title: Population, human capital and development in the Maldives

authors: Niyaaz, Hussain

abstract: The relationship between population and development has drawn the attention of economists and demographers for a long time. While academic interest has focused on population and development problems of small island countries, much of it is centred on the Pacific countries and the island states of the Caribbean, but it may be argued that these problems are common to all small island countries.

Past demographic trends in the Maldives have created a young population structure. The negative impacts of these rapid demographic changes on the national economy have been significantly minimised by rapid economic growth in the past three decades. However, it may be argued that the presence of a large and growing expatriate labour force may hinder the socio-economic development of households in the rural areas by impeding the flow of incomes from the modern sectors to the households in the islands. Development of indigenous human capital is thus crucial in ensuring equitable development, especially in a small, resource-scarce nation like the Maldives.

The links between population growth, human capital and development are determined by actions taken at the micro (family) level. Understanding which of these micro-level factors encourage or hinder the development of human capital and labour supply - particularly for women and people living in the far-flung atolls - is therefore crucial.

The present thesis explores the following broad questions; what are the trends and differentials in population, human capital, and development at the macro-level in the Maldives? What are the interrelationships between population, human capital and development at the household level? How do changes in the modern economic sectors translate to basic development across all social, economic and human capital sectors? How do the micro-macro and macro-micro links between population, human capital, and development described above interact in the present context?

Analysis is conducted at two levels. Aggregated census data from different sources, published and computerised, for the years 1977, 1985 and 1995, and published data from other documents are used to study macro-level trends and differentials. At the micro-level, random samples for urban and rural populations, drawn from the computerised individual-level data for the 1995 census are used to explore the interlinkages between fertility, human capital and development. Statistical analysis is performed using logistic and multinomial logistic regression techniques. Findings from the multivariate analyses are supported by qualitative data collected by the author in three different inhabited islands of the Maldives during December 1998 to February 1999. Qualitative data also provide some insights to the macro-micro interlinkages between the key concepts studied in this thesis.

Macro-level analysis shows that overall levels of fertility have declined in the
Maldives during the period 1985 to 1995. Through its influence on increasing contraceptive use and delayed marriage, growth of education is found to be the most important factor of this decline. An important aspect of human capital, nutrition, is found to have lagged behind the general improvements in overall health. This is due to the dietary habits rather than lack of affordability. 
Past demographic trends and future projections suggest that the momentum effect of the present age structure is expected to continue. In addition to age-structural effects of population growth, the study shows that internal migration and the resulting spatial imbalances in population distribution have also affected social and economic infrastructures. However, internal migration and urbanisation have also been crucial for the creation of a scale economy in the urban area that has boosted macro-economic growth during the past three decades.

At the micro-level, despite the effects of an increasing expatriate labour force and a largely segregated tourism industry, the present study shows that the families in the rural households have benefited greatly from economic growth. Rural to urban circular migration of males is found to be the route of the flow of income from the largely urban centred economic growth to the rural households. With the exception of the southernmost islands, geographical factors are found to be important in the distribution of economic benefits to the population.

The study also shows that, perhaps due to socio-cultural factors, women in the Maldives seem to be increasingly marginalised from the workforce. Increasing household income appears to have a depressing effect on the participation of women in economic activities.

To the knowledge of the author, no other research has been undertaken to study the interlinkages between population, human capital and development in such detail in the Maldivian context. The thesis therefore provides valuable insights into the relationships between these variables in a small island setting, and thus contributes to expanding the knowledge base on the relationships between population, human capital and development. The findings from this study may also provide important policy directions for other small islands populations.

text: Population, human capital and development in the Maldives The relationship between population and development has drawn the attention of economists and demographers for a long time. While academic interest has focused on population and development problems of small island countries, much of it is centred on the Pacific countries and the island states of the Caribbean, but it may be argued that these problems are common to all small island countries.

Past demographic trends in the Maldives have created a young population structure. The negative impacts of these rapid demographic changes on the national economy have been significantly minimised by rapid economic growth in the past three decades. However, it may be argued that the presence of a large and growing expatriate labour force may hinder the socio-economic development of households in the rural areas by impeding the flow of incomes from the modern sectors to the households in the islands. Development of indigenous human capital is thus crucial in ensuring equitable development, especially in a small, resource-scarce nation like the Maldives.

The links between population growth, human capital and development are determined by actions taken at the micro (family) level. Understanding which of these micro-level factors encourage or hinder the development of human capital and labour supply - particularly for women and people living in the far-flung atolls - is therefore crucial.

The present thesis explores the following broad questions; what are the trends and differentials in population, human capital, and development at the macro-level in the Maldives? What are the interrelationships between population, human capital and development at the household level? How do changes in the modern economic sectors translate to basic development across all social, economic and human capital sectors? How do the micro-macro and macro-micro links between population, human capital, and development described above interact in the present context?

Analysis is conducted at two levels. Aggregated census data from different sources, published and computerised, for the years 1977, 1985 and 1995, and published data from other documents are used to study macro-level trends and differentials. At the micro-level, random samples for urban and rural populations, drawn from the computerised individual-level data for the 1995 census are used to explore the interlinkages between fertility, human capital and development. Statistical analysis is performed using logistic and multinomial logistic regression techniques. Findings from the multivariate analyses are supported by qualitative data collected by the author in three different inhabited islands of the Maldives during December 1998 to February 1999. Qualitative data also provide some insights to the macro-micro interlinkages between the key concepts studied in this thesis.

Macro-level analysis shows that overall levels of fertility have declined in the
Maldives during the period 1985 to 1995. Through its influence on increasing contraceptive use and delayed marriage, growth of education is found to be the most important factor of this decline. An important aspect of human capital, nutrition, is found to have lagged behind the general improvements in overall health. This is due to the dietary habits rather than lack of affordability. 
Past demographic trends and future projections suggest that the momentum effect of the present age structure is expected to continue. In addition to age-structural effects of population growth, the study shows that internal migration and the resulting spatial imbalances in population distribution have also affected social and economic infrastructures. However, internal migration and urbanisation have also been crucial for the creation of a scale economy in the urban area that has boosted macro-economic growth during the past three decades.

At the micro-level, despite the effects of an increasing expatriate labour force and a largely segregated tourism industry, the present study shows that the families in the rural households have benefited greatly from economic growth. Rural to urban circular migration of males is found to be the route of the flow of income from the largely urban centred economic growth to the rural households. With the exception of the southernmost islands, geographical factors are found to be important in the distribution of economic benefits to the population.

The study also shows that, perhaps due to socio-cultural factors, women in the Maldives seem to be increasingly marginalised from the workforce. Increasing household income appears to have a depressing effect on the participation of women in economic activities.

To the knowledge of the author, no other research has been undertaken to study the interlinkages between population, human capital and development in such detail in the Maldivian context. The thesis therefore provides valuable insights into the relationships between these variables in a small island setting, and thus contributes to expanding the knowledge base on the relationships between population, human capital and development. The findings from this study may also provide important policy directions for other small islands populations.

year: 2000

title: Intragastric preloads of L-tryptophan reduce ingestive behavior via oxytocinergic neural mechanisms in male mice

authors: Gartner, Sarah Nicole

subjects: Science & Technology

abstract: Human and laboratory animal studies suggest that dietary supplementation of a free essential amino acid, l-tryptophan (TRP), reduces food intake. It is unclear whether an acute gastric preload of TRP decreases consumption and whether central mechanisms underlie TRP-driven hypophagia. We examined the effect of TRP administered via intragastric gavage on energy- and palatability-induced feeding in mice. We sought to identify central mechanisms through which TRP suppresses appetite. Effects of TRP on consumption of energy-dense and energy-dilute tastants were established in mice stimulated to eat by energy deprivation or palatability. A conditioned taste aversion (CTA) paradigm was used to assess whether hypophagia is unrelated to sickness. c-Fos immunohistochemistry was employed to detect TRP-induced activation of feeding-related brain sites and of oxytocin (OT) neurons, a crucial component of satiety circuits. Also, expression of OT mRNA was assessed with real-time PCR. The functional importance of OT in mediating TRP-driven hypophagia was substantiated by showing the ability of OT receptor blockade to abolish TRP-induced decrease in feeding. TRP reduced intake of energy-dense standard chow in deprived animals and energy-dense palatable chow in sated mice. Anorexigenic doses of TRP did not cause a CTA. TRP failed to affect intake of palatable yet calorie-dilute or noncaloric solutions (10% sucrose, 4.1% Intralipid or 0.1% saccharin) even for TRP doses that decreased water intake in thirsty mice. Fos analysis revealed that TRP increases activation of several key feeding-related brain areas, especially in the brain stem and hypothalamus. TRP activated hypothalamic OT neurons and increased OT mRNA levels, whereas pretreatment with an OT antagonist abolished TRP-driven hypophagia. We conclude that intragastric TRP decreases food and water intake, and TRP-induced hypophagia is partially mediated via central circuits that encompass OT.

text: Intragastric preloads of L-tryptophan reduce ingestive behavior via oxytocinergic neural mechanisms in male mice Human and laboratory animal studies suggest that dietary supplementation of a free essential amino acid, l-tryptophan (TRP), reduces food intake. It is unclear whether an acute gastric preload of TRP decreases consumption and whether central mechanisms underlie TRP-driven hypophagia. We examined the effect of TRP administered via intragastric gavage on energy- and palatability-induced feeding in mice. We sought to identify central mechanisms through which TRP suppresses appetite. Effects of TRP on consumption of energy-dense and energy-dilute tastants were established in mice stimulated to eat by energy deprivation or palatability. A conditioned taste aversion (CTA) paradigm was used to assess whether hypophagia is unrelated to sickness. c-Fos immunohistochemistry was employed to detect TRP-induced activation of feeding-related brain sites and of oxytocin (OT) neurons, a crucial component of satiety circuits. Also, expression of OT mRNA was assessed with real-time PCR. The functional importance of OT in mediating TRP-driven hypophagia was substantiated by showing the ability of OT receptor blockade to abolish TRP-induced decrease in feeding. TRP reduced intake of energy-dense standard chow in deprived animals and energy-dense palatable chow in sated mice. Anorexigenic doses of TRP did not cause a CTA. TRP failed to affect intake of palatable yet calorie-dilute or noncaloric solutions (10% sucrose, 4.1% Intralipid or 0.1% saccharin) even for TRP doses that decreased water intake in thirsty mice. Fos analysis revealed that TRP increases activation of several key feeding-related brain areas, especially in the brain stem and hypothalamus. TRP activated hypothalamic OT neurons and increased OT mRNA levels, whereas pretreatment with an OT antagonist abolished TRP-driven hypophagia. We conclude that intragastric TRP decreases food and water intake, and TRP-induced hypophagia is partially mediated via central circuits that encompass OT.

year: 2018

title: The role of mānuka (Leptospermum scoparium) riparian plantings in the mitigation of diffuse agricultural nitrogen

authors: Adamson, Olivia María

subjects: Manuka

abstract: The disruption of nutrient cycles in agricultural settings, particularly pastoral farming, is responsible for up to 70% of the nitrogen (N) loads entering streams in New Zealand (NZ) — resulting in the widespread degradation of freshwater ecosystems. Riparian plantings are one strategy to mitigate the losses of N from land to water, removing N by denitrification and plant uptake. Some types of vegetation are more effective than others at intercepting N, due to their ecology, impact on soil quality and root exudates. Mānuka (Leptospermum scoparium) is a plant native to NZ, and the species could be a good candidate to mitigate N losses due its ability to tolerate high N loads and co-benefits such as farm diversification through apiculture or essential oil production. Previous work also suggests that L. scoparium could be a biological nitrification inhibitor (BNI), limiting nitrate (NO₃⁻) production in soil.

The aim of this study was to investigate the potential of mānuka to intercept and remove N in an experimental riparian buffer in Lake Waikare. Currently, the lake is eutrophic due to high nutrient and sediment inputs. Significant restoration efforts have been made in recent years, led by many hapuu around the lake. All are very passionate and determined to recover the mauri of this ecosystem and reconnect the people to the lake, as well as provide economic opportunities. The riparian band had been established for four years and was set up as a series of experimental plots with different vegetation types, including plots solely in mānuka, and grassed controls. The plots are on a Perch- Gley Ultic Soil underlain by a slowly permeable clay layer— the Hamilton Ash. Further, the study sought to explore the relationship between soil physical properties and N cycling, and to identify influences expected by the local hydrology— as there was evidence of perching and lateral flow in the site. A series of suction-cup lysimeters were installed and pore water was sampled seven times between May and July 2021. Samples were analysed for total N (TN), total Kjeldahl N (TKN), NO₃⁻ and ammonium (NH₄⁺).

The results show that the riparian buffer is effectively removing N from subsurface flows, with TN declining from an average of 9.32 mg/l at 1 m into the buffer to 2.03 mg/l at 7 m. Although N concentrations were higher under mānuka, the total amount of N extracted from those plots was 21% less due to high rainfall interception by the canopy (63.9%), limiting the transport of the solute. Indicators of soil physical quality, bulk density (ρb) and macroporosity (MP), were investigated as potential causes for differences in the movement of N. There was a 17% improvement in ρb, and 38% improvement in MP relative to 2017 measurements, before the riparian band was established. No appreciable differences in soil physical properties were found between vegetation types at this early stage in the inception of the riparian buffer, although changes are likely to occur as the mānuka trees mature and the impact of roots is more developed. Shallow wells were deployed to monitor the dynamics of the water table, as there was evidence of winter perching. Dip wells demonstrated the existence of a short- lived perched water table, resulting in lateral flow, and likely impacting the degree of soil gleying in different parts of the riparian band. Water and contaminants are likely to move laterally over the Hamilton Ash towards the drain, supported by the accumulation of NO₃⁻ at the boundary with the clay layer.
Future work should be devoted to better quantifying NO₃⁻ leaching from the riparian plot by incorporating a drainage model, as well as further investigating the relative importance of N removal pathways at this site (i.e. denitrification and plant uptake)— including the potential for the lower part of the riparian band, closest to the drain, to become a hotspot for nitrous oxide (N₂O) emissions. It would also be of value to revisit this study in 4-10 years to explore how the buffer impacts soil quality and N dynamics in the subsurface as it matures.

text: The role of mānuka (Leptospermum scoparium) riparian plantings in the mitigation of diffuse agricultural nitrogen The disruption of nutrient cycles in agricultural settings, particularly pastoral farming, is responsible for up to 70% of the nitrogen (N) loads entering streams in New Zealand (NZ) — resulting in the widespread degradation of freshwater ecosystems. Riparian plantings are one strategy to mitigate the losses of N from land to water, removing N by denitrification and plant uptake. Some types of vegetation are more effective than others at intercepting N, due to their ecology, impact on soil quality and root exudates. Mānuka (Leptospermum scoparium) is a plant native to NZ, and the species could be a good candidate to mitigate N losses due its ability to tolerate high N loads and co-benefits such as farm diversification through apiculture or essential oil production. Previous work also suggests that L. scoparium could be a biological nitrification inhibitor (BNI), limiting nitrate (NO₃⁻) production in soil.

The aim of this study was to investigate the potential of mānuka to intercept and remove N in an experimental riparian buffer in Lake Waikare. Currently, the lake is eutrophic due to high nutrient and sediment inputs. Significant restoration efforts have been made in recent years, led by many hapuu around the lake. All are very passionate and determined to recover the mauri of this ecosystem and reconnect the people to the lake, as well as provide economic opportunities. The riparian band had been established for four years and was set up as a series of experimental plots with different vegetation types, including plots solely in mānuka, and grassed controls. The plots are on a Perch- Gley Ultic Soil underlain by a slowly permeable clay layer— the Hamilton Ash. Further, the study sought to explore the relationship between soil physical properties and N cycling, and to identify influences expected by the local hydrology— as there was evidence of perching and lateral flow in the site. A series of suction-cup lysimeters were installed and pore water was sampled seven times between May and July 2021. Samples were analysed for total N (TN), total Kjeldahl N (TKN), NO₃⁻ and ammonium (NH₄⁺).

The results show that the riparian buffer is effectively removing N from subsurface flows, with TN declining from an average of 9.32 mg/l at 1 m into the buffer to 2.03 mg/l at 7 m. Although N concentrations were higher under mānuka, the total amount of N extracted from those plots was 21% less due to high rainfall interception by the canopy (63.9%), limiting the transport of the solute. Indicators of soil physical quality, bulk density (ρb) and macroporosity (MP), were investigated as potential causes for differences in the movement of N. There was a 17% improvement in ρb, and 38% improvement in MP relative to 2017 measurements, before the riparian band was established. No appreciable differences in soil physical properties were found between vegetation types at this early stage in the inception of the riparian buffer, although changes are likely to occur as the mānuka trees mature and the impact of roots is more developed. Shallow wells were deployed to monitor the dynamics of the water table, as there was evidence of winter perching. Dip wells demonstrated the existence of a short- lived perched water table, resulting in lateral flow, and likely impacting the degree of soil gleying in different parts of the riparian band. Water and contaminants are likely to move laterally over the Hamilton Ash towards the drain, supported by the accumulation of NO₃⁻ at the boundary with the clay layer.
Future work should be devoted to better quantifying NO₃⁻ leaching from the riparian plot by incorporating a drainage model, as well as further investigating the relative importance of N removal pathways at this site (i.e. denitrification and plant uptake)— including the potential for the lower part of the riparian band, closest to the drain, to become a hotspot for nitrous oxide (N₂O) emissions. It would also be of value to revisit this study in 4-10 years to explore how the buffer impacts soil quality and N dynamics in the subsurface as it matures.

year: 2021