| 1. |
- Marchant, Rob, et al.
(författare)
-
Drivers and trajectories of land cover change in East Africa : Human and environmental interactions from 6000 years ago to present
- 2018
-
Ingår i: Earth-Science Reviews. - : Elsevier. - 0012-8252 .- 1872-6828. ; 178, s. 322-378
-
Tidskriftsartikel (refereegranskat)abstract
- East African landscapes today are the result of the cumulative effects of climate and land-use change over millennial timescales. In this review, we compile archaeological and palaeoenvironmental data from East Africa to document land-cover change, and environmental, subsistence and land-use transitions, over the past 6000 years. Throughout East Africa there have been a series of relatively rapid and high-magnitude environmental shifts characterised by changing hydrological budgets during the mid- to late Holocene. For example, pronounced environmental shifts that manifested as a marked change in the rainfall amount or seasonality and subsequent hydrological budget throughout East Africa occurred around 4000, 800 and 300 radiocarbon years before present (yr BP). The past 6000 years have also seen numerous shifts in human interactions with East African ecologies. From the mid-Holocene, land use has both diversified and increased exponentially, this has been associated with the arrival of new subsistence systems, crops, migrants and technologies, all giving rise to a sequence of significant phases of land-cover change. The first large-scale human influences began to occur around 4000 yr BP, associated with the introduction of domesticated livestock and the expansion of pastoral communities. The first widespread and intensive forest clearances were associated with the arrival of iron-using early farming communities around 2500 yr BP, particularly in productive and easily-cleared mid-altitudinal areas. Extensive and pervasive land-cover change has been associated with population growth, immigration and movement of people. The expansion of trading routes between the interior and the coast, starting around 1300 years ago and intensifying in the eighteenth and nineteenth centuries CE, was one such process. These caravan routes possibly acted as conduits for spreading New World crops such as maize (Zea mays), tobacco (Nicotiana spp.) and tomatoes (Solanum lycopersicum), although the processes and timings of their introductions remains poorly documented. The introduction of southeast Asian domesticates, especially banana (Musa spp.), rice (Oryza spp.), taro (Colocasia esculenta), and chicken (Gallus gallus), via transoceanic biological transfers around and across the Indian Ocean, from at least around 1300 yr BP, and potentially significantly earlier, also had profound social and ecological consequences across parts of the region. Through an interdisciplinary synthesis of information and metadatasets, we explore the different drivers and directions of changes in land-cover, and the associated environmental histories and interactions with various cultures, technologies, and subsistence strategies through time and across space in East Africa. This review suggests topics for targeted future research that focus on areas and/or time periods where our understanding of the interactions between people, the environment and land-cover change are most contentious and/or poorly resolved. The review also offers a perspective on how knowledge of regional land-use change can be used to inform and provide perspectives on contemporary issues such as climate and ecosystem change models, conservation strategies, and the achievement of nature-based solutions for development purposes.
|
|
| 2. |
- Crowther, Alison, et al.
(författare)
-
Coastal Subsistence, Maritime Trade, and the Colonization of Small Offshore Islands in Eastern African Prehistory
- 2016
-
Ingår i: Journal of Island & Coastal Archaeology. - : Informa UK Limited. - 1556-4894 .- 1556-1828. ; 11:2, s. 211-237
-
Tidskriftsartikel (refereegranskat)abstract
- Recent archaeological research has firmly established eastern Africa's offshore islands as important localities for understanding the region's pre-Swahili maritime adaptations and early Indian Ocean trade connections. While the importance of the sea and small offshore islands to the development of urbanized and mercantile Swahili societies has long been recognized, the formative stages of island colonizationand in particular the processes by which migrating Iron Age groups essentially became maritimeare still relatively poorly understood. Here we present the results of recent archaeological fieldwork in the Mafia Archipelago, which aims to understand these early adaptations and situate them within a longer-term trajectory of island settlement and pre-Swahili cultural developments. We focus on the results of zooarchaeological, archaeobotanical, and material culture studies relating to early subsistence and trade on this island to explore the changing significance of marine resources to the local economy. We also discuss the implications of these maritime adaptations for the development of local and long-distance Indian Ocean trade networks.
|
|
| 3. |
- Streit, Sven, et al.
(författare)
-
Burden of cardiovascular disease across 29 countries and GPs' decision to treat hypertension in oldest-old.
- 2018
-
Ingår i: Scandinavian Journal of Primary Health Care. - : Taylor & Francis. - 0281-3432 .- 1502-7724. ; 36:1, s. 89-98
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES: We previously found large variations in general practitioner (GP) hypertension treatment probability in oldest-old (>80 years) between countries. We wanted to explore whether differences in country-specific cardiovascular disease (CVD) burden and life expectancy could explain the differences.DESIGN: This is a survey study using case-vignettes of oldest-old patients with different comorbidities and blood pressure levels. An ecological multilevel model analysis was performed.SETTING: GP respondents from European General Practice Research Network (EGPRN) countries, Brazil and New Zeeland.SUBJECTS: This study included 2543 GPs from 29 countries.MAIN OUTCOME MEASURES: GP treatment probability to start or not start antihypertensive treatment based on responses to case-vignettes; either low (<50% started treatment) or high (≥50% started treatment). CVD burden is defined as ratio of disability-adjusted life years (DALYs) lost due to ischemic heart disease and/or stroke and total DALYs lost per country; life expectancy at age 60 and prevalence of oldest-old per country.RESULTS: Of 1947 GPs (76%) responding to all vignettes, 787 (40%) scored high treatment probability and 1160 (60%) scored low. GPs in high CVD burden countries had higher odds of treatment probability (OR 3.70; 95% confidence interval (CI) 3.00-4.57); in countries with low life expectancy at 60, CVD was associated with high treatment probability (OR 2.18, 95% CI 1.12-4.25); but not in countries with high life expectancy (OR 1.06, 95% CI 0.56-1.98).CONCLUSIONS: GPs' choice to treat/not treat hypertension in oldest-old was explained by differences in country-specific health characteristics. GPs in countries with high CVD burden and low life expectancy at age 60 were most likely to treat hypertension in oldest-old. Key Points • General practitioners (GPs) are in a clinical dilemma when deciding whether (or not) to treat hypertension in the oldest-old (>80 years of age). • In this study including 1947 GPs from 29 countries, we found that a high country-specific cardiovascular disease (CVD) burden (i.e. myocardial infarction and/or stroke) was associated with a higher GP treatment probability in patients aged >80 years. • However, the association was modified by country-specific life expectancy at age 60. While there was a positive association for GPs in countries with a low life expectancy at age 60, there was no association in countries with a high life expectancy at age 60. • These findings help explaining some of the large variation seen in the decision as to whether or not to treat hypertension in the oldest-old.
|
|
| 4. |
- Streit, Sven, et al.
(författare)
-
Variation in GP decisions on antihypertensive treatment in oldest-old and frail individuals across 29 countries.
- 2017
-
Ingår i: BMC Geriatrics. - : BioMed Central. - 1471-2318 .- 1471-2318. ; 17:1, s. 1-7
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In oldest-old patients (>80), few trials showed efficacy of treating hypertension and they included mostly the healthiest elderly. The resulting lack of knowledge has led to inconsistent guidelines, mainly based on systolic blood pressure (SBP), cardiovascular disease (CVD) but not on frailty despite the high prevalence in oldest-old. This may lead to variation how General Practitioners (GPs) treat hypertension. Our aim was to investigate treatment variation of GPs in oldest-olds across countries and to identify the role of frailty in that decision.METHODS: Using a survey, we compared treatment decisions in cases of oldest-old varying in SBP, CVD, and frailty. GPs were asked if they would start antihypertensive treatment in each case. In 2016, we invited GPs in Europe, Brazil, Israel, and New Zealand. We compared the percentage of cases that would be treated per countries. A logistic mixed-effects model was used to derive odds ratio (OR) for frailty with 95% confidence intervals (CI), adjusted for SBP, CVD, and GP characteristics (sex, location and prevalence of oldest-old per GP office, and years of experience). The mixed-effects model was used to account for the multiple assessments per GP.RESULTS: The 29 countries yielded 2543 participating GPs: 52% were female, 51% located in a city, 71% reported a high prevalence of oldest-old in their offices, 38% and had >20 years of experience. Across countries, considerable variation was found in the decision to start antihypertensive treatment in the oldest-old ranging from 34 to 88%. In 24/29 (83%) countries, frailty was associated with GPs' decision not to start treatment even after adjustment for SBP, CVD, and GP characteristics (OR 0.53, 95%CI 0.48-0.59; ORs per country 0.11-1.78).CONCLUSIONS: Across countries, we found considerable variation in starting antihypertensive medication in oldest-old. The frail oldest-old had an odds ratio of 0.53 of receiving antihypertensive treatment. Future hypertension trials should also include frail patients to acquire evidence on the efficacy of antihypertensive treatment in oldest-old patients with frailty, with the aim to get evidence-based data for clinical decision-making.
|
|
| 5. |
- van der Ploeg, Milly A., et al.
(författare)
-
Patient Characteristics and General Practitioners' Advice to Stop Statins in Oldest-Old Patients : a Survey Study Across 30 Countries
- 2019
-
Ingår i: Journal of general internal medicine. - : Springer. - 0884-8734 .- 1525-1497. ; 34:9, s. 1751-1757
-
Tidskriftsartikel (refereegranskat)abstract
- Background Statins are widely used to prevent cardiovascular disease (CVD). With advancing age, the risks of statins might outweigh the potential benefits. It is unclear which factors influence general practitioners' (GPs) advice to stop statins in oldest-old patients. Objective To investigate the influence of a history of CVD, statin-related side effects, frailty and short life expectancy, on GPs' advice to stop statins in oldest-old patients. Design We invited GPs to participate in this case-based survey. GPs were presented with 8 case vignettes describing patients > 80 years using a statin, and asked whether they would advise stopping statin treatment. Main Measures Cases varied in history of CVD, statin-related side effects and frailty, with and without shortened life expectancy (< 1 year) in the context of metastatic, non-curable cancer. Odds ratios adjusted for GP characteristics (ORadj) were calculated for GPs' advice to stop. Key Results Two thousand two hundred fifty GPs from 30 countries participated (median response rate 36%). Overall, GPs advised stopping statin treatment in 46% (95%CI 45-47) of the case vignettes; with shortened life expectancy, this proportion increased to 90% (95CI% 89-90). Advice to stop was more frequent in case vignettes without CVD compared to those with CVD (ORadj 13.8, 95%CI 12.6-15.1), with side effects compared to without ORadj 1.62 (95%CI 1.5-1.7) and with frailty (ORadj 4.1, 95%CI 3.8-4.4) compared to without. Shortened life expectancy increased advice to stop (ORadj 50.7, 95%CI 45.5-56.4) and was the strongest predictor for GP advice to stop, ranging across countries from 30% (95%CI 19-42) to 98% (95% CI 96-99). Conclusions The absence of CVD, the presence of statin-related side effects, and frailty were all independently associated with GPs' advice to stop statins in patients aged > 80 years. Overall, and within all countries, cancer-related short life expectancy was the strongest independent predictor of GPs' advice to stop statins.
|
|
| 6. |
|
|
