71 resultados para University of Michigan. College of Literature, Science and the Arts
Resumo:
Beds of nonattached coralline algae (maerl or rhodoliths) are widespread and considered relatively species rich. This habitat is generally found in areas where there is chronic physical disturbance such that maerl thalli are frequently moved. Little is known, however, about how natural disturbance regimes affect the species associated with maerl. This study compared the richness, animal abundance, and algal biomass of maerl-associated species over a two-year period in a wave-disturbed bed and a sheltered maerl bed. Changes in associated species over time were assessed for departures from a neutral model in which the dissimilarity between samples reflects random sampling from a common species pool. Algal biomass and species richness at the wave-exposed site and on stabilized maerl at the sheltered site were reduced at times of higher wind speeds. The changes in species richness were not distinguishable from a neutral model, implying that algal species were added at random to the assemblage as the level of disturbance lessened. Results for animal species were more mixed. Although mobile species were less abundant during windy periods at the exposed site, both neutral and non-neutral patterns were evident in the assemblages. Artificial stabilization of maerl had inconsistent effects on the richness of animals but always resulted in more attached algal species. While the results show that the response of a community to disturbance can be neutral, the domain of neutral changes in communities may be relatively small. Alongside non-neutral responses to natural disturbance, artificial stabilization always resulted in an assemblage that was more distinct than would be expected under random sampling from a common pool. Community responses to stabilization treatments did not consistently follow the predictions of the dynamic equilibrium model, the intermediate disturbance model, or a facilitation model. These inconsistencies may reflect site-specific variation in both the disturbance regime and the adjacent habitats that provide source populations for many of the species found associated with maerl.
Resumo:
In the JFS case, the Supreme Court of the United Kingdom held that the admissions policy of a Jewish faith school constituted unlawful racial discrimination because it used the Orthodox Jewish interpretation of who is Jewish as a criterion for determining admission to the school. A detailed discussion of the case is located in the context of two broader debates in Britain, which are characterized as constitutional in character or, at least, as possessing constitutional properties. The first is the debate concerning the treatment of minority groups, multiculturalism, and the changing perceptions in public policy of the role of race and religion in national life. It is suggested that this debate has become imbued with strong elements of what has been termed “post-multiculturalism”. The second debate is broader still, and pertains to shifting approaches to “constitutionalism” in Britain. It is suggested that, with the arrival of the European Convention on Human Rights and EU law, the U.K. has seen a shift from a pragmatic approach to constitutional thinking, in which legislative compromise played a key part, to the recognition of certain quasi-constitutional principles, allowing the judiciary greatly to expand its role in protecting individual rights while requiring the judges, at the same time, to articulate a principled basis for doing so. In both these debates, the principle of equality plays an important role. The JFS case is an important illustration of some of the implications of these developments.