种确定的主要因素,引入灰色局势决策法,解决了按维修级别进行备件品种确定的问题,提供一种新的备件品种量化方法.

  7. Do Tetranychus urticae males avoid mating with familiar females?

    Science.gov (United States)

    Yoshioka, T; Yano, S

    2014-07-01

    The two-spotted spider mite, Tetranychus urticae, usually lives in kin groups under common webs. Because only the first mating results in fertilisation in female T. urticae, adult males guard quiescent deutonymph females, those at the stage immediately before maturation, to ensure paternity. Therefore, the cost of precopulatory guarding time seems considerable for males. Moreover, the fitness indices of daughters from intra-population crosses were significantly lower than those of daughters from inter-population crosses, indicating that inbreeding depression exists in T. urticae. Therefore, we hypothesised that T. urticae males should be choosy in guarding familiar females to avoid inbreeding depression. Furthermore, webs should be a key element of the environment shared by familiar individuals. In this study, we demonstrated the inbreeding avoidance mechanism of T. urticae males in relation to webs produced by familiar females (known webs) or unfamiliar females (unknown webs). Regardless of surrounding webs (known or unknown), males preferred unfamiliar to familiar females. We further examined whether males detect unfamiliar females by their webs. When males had experienced a female's web without encountering that female, they subsequently preferred females that did not produce the surrounding webs in which the choice experiment was conducted. Results suggest that putative kin recognition for inbreeding avoidance in T. urticae males is based on the relationship between webs and females, and not on the discrimination of webs in shared environments.

  8. Preference Externalities in Media Markets

    OpenAIRE

    Simon P. Anderson; Waldfogel, Joel

    2015-01-01

    Media industries typically exhibit two fundamental features, high fixed costs and heterogeneity of consumer preferences. Daily newspaper markets, for example, tend to support a single product. In other examples, such as radio broadcasting, markets often support multiple differentiated offerings. Both contexts can deliver preference externalities, when the options and well-being for consumers depend on the number and mix of consumers according to their content preferences. This chapter present...

  9. Option values and flexibility preference

    OpenAIRE

    Strazzera, Elisabetta

    1998-01-01

    Preference for flexibility is a behavioral attitude displayed by people that prefer reversible to irreversible actions, and that are willing to pay a premium in order to maintain the possibility of changing their decision. This paper provides a functional characterization of preference for flexibility, based on the notion of option value. The proposed theory is shown to be useful to explain the success of marketing policies that guarantee reimbursement in consumption goods and financial marke...

  10. Music preferences and tobacco smoking.

    Science.gov (United States)

    Posluszna, Joanna; Burtowy, Agnieszka; Palusinski, Robert

    2004-02-01

    This study investigated the association of music preferences with tobacco smoking in a group of 152 high school and college students. Both the questionnaire and the listening survey indicated a higher preference for music associated with anxiety and depressed mood among smokers. These findings may reflect a common etiology of tobacco addiction and a specific type of music preferences. To elucidate this phenomenon further studies are needed. PMID:15077771

  11. Social Preferences and Portfolio Choice

    OpenAIRE

    Riedl, A.M.; Smeets, P.M.A.

    2013-01-01

    This paper explores whether social preferences influence portfolio choices of retail investors. We use administrative investor trading records which we link to decisions of the same investors in experiments with real money at stake. We show that social preferences rather than return expectations or risk perceptions are the main driver of investments in socially responsible (SRI) mutual funds. Social preferences are only associated with investments in SRI funds without tax benefits, but are un...

  12. Male size does not correlate with fertilization success in two bufonid toads that show size-assortative mating

    OpenAIRE

    Xiao-Li FAN, Zhi-Hua LIN, Xiang JI

    2013-01-01

    We examined sexual size dimorphism (SSD), mating pattern, fertilization efficiency and female reproductive traits in two bufonid toads (Bufo gargarizans and Duttaphrynus melanostictus) to test the idea that importance of male body size for egg fertilization success depends on the mating pattern. Female-biased SSD was evident only in D. melanostictus. Female B. gargarizans laid fewer larger eggs nearly three months earlier than did female D. melanostictus. Fertilization efficiencies on average...

  13. Preference formation and institutional change

    Directory of Open Access Journals (Sweden)

    Sérgio Praça

    2009-06-01

    Full Text Available This essay critically analyses how historical institutionalists and rational choice scholars study institutional stability and change. Special attention is paid to the thorny issued of how political actors’ preferences are formed, with historical institutionalists considering preferences as endogenously formed, and rational choice analysts postulating that preferences are fixed and exogenous. An argument is made in favour of the perspective that considers preferences as being formed within the functioning of the political system over time, endogenously. The essay also proposes the incorporation of ideas and non-decisions as tools to elucidate processes of change.

  14. Application Effect Analyses of Computer Cotton Assorting System%计算机配棉系统的应用效果分析

    Institute of Scientific and Technical Information of China (English)

    丁忠平; 袁安民

    2011-01-01

    Cotton assorting and prediction yarn quality effect by computer cotton assorting system was analyzed. Functions of computer cotton assorting system were introduced. Micronaire value and fiber length were selected as the first case,micronaire value,fiber length and fiber uniform were selected as the second case,cotton assorting and spinning test were done in the two cases. The result shows that the error between prediction data of the first case and practical data are larger. While the error between prediction data of the second case and practical data are less, the yam quality can fit use demands. It is considered that better yarn quality prediction result can be got when cotton bales classification of computer cotton assorting system can be set rationally according to raw material. Prediction result of computer cotton assorting system can be more accurate when equipment, processing etc are considered comprehensively.%分析计算机配棉系统配棉及预测成纱质量的效果.介绍了计算机配棉系统的功能,分别选取马克隆值和长度(方案1)及马克隆值、长度和纤维整齐度(方案2)为参数进行配棉及纺纱试验.试验结果表明:方案1的预测理论数据与实际生产数据误差较大,而方案2的误差明显减小,生产出的成纱质量符合使用要求.认为:根据原料情况合理设置计算机配棉系统的棉包分类分组方能取得理想的成纱质量预测结果,如能综合考虑设备、工艺等因素,计算机配棉系统的预测结果会更加精确.

  15. An Experimental Study of Gender and Cultural Differences in Hue Preference

    Directory of Open Access Journals (Sweden)

    Abdulrahman Saud Al-Rasheed

    2015-01-01

    Full Text Available This paper investigates the influence of both gender and culture on colour preference. Inspection of previous studies of colour preference reveals that many of these studies have poor control over the colours that are shown – the chromatic co-ordinates of colours are either not noted or the illuminant that colours are shown under is not controlled. This means that conclusions about colour preference are made using subjective terms for hue with little knowledge about the precise colours that were shown. However, recently, a new quantitative approach to investigating colour preference has been proposed, where there is no need to summarise colour preference using subjective terms for hue (Ling et al., 2007; Hurlbert & Ling, 2007. This approach aims to quantitatively summarise hue preference in terms of weights on the two channels or ‘cardinal axes’ underlying colour vision. Here I further extend Hurlbert and Ling’s (2007 approach to investigating colour preference, by replicating their study but with Arabic and English participants, and to answer several questions: First, are there cultural differences in the shape of the overall preference curve for English and Arabic participants? Second, are there gender differences in the shape of the overall preference curve for English and Arabic participants?. Thirty eight British and 71 Saudi Arabian (Arabic participants were compared. Results revealed that Arabic and English preference curves were found to differ, yet there was greater similarity for Arabic and English males than Arabic and English females. There was also a sex difference that was present for both Arabic and English participants. The male curve is fairly similar for both samples: peak-preference is in the blue-green region, and a preference minimum is in the red-pink/purple region. For Arabic females the preference peak appears to be in the red-pink region, whilst for English females it is shifted towards purple/blue-green.

  16. Effects of nutrition label format and product assortment on the healthfulness of food choice.

    Science.gov (United States)

    Aschemann-Witzel, Jessica; Grunert, Klaus G; van Trijp, Hans C M; Bialkova, Svetlana; Raats, Monique M; Hodgkins, Charo; Wasowicz-Kirylo, Grazyna; Koenigstorfer, Joerg

    2013-12-01

    This study aims to find out whether front-of-pack nutrition label formats influence the healthfulness of consumers' food choices and important predictors of healthful choices, depending on the size of the choice set that is made available to consumers. The predictors explored were health motivation and perceived capability of making healthful choices. One thousand German and Polish consumers participated in the study that manipulated the format of nutrition labels. All labels referred to the content of calories and four negative nutrients and were presented on savoury and sweet snacks. The different formats included the percentage of guideline daily amount, colour coding schemes, and text describing low, medium and high content of each nutrient. Participants first chose from a set of 10 products and then from a set of 20 products, which was, on average, more healthful than the first choice set. The results showed that food choices were more healthful in the extended 20-product (vs. 10-product) choice set and that this effect is stronger than a random choice would produce. The formats colour coding and texts, particularly colour coding in Germany, increased the healthfulness of product choices when consumers were asked to choose a healthful product, but not when they were asked to choose according to their preferences. The formats did not influence consumers' motivation to choose healthful foods. Colour coding, however, increased consumers' perceived capability of making healthful choices. While the results revealed no consistent differences in the effects between the formats, they indicate that manipulating choice sets by including healthier options is an effective strategy to increase the healthfulness of food choices.

  17. Risk preferences and prenatal exposure to sex hormones for ladinos.

    Directory of Open Access Journals (Sweden)

    Diego Aycinena

    Full Text Available Risk preferences drive much of human decision making including investment, career and health choices and many more. Thus, understanding the determinants of risk preferences refines our understanding of choice in a broad array of environments. We assess the relationship between risk preferences, prenatal exposure to sex hormones and gender for a sample of Ladinos, which is an ethnic group comprising 62.86% of the population of Guatemala. Prenatal exposure to sex hormones has organizational effects on brain development, and has been shown to partially explain risk preferences for Caucasians. We measure prenatal exposure to sex hormones using the ratio of the length of the index finger to the length of the ring finger (2D:4D, which is negatively (positively correlated with prenatal exposure to testosterone (estrogen. We find that Ladino males are less risk averse than Ladino females, and that Ladino males have lower 2D:4D ratios than Ladino females on both hands. We find that the 2D:4D ratio does not explain risk preferences for Ladinos. This is true for both genders, and both hands. Our results highlight the importance of exploring the behavioral significance of 2D:4D in non-Caucasian racial groups.

  18. Food preferences of older adults in senior nutrition programs.

    Science.gov (United States)

    Song, Hee-Jung; Simon, Judy R; Patel, Dhruti U

    2014-01-01

    The Elderly Nutrition Program (ENP) is being challenged to improve the quality of meal programs. The purpose of this study was to explore how food preferences varied depending on gender and ethnic groups. A total of 2,024 participants in the ENP aged 60 years or older were interviewed. A majority of the participants were female (74.7%), served by congregate meal programs (71.7%), with the mean ± SD age of 76.9 ± 9.2 years. A general impression of the meals and preferences for 13 food groups (fresh fruit, chicken, soup, salad, vegetables, potatoes, meat, sandwiches, pasta, canned fruit, legumes, deli meats, and ethnic foods) were assessed. After adjusting other variables, older males were significantly more likely to prefer deli meats, meat, legumes, canned fruit, and ethnic foods compared to females. In addition, compared with African Americans, Caucasians demonstrated higher percentages of preference for 9 of 13 food groups including pasta, meat, and fresh fruit. To improve the quality of the ENP, and to increase dietary compliance of the older adults to the programs, the nutritional services require a strategic meal plan that solicits and incorporates older adults' food preferences.

  19. Do female Nicrophorus vespilloides reduce direct costs by choosing males that mate less frequently?

    Science.gov (United States)

    Mazué, G. P. F.; Carter, M. J.; Head, M. L.; Moore, A. J.; Royle, N. J.

    2016-01-01

    Sexual conflict occurs when selection to maximize fitness in one sex does so at the expense of the other sex. In the burying beetle Nicrophorus vespilloides, repeated mating provides assurance of paternity at a direct cost to female reproductive productivity. To reduce this cost, females could choose males with low repeated mating rates or smaller, servile males. We tested this by offering females a dichotomous choice between males from lines selected for high or low mating rate. Each female was then allocated her preferred or non-preferred male to breed. Females showed no preference for males based on whether they came from lines selected for high or low mating rates. Pairs containing males from high mating rate lines copulated more often than those with low line males but there was a negative relationship between female size and number of times she mated with a non-preferred male. When females bred with their preferred male the number of offspring reared increased with female size but there was no such increase when breeding with non-preferred males. Females thus benefited from being choosy, but this was not directly attributable to avoidance of costly male repeated mating. PMID:26979560

  20. Male chimpanzees' grooming rates vary by female age, parity, and fertility status.

    Science.gov (United States)

    Proctor, Darby P; Lambeth, Susan P; Schapiro, Steven J; Brosnan, Sarah F

    2011-10-01

    Copulation preferences in our closest living relative, the chimpanzee, suggest that males prefer older females who have had previous offspring. However, this finding is counter to some behavioral models, which predict that chimpanzee males, as promiscuous breeders with minimal costs to mating, should show little or no preference when choosing mating partners (e.g. should mate indiscriminately). To determine if the preferences indicated by copulations appear in other contexts as well as how they interact, we examined how male chimpanzees' grooming patterns varied amongst females. We found that males' preferences were based on interactions among females' fertility status, age, and parity. First, grooming increased with increasing female parity. We further found an effect of the estrous cycle on grooming; when females were at the lowest point of their cycle, males preferentially groomed parous females at peak reproductive age, but during maximal tumescence, males preferred the oldest multiparous females. Nulliparous females received relatively little grooming regardless of age or fertility. Thus, male chimpanzees apparently chose grooming partners based on both female's experience and fertility, possibly indicating a two-pronged social investment strategy. Male selectivity seems to have evolved to effectively distribute costly social resources in a pattern which may increase their overall reproductive success.

  1. A Darker Shade of Love: Machiavellianism and Positive Assortative Mating Based on Romantic Ideals.

    Science.gov (United States)

    Ináncsi, Tamás; Láng, András; Bereczkei, Tamás

    2016-02-01

    Machiavellianism is a personality trait that is characterized by manipulative and exploitative attitude toward others, lack of empathy, and a cynical view of human nature. In itself or as part of the Dark Triad it has been the target of several studies investigating romantic relations. Nevertheless, the relationship between Machiavellianism and romantic ideals has not been revealed yet. An undergraduate sample of 143 (92 females) with an average age of 19.83 years (SD = 1.51 years) filled out self-report measures of Machiavellianism (Mach-IV Scale) and romantic ideals (Ideal Standards Scale and NEO-FFI-IDEAL). According to our results, Machiavellianism correlated negatively with the importance of partner's warmth-trustworthiness, extraversion, openness, agreeableness, and with the importance of intimacy and loyalty in their ideal relationships. Machiavellianism correlated positively with the ideal partner's possession over status and resources. Explorative factor analysis revealed three components of ideal partner's characteristics. Machiavellianism loaded significantly on two out of three components. Results are discussed with regard to Ideal Standards Model and the Big Five model of personality. PMID:27247697

  2. Female mate-choice behavior and sympatric speciation.

    Science.gov (United States)

    Verzijden, Machteld N; Lachlan, Robert F; Servedio, Maria R

    2005-10-01

    Many models have investigated how the process of speciation may occur in sympatry. In these models, individuals are either asexual or mate choice is determined by very simple rules. Females, for example, may be assumed either to compare their phenotype to that of a potential mate, preferring to mate with similar males (phenotype matching), or to possess preference genes that determine which male phenotype they prefer. These rules often do not reflect the mate-choice rules found in empirical studies. In this paper, we compare these two modes of female choice with various types of sexual imprinting. We examine the efficacy of different mate-choice behavior in causing divergence in male traits under simple deterministic one-locus population genetic models as well as under polygenic, individual-based simulations based on the models of Dieckmann and Doebeli (1999). We find that the inheritance mechanism of mate choice can have a large effect on the ease of sympatric speciation. When females imprint on their mothers, the result of the model is similar to phenotype matching, where speciation can occur fairly easily. When females imprint on their fathers or imprint obliquely, speciation becomes considerably less likely. Finally, when females rely on preference genes, male trait evolution occurs easily, but the correlation between trait and preference can be weak, and interpreting these results as speciation may be suspect.

  3. Incongruence between the sexes in preferences for body and dorsal fin size in Xiphophorus variatus.

    Science.gov (United States)

    MacLaren, R David; Fontaine, Adam

    2013-01-01

    Female preference for male fin enhancements in poeciliid fishes may be driven by a preexisting perceptual bias for increased male lateral projection area (LPA). This hypothesis suggests that a male with enlarged body and/or fin size projects a larger image onto the female's retina at a given viewing distance, eliciting a greater sensory and thus behavioral response out of the female than a smaller male. Given the shared sensory/neural systems of opposite sex conspecifics, we might expect the LPA bias to also be present in males of at least some poeciliid species. However, we need not expect congruence between the sexes in the state of the bias over evolutionary time. To examine whether the sexes share a bias for sailfin-like dorsal fins, a trait not present in their evolutionary history, the bias favoring increased dorsal fin size and LPA observed in female Xiphophorus variatus, among other poeciliids, was investigated by testing male preference for dummy females varying in dorsal fin size, body size, and dorsal fin:body size ratio. In three sets of simultaneous choice experiments, males preferred females of larger body size when fin size was held constant and when total LPA was held constant, but showed no preference for larger fins when body size was held constant. The LPA bias is therefore less permissive in males than females with selection favoring a male's ability to discriminate between female body size - an indicator of fertility/fecundity - and fin size, which offers no known fitness benefits. PMID:23137586

  4. Squirrel Foraging Preferences: Gone Nuts?

    Science.gov (United States)

    Darling, Randi A.

    2007-01-01

    This field exercise examines the feeding preferences of Gray Squirrels ("Sciurus carolinensis"). Students present squirrels with a variety of food types in a cafeteria-style arrangement in order to test hypotheses about foraging preferences. This exercise, which is appropriate for introductory biology, ecology, and animal behavior classes, is…

  5. Interest-based preference reasoning

    NARCIS (Netherlands)

    Visser, W.M.; Hindriks, K.V.; Jonker, C.M.

    2011-01-01

    In the context of practical reasoning, such as decision making and negotiation, it is necessary to model preferences over possible outcomes. Such preferences usually depend on multiple criteria. We argue that the criteria by which outcomes are evaluated should be the satisfaction of a person’s under

  6. Job satisfaction and preference drift.

    NARCIS (Netherlands)

    H. Maassen van den Brink; W.J.N. Groot

    1999-01-01

    Most empirical studies do not find that higher wages lead to more job satisfaction. In this paper we argue that the insignificant effect of wages on job satisfaction is due to preference drift. We adapt the standard ordered response model to allow for preference shifts. The empirical results support

  7. Endogenous scheduling preferences and congestion

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Small, Kenneth

    2010-01-01

    Dynamic models of congestion so far rely on exogenous scheduling preferences of travelers, based for example on disutility of deviation from a preferred departure or arrival time for a trip. This paper provides a more fundamental view in which travelers derive utility just from consumption and le...

  8. Evidence indicating independent assortment of framework and complementarity-determining segments of the variable regions of rabbit light chains. Delineation of a possible J minigene.

    Science.gov (United States)

    Kabat, E A; Wu, T T; Bilofsky, H

    1980-07-01

    Amino acid sequences of rabbit light chains show considerable evidence of independent assortment of framework (FR) and complementarity-determining (CDR) segments. This suggests that they are coded for by independent genetic units (minigaenes) and that individual light chains are assembled somatically by recombining these units. Identical FR sets with multiple members generally comprise chains with different specificities, whereas identical CDR sets tend to have chains of a single specificity. A J segment, which, by analogy with mouse light chains, is made up of the last two residues of CDR3 plus all of FR4, contained 18 different sets and could contribute to diversity generated by CDR3. The longest segment, FR3, had a very large number of sets. Evidence is presented showing that the number of sets could be substantially reduced by permitting FR3 to be formed by two independently assorting segments comprising residues 57-68 and 69-88.

  9. Application of statistical emulation to an agent-based model: assortative mating and the reversal of gender inequality in education in Belgium.

    OpenAIRE

    De Mulder, Wim; Grow, André; Molenberghs, Geert; Verbeke, Geert

    2015-01-01

    We describe the application of statistical emulation to the outcomes of an agent-based model. The agent-based model simulates the mechanisms that might have linked the reversal of gender inequality in higher education with observed changes in educational assortative mating in Belgium. Using the statistical emulator as a computationally fast approximation to the expensive agent-based model, it is feasible to use a genetic algorithm in nding the parameter values for which the correspondin...

  10. Dissortative From the Outside, Assortative From the Inside: Social Structure and Behavior in the Industrial Trade Network

    CERN Document Server

    Kelman, Guy; Manes, Eran; Lamieri, Marco; Golo, Natasa; Solomon, Sorin

    2014-01-01

    It is generally accepted that neighboring nodes in financial networks are negatively assorted with respect to the correlation between their degrees. This feature would play an important 'damping' role in the market during downturns (periods of distress) since this connectivity pattern between firms lowers the chances of auto-amplifying (the propagation of) distress. In this paper we explore a trade-network of industrial firms where the nodes are suppliers or buyers, and the links are those invoices that the suppliers send out to their buyers and then go on to present to their bank for discounting. The network was collected by a large Italian bank in 2007, from their intermediation of the sales on credit made by their clients. The network also shows dissortative behavior as seen in other studies on financial networks. However, when looking at the credit rating of the firms, an important attribute internal to each node, we find that firms that trade with one another share overwhelming similarity. We know that m...

  11. I. V. Michurin’S Work on Expansion of the Plant Horticulture Assortment and Improvement of Food Quality

    Directory of Open Access Journals (Sweden)

    Sokolov Viktor V.

    2015-09-01

    Full Text Available October 2015 marks the 160th anniversary of the birth of Ivan V. Michurin. As a scientist and plant breeder, he made a significant improvement of many fruit and berry plants, and flowers. He developed methods of plant breeding, especially regarding long-distance hybridisation of fruit plants, and promoted gardening to the north and east of Russia. He introduced some new berry species, such as Actinidia and black chokeberry, and was the first in Russia to use dwarf and semi dwarf stocks of apples. Michurin initiated the mass movement of gardeners and horticulture experimenters in USSR who changed and significantly extended the assortment and areas of fruit and berries cultivation in the country. He not only brought together a representative collection of species and varieties of fruit, berry and flower plants from around the world, but also used them in breeding by hybridization, including interspecific. He created some new artificial interspecific hybrids such as Cerapadus (cherry and bird cherry tree hybrid, and others. Michurin created 132 cultivars. Eleven of them are not only cultivated, but are also included in “The State Register of Protected Plant Breeding of the Russian Federation”.

  12. Possible assortment of a1 and a2 region gene segments in human MHC class I molecules.

    Science.gov (United States)

    Johnson, G; Wu, T T

    1998-06-01

    Using pair-wise comparison of aligned nucleotide sequences of distinct and complete human MHC class I molecules, we have constructed triangular tables to study the similarities and differences of various a1 (exon 2) and a2 (exon 3) region sequences. There are two HLA-A (A*6901 and A*6601) and 13 HLA-B (B*4201, B*8101, B*4102, B*4801, B*4007, B*4001, B*4802, Dw53, B*4406, B*4402, B*3901, B*1514 and B*3702) sequences that have identical a1 sequences with other known MHC class I molecules, while their a2 sequences are the same as those of different ones. Of these 15, A*6901, B*4001 and B*4802 have previously been suggested as the results of recombination between A*6801 and A*0201, B*4101 and B*8101, and B*4801 and B*3501, respectively. However, many other sequences can also be used to generate them by recombination. Furthermore, their reciprocal products have never been identified. Thus, gene conversion has subsequently been suggested as an alternative. Another possible genetic mechanism for generating these nucleotide sequence similarities can be assortment, or that some gene segments can be duplicated or multiplicated to be used in different human MHC class I molecules. Interestingly, this genetic mechanism is probably absent for the generation of different mouse MHC class I molecules.

  13. HLA and epidermolysis bullosa: evidence for independent assortment of Weber-Cockayne subtype of epidermolysis bullosa and HLA complex.

    Science.gov (United States)

    Vaidya, S; Tyring, S K; Feldkamp, M; Johnson, L B; Fine, J D

    1991-05-01

    The purpose of this study was to examine the genetic linkage (but not the association) between HLA complex and Weber-Cockayne Subtype of epidermolysis bullosa (EBS-WC). We HLA typed 44 members of three multi-generation families in which 24 members have the clinical evidence of EBS-WC. The patterns of inheritance of various HLA haplotypes and the disease were mathematically analyzed to estimate frequency of recombination (i.e. genetic distance) between HLA complex and the disease by calculating Lod Scores for each family separately as well as all for three families combined. Our results show that only one family had a positive Lod Score. The Lod Scores for the remaining two families as well as the combined Lod Score for all three families were negative. These data suggest that odds are against the genetic linkage between HLA complex and Weber-Cockayne Subtype of epidermolysis bullosa and in favor of independent assortment of the disease and HLA complex.

  14. The Analysis Of The Strain Influence On Some Yield Elemnts On An Assortment Of Isogenic Wheat Varieties

    Science.gov (United States)

    Păniţă, Ovidiu

    2015-09-01

    In the years 2012-2014 on Banu-Maracine DRS were tested an assortment consists of 25 isogenic lines of common wheat (Triticum aestivum ssp.vulgare), with the combination of Rht1&rht8 genes, the analyzed characters being the hight of the strain (cm), the number of seeds/spike, seeds weight/spike (g), no. of spikes/m2, weight of a thousand seeds (WTS) (g) and no. of emerged plants/m2. Based on recorded data and statistical processing of those, they were identified a numbers of links between these characters, links quantified by using the correlation. Regarding the classification based on the average high of the strain, it was found that that there is a strong link between some characters too. Based on component analysis, the no. of seeds/spike and the seeds weight/spikes are components that influence in excess of 83% variance analysis, a total of five genotypes having positive scores for both factors.

  15. Are high-quality mates always attractive?: State-dependent mate preferences in birds and humans

    OpenAIRE

    Riebel, Katharina; Holveck, Marie-Jeanne; Verhulst, Simon; Fawcett, Tim W.

    2010-01-01

    Sexual selection theory posits that females should choose mates in a way that maximizes their reproductive success. But what exactly is the optimal choice? Most empirical research is based on the assumption that females seek a male of the highest possible quality (in terms of the genes or resources he can provide), and hence show directional preferences for indicators of male quality. This implies that attractiveness and quality should be highly correlated. However, females frequently differ ...

  16. Mate preference and disease risk in Zootermopsis angusticollis (Isoptera: Termopsidae).

    Science.gov (United States)

    Rosengaus, Rebeca B; James, Lady-Thelma; Hartke, Tamara R; Brent, Colin S

    2011-12-01

    Termites face significant and chronic intranidal selection pressures from parasites and pathogens that colonize their nests. They also encounter microbes outside their nest while foraging and during dispersal of winged primary reproductives to establish new colonies. The latter run the additional risk of becoming infected by a mating partner. Indeed, death of reproductives because of disease is a major cause of incipient colony failure and may favor prescreening prospective mates for signs of illness. To determine the role of disease on mate preference in termites, female primary reproductives of the Pacific dampwood termite Zootermopsis angusticollis (Hagen) simultaneously were presented with reproductive males that were either healthy or exhibiting a progression of symptoms associated with infection by the entomopathogenic fungus Metarhizium anisopliae (Metchnikoff Sorokin). We compared duration and frequency of female visits to healthy and infected males. In addition, we determined the physiological consequences for females exposed to fungal conidia, either directly or indirectly through their mate. Females showed no preference for healthy rather than infected males. Moreover, only directly-exposed females experienced negative physiological effects, having a reduced chance of survival, gaining less weight, developing fewer functional ovarioles, and producing significantly fewer vitellogenic oocytes than controls. Although there are important fitness-related costs of direct exposure, the lack of mate selection based on disease risk suggests that more imminent ecological pressures (e.g., predators, desiccation) override the need for a careful and time-consuming assessment of a potential mate's health. PMID:22217773

  17. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M;

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...

  18. Planning with Partial Preference Models

    CERN Document Server

    Nguyen, Tuan; Gerevini, Alfonso; Serina, Ivan; Srivastava, Biplav; Kambhampati, Subbarao

    2011-01-01

    Current work in planning with preferences assume that the user's preference models are completely specified and aim to search for a single solution plan. In many real-world planning scenarios, however, the user probably cannot provide any information about her desired plans, or in some cases can only express partial preferences. In such situations, the planner has to present not only one but a set of plans to the user, with the hope that some of them are similar to the plan she prefers. We first propose the usage of different measures to capture quality of plan sets that are suitable for such scenarios: domain-independent distance measures defined based on plan elements (actions, states, causal links) if no knowledge of the user's preferences is given, and the Integrated Convex Preference measure in case the user's partial preference is provided. We then investigate various heuristic approaches to find set of plans according to these measures, and present empirical results demonstrating the promise of our app...

  19. Neural signatures of intransitive preferences

    Directory of Open Access Journals (Sweden)

    Tobias Kalenscher

    2010-06-01

    Full Text Available It is often assumed that decisions are made by rank-ordering and thus comparing the (subjective value of available choice options. Rank-ordering requires that alternatives are mentally represented at least on an ordinal scale. Because one alternative cannot be at the same time better or worse than another alternative, choices should satisfy transitivity (if alternative A is preferred over B, and B is preferred over C, A should be preferred over C. Yet, individuals often demonstrate striking violations of transitivity (preferring C over A. We used functional magnetic resonance imaging to study the neural correlates of intransitive choices between gambles varying in magnitude and probability of financial gains. Behavioral intransitivities were common. They occurred because participants did not evaluate the gambles independently, but in comparison with the alternative gamble presented. Neural value signals in prefrontal and parietal cortex were not ordinal-scaled and transitive, but reflected fluctuations in the gambles’ local, pairing-dependent preference-ranks. Detailed behavioural analysis of gamble preferences showed that, depending on the difference in the offered gambles’ attributes, participants gave variable priority to magnitude or probability and thus shifted between preferring richer or safer gambles. The variable, context-dependent priority given to magnitude and probability was tracked by insula (magnitude and posterior cingulate (probability. Their activation-balance may reflect the individual decision rules leading to intransitivities. Thus, the phenomenon of intransitivity is reflected in the organisation of the neural systems involved in risky decision-making.

  20. Female reproductive disorders

    DEFF Research Database (Denmark)

    Crain, D Andrew; Janssen, Sarah J; Edwards, Thea M;

    2008-01-01

    To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive disrupti......To evaluate the possible role of endocrine-disrupting compounds (EDCs) on female reproductive disorders emphasizing developmental plasticity and the complexity of endocrine-dependent ontogeny of reproductive organs. Declining conception rates and the high incidence of female reproductive...

  1. Employer recruitment preferences and discrimination: a stated preference experiment

    OpenAIRE

    Mc Quaid, Ronald; Bergmann, Ariel

    2008-01-01

    This paper presents a novel approach of applying stated preference methods in the field of labour economics. Differences in behaviour and labour market disadvantage are connected to the presence, and ages of children, the so-called „family gap‟. There are major difficulties in collecting accurate information about the recruiting practices of employers and identifying their preferences towards different characteristics of new recruits. Employer answers to direct questions may not illicit relia...

  2. Towards an improved variety assortment for the Dutch organic sector : case studies on onion and spring wheat

    NARCIS (Netherlands)

    Osman, A.M.

    2014-01-01

    Key words: organic farming; principles of organic agriculture; food production chain; plant breeding; genetic correlation; plant traits; farmers’ preferences; variety testing; Value for Cultivation and Use; EU seed legislation; onion; Allium cepa; spring wheat; Triticum aestivum; baking qualit

  3. Stated preference methods using R

    CERN Document Server

    Aizaki, Hideo; Sato, Kazuo

    2014-01-01

    Stated Preference Methods Using R explains how to use stated preference (SP) methods, which are a family of survey methods, to measure people's preferences based on decision making in hypothetical choice situations. Along with giving introductory explanations of the methods, the book collates information on existing R functions and packages as well as those prepared by the authors. It focuses on core SP methods, including contingent valuation (CV), discrete choice experiments (DCEs), and best-worst scaling (BWS). Several example data sets illustrate empirical applications of each method with R

  4. Endogenous scheduling preferences and congestion

    DEFF Research Database (Denmark)

    Fosgerau, Mogens; Small, Kenneth

    2010-01-01

    Dynamic models of congestion so far rely on exogenous scheduling preferences of travelers, based for example on disutility of deviation from a preferred departure or arrival time for a trip. This paper provides a more fundamental view in which travelers derive utility just from consumption and....... Compared to the predictions of an analyst observing untolled equilibrium and taking scheduling preferences as exogenous, we find that both the optimal capacity and the marginal external cost of congestion have changed. The benefits of tolling are greater, and the optimal time varying toll is different....

  5. Are Female Supervisors More Female-Friendly?

    OpenAIRE

    Steven Bednar; Dora Gicheva

    2014-01-01

    We introduce the idea that easily inferable demographic characteristics such as gender may not be sufficient to define type in the supervisor-employee mentoring relationship. We use longitudinal data on athletic directors at NCAA Division I programs to identify through observed mobility the propensity of top-level administrators to hire and retain female head coaches, above and beyond an organization's culture. We show that supervisor gender appears to be unrelated to female friendliness in t...

  6. Cotton Assorting Technical Standard and Application Research Based on HVI Data%基于HVI数据的配棉技术标准及应用研究

    Institute of Scientific and Technical Information of China (English)

    邱兆宝; 张红

    2012-01-01

    Cotton assorting technical standard and application effect based on HVI data were researched. Cotton assorting technical standard consisted by technical grade, coefficient of variation of technical grade, color grade, yellow degree coefficient of variation were introduced. Effects of raw cotton internal and external quality index to yarn quality were analyzed. The data show when yellow degree coefficient of variation exceed 12% ,yarn color difference will be larger. In this condition, the cotton assorting case is not feasible even if yarn quality forecast value can fit the demands. It is considered that technical standard and coefficient of variation of technical grade is related closely with yarn inner quality , color grade and yellow degree coefficient of variation effect yarn color difference directly. Cotton assorting technical standard is the important foundation of making cotton assorting case and designing yarn processing.%研究基于HVI数据的配棉技术标准及应用效果.介绍了由技术品级、技术品级变异系数、色特征级和黄度变异系数组成的配棉技术标准,分析了原棉内外在质量指标对成纱质量的影响.通过实例数据表明:当黄度变异系数超过12%时,成纱色差将逐渐加重,这时即便成纱质量预测值符合要求,其配棉方案也不可行.认为:技术品级和技术品级变异系数与成纱内在质量密切相关,色特征级和黄度变异系数对成纱的色差有直接影响.配棉技术标准是制订配棉方案和设计纺纱工艺的重要依据.

  7. Algorithm design and influence analysis of assortativity changing in given degree distribution%确定度分布条件下可变同配系数的算法构造与影响分析∗

    Institute of Scientific and Technical Information of China (English)

    李静; 张洪欣; 王小娟; 金磊

    2016-01-01

    Complex network is the abstract topology of a large number of nodes and edges in reality. How to reveal the influences of internal network topology on network connectivity and vulnerability characteristics is a hotspot of current research. In this paper, we analyze the influence of assortativity according to Newman’s definition of assortativity in a given degree distribution. To fully understand the influence of assortativity we should change the assortativity to see how the topology of network changes. But we find the existing greedy algorithm cannot improve assortativity effectively. First we put forward a deterministic algorithm based on degree distribution and an uncertain algorithm based on probability distribution to increase assortativity. The deterministic algorithm can create a certain network which has a large assortativity without changing node degree. The uncertain algorithm can increase the assortativity continuously by changing the connection of edges. And the uncertain algorithm creates different graphs each time, so the result of the algorithm is uncertain. Then we test our algorithms on three networks (ER network, BA network, Email network) and compare with greedy algorithm, and the experimental results show that the uncertain algorithm performs better than greedy algorithm in three networks which have a large span of assortativity. And our deterministic algorithm performs well in a real world network. We find that we can increase assortativity coefficient up to 1 in ER network. This is because nodes in the ER network are peer to peer. We can also show that that the assortativity cannot increase up to 1 in some networks because nodes in these networks are not in the same status. Because we obtain a large span of assortativity, we can fully understand the change of network topology. On this basis, we analyze the changes of clustering coefficient when using the uncertain algorithm based on a probability distribution to increase the assortativity

  8. Perceived stimulus complexity and food preference development.

    Science.gov (United States)

    Lévy, C M; MacRae, A; Köster, E P

    2006-11-01

    The importance of perceived complexity, a "collative property" as defined by [Berlyne, D. E. (1967). Arousal and reinforcement. In Nebraska symposium on motivation (pp. 1-110). University of Nebraska Press], to the dynamic development of preference was investigated. Eighty-six female and 82 male subjects rated their liking for and various collative properties of seven very similar orange drinks that differed only in perceived complexity as a result of adding small quantities of other flavours. This was done before and after giving each subject extended experience of one of the drinks, each being used equally often for this purpose. As predicted by the theory of [Dember, W. N., & Earl, R. W. (1957). Analysis of exploratory, manipulatory and curiosity behavior. Psychological Review, 64 (2), 91-96] exposure to a stimulus with a slightly higher complexity than an individual subject's optimally preferred level of perceived complexity, caused an upwards shift in that level, whereas exposure to a less complex stimulus had no such effect. Changes in the appreciation of the drinks predicted by the theory were also observed.

  9. First experimental evidence for female mate choice in a nocturnal primate.

    Science.gov (United States)

    Craul, Mathias; Zimmermann, Elke; Radespiel, Ute

    2004-10-01

    Female mate choice can be hypothesised in most nocturnal primates, since females show a higher investment in their offspring than males. The aim of this experimental study was to investigate if female grey mouse lemurs perform mate choice and whether age, relatedness (to the male), or male advertisement call activity systematically influence their decisions. A two-way mate choice design was developed in which females could choose between two males. Mate choice was deduced from the time spent in proximity to the males and from mating behaviour. During oestrus 12 of 17 females participated actively in the experiment and all of them showed either a significant spatial (n = 11) or behavioural (n = 1) preference for one male. In four cases copulations were observed. The influence of age on female mate choice was not statistically significant. In the cases with copulations, however, females mostly preferred the older male. This might indicate a preference for older age as an indicator of experience, fitness, and/or status. The influence of relatedness on female mate choice could not be definitely clarified. However, results imply a mechanism of kin recognition on the basis of familiarity. In the majority of choices, females preferred the male with higher trill call activity. Since trill call activity correlates with the relative dominance status of males, these results suggest an importance of the male dominance status for female mate choice in grey mouse lemurs. Altogether our findings indicate that females use a complex of different cues to choose their mates. PMID:15241637

  10. Stevia and Saccharin Preferences in Rats and Mice

    OpenAIRE

    Sclafani, Anthony; Bahrani, Mahsa; Zukerman, Steven; Ackroff, Karen

    2010-01-01

    Use of natural noncaloric sweeteners in commercial foods and beverages has expanded recently to include compounds from the plant Stevia rebaudiana. Little is known about the responses of rodents, the animal models for many studies of taste systems and food intake, to stevia sweeteners. In the present experiments, preferences of female Sprague–Dawley rats and C57BL/6J mice for different stevia products were compared with those for the artificial sweetener saccharin. The stevia component rebaud...

  11. Older breast cancer survivors' views and preferences for physical activity.

    Science.gov (United States)

    Whitehead, Sarah; Lavelle, Katrina

    2009-07-01

    Evidence suggests that physical activity improves quality of life and physical functioning among breast cancer patients and survivors. However, previous studies have tended to focus on younger patients, despite higher incidence and lower survival among older breast cancer survivors. In this study we explored physical activity preferences of older breast cancer survivors to inform the development of future targeted interventions. Twenty-nine female breast cancer survivors (1 to 5 years postdiagnosis) aged 59 to 86 (mean 66.54, SD 6.50) took part in either a semistructured interview or a focus group exploring physical activity patterns, motivators, facilitators, barriers, and preferences. The main factors influencing physical activity were body image, weight issues, vitality, mood, and the desire to carry on as normal. Preference was expressed for activities that were gentle, tailored to age and cancer-related abilities, holistic, involving other older breast cancer survivors, and with an instructor who was knowledgeable about both breast cancer and aging.

  12. Taste preference thresholds for Polycose, maltose, and sucrose in rats.

    Science.gov (United States)

    Sclafani, A; Nissenbaum, J W

    1987-01-01

    The taste preference thresholds of adult female rats for polysaccharide (Polycose), maltose, and sucrose were compared. The nondeprived animals were given 24-hr two-bottle preference tests (saccharide solution vs. water) and, starting at 0.008%, the saccharide concentration was increased daily. The rats first preferred the Polycose solution to water at 0.01% (0.0001 M), the maltose solution to water at 0.09% (0.0025 M), and the sucrose solution to water at 0.09% (0.0026 M). Thus, on a molar basis the rats' Polycose threshold was 25 to 26 times lower than their maltose and sucrose threshold. It was postulated that the low taste threshold for polysaccharides allows the rat to detect starch which, unlike sugar, is very low in solubility.

  13. Fairness State with Plastic Preferences

    CERN Document Server

    Barrios, E R; Barrios, Elena Ramirez; Ochoa, Juan G. Diaz

    2006-01-01

    The definition of preferences assigned to individuals is a concept that concerns many disciplines, from economics, with the search of an acceptable outcome for an ensemble of individuals, to decision making an analysis of vote systems. We are concerned in the phenomena of good selection and economic fairness. In Arrow's theorem this situation is expressed as the impossibility of aggregate preferences among individuals falling down into some unfairness state. This situation was also analyzed in a previous model in a network of individuals with a random allocation. Both analysis are based on static preferences. In a real society the individuals are confronted to information exchange which can modify the way that they think. Also, the preference formation of each individual is influenced by this exchange. This consideration reveals why the actual theory is not able to make an accurate analysis of the influence of the individual, or cluster of individuals, in the fairness state. The aim of this investigation is t...

  14. From preferred to actual mate characteristics: the case of human body shape.

    Science.gov (United States)

    Courtiol, Alexandre; Picq, Sandrine; Godelle, Bernard; Raymond, Michel; Ferdy, Jean-Baptiste

    2010-01-01

    The way individuals pair to produce reproductive units is a major factor determining evolution. This process is complex because it is determined not only by individual mating preferences, but also by numerous other factors such as competition between mates. Consequently, preferred and actual characteristics of mates obtained should differ, but this has rarely been addressed. We simultaneously measured mating preferences for stature, body mass, and body mass index, and recorded corresponding actual partner's characteristics for 116 human couples from France. Results show that preferred and actual partner's characteristics differ for male judges, but not for females. In addition, while the correlation between all preferred and actual partner's characteristics appeared to be weak for female judges, it was strong for males: while men prefer women slimmer than their actual partner, those who prefer the slimmest women also have partners who are slimmer than average. This study therefore suggests that the influences of preferences on pair formation can be sex-specific. It also illustrates that this process can lead to unexpected results on the real influences of mating preferences: traits considered as highly influencing attractiveness do not necessarily have a strong influence on the actual pairing, the reverse being also possible. PMID:20885953

  15. From preferred to actual mate characteristics: the case of human body shape.

    Directory of Open Access Journals (Sweden)

    Alexandre Courtiol

    Full Text Available The way individuals pair to produce reproductive units is a major factor determining evolution. This process is complex because it is determined not only by individual mating preferences, but also by numerous other factors such as competition between mates. Consequently, preferred and actual characteristics of mates obtained should differ, but this has rarely been addressed. We simultaneously measured mating preferences for stature, body mass, and body mass index, and recorded corresponding actual partner's characteristics for 116 human couples from France. Results show that preferred and actual partner's characteristics differ for male judges, but not for females. In addition, while the correlation between all preferred and actual partner's characteristics appeared to be weak for female judges, it was strong for males: while men prefer women slimmer than their actual partner, those who prefer the slimmest women also have partners who are slimmer than average. This study therefore suggests that the influences of preferences on pair formation can be sex-specific. It also illustrates that this process can lead to unexpected results on the real influences of mating preferences: traits considered as highly influencing attractiveness do not necessarily have a strong influence on the actual pairing, the reverse being also possible.

  16. 'Green' Preferences as Regulatory Policy

    OpenAIRE

    Brennan, Timothy

    2001-01-01

    We examine the suggestion that if consumers in sufficient numbers are willing to pay the premium to have power generated using low-emission technologies, tax or permit policies become less necessary or stringent. While there are implementation difficulties with this proposal, our purpose is more fundamental: can economics make sense of using preferences as a regulatory instrument? If “green” preferences are exogenously given, to what extent can or should they be regarded as a substitute for o...

  17. Alcohol demand and risk preference.

    Science.gov (United States)

    Dave, Dhaval; Saffer, Henry

    2008-12-01

    Both economists and psychologists have studied the concept of risk preference. Economists categorize individuals as more or less risk-tolerant based on the marginal utility of income. Psychologists categorize individuals' propensity towards risk based on harm avoidance, novelty seeking and reward dependence traits. The two concepts of risk are related, although the instruments used for empirical measurement are quite different. Psychologists have found risk preference to be an important determinant of alcohol consumption; however economists have not included risk preference in studies of alcohol demand. This is the first study to examine the effect of risk preference on alcohol consumption in the context of a demand function. The specifications employ multiple waves from the Panel Study of Income Dynamics (PSID) and the Health and Retirement Study (HRS), which permit the estimation of age-specific models based on nationally representative samples. Both of these data sets include a unique and consistent survey instrument designed to directly measure risk preference in accordance with the economist's definition. This study estimates the direct impact of risk preference on alcohol demand and also explores how risk preference affects the price elasticity of demand. The empirical results indicate that risk preference has a significant negative effect on alcohol consumption, with the prevalence and consumption among risk-tolerant individuals being 6-8% higher. Furthermore, the tax elasticity is similar across both risk-averse and risk-tolerant individuals. This suggests that tax policies are as equally effective in deterring alcohol consumption among those who have a higher versus a lower propensity for alcohol use. PMID:19956353

  18. Human preference for individual colors

    Science.gov (United States)

    Palmer, Stephen E.; Schloss, Karen B.

    2010-02-01

    Color preference is an important aspect of human behavior, but little is known about why people like some colors more than others. Recent results from the Berkeley Color Project (BCP) provide detailed measurements of preferences among 32 chromatic colors as well as other relevant aspects of color perception. We describe the fit of several color preference models, including ones based on cone outputs, color-emotion associations, and Palmer and Schloss's ecological valence theory. The ecological valence theory postulates that color serves an adaptive "steering' function, analogous to taste preferences, biasing organisms to approach advantageous objects and avoid disadvantageous ones. It predicts that people will tend to like colors to the extent that they like the objects that are characteristically that color, averaged over all such objects. The ecological valence theory predicts 80% of the variance in average color preference ratings from the Weighted Affective Valence Estimates (WAVEs) of correspondingly colored objects, much more variance than any of the other models. We also describe how hue preferences for single colors differ as a function of gender, expertise, culture, social institutions, and perceptual experience.

  19. Correlated Preferences for Male Facial Masculinity and Partner Traits in Gay and Bisexual Men in China.

    Science.gov (United States)

    Zheng, Lijun; Zheng, Yong

    2015-07-01

    Previous studies have documented the correlation between preferences for male facial masculinity and perceived masculinity: women who rate their male partner as more masculine tend to prefer more masculine faces. Men's self-rated masculinity predicts their female partner's preference for masculinity. This study examined the association between other trait preferences and preference for male facial masculinity among 556 gay and bisexual men across multiple cities in China. Participants were asked to choose the three most important traits in a romantic partner from a list of 23 traits. Each participant was then asked to choose a preferred face in each of 10 pairs of male faces presented sequentially, with each pair consisting of a masculinized and feminized version of the same base face. The results indicated that preferences for health and status-related traits were correlated with preferences for male facial masculinity in gay and bisexual men in China; individuals who were more health- or status-oriented in their preferences for a romantic partner preferred more masculine male faces than individuals with lower levels of these orientations. The findings have implications for the correlated preferences for facial masculinity and health- and status-related traits and may be related to perceived health and dominance/aggression of masculine faces based on a sample of non-Western gay and bisexual men.

  20. Along came a spider who sat down beside her: Perceived predation risk, but not female age, affects female mate choosiness.

    Science.gov (United States)

    Atwell, Ashley; Wagner, William E

    2015-06-01

    Organisms often exhibit behavioral plasticity in response to changes in factors, such as predation risk, mate density, and age. Particularly, female mate choosiness (the strength of female's attraction to male traits as they deviate from preferred trait values) has repeatedly been shown to be plastic. This is due to the costs associated with searching for preferred males fluctuating with changes in such factors. Because these factors can interact naturally, it is important to understand how female mate choosiness responds to these interactions. We studied the interaction between perceived predation risk and female age on the variable field cricket, Gryllus lineaticeps. Females were either exposed or not exposed to predation cues from a sympatric, cursorial, wolf spider predator, Hogna sp. We then tested the females at one of three adult ages and measured their choosiness by recording their responsiveness to a low quality male song. We found female choosiness plasticity was affected by neither age nor the interaction between age and perceived predation risk. Perceived predation risk was the only factor to significantly affect the plasticity of female mate choosiness: females were less choosy when they perceived predation risk and were more choosy when they did not. Predation may be such a strong source of selection that, regardless of differences in other factors, most individuals respond similarly. PMID:25857998