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Extensive land-use by pastoralists and their livestock in arid lands can enhance biodiversity and support the long-term conservation of important wildlife habitats. Pastoralists are sophisticated and dynamic managers of their natu...
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Extensive land-use by pastoralists and their livestock in arid lands can enhance biodiversity and support the long-term conservation of important wildlife habitats. Pastoralists are sophisticated and dynamic managers of their natural resource base and they employ elaborate land use strategies for conserving species and important habitats. However, the institutions, knowledge and practices that enable pastoralists to conserve and enhance arid lands have been seriously compromized by inappropriate policies and development interventions. Furthermore, while the social and environmental arguments highlighting the conservation outcomes of mobile pastoralism are numerous and convincing, pastoralists continue to compete with the conservation movement for land and key resources. Policy makers and conservationists are now beginning to recognize the compatibility of pastoralism and conservation. This paper describes how pastoralism can enhance biodiversity and the conservation of wildlife and arid land resources, and how future policy changes could become more supportive of pastoralism and its conservation outcomes.
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Whether people appreciate the importance of saving for the future, and whether they intend to do so, are not well understood. On the basis of a representative sample of UK residents, we show that the perceived importance of pensio...
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Whether people appreciate the importance of saving for the future, and whether they intend to do so, are not well understood. On the basis of a representative sample of UK residents, we show that the perceived importance of pension planning is positively correlated with respondents' risk tolerance, age, and income, and whether their spouses participate in employer-sponsored pension plans. Those less likely to believe planning for the future is important are younger, earn less, are women, and will rely upon others for their expected retirement welfare. It is also apparent that generic sources of information provided remotely or at the national scale for individual and household pension planning, preparedness, and knowledge of annuities do not stand comparison with the perceived value of intimate and specialist advisory relationships. The unit of retirement planning is typically the household; it rarely functions at the region and national scales. To understand these findings better we frame their interpretation with reference to recent behavioural research that emphasises people's limited cognitive and social resources and the use of heuristics such as salience in setting priorities. Our findings have important implications for the scope and significance of the relational turn in economic geography.
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For almost two decades, politicians have been negotiating temperature limits to which anthropogenic global warming should be restricted, and 2 °C has emerged as benchmark for danger. However, there has been a lack of scientific r...
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For almost two decades, politicians have been negotiating temperature limits to which anthropogenic global warming should be restricted, and 2 °C has emerged as benchmark for danger. However, there has been a lack of scientific research into the implications of such a change for African climate. This study aims to provide information for mitigation debates; through an examination of temperature and precipitation changes in Africa associated with 1 °C, 2 °C, 3 °C, and 4 °C of global warming. Datafrom Global Climate Models show little significant precipitation change at 1 °C, then larger anomalies at 2 °C which are strengthened and extended at 3 °C and 4 °C, including a wet signal in East Africa, and dry signals in Southern Africa, the Guinea Coast, and the west of the Sahel. Some of the models project changes with potential for severe societal implications. Despite the uncertainty attached to these projections, they highlight risks associated with 2 °C and beyond. Using these findings asa framework for impact assessment and evaluation, further research has the potential to uncover the implications of global warming for African regions.
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The re-establishment of soil-crust lichens following disturbances may be enhanced or discouraged by human-altered microtopographies. This research asks whether such microtopographic changes alter microclimates significantly, and w...
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The re-establishment of soil-crust lichens following disturbances may be enhanced or discouraged by human-altered microtopographies. This research asks whether such microtopographic changes alter microclimates significantly, and whether changes affect metabolically active periods of recolonizing lichens. In the fog-driven Namib Desert, the water relations of five lichen species were investigated and photosynthetic activity (PSII) was assessed via chlorophyll a fluorescence under natural and altered conditions, based on measured microclimates in vehicular disturbances. Surface temperatures in vehicle tracks were significantly higher than controls by up to 2 degrees C. Fog deposition was significantly lower in tracks, and evaporation rates were higher. Foliose and fruticose lichens retained fog moisture for long periods, and carried out PSII at low relative moisture contents. Desiccation rates of lichens were estimated to increase by 36% in tracks, which reduces PSII durations by as much as 50% in the critical hours following sunrise. Lecidella crystallina was least affected due to a pre-existing low water-holding capacity. Extreme temperatures (>45 degrees C) halted PSII in certain species. These results illustrate the importance of temperature-moisture ratios on desert soil surfaces. Reduced periods of photosynthesis caused by human-induced microtopographic changes, as predicted here, may have important ecological implications by reducing productivity in lichen communities..
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The aim of this article is to assess the connections between the continued expansion of forms of insecure work and the impact of rising numbers of economic migrants employed in UK labour markets. It shows how competition between f...
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The aim of this article is to assess the connections between the continued expansion of forms of insecure work and the impact of rising numbers of economic migrants employed in UK labour markets. It shows how competition between foreign-born workers for jobs in the UK is currently being recast by changes in the jobs available, in forms of precarious labour market attachment and by new patterns of migration into the UK since EU expansion in 2004. The article documents the ways in which migrants with different sets of social characteristics (nationality, gender and skin colour) and different sets of legal entitlements (legal citizenship, EU membership and entitlement to residence) are differentially placed in their competition for some of the poorest jobs in the British economy, drawing on an empirical study of the migrant divisions of labour emerging in two significant sectors in the service industries. It concludes by arguing that new and deeper divisions are emerging between foreign-born workers in the UK.
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Optically stimulated luminescence (OSL) dating of dune deposits has increasingly been used as a tool to investigate the response of aeolian systems to environmental change. Amalgamation of individual dune accumulation chronologies...
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Optically stimulated luminescence (OSL) dating of dune deposits has increasingly been used as a tool to investigate the response of aeolian systems to environmental change. Amalgamation of individual dune accumulation chronologies has been employed in order to distinguish regional from local geomorphic responses to change. However, advances in dating have produced chronologies of increasing complexity. In particular, questions regarding the interpretation of dune ages have been raised, including over the most appropriate method to evaluate the significance of suites of OSL ageswhen local 'noisy' and discontinuous records are combined. In this paper, these issues are reviewed and the reproducibility of dune chronologies is assessed. OSL ages fromtwo cores sampled from the same dune in the northeast Rub' al Khali, United Arab Emirates, are presented and compared, alongside an analysis of previously published dune ages dated towithin the last 30 ka. Distinct periods of aeolian activity and preservation are identified, which can be tied to regional climatic and environmental changes. This case study is used to address fundamental questions that are persistently asked of dune dating studies, including the appropriate spatial scale overwhich to infer environmental and climatic change based on dune chronologies, whether chronological hiatuses can be interpreted, howtomost appropriately combine and display datasets, and the relationship between geomorphic and palaeoclimatic signals. Chronological profiles reflect localised responses to environmental variability and climatic forcing, and amalgamation of datasets, with consideration of sampling resolution, is required; otherwise local factors are always likely to dominate. Using net accumulation rates to display ages may provide an informative approach of analysing and presenting dune OSL chronologies less susceptible to biases resulting from insufficient sampling resolution.
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One of the fundamental questions in the reconstruction of Quaternary dryland environmental conditions is: what do dune OSL ages mean in terms of palaeoenvironmental change? This paper investigates the relationship between dune chr...
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One of the fundamental questions in the reconstruction of Quaternary dryland environmental conditions is: what do dune OSL ages mean in terms of palaeoenvironmental change? This paper investigates the relationship between dune chronological records and external environmental forcing in the southern Arabian Peninsula during the last 30 ka. Aeolian records from the region are reviewed with reference to other regional palaeoenvironmental proxies, and these findings are related to a modelled assessment of dune response to the aeolian system state of the northeastern Rub' al Khali. The model replicates a range of features of the regional dune chronology when forced by three external parameters (sediment supply, sediment availability, and transport capacity), including extensive regional dune accumulation during the late PleistoceneeHolocene transition and reduced activity during the early Holocene humid period. Dune chronologies incorporate the influence of both external forcing parameters and localised shortterm factors included as stochastic processes. Thick sedimentary units most likely represent external forcing conditions conducive to aeolian sediment transport and deposition, but at the same time these factors may be represented by periods of erosion of sediment at different sites. Confident interpretation of past environmental conditions is therefore not possible based on results from individual stratigraphic records. Sampling at multiple locations is needed in order to distinguish dune accumulation and preservation due to external forcing from stochastic processes of dune development.
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Diketopiperazinespirocyclopropane 12 is prepared in > 98% d. e. via the conjugate addition of a phosphorus ylide to (6S)-N,N'-bis (p-methoxybenzyl)-3-methylenepiperazine-2,5-dione 2. Deprotection and hydrolysis of adduct 12 and su...
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Diketopiperazinespirocyclopropane 12 is prepared in > 98% d. e. via the conjugate addition of a phosphorus ylide to (6S)-N,N'-bis (p-methoxybenzyl)-3-methylenepiperazine-2,5-dione 2. Deprotection and hydrolysis of adduct 12 and subsequent peptide coupling demonstrate the applicability of this methodology to the asymmetric synthesis of 1-aminocyclopropane-1-carboxylic acids for incorporation into novel peptides. A model for the high level of diastereofacial selectivity observed in the cyclopropanation reaction is presented. A highly selective asymmetric approach (> 98% d.e.) to (S)-[2,2-~2H_2]-1-aminocyclopropane-1-carboxylic acid 29 is also reported via a deuterated sulfur ylide addition to acceptor 2.
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Whilst global environmental change in the 21st century will undoubtedly have direct impacts on built heritage, it will also have important indirect effects through its influence on microbial, plant and animal life on heritage site...
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Whilst global environmental change in the 21st century will undoubtedly have direct impacts on built heritage, it will also have important indirect effects through its influence on microbial, plant and animal life on heritage sites. Environmental change will affect both the structure of biotic communities and the function of such communities. Both impacts will, in turn, influence the deterioration and conservation of heritage sites. Changes in precipitation will exert a major, but as yet poorly understood, control on heritage biotas, whilst changes in atmospheric composition may also be important. Climatic changes will cause range shifts for some taxa, further influencing community composition. Whilst there are many unknowns, making prediction difficult, some scenarios can be proposed based on ecological response to stress and disturbance. This approach indicates some 'hotspots' at risk of experiencing dramatic shifts in biotic communities and their impacts, which may switch from biodeteriogenic to bioprotective or vice versa. Such hotspots include vulnerable sandstone and limestone heritage structures in areas of the Mediterranean, Middle East, Caribbean and Southern Africa.
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Conjugate addition of homochiral lithium N-benzyl-N-α-methylbenzylamide to tert-butyl(E)-cinnamate or tert-butyl (E)-crotonate and in situ amination with trisyl azide results in the exclusive formation of the corresponding 2-diaz...
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Conjugate addition of homochiral lithium N-benzyl-N-α-methylbenzylamide to tert-butyl(E)-cinnamate or tert-butyl (E)-crotonate and in situ amination with trisyl azide results in the exclusive formation of the corresponding 2-diazo-3-amino esters in >95% de. Amination of the lithium (E)-enolates of tert-butyl (3S,αR)-3-N-benzyl-N-α-methylbenzylamino-3-phenylpropanoate or tert-butyl (3S, αR)-3-N-benzyl-N-methylbenzylaminobutanoate with trisyl azide gives the (2R,3R,αR)-and (2S,3S,αS0-anti-azido-3-amino esters in good yields and in 85% de and >95% de respectively. Alternatively, tert-butyl anti-(2S,3S,αS)-2-hydroxy-3-N-benzyl-N-α-methylbenzylaminobutanoate may be converted selectively to tert-butyl anti-(2S,3S,αS)-2-azido-3-N-benzyl-N-α-methylbenzylaminobutanoate by aziridinium ion formation and regioselective opening with azide. Deprotection of tert-butyl(2S,3S,αS)-2-azido-3-aminobutanoate via Staudinger reduction, hydrogenolysis and ester hydrolysis furnishes anti-(2R,3S)-diaminobutanoic acid in 98% de and 98% ee. The asymmetric synthesis of the diastereometric syn-(2R,3S)-diaminobutanoic acid 998% de and 98% ee)was accomplished via functional group manipulation of tert-butly anti-92S,3S,αS)-2-hydroxy-3-N-benzyl-N-α-methylbenzylaminobutanoate in a protocol involving azide inversion of tert-butyl (2S,3S)-2-mesyloxy-3-N-Boc-butanoate and subsequent deprotection.
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