| 1. |
- Murray, Christopher J. L., et al.
(författare)
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Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017
- 2018
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Ingår i: The Lancet. - 1474-547X .- 0140-6736. ; 392:10159, s. 1995-2051
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Tidskriftsartikel (refereegranskat)abstract
- Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49·4% (95% uncertainty interval [UI] 46·4–52·0). The TFR decreased from 4·7 livebirths (4·5–4·9) to 2·4 livebirths (2·2–2·5), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83·8 million people per year since 1985. The global population increased by 197·2% (193·3–200·8) since 1950, from 2·6 billion (2·5–2·6) to 7·6 billion (7·4–7·9) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2·0%; this rate then remained nearly constant until 1970 and then decreased to 1·1% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2·5% in 1963 to 0·7% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2·7%. The global average age increased from 26·6 years in 1950 to 32·1 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59·9% to 65·3%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1·0 livebirths (95% UI 0·9–1·2) in Cyprus to a high of 7·1 livebirths (6·8–7·4) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0·08 livebirths (0·07–0·09) in South Korea to 2·4 livebirths (2·2–2·6) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0·3 livebirths (0·3–0·4) in Puerto Rico to a high of 3·1 livebirths (3·0–3·2) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2·0% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation.
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| 2. |
- Posthouwer, Chantal, et al.
(författare)
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Quantitative market survey of non-woody plants sold at Kariakoo Market in Dar es Salaam, Tanzania
- 2018
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Ingår i: Journal of Ethnopharmacology. - : Elsevier BV. - 0378-8741 .- 1872-7573. ; 222, s. 280-287
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Tidskriftsartikel (refereegranskat)abstract
- Ethnopharmacological relevance: In Tanzania, traditional medicine plays a significant role in health care and local economies based on the harvesting, trade and sale of medicinal plant products. The majority of this plant ma- terial is said to originate from wild sources, and both traditional healers and vendors are concerned about the increasing scarcity of certain species.Aim of the study: A market survey of non-powdered, non-woody medicinal plants was conducted at Kariakoo Market in Dar es Salaam, the major hub for medicinal plant trade in Tanzania, to assess sustainability of traded herbal medicine. Materials and Methods: For this study, fresh and dried herbs, seeds and fruits were collected and interviews were conducted to obtain information on vernacular names, preparation methods, monthly sales, uses and prices. Bundles of herbal medicine offered for sale were weighed and counted to calculate the value and volumes of daily stock at the market.Results: A total of 71 medicinal plant products belonging to 62–67 different species from at least 41 different plant families were identified. We identified 45 plant products to species level, 20 products to genus level and four to family level. Plant species most encountered at the market were Suregada zanzibariensis, Myrothamnus flabellifolia and Sclerocarya birrea. The major use categories reported by the vendors were ritual purposes, di- gestive disorders and women's health. Annual sales are estimated to be in excess of 30 t and close to 200,000 USD, and trade in herbal medicine at Kariakoo Market provides subsistence income to many local vendors. Conclusions: A large diversity of wild-harvested plant species is traded as medicinal products in Tanzania, in- cluding species listed on CITES Appendices. Identifying and monitoring temporal changes in availability per season and from year to year will reveal which species are most affected by this trade, and help relevant au- thorities in Tanzania to find alternative sources of income for dependent stakeholders and initiate targeted efforts to protect threatened plant species.
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| 3. |
- Veldman, Sarina
(författare)
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Markets, mixtures and molecular methods : Investigating medicinal plant and edible orchid diversity in Tanzania and Zambia
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Medicinal plants are an important source of primary healthcare for many people in Tanzania. These medicinal plants are harvested from the wild, and increasing commercial trade poses a serious threat to local plant populations. Currently it is unknown which species are traded and in what amounts. Across the southwestern border in Zambia, the traditional dish chikanda has transformed from a niche product to being a mainstream delicacy. One of the main ingredients are wild-harvested orchids, and these have become depleted throughout the country as an effect of the increased trade. It is unclear which orchid species are targeted and might be at risk of overharvesting. The aims of my doctorate are to map harvest and trade of Tanzanian medicinal plants and Tanzanian and Zambian edible orchids, to investigate whether species that are traded on local markets can be identified using molecular methods such as DNA barcoding and metabarcoding and identify conservation issues arising from wild-harvesting of medicinal plants and edible orchids.In Paper I DNA metabarcoding analysis of Tanzanian chikanda cake show the presence of 17 different orchids species belonging to the genera Disa, Satyrium and Habenaria, and in Paper V the analysis of chikanda tubers sold on Zambian markets reveals that at least 16 orchid species from 6 different orchid genera are targeted in local orchid trade. Paper II describes a quantitative market survey of the non-woody, non-powdered medicinal plants sold on Kariakoo market in Dar-es-Salaam that shows that a total of 67 species are traded in an annual volume of nearly 31 tonnes of fresh and dried medicinal leaves, seeds and fruits with an estimated value of 200,000 USD. For Paper III 873 medicinal plant products were analysed using DNA barcoding, literature and morphology to determine which species are traded on the Dar-es-Salaam and Tanga markets. In total, 509 identifications could be made corresponding to 91 species, 124 genera and 65 plant families, and several cases of over- and under-differentiation were detected. Paper IV builds upon the identifications in Paper III to determine in what amount the medicinal plant species present at the local markets are traded and to investigate if commercial trade poses a threat to local plant populations. It was found that several of the most highly favored medicinal plants were perceived to becoming more difficult to obtain in the wild.This thesis shows that DNA barcoding is a powerful rapid identification method for morphologically unidentifiable specimens. It also shows that commercialization of wild-harvested plant products threatens local plant populations, and highlights the need for conservation measures to avoid local extinction of economically and socially important plant species.
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