Structure variation and evolution in microphase-separated grafted diblock copolymer films

The phase behavior of grafted d-polystyrene-block-poly(methyl methacrylate) diblock copolymer films is examined, with particular focus on the effect of solvent and annealing time. It was observed that the films undergo a two-step transformation from an initially disordered state, through an ordered metastable state, to the final equilibrium configuration. It was also found that altering the solvent used to wash the films, or complete removal of the solvent prior to thermal annealing using supercritical CO2, could influence the structure of the films in the metastable state, though the final equilibrium state was unaffected. To aid in the understanding to these experimental results, a series of self-consistent field theory calculations were done on a model diblock copolymer brush containing solvent. Of the different models examined, those which contained a solvent selective for the grafted polymer block most accurately matched the observed experimental behavior. We hypothesize that the structure of the films in the metastable state results from solvent enrichment of the film near the film/substrate interface in the case of films washed with solvent or faster relaxation of the nongrafted block for supercritical CO2 treated (solvent free) films. The persistence of the metastable structures was attributed to the slow reorganization of the polymer chains in the absence of solvent.

Flooding, resettlement and change in livelihoods: evidence from rural Mozambique

Post-disaster development policies, such as resettlement, can have major impacts on communities. This article concerns how and why people's livelihoods change as a result of resettlement, and what relocated people's views of such changes are, in the context of natural disasters. It presents two historically-grounded, comparative case studies of post-flood resettlement in rural Mozambique. The studies show a movement away from rain-fed subsistence agriculture towards commercial agriculture and non-agricultural activities. Ability to secure a viable livelihood was a major determinant of whether resettlers remained in their new locations or returned to the river valleys despite the risks that floods posed. The findings suggest that more research is required into 1) understanding why resettlers choose to stay in or abandon designated resettlement areas; 2) what is meant by 'voluntary' and 'involuntary' resettlement in the context of post-disaster reconstruction; and 3) what the policy drivers for resettlement are in developing countries.

Choices, chance and change: luck egalitarianism over time

The family of theories dubbed ‘luck egalitarianism’ represent an attempt to infuse egalitarian thinking with a concern for personal responsibility, arguing that inequalities are just when they result from, or the extent to which they result from, choice, but are unjust when they result from, or the extent to which they result from, luck. In this essay I argue that luck egalitarians should sometimes seek to limit inequalities, even when they have a fully choice-based pedigree (i.e., result only from the choices of agents). I grant that the broad approach is correct but argue that the temporal standpoint from which we judge whether the person can be held responsible, or the extent to which they can be held responsible, should be radically altered. Instead of asking, as Standard (or Static) Luck Egalitarianism seems to, whether or not, or to what extent, a person was responsible for the choice at the time of choosing, and asking the question of responsibility only once, we should ask whether, or to what extent, they are responsible for the choice at the point at which we are seeking to discover whether, or to what extent, the inequality is just, and so the question of responsibility is not settled but constantly under review. Such an approach will differ from Standard Luck Egalitarianism only if responsibility for a choice is not set in stone – if responsibility can weaken then we should not see the boundary between luck and responsibility within a particular action as static. Drawing on Derek Parfit’s illuminating discussions of personal identity, and contemporary literature on moral responsibility, I suggest there are good reasons to think that responsibility can weaken – that we are not necessarily fully responsible for a choice for ever, even if we were fully responsible at the time of choosing. I call the variant of luck egalitarianism that recognises this shift in temporal standpoint and that responsibility can weaken Dynamic Luck Egalitarianism (DLE). In conclusion I offer a preliminary discussion of what kind of policies DLE would support.

Revisiting Asian monsoon formation and change associated with Tibetan Plateau forcing: II. Change

Data analysis based on station observations reveals that many meteorological variables averaged over the Tibetan Plateau (TP) are closely correlated, and their trends during the past decades are well correlated with the rainfall trend of the Asian summer monsoon. However, such correlation does not necessarily imply causality. Further diagnosis confirms the existence of a weakening trend in TP thermal forcing, characterized by weakened surface sensible heat flux in spring and summer during the past decades. This weakening trend is associated with decreasing summer precipitation over northern South Asia and North China and increasing precipitation over northwestern China, South China, and Korea. An atmospheric general circulation model, the HadAM3, is employed to elucidate the causality between the weakening TP forcing and the change in the Asian summer monsoon rainfall. Results demonstrate that a weakening in surface sensible heating over the TP results in reduced summer precipitation in the plateau region and a reduction in the associated latent heat release in summer. These changes in turn result in the weakening of the near-surface cyclonic circulation surrounding the plateau and the subtropical anticyclone over the subtropical western North Pacific, similar to the results obtained from the idealized TP experiment in Part I of this study. The southerly that normally dominates East Asia, ranging from the South China Sea to North China, weakens, resulting in a weaker equilibrated Sverdrup balance between positive vorticity generation and latent heat release. Consequently, the convergence of water vapor transport is confined to South China, forming a unique anomaly pattern in monsoon rainfall, the so-called “south wet and north dry.” Because the weakening trend in TP thermal forcing is associated with global warming, the present results provide an effective means for assessing projections of regional climate over Asia in the context of global warming.

Revisiting Asian monsoon formation and change associated with Tibetan Plateau forcing: I. Formation

Numerical experiments with different idealized land and mountain distributions are carried out to study the formation of the Asian monsoon and related coupling processes. Results demonstrate that when there is only extratropical continent located between 0 and 120°E and between 20/30°N and the North Pole, a rather weak monsoon rainband appears along the southern border of the continent, coexisting with an intense intertropical convergence zone (ITCZ). The continuous ITCZ surrounds the whole globe, prohibits the development of near-surface cross-equatorial flow, and collects water vapor from tropical oceans, resulting in very weak monsoon rainfall. When tropical lands are integrated, the ITCZ over the longitude domain where the extratropical continent exists disappears as a consequence of the development of a strong surface cross-equatorial flow from the winter hemisphere to the summer hemisphere. In addition, an intense interaction between the two hemispheres develops, tropical water vapor is transported to the subtropics by the enhanced poleward flow, and a prototype of the Asian monsoon appears. The Tibetan Plateau acts to enhance the coupling between the lower and upper tropospheric circulations and between the subtropical and tropical monsoon circulations, resulting in an intensification of the East Asian summer monsoon and a weakening of the South Asian summer monsoon. Linking the Iranian Plateau to the Tibetan Plateau substantially reduces the precipitation over Africa and increases the precipitation over the Arabian Sea and the northern Indian subcontinent, effectively contributing to the development of the South Asian summer monsoon.

Linguistic interfaces and language acquisition in childhood: introduction to the special issue

Much contemporary L1 acquisition theory and empirical research are guided by the hypothesis that acquisition delays in children are often related to the integration of information across grammatical and other cognitive modules, such as syntax and discourse-pragmatics (see e.g., Grinstead, 2010). This special issue brings together cutting edge research from all relevant paradigms addressing interface issues in child language acquisition and provides a platform for the study of the interaction between different levels of linguistic knowledge. In this introduction, we present the reader with the tools needed to best understand the contributions of the individual studies and what they bring to bear on larger theoretical questions as a collective.

Linguistic epistemology and the notion of monolingualism

This article has several interrelated goals, all of which relate to an attempt at understanding why monolingualism is taken to be the default norm in linguistic inquiry (from sociolinguistics to formal linguistic theorizing). With others, I will take the position that comparing instances of multilingualism to so-called monolingualism is an unfair and inevitably inaccurate comparison since, among other variables, the social environments and access to input of multilinguals compared to monolinguals is most often unavoidably different (cf. Cruz-Ferreira 2006; Edwards 2004). Additionally, I will attempt to demonstrate that even so-called monolinguals have access to a variety of grammars related to different registers of speech and, therefore, are not truly monolingual in the sense that they poses one monolithic grammatical competence. Taken together, the present discussion questions both the default status of monolingualism as well as the functional adequacy of the term monolingualism.

The impact of overseas training on curriculum innovation and change in English language education in Western China

This article assesses the impact of a UK-based professional development programme on curriculum innovation and change in English Language Education (ELE) in Western China. Based on interviews, focus group discussions and observation of a total of 48 English teachers who had participated in an overseas professional development programme influenced by modern approaches to education and ELE, and 9 of their colleagues who had not taken part, it assesses the uptake of new approaches on teachers’ return to China. Interviews with 10 senior managers provided supplementary data. Using Diffusion of Innovations Theory as the conceptual framework, we examine those aspects of the Chinese situation that are supportive of change and those that constrain innovation. We offer evidence of innovation in classroom practice on the part of returnees and ‘reinvention’ of the innovation to ensure a better fit with local needs. The key role of course participants as opinion leaders in the diffusion of new ideas is also explored. We conclude that the selective uptake of this innovation is under way and likely to be sustained against a background of continued curriculum reform in China.

Linguistic experiments and ordinary language philosophy

J.L. Austin is regarded as having an especially acute ear for fine distinctions of meaning overlooked by other philosophers. Austin employs an informal experimental approach to gathering evidence in support of these fine distinctions in meaning, an approach that has become a standard technique for investigating meaning in both philosophy and linguistics. In this paper, we subject Austin's methods to formal experimental investigation. His methods produce mixed results: We find support for his most famous distinction, drawn on the basis of his `donkey stories', that `mistake' and `accident' apply to different cases, but not for some of his other attempts to distinguish the meaning of philosophically significant terms (such as `intentionally' and `deliberately'). We critically examine the methodology of informal experiments employed in ordinary language philosophy and much of contemporary philosophy of language and linguistics, and discuss the role that experimenter bias can play in influencing judgments about informal and formal linguistic experiments.