47 resultados para dominance parétienne
em University of Queensland eSpace - Australia
Resumo:
The diversity and community structures of symbiotic dinoflagellates are described from reef invertebrates in southern and central provinces of the Great Barrier Reef (GBR), Australia, and Zamami Island, Okinawa, Japan. The symbiont assemblages from region to region were dominated by Clade C Symbiodinium spp. and consisted of numerous host-specific and/or rare types (specialists), and several types common to many hosts (generalists). Prevalence in the host community among certain host-generalist symbionts differed between inshore and offshore environments, across latitudinal (central versus southern GBR) gradients, and over wide geographic ranges (GBR versus Okinawa). One particular symbiont (C3h) from the GBR had a dramatic shift in dominance. Its prevalence ranged from being extremely rare, or absent on high-latitude reefs to dominating the scleractinian diversity on a mid-latitude inshore reef. These changes occurred among coral fauna whose larvae must acquire symbionts from environmental sources (horizontal symbiont acquisition). Such differences did not occur among 'vertical transmitters' such as Porites spp., Montipora spp. and pocilloporids (corals that directly transmit symbionts to their offspring) or among those hosts displaying 'horizontal acquisition', but that associate with specific symbionts. Most host-specialized types were found to be characteristic of a particular geographic region (i.e. Okinawa versus Central GBR versus Southern GBR). The mode of symbiont acquisition may play an important role in how symbiont composition may shift in west Pacific host communities in response to climate change. There is no indication that recent episodes of mass bleaching have provoked changes in host-symbiont combinations from the central GBR.
Resumo:
We examined the role of cytokinins (CKs) in release of apical dominance in lateral buds of chickpea (Cicer arietinum L.). Shoot decapitation or application of CKs (benzyladenine, zeatin or dihydrozeatin) stimulated rapid bud growth. Time-lapse video recording revealed growth initiation within 2 h of application of 200 pmol benzyladenine or within 3 h of decapitation. Endogenous CK content in buds changed little in the first 2 h after shoot decapitation, but significantly increased by 6 h, somewhat later than the initiation of bud growth. The main elevated CK was zeatin riboside, whose content per bud increased 7-fold by 6 h and 25-fold by 24 h. Lesser changes were found in amounts of zeatin and isopentenyl adenine CKs. We have yet to distinguish whether these CKs are imported from the roots via the xylem stream or are synthesised in situ in the buds, but CKs may be part of an endogenous signal involved in lateral bud growth stimulation following shoot decapitation. To our knowledge, this is the first detailed report of CK levels in buds themselves during release of apical dominance.
Resumo:
Suggests that one's sense of one's self and one's sexuality may also have a close relationship to non-fiction texts about gay and lesbian cultures. Reliance of people's sense of being gay on literary representations; Popularity and authority of the book "Queer Theory," by Annamarie Jagose; Disagreements that characterize lesbian and gay historiography in Australia.
Resumo:
Differences between island- and mainland-dwelling forms provide several classic ecological puzzles. Why, for instance, are island-dwelling passerine birds consistently larger than their mainland counterparts? We examine the 'Dominance hypothesis', based on intraspecific competition, which states that large size in island passerines evolves through selection for success in agonistic encounters. We use the Heron Island population of Capricorn silvereyes (Zosterops lateralis chlorocephalus), a large-bodied island-dwelling race of white-eye (Zosteropidae), to test three assumptions of this hypothesis; that (i) large size is positively associated with high fitness, (ii) large size is associated with dominance, and (iii) the relationship between size and dominance is particularly pronounced under extreme intraspecific competition. Our results supported the first two of these assumptions, but provided mixed evidence on the third. On balance, we suggest that the Dominance Hypothesis is a plausible mechanism for the evolution of large size of island passerines, but urge further empirical tests on the role of intraspecific competition on oceanic islands versus that on mainlands.
Resumo:
Plant breeders use many different breeding methods to develop superior cultivars. However, it is difficult, cumbersome, and expensive to evaluate the performance of a breeding method or to compare the efficiencies of different breeding methods within an ongoing breeding program. To facilitate comparisons, we developed a QU-GENE module called QuCim that can simulate a large number of breeding strategies for self-pollinated species. The wheat breeding strategy Selected Bulk used by CIMMYT's wheat breeding program was defined in QuCim as an example of how this is done. This selection method was simulated in QuCim to investigate the effects of deviations from the additive genetic model, in the form of dominance and epistasis, on selection outcomes. The simulation results indicate that the partial dominance model does not greatly influence genetic advance compared with the pure additive model. Genetic advance in genetic systems with overdominance and epistasis are slower than when gene effects are purely additive or partially dominant. The additive gene effect is an appropriate indicator of the change in gene frequency following selection when epistasis is absent. In the absence of epistasis, the additive variance decreases rapidly with selection. However, after several cycles of selection it remains relatively fixed when epistasis is present. The variance from partial dominance is relatively small and therefore hard to detect by the covariance among half sibs and the covariance among full sibs. The dominance variance from the overdominance model can be identified successfully, but it does not change significantly, which confirms that overdominance cannot be utilized by an inbred breeding program. QuCim is an effective tool to compare selection strategies and to validate some theories in quantitative genetics.
Resumo:
Sexual selection involves two main mechanisms: intrasexual competition for mates and intersexual mate choice. We experimentally separated intrasexual (male-male interference competition) and intersexual (female choice) components of sexual selection in a freshwater fish, the European bitterling (Rhodeus sericeus). We compared the roles of multiple morphological and behavioural traits in male success in both components of sexual competition, and their relation to male reproductive success, measured as paternity of offspring. Body size was important for both female choice and male-male competition, though females also preferred males that courted more vigorously. However, dominant males often monopolized females regardless of female preference. Subordinate males were not excluded from reproduction and sired some offspring, possibly through sneaked ejaculations. Male dominance and a greater intensity of carotenoid-based red colouration in their iris were the best predictors of male reproductive success. The extent of red iris colouration and parasite load did not have significant effects on female choice, male dominance or male reproductive success. No effect of parasite load on the expression of red eye colouration was detected, though this may have been due to low parasite prevalence in males overall. In conclusion, we showed that even though larger body size was favoured in both intersexual and intrasexual selection, male-male interference competition reduced opportunities for female choice. Females, despite being choosy, had limited control over the paternity of their offspring. Our study highlights the need for reliable measures of male reproductive success in studies of sexual selection.
Resumo:
Ethological studies of animals in groups and sociobiology indicate that hierarchies of dominance amongst some species ensure the survival of the group. When transferred to human groups, dominance hierarchies suggest a crucial role played by recasting the scope of such hierarchies of dominant and subordinate members to included hyper-dominant beings. A recognition of such beings as even more dominant than the socially dominant members of a hierarchy facilitates the empowerment of the socially subordinate members. Religious belief and practice works to establish such hyper-dominant beings (gods, goddesses, and so forth) as superior members of human groups. Doing so is a means of ensuring the survival of the species and, thus, enhancing healing and human health. The doctor-patient relationship is examined from such a point of view, with an emphasis on whether the hierarchy created by the relationship allows consideration of alternative and complementary forms of medical treatment.
Resumo:
Crises persist in Australian Indigenous affairs because current policy approaches do not address the intersection of Indigenous and European political worlds. This paper responds to this challenge by providing a heuristic device for delineating Settler and Indigenous Australian political ontologies and considering their interaction. It first evokes Settler and Aboriginal ontologies as respectively biopolitical (focused through life) and terrapolitical (focused through land). These ideal types help to identify important differences that inform current governance challenges. The paper discusses the entwinement of these traditions as a story of biopolitical dominance wherein Aboriginal people are governed as an “included-exclusion” within the Australian political community. Despite the overall pattern of dominance, this same entwinement offers possibilities for exchange between biopolitics and terrapolitics, and hence for breaking the recurrent crises of Indigenous affairs.
Resumo:
Examines empirically the relative influence of the degree of endangerment of wildlife species and their stated likeability on individuals’ willingness to pay (WTP) for their conservation. To do this, it utilises data obtained from the IUCN Red List and likeability and WTP data obtained from two serial surveys of a sample of the Australian public who were requested to assess 24 Australian wildlife species in each of three animal classes: mammals, birds and reptiles. Between the first and second survey, respondents were provided with extra information about the focal species. This information resulted in the clear dominance of endangerment as the major influence on the WTP of respondents for the conservation of the focal wildlife species. Our results throw doubts on the proposition in the literature that the likeability of species is the dominant influence on WTP for conservation of wildlife species. Furthermore, our results suggest that the relationship between WTP for the conservation of wildlife in relation to their population levels may be more complex and different to that suggested in some of the literature on ecological economics.
Resumo:
Researchers within the field of cultural imperialism as well as the more recently developed globalisation paradigm have tended to dwell upon the economic or corporate dimensions of global cultural flows and have been largely indifferent to the domain of the everyday cultural tastes and forms of cultural consumption that exist in particular national contexts. This article seeks to redress this focus through an examination of one particular instance of cultural imperialism, the widely held belief in ?he Americanisation of Australian society. Using data from a major research project inquiring into Australian everyday culture the article focuses on the changes in cultural tastes and preferences that are evident in three generational cohorts: contemporary young adults, a segment of the 'baby-boom' generation now in middle age, and a group of older Australians born in the years following World War I and the 1920s. The article documents a trend in which overseas influences, particularly those originating from America, appear to be increasingly shaping Australians' tastes in a wide range of cultural domains. Nevertheless, despite these changes in cultural taste Australians of ail ages retain a strong sense of a distinctive national identity. Such findings have implications for an understanding of cultural globalisation as a process of hybridisation and intermixing.
Resumo:
At the present time, it is clear that Th1 responses afford protection against the fungi; however, the development, maintenance and function of the protective immune responses are complex mechanisms and are influenced by multiple factors. The route of infection has been shown to affect initial cytokine production and, consequently, the induction of protective Th1 responses. The ability of different isolates of the same fungal agent to induce and sustain a protective response has also been emphasized. Protective immune responses have been shown to vary in genetically different mouse strains after infection. In addition, these protective responses, such as cellular influx and cytokine production, also vary within the same animal depending on the tissue infected. The functional dominance of certain cytokines over others in influencing development and maintenance of protective responses has been discussed. Certain cytokines may act differently in hosts lacking important components of their innate or immune repertoire. It is evident from these presentations that a more comprehensive understanding of the protective mechanisms against different fungal agents is emerging. However, there is still much to learn before cytokine modulatory therapy can be used effectively without risk in the human host.
Resumo:
In the first of three experiments, 11 participants generated pronation and supination movements of the forearm, in time with an auditory metronome. The metronome frequency was increased in eight steps (0.25 Hz) from a base frequency of 1.75 Hz. On alternating trials, participants were required to coordinate either maximum pronation or maximum supination with each beat of the metronome. In each block of trials, the axis of rotation was either coincident with the long axis of the forearm, above this axis, or below this axis. The stability of the pronate-on-the-beat pattern, as indexed by the number of pattern changes, and the time of onset of pattern change, was greatest when the axis of rotation of the movement was below the long axis of the forearm. In contrast, the stability of the supinate-on-the-beat pattern was greatest when the axis of rotation of the movement was above the long axis of the forearm. In a second experiment, we examined how changes in the position of the axis of rotation alter the activation patterns of muscles that contribute to pronation and supination of the forearm. Variations in the relative dominance of the pronation and supination phases of the movement cycle across conditions were accounted for primarily by changes in the activation profile of flexor carpi radialis (FCR) and extensor carpi radialis longus (ECR). In the Final experiment we examined how these constraints impact upon the stability of bimanual coordination. Thirty-two participants were assigned at random to one of four conditions, each of which combined an axis of rotation configuration (bottom or top) for each limb. The participants generated both inphase (both limbs pronating simultaneously, and supinating simultaneously) and antiphase (left limb pronating and right limb supinating simultaneously, and vice versa) patterns of coordination. When the position of the axis of rotation was equivalent for the left and the right limb, transitions from antiphase to inphase patterns of coordination were Frequently observed. In marked contrast, when the position of the axis of rotation for the left and right limb was contradistinct, transitions From inphase to antiphase patterns of coordination occurred. The results demonstrated that when movements are performed in an appropriate mechanical context, inphase patterns of coordination are less stable than antiphase patterns.
Resumo:
The authors argue that complementary hostile and benevolent components of sexism exist across cultures. Male dominance creates hostile sexism IHS), but men's dependence on women fosters benevolent sexism (BS)-subjectively positive attitudes that put women on a pedestal but reinforce their subordination. Research with 15,000 men and women in 19 nations showed that (a) HS and BS are coherent constructs that correlate positively across nations, but (b) HS predicts the ascription of negative and BS the ascription of positive traits to women, (c) relative to men, women are more likely to reject HS than BS, especially when overall levels of sexism in a culture are high, and (d) national averages on BS and HS predict gender inequality across nations. These results challenge prevailing notions of prejudice as an antipathy in that BS tan affectionate, patronizing ideology) reflects inequality and is a cross-culturally pervasive complement to HS.