1,113 research outputs found
Optimum Saving and Growth: Harrod on Dynamic Welfare Economics
In the 1960s and 1970s Harrod shifted the emphasis of his research in economic dynamics from the study of business cycles (instability principle) to the investigation of the growth process. As part of that, he restated his concept of the natural growth rate as an optimum welfare rate. The present paper examines Harrod's dynamic welfare economics, built around his concept of optimum saving developed as a reaction to Ramsey's approach to capital accumulation. It is shown that, according to Harrod, the saving rate does not affect the long-run growth rate of per capita income, which is determined by technical progress. Moreover, the economy will grow at the natural (full employment) rate only if economic policy is able to bring saving to its "optimum" level in macroeconomic equilibrium. Harrod's interest in optimal growth was motivated by his double concern with growth policy in mature economies and economic development in poor countries
Unravelling the macro-evolutionary ecology of fishâjellyfish associations: life in the âgingerbread houseâ
Fishâjellyfish interactions are important factors contributing to fish stock success. Jellyfish can compete with fish for food resources, or feed on fish eggs and larvae, which works to reduce survivorship and recruitment of fish species. However, jellyfish also provide habitat and space for developing larval and juvenile fish which use their hosts as means of protection from predators and feeding opportunities, helping to reduce fish mortality and increase recruitment. Yet, relatively little is known about the evolutionary dynamics and drivers of such associations which would allow for their more effective incorporation into ecosystem models. Here, we found that jellyfish association is a probable adaptive anti-predator strategy for juvenile fish, more likely to evolve in benthic (fish living on the sea floor), benthopelagic (fish living just above the bottom of the seafloor), and reef-associating species than those adapted to other marine habitats. We also found that jellyfish association likely preceded the evolution of a benthic, benthopelagic, and reef-associating lifestyle rather than its evolutionary consequence, as we originally hypothesized. Considering over two-thirds of the associating fish identified here are of economic importance, and the wide-scale occurrence and diversity of species involved, it is clear the formation of fishâjellyfish associations is an important but complex process in relation to the success of fish stocks globally
Barriers to help-seeking among music festival attendees in New South Wales, Australia
Introduction: Prompt help-seeking behaviour by music festival attendees can reduce risks associated with drug use; however, little is known about perceived barriers to help-seeking when experiencing or witnessing illness at music festivals. We explored potential barriers and their association with festivalgoer characteristics. Methods: We conducted an on-site cross-sectional survey of attendees at New South Wales music festivals in 2019/2020. Perceived barriers to help-seeking in the hypothetical event of the respondent or a friend becoming unwell at the festival were assessed, and regression analyses were conducted to identify characteristics associated with these barriers. Results: Across six festivals, 1229 people were surveyed and four-fifths (83.2%) reported â„1 barrier: 32.7% fear of getting in trouble with the police, 20.6% not knowing where to find help, 17.2% not knowing how unwell someone might be and 15.3% concern about friends or relatives finding out. In multivariable analyses, people of diverse sexuality and people using drugs that day had greater odds of reporting fear of trouble with the police. People reporting drug use that day had lower odds of reporting not knowing where to find help. Men, gender-diverse people and people using drugs that day had greater odds of reporting concern about friends or relatives finding out. Discussion and Conclusions: Our data substantiate concerns regarding policing strategies and their impact on festivals. Initiatives to support conversations about drugs with friends and families may be best targeted to younger people and those from gender-diverse backgrounds
educationUndergraduate: Journal of undergraduate research in education (Volume 2)
Edited by Claire Taylor, Peter Harrod, Richard Woolley, Karl Aubrey and Nick Edmonds.
Contents:
Factors Affecting the Use of Experiential Learning in Teaching Religious Education in Schools by Rachel Day; An Investigation Into the Attitudes and Use of Resources for Life-long Learning in the Heritage Sector by Esther Horner; An Investigation into Teachersâ Views on Childrenâs Spirituality, with Particular Reference to âGodly Playâ by Cheryl Livingstone; The Role of Fiction in Motivating Boys to Read by Julie Robinson; The Effect of Role-Play on Children's Speaking Skills by Julia Newton; Pupils' Attitudes Towards Practical Work in Science: Motivating or Monotonous? by Rachel Meek
Managing cryptic biodiversity: fine-scale intralacustrine speciation along a benthic gradient in Alpine whitefish ( Coregonus spp.)
Whitefish (Coregonus spp.) are an important catch for many freshwater fisheries, particularly in Switzerland. In support of this, supplemental stocking of whitefish species is carried out, despite lacking complete knowledge of the extent, distribution and origin of whitefish diversity in these lakes, potentially threatening local endemics via artificial gene flow. Here, we investigate phenotypic and genetic differentiation among coexisting whitefish species spawning along a depth gradient in a subalpine Swiss lake to better delineate intralacustrine whitefish biodiversity. We find depth-related clines in adaptive morphology and in neutral genetic markers. This individual variation is structured in three distinct clusters with spatial overlap. Individual genetic distances correlate strongly with differences in growth rate and gill-raker number, consistent with predictions of isolation-by-adaptation and ecological speciation. Genetic differentiation between species suggests reproductive isolation, despite demographic admixture on spawning grounds. Our results are consistent with clinal speciation resulting in three species coexisting in close ecological parapatry, one (C. sp. âbenthic intermediateâ) being previously unknown. A second unknown species spawning in close proximity, was found to be of potential allochthonous origin. This study highlights the importance of taxonomically unbiased sampling strategies to both understand evolutionary mechanisms structuring biodiversity and to better inform conservation and fisheries management
From clear lakes to murky waters - tracing the functional response of high-latitude lake communities to concurrent 'greening' and 'browning'
Climate change and the intensification of land use practices are causing widespread eutrophication of subarctic lakes. The implications of this rapid change for lake ecosystem function remain poorly understood. To assess how freshwater communities respond to such profound changes in their habitat and resource availability, we conducted a space-for-time analysis of food-web structure in 30 lakes situated across a temperature-productivity gradient equivalent to the predicted future climate of subarctic Europe (temperature +3 degrees C, precipitation +30% and nutrient +45 mu g L-1 total phosphorus). Along this gradient, we observed an increase in the assimilation of pelagic-derived carbon from 25 to 75% throughout primary, secondary and tertiary consumers. This shift was overwhelmingly driven by the consumption of pelagic detritus by benthic primary consumers and was not accompanied by increased pelagic foraging by higher trophic level consumers. Our data also revealed a convergence of the carbon isotope ratios of pelagic and benthic food web endmembers in the warmest, most productive lakes indicating that the incorporation of terrestrial derived carbon into aquatic food webs increases as land use intensifies. These results, reflecting changes along a gradient characteristic of the predicted future environment throughout the subarctic, indicate that climate and land use driven eutrophication and browning are radically altering the function and fuelling of aquatic food webs in this biome.Peer reviewe
Are Labour Markets Necessarily Local? Spatiality, Segmentation and Scale
This paper draws on recent debates about scale to approach the geography of labour markets from a dynamic perspective sensitive to the spatiality and scale of labour market
restructuring. Its exploration of labour market reconfigurations after the collapse of a major firm (Ansett Airlines) raises questions about geographyâs faith in the inherently âlocalâ constitution of labour markets. Through an examination of the job reallocation process after redundancy, the paper suggests that multiple labour markets use and articulate scale in different ways. It argues that labour market rescaling processes are enacted at the critical moment of recruitment, where social networks, personal aspirations and employer preferences combine to shape workersâ destinations
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