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110 Research products, page 1 of 11

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  • Open Access English
    Authors: 
    Judith Green; Rebecca Steinbach; Alasdair Jones; Phil Edwards; Charlotte Kelly; John Nellthorp; Anna Goodman; Helen Roberts; Mark Petticrew; Paul Wilkinson;
    Publisher: National Institute for Health Research (NIHR)
    Country: United Kingdom
    Project: CIHR

    BackgroundIn September 2005 London introduced a policy granting young people aged < 17 years access to free bus and tram travel. A year later this policy was extended to people aged < 18 years in education, work or training. This intervention was part of a broader environmental strategy in London to reduce private car use, but its primary aim was to decrease ‘transport exclusion’, and ensure that access to goods, services, education and training opportunities were not denied to some young people because of transport poverty. However, there were also likely to be positive and negative health implications, which were difficult to assess in the absence of a robust evidence base on the impact of transport policies on health and well-being.ObjectivesTo evaluate the impact of free bus travel for young people in London on the public health. Specifically, to provide empirical evidence for the impact of this ‘natural experiment’ on health outcomes and behaviours (e.g. injuries, active travel) for young people; explore the effects on the determinants of health; identify the effects on older citizens of increased access to bus travel for young people and to identify whether or not the intervention represented value for money.DesignQuasi-experimental design, using secondary analysis of routine data, primary qualitative data and literature reviews.SettingLondon, UK.ParticipantsYoung people aged 12–17 years and older citizens aged ≥ 60 years.InterventionThe introduction of free bus travel for those aged < 17 years living in London in 2005, extended to those aged < 18 years in 2006.Main outcome measuresQuantitative: number of journeys to school or work; frequency and distance of active travel (i.e. walking and/or cycling), bus travel, car travel; incidence of road traffic injuries and assaults and socioeconomic gradients in travel patterns. Qualitative: how free bus travel affected young people and older citizens’ travel and well-being.MethodsQuantitative component: change-on-change analysis comparing pre–post change in the target age group (12–17 years) against that seen in ‘non-exposed’ groups [for travel mode, road traffic injury (RTI) and assaults]. Qualitative component: interviews analysed using both deductive and inductive methods. Economic evaluation: cost–benefit analysis (CBA).Data sourcesLondon Area Transport Survey (LATS) and London Travel Demand Survey (LTDS) (travel mode); STATS19 Road Accident data set (RTI); Hospital Episode Statistics (HES) (assaults); interviews with young people and older citizens; and cost data from providers and literature reviews.ResultsThe introduction of free bus travel for young people was associated with higher use of bus travel by adults and young people [31% increase, 95% confidence interval (CI) 19% to 42%; and 26% increase, 95% CI 13% to 41%, respectively], especially for short journeys, and lower car distances relative to adults (relative change 0.73, 95% CI 0.55 to 0.94); no significant overall reduction in ‘active travel’ [reduction in number of walking trips but no evidence of change in distance walked (relative change 0.99, 95% CI 0.92 to 1.07)]; significant reduction in cycling relative to adults (but from a very low base); a reduction in road traffic injuries for car occupants (relative change 0.89, 95% CI 0.84 to 0.95) and cyclists (relative change 0.60, 95% CI 0.55 to 0.66), but not pedestrians; an overall modest increase in journeys to work or school (relative change 1.09, 95% CI 1.06 to 1.14); equivocal evidence of impact on socioeconomic gradients in travel behaviour and no evidence of adverse impact on travel of older people aged > 60 years. An increase in assaults largely preceded the scheme. Qualitative data suggested that the scheme increased opportunities for independent travel, social inclusion, and a sense of belonging and that it ‘normalised’ bus travel. The monetised benefits of the scheme substantially outweighed the costs, providing what the Department for Transport (DfT) considers ‘high’ value for money.ConclusionThe free bus travel scheme for young people appears to have encouraged their greater use of bus transport for short trips without significant impact on their overall active travel. There was qualitative evidence for benefits on social determinants of health, such as normalisation of bus travel, greater social inclusion and opportunities for independent travel. In the context of a good bus service, universal free bus travel for young people appears to be a cost-effective contributor to social inclusion and, potentially, to increasing sustainable transport in the long term. Further research is needed on the effects of both active and other travel modes on the determinants of health; the factors that influence maintenance of travel mode change; travel as ‘social practice’; the impact of driving license changes on injury rates for young adults and the value of a statistical life for young people.FundingThe National Institute for Health Research Public Health Research programme.

  • Open Access English
    Authors: 
    Allie Shier; Eran Shor;
    Publisher: Sage
    Country: United Kingdom

    This article compares murder cases labeled “honor killings” with cases labeled “family/spousal murders” in the Canadian news media, exploring the construction of boundaries between these two practices. We conducted a systematic qualitative content analysis, examining a sample of 486 articles from three major Canadian newspapers between 2000 and 2012. Our analysis shows that “honor killings” are framed in terms of culture and ethnic background, presenting a dichotomy between South Asian/Muslim and Western values. Conversely, articles presenting cases as “family/spousal murders” tend to focus on the perpetrators’ personalities or psychological characteristics, often ignoring factors such as culture, patriarchy, honor, and shame.

  • Open Access English
    Authors: 
    David J. Nutt; Lawrence D. Phillips; David J.K. Balfour; H. Valerie Curran; Martin Dockrell; Jonathan Foulds; Karl Fagerström; Kgosi Letlape; Anders Milton; Riccardo Polosa; +2 more
    Publisher: Karger
    Countries: United Kingdom, Australia

    <b><i>Background:</i></b> An international expert panel convened by the Independent Scientific Committee on Drugs developed a multi-criteria decision analysis model of the relative importance of different types of harm related to the use of nicotine-containing products. <b><i>Method:</i></b> The group defined 12 products and 14 harm criteria. Seven criteria represented harms to the user, and the other seven indicated harms to others. The group scored all the products on each criterion for their average harm worldwide using a scale with 100 defined as the most harmful product on a given criterion, and a score of zero defined as no harm. The group also assessed relative weights for all the criteria to indicate their relative importance. <b><i>Findings:</i></b> Weighted averages of the scores provided a single, overall score for each product. Cigarettes (overall weighted score of 100) emerged as the most harmful product, with small cigars in second place (overall weighted score of 64). After a substantial gap to the third-place product, pipes (scoring 21), all remaining products scored 15 points or less. <b><i>Interpretation:</i></b> Cigarettes are the nicotine product causing by far the most harm to users and others in the world today. Attempts to switch to non-combusted sources of nicotine should be encouraged as the harms from these products are much lower.

  • Open Access English
    Authors: 
    Mark S. Manger;
    Publisher: Taylor & Francis
    Country: United Kingdom

    Why do major economic powers seek more and more free trade agreements (FTAs) with smaller partners? Recently, Japan has joined the bandwagon by signing its first bilateral FTA. The decision, highly contested domestically, represents a sea change in Japanese trade policy and a challenging case for theories of regionalism. This paper lays out a theoretical appraisal for why more and more industrialized countries join FTAs with emerging markets and illustrates the argument with an analysis of the Japanese case. The paper argues that foreign direct investment (FDI) changes the incentives for states in favour of preferential trade agreements. Increased FDI and shifts in multina- tional firm strategies increase flows of intermediate goods. As a result, firms lobby their home governments to bolster their competitive position by sign- ing preferential agreements. Yet, FTAs also discriminate against firms from third parties, motivating them to lobby for defensive agreements. The qual- itative case studies show how NAFTA discriminates against Japanese FDI in Mexico. As a result, firms began to lobby the Japanese trade bureaucracy, changing the perception of key policymakers who developed a strategy of pursuing preferential trade agreements in the Asia Pacific region, as shown in a case study of the initiative for an FTA with Thailand.

  • English
    Authors: 
    Lychagin, Sergey; Slade, Margaret E.;
    Publisher: Centre for Economic Performance, London School of Economics and Political Science
    Country: United Kingdom
    Project: NSF | Quantile models, endogene... (0922127), SSHRC

    We simultaneously assess the contributions to productivity of three sources of research anddevelopment spillovers: geographic, technology and product - market proximity. To do this,we construct a new measure of geographic proximity that is based on the distribution of afirm's inventor locations rather than its headquarters, and we report both parametric and semiparametric estimates of our geographic-distance functions. We find that: i) Geographicspace matters even after conditioning on horizontal and technological spillovers; ii)Technological proximity matters; iii) Product-market proximity is less important; iv)Locations of researchers are more important than headquarters but both have explanatory power; and v) Geographic markets are very local.

  • Open Access English
    Authors: 
    Stephanie A. Alexander; Catherine M. Jones; Marie-Claude Tremblay; Nicole Beaudet; Morten Hulvej Rod; Michael T. Wright;
    Country: United Kingdom
    Project: SSHRC , CIHR

    Reflexivity has emerged as a key concept in the field of health promotion (HP). Yet it remains unclear how diverse forms of reflexivity are specifically relevant to HP concerns, and how these “reflexivities” are interconnected. We argue that frameworks are needed to support more systematic integration of reflexivity in HP training and practice. In this article, we propose a typology of reflexivity in HP to facilitate the understanding of reflexivity in professional training. Drawing from key theories and models of reflexivity, this typology proposes three reflexive positions (ideal-types) with specific purposes for HP: reflexivity in, on, and underlying action. This article illustrates our typology’s ideal-types with vignettes collected from HP actors working with reflexivity in North America and Europe. We suggest that our typology constitutes a conceptual device to organize and discuss a variety of experiences of engaging with reflexivity for HP. We propose the typology may support integrating reflexivity as a key feature in training a future cadre of health promoters and as a means for building a responsible HP practice.

  • English
    Authors: 
    LSE Public Policy Group, Jane;
    Publisher: LSE Public Policy Group
    Country: United Kingdom
    Project: WT , CIHR
  • English
    Authors: 
    Ahmad Abdi; Kanstantsin Pashkovich;
    Country: United Kingdom
    Project: NSERC

    For an integer n ≥ 3, the clutter ∆n := {1, 2}, {1, 3}, . . ., {1, n}, {2, 3, . . ., n} is called a delta of dimension n, whose members are the lines of a degenerate projective plane. In his seminal paper on nonideal clutters, Lehman revealed the role of the deltas as a distinct class of minimally nonideal clutters [The width length inequality and degenerate projective planes, DIMACS Ser. Discrete Math. Theoret. Comput. Sci. 1, AMS, Providence, RI, 1990, pp. 101-105]. A clutter is delta free if it has no delta minor. Binary clutters, ideal clutters, and clutters with the packing property are examples of delta free clutters. In this paper, we introduce and study basic geometric notions defined on clutters, including entanglement between clutters, a notion that is intimately linked with set covering polyhedra having a convex union. We will then investigate the surprising geometric attributes of delta minors and delta free clutters.

  • Publication . Article . Other literature type . 2013
    Open Access English
    Authors: 
    Simon L. Lewis; Bonaventure Sonké; Terry Sunderland; Serge K. Begne; Gabriela Lopez-Gonzalez; Geertje M. F. van der Heijden; Oliver L. Phillips; Kofi Affum-Baffoe; Timothy R. Baker; Lindsay F. Banin; +53 more
    Publisher: Royal Society, The
    Countries: Belgium, France, Netherlands, Netherlands, Belgium, Belgium, United Kingdom
    Project: EC | GEOCARBON (283080)

    We report above-ground biomass (AGB), basal area, stemdensity and wood mass density estimates from 260 sample plots (mean size: 1.2 ha) in intact closed-canopy tropical forests across 12 African countries. Mean AGB is 395.7 Mg dry mass ha-1 (95% CI: 14.3), substantially higher than Amazonian values, with the Congo Basin and contiguous forest region attaining AGB values (429 Mg ha-1) similar to those of Bornean forests, and significantly greater than East or West African forests. AGB therefore appears generally higher in palaeo- comparedwithneotropical forests.However, mean stem density is low(426±11 stems ha-1 greater than or equal to 100 mm diameter) compared with both Amazonian and Bornean forests (cf. approx. 600) and is the signature structural feature of African tropical forests. While spatial autocorrelation complicates analyses, AGB shows a positive relationship with rainfall in the driest nine months of the year, and an opposite association with the wettest three months of the year; a negative relationship with temperature; positive relationship with clay-rich soils; and negative relationshipswith C:Nratio (suggesting a positive soil phosphorus- AGB relationship), and soil fertility computed as the sum of base cations. The results indicate that AGB is mediated by both climate and soils, and suggest that the AGB of African closed-canopy tropical forests may be particularly sensitive to future precipitation and temperature changes. © 2013 The Authors. info:eu-repo/semantics/published SCOPUS: ar.j 0

  • Open Access English
    Authors: 
    Scholten, Marc; Read, Daniel;
    Publisher: Department of Operational Research, London School of Economics and Political Science
    Country: United Kingdom

    Time discounting is influenced both by the delay to outcomes, and by the interval separating them. In contrast to the effects of delay, interval effects have received relatively little research attention. Previous research has shown that for intervals of moderate length, the rate of discounting decreases as intervals get longer (subadditive discounting). In this paper we show that, in addition, for short intervals the rate of discounting increases as intervals get longer, implying a U-shaped relationship between discounting and interval length. Superadditive discounting is shown in two studies. In Experiment 1, we show that short intervals are more likely to give rise to superadditive than subadditive discounting. In Experiment 2, we show that discounting for short intervals is lower than that for intervals of moderate length, but that discounting for moderate-length intervals is greater than that for long ones. In the discussion we place these findings in a broader context.

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Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
110 Research products, page 1 of 11
  • Open Access English
    Authors: 
    Judith Green; Rebecca Steinbach; Alasdair Jones; Phil Edwards; Charlotte Kelly; John Nellthorp; Anna Goodman; Helen Roberts; Mark Petticrew; Paul Wilkinson;
    Publisher: National Institute for Health Research (NIHR)
    Country: United Kingdom
    Project: CIHR

    BackgroundIn September 2005 London introduced a policy granting young people aged < 17 years access to free bus and tram travel. A year later this policy was extended to people aged < 18 years in education, work or training. This intervention was part of a broader environmental strategy in London to reduce private car use, but its primary aim was to decrease ‘transport exclusion’, and ensure that access to goods, services, education and training opportunities were not denied to some young people because of transport poverty. However, there were also likely to be positive and negative health implications, which were difficult to assess in the absence of a robust evidence base on the impact of transport policies on health and well-being.ObjectivesTo evaluate the impact of free bus travel for young people in London on the public health. Specifically, to provide empirical evidence for the impact of this ‘natural experiment’ on health outcomes and behaviours (e.g. injuries, active travel) for young people; explore the effects on the determinants of health; identify the effects on older citizens of increased access to bus travel for young people and to identify whether or not the intervention represented value for money.DesignQuasi-experimental design, using secondary analysis of routine data, primary qualitative data and literature reviews.SettingLondon, UK.ParticipantsYoung people aged 12–17 years and older citizens aged ≥ 60 years.InterventionThe introduction of free bus travel for those aged < 17 years living in London in 2005, extended to those aged < 18 years in 2006.Main outcome measuresQuantitative: number of journeys to school or work; frequency and distance of active travel (i.e. walking and/or cycling), bus travel, car travel; incidence of road traffic injuries and assaults and socioeconomic gradients in travel patterns. Qualitative: how free bus travel affected young people and older citizens’ travel and well-being.MethodsQuantitative component: change-on-change analysis comparing pre–post change in the target age group (12–17 years) against that seen in ‘non-exposed’ groups [for travel mode, road traffic injury (RTI) and assaults]. Qualitative component: interviews analysed using both deductive and inductive methods. Economic evaluation: cost–benefit analysis (CBA).Data sourcesLondon Area Transport Survey (LATS) and London Travel Demand Survey (LTDS) (travel mode); STATS19 Road Accident data set (RTI); Hospital Episode Statistics (HES) (assaults); interviews with young people and older citizens; and cost data from providers and literature reviews.ResultsThe introduction of free bus travel for young people was associated with higher use of bus travel by adults and young people [31% increase, 95% confidence interval (CI) 19% to 42%; and 26% increase, 95% CI 13% to 41%, respectively], especially for short journeys, and lower car distances relative to adults (relative change 0.73, 95% CI 0.55 to 0.94); no significant overall reduction in ‘active travel’ [reduction in number of walking trips but no evidence of change in distance walked (relative change 0.99, 95% CI 0.92 to 1.07)]; significant reduction in cycling relative to adults (but from a very low base); a reduction in road traffic injuries for car occupants (relative change 0.89, 95% CI 0.84 to 0.95) and cyclists (relative change 0.60, 95% CI 0.55 to 0.66), but not pedestrians; an overall modest increase in journeys to work or school (relative change 1.09, 95% CI 1.06 to 1.14); equivocal evidence of impact on socioeconomic gradients in travel behaviour and no evidence of adverse impact on travel of older people aged > 60 years. An increase in assaults largely preceded the scheme. Qualitative data suggested that the scheme increased opportunities for independent travel, social inclusion, and a sense of belonging and that it ‘normalised’ bus travel. The monetised benefits of the scheme substantially outweighed the costs, providing what the Department for Transport (DfT) considers ‘high’ value for money.ConclusionThe free bus travel scheme for young people appears to have encouraged their greater use of bus transport for short trips without significant impact on their overall active travel. There was qualitative evidence for benefits on social determinants of health, such as normalisation of bus travel, greater social inclusion and opportunities for independent travel. In the context of a good bus service, universal free bus travel for young people appears to be a cost-effective contributor to social inclusion and, potentially, to increasing sustainable transport in the long term. Further research is needed on the effects of both active and other travel modes on the determinants of health; the factors that influence maintenance of travel mode change; travel as ‘social practice’; the impact of driving license changes on injury rates for young adults and the value of a statistical life for young people.FundingThe National Institute for Health Research Public Health Research programme.

  • Open Access English
    Authors: 
    Allie Shier; Eran Shor;
    Publisher: Sage
    Country: United Kingdom

    This article compares murder cases labeled “honor killings” with cases labeled “family/spousal murders” in the Canadian news media, exploring the construction of boundaries between these two practices. We conducted a systematic qualitative content analysis, examining a sample of 486 articles from three major Canadian newspapers between 2000 and 2012. Our analysis shows that “honor killings” are framed in terms of culture and ethnic background, presenting a dichotomy between South Asian/Muslim and Western values. Conversely, articles presenting cases as “family/spousal murders” tend to focus on the perpetrators’ personalities or psychological characteristics, often ignoring factors such as culture, patriarchy, honor, and shame.

  • Open Access English
    Authors: 
    David J. Nutt; Lawrence D. Phillips; David J.K. Balfour; H. Valerie Curran; Martin Dockrell; Jonathan Foulds; Karl Fagerström; Kgosi Letlape; Anders Milton; Riccardo Polosa; +2 more
    Publisher: Karger
    Countries: United Kingdom, Australia

    <b><i>Background:</i></b> An international expert panel convened by the Independent Scientific Committee on Drugs developed a multi-criteria decision analysis model of the relative importance of different types of harm related to the use of nicotine-containing products. <b><i>Method:</i></b> The group defined 12 products and 14 harm criteria. Seven criteria represented harms to the user, and the other seven indicated harms to others. The group scored all the products on each criterion for their average harm worldwide using a scale with 100 defined as the most harmful product on a given criterion, and a score of zero defined as no harm. The group also assessed relative weights for all the criteria to indicate their relative importance. <b><i>Findings:</i></b> Weighted averages of the scores provided a single, overall score for each product. Cigarettes (overall weighted score of 100) emerged as the most harmful product, with small cigars in second place (overall weighted score of 64). After a substantial gap to the third-place product, pipes (scoring 21), all remaining products scored 15 points or less. <b><i>Interpretation:</i></b> Cigarettes are the nicotine product causing by far the most harm to users and others in the world today. Attempts to switch to non-combusted sources of nicotine should be encouraged as the harms from these products are much lower.

  • Open Access English
    Authors: 
    Mark S. Manger;
    Publisher: Taylor & Francis
    Country: United Kingdom

    Why do major economic powers seek more and more free trade agreements (FTAs) with smaller partners? Recently, Japan has joined the bandwagon by signing its first bilateral FTA. The decision, highly contested domestically, represents a sea change in Japanese trade policy and a challenging case for theories of regionalism. This paper lays out a theoretical appraisal for why more and more industrialized countries join FTAs with emerging markets and illustrates the argument with an analysis of the Japanese case. The paper argues that foreign direct investment (FDI) changes the incentives for states in favour of preferential trade agreements. Increased FDI and shifts in multina- tional firm strategies increase flows of intermediate goods. As a result, firms lobby their home governments to bolster their competitive position by sign- ing preferential agreements. Yet, FTAs also discriminate against firms from third parties, motivating them to lobby for defensive agreements. The qual- itative case studies show how NAFTA discriminates against Japanese FDI in Mexico. As a result, firms began to lobby the Japanese trade bureaucracy, changing the perception of key policymakers who developed a strategy of pursuing preferential trade agreements in the Asia Pacific region, as shown in a case study of the initiative for an FTA with Thailand.

  • English
    Authors: 
    Lychagin, Sergey; Slade, Margaret E.;
    Publisher: Centre for Economic Performance, London School of Economics and Political Science
    Country: United Kingdom
    Project: NSF | Quantile models, endogene... (0922127), SSHRC

    We simultaneously assess the contributions to productivity of three sources of research anddevelopment spillovers: geographic, technology and product - market proximity. To do this,we construct a new measure of geographic proximity that is based on the distribution of afirm's inventor locations rather than its headquarters, and we report both parametric and semiparametric estimates of our geographic-distance functions. We find that: i) Geographicspace matters even after conditioning on horizontal and technological spillovers; ii)Technological proximity matters; iii) Product-market proximity is less important; iv)Locations of researchers are more important than headquarters but both have explanatory power; and v) Geographic markets are very local.

  • Open Access English
    Authors: 
    Stephanie A. Alexander; Catherine M. Jones; Marie-Claude Tremblay; Nicole Beaudet; Morten Hulvej Rod; Michael T. Wright;
    Country: United Kingdom
    Project: SSHRC , CIHR

    Reflexivity has emerged as a key concept in the field of health promotion (HP). Yet it remains unclear how diverse forms of reflexivity are specifically relevant to HP concerns, and how these “reflexivities” are interconnected. We argue that frameworks are needed to support more systematic integration of reflexivity in HP training and practice. In this article, we propose a typology of reflexivity in HP to facilitate the understanding of reflexivity in professional training. Drawing from key theories and models of reflexivity, this typology proposes three reflexive positions (ideal-types) with specific purposes for HP: reflexivity in, on, and underlying action. This article illustrates our typology’s ideal-types with vignettes collected from HP actors working with reflexivity in North America and Europe. We suggest that our typology constitutes a conceptual device to organize and discuss a variety of experiences of engaging with reflexivity for HP. We propose the typology may support integrating reflexivity as a key feature in training a future cadre of health promoters and as a means for building a responsible HP practice.

  • English
    Authors: 
    LSE Public Policy Group, Jane;
    Publisher: LSE Public Policy Group
    Country: United Kingdom
    Project: WT , CIHR
  • English
    Authors: 
    Ahmad Abdi; Kanstantsin Pashkovich;
    Country: United Kingdom
    Project: NSERC

    For an integer n ≥ 3, the clutter ∆n := {1, 2}, {1, 3}, . . ., {1, n}, {2, 3, . . ., n} is called a delta of dimension n, whose members are the lines of a degenerate projective plane. In his seminal paper on nonideal clutters, Lehman revealed the role of the deltas as a distinct class of minimally nonideal clutters [The width length inequality and degenerate projective planes, DIMACS Ser. Discrete Math. Theoret. Comput. Sci. 1, AMS, Providence, RI, 1990, pp. 101-105]. A clutter is delta free if it has no delta minor. Binary clutters, ideal clutters, and clutters with the packing property are examples of delta free clutters. In this paper, we introduce and study basic geometric notions defined on clutters, including entanglement between clutters, a notion that is intimately linked with set covering polyhedra having a convex union. We will then investigate the surprising geometric attributes of delta minors and delta free clutters.

  • Publication . Article . Other literature type . 2013
    Open Access English
    Authors: 
    Simon L. Lewis; Bonaventure Sonké; Terry Sunderland; Serge K. Begne; Gabriela Lopez-Gonzalez; Geertje M. F. van der Heijden; Oliver L. Phillips; Kofi Affum-Baffoe; Timothy R. Baker; Lindsay F. Banin; +53 more
    Publisher: Royal Society, The
    Countries: Belgium, France, Netherlands, Netherlands, Belgium, Belgium, United Kingdom
    Project: EC | GEOCARBON (283080)

    We report above-ground biomass (AGB), basal area, stemdensity and wood mass density estimates from 260 sample plots (mean size: 1.2 ha) in intact closed-canopy tropical forests across 12 African countries. Mean AGB is 395.7 Mg dry mass ha-1 (95% CI: 14.3), substantially higher than Amazonian values, with the Congo Basin and contiguous forest region attaining AGB values (429 Mg ha-1) similar to those of Bornean forests, and significantly greater than East or West African forests. AGB therefore appears generally higher in palaeo- comparedwithneotropical forests.However, mean stem density is low(426±11 stems ha-1 greater than or equal to 100 mm diameter) compared with both Amazonian and Bornean forests (cf. approx. 600) and is the signature structural feature of African tropical forests. While spatial autocorrelation complicates analyses, AGB shows a positive relationship with rainfall in the driest nine months of the year, and an opposite association with the wettest three months of the year; a negative relationship with temperature; positive relationship with clay-rich soils; and negative relationshipswith C:Nratio (suggesting a positive soil phosphorus- AGB relationship), and soil fertility computed as the sum of base cations. The results indicate that AGB is mediated by both climate and soils, and suggest that the AGB of African closed-canopy tropical forests may be particularly sensitive to future precipitation and temperature changes. © 2013 The Authors. info:eu-repo/semantics/published SCOPUS: ar.j 0

  • Open Access English
    Authors: 
    Scholten, Marc; Read, Daniel;
    Publisher: Department of Operational Research, London School of Economics and Political Science
    Country: United Kingdom

    Time discounting is influenced both by the delay to outcomes, and by the interval separating them. In contrast to the effects of delay, interval effects have received relatively little research attention. Previous research has shown that for intervals of moderate length, the rate of discounting decreases as intervals get longer (subadditive discounting). In this paper we show that, in addition, for short intervals the rate of discounting increases as intervals get longer, implying a U-shaped relationship between discounting and interval length. Superadditive discounting is shown in two studies. In Experiment 1, we show that short intervals are more likely to give rise to superadditive than subadditive discounting. In Experiment 2, we show that discounting for short intervals is lower than that for intervals of moderate length, but that discounting for moderate-length intervals is greater than that for long ones. In the discussion we place these findings in a broader context.