In this study, historical surface solar radiation (1850–2005) and future photovoltaic power output (2006–2100) are analyzed to investigate the spatial distribution and long-term variation in global ...solar energy based on the Coupled Model Intercomparison Project Phase 5 (CMIP5) models and the Global Energy Balance Archive (GEBA) database. The results show that global mean surface solar radiation significantly decreased by 0.014 W m−2 year−1 in 1850–2005. According to the Model for Interdisciplinary Research on Climate (MIROC5), surface solar radiation significantly decreased by 3.42 W m−2 year−1 in 1951–1992 and increased by 4.75 W m−2 year−1 in 1993–2005. Global dimming and brightening were observed before and after the 1990s, respectively. The transition of surface solar radiation from dimming to brightening in Europe and the southeastern United States was detected in the 1980s. Stations in Northeast China, Japan, Southeast Africa, the Middle East, and the west coast of India all showed renewed decreasing trends after the 1990s. The direct and indirect effects of anthropogenic aerosols and cloudiness in different periods and regions were the main causes of the changes. To better understand the utilization of global solar energy, global potential photovoltaic power outputs were estimated in future scenarios with an empirical model. Significant increases in potential photovoltaic power are expected in East Asia, Europe, Central Africa and Central America in 2006–2100. The largest increase is expected in central China, where increases are occurring at 3 kWh m−2 year−1. Significantly decreasing potential photovoltaic power is observed in North Africa, the Middle East, Central Asia and Australia. The greatest decrease is observed in the Tibetan Plateau area (approximately −3.0 kWh m−2 year−1 in 2006–2100). With respect to the global distribution of potential photovoltaic power output, large quantities of photovoltaic power are distributed in the northern and southern parts of Africa, the Middle East, the Tibetan Plateau area, the west coasts of North and South America and most of Australia. The yearly mean sum photovoltaic power in these regions is larger than 2000 kW h m−2. Due to the long-term decreasing photovoltaic power (0.67 kWh m−2 year−1) expected worldwide in 2006–2100, effective and rational utilization of solar energy is of great importance.
Annual PV power for 34 CMIP5 model mean and MIRCO5 in historical experiments, RCP4.5 and RCP8.5 scenarios. Display omitted
•Global mean Surface downwelling shortwave radiation decreased during 1850–2005.•The predicted global mean potential photovoltaic power will decrease from 2006 to 2100.•High photovoltaic power is located in North Africa, Middle East, Central Asia and Australia.•Photovoltaic power in East Asia, Europe, Central Africa and America will increase in future.
There has been a growing interest in jatropha- and sugarcane-based biofuels across Sub-Sahara Africa. Biofuel expansion in the region reflects policy concerns related to energy security, poverty ...alleviation and economic development. However, biofuels have also been linked to numerous environmental and socioeconomic impacts such as GHG emissions, water availability/pollution, deforestation, biodiversity loss, poverty alleviation, energy security, loss of access to land and food security to name just a few. Yet there is (a) an insufficient understanding of these impacts (and their synergies) in Sub-Sahara Africa, and (b) a lack of policies that could regulate the biofuel sector and ensure its viability while at the same time preventing its negative impact. The aim of this literature review is to synthesize the current knowledge about biofuel impacts in Africa and to identify priority policy areas that should be targeted for enhancing biofuel sustainability in the continent. The findings of this review indicate that biofuel impacts can be positive or negative depending on several factors such as the feedstock, the environmental/socio-economic context of biofuel production, and the policy instruments in place during biofuel production, use and trade. In most cases there are significant trade-offs but at least part of the negative impacts can be mitigated through careful planning. The incomplete and piecemeal understanding of these trade-offs combined with agronomic, institutional and market failures are currently the most important barriers for the viability and sustainability of biofuel investments in the continent.
While it is commonly believed that democracy influences public service provision, comparably few studies have assessed how recent democratisation in developing countries has impacted tangible public ...service outcomes for economically deprived population shares. Using panel data from 46 sub-Saharan African countries between 1990 and 2010 as well as qualitative country case examples from Ghana, Swaziland, Uganda, Senegal and Rwanda, this paper examines considerable and growing rural electrification variations in terms of political, economic and demographic variables. The analyses suggest that democracy is strongly associated with rural electrification increases and rural versus urban electrification inequality decreases in sub-Saharan Africa. This result is robust to a variety of political, economic and demographic control variables as well as different econometric modelling assumptions. The paper further presents novel multi-variant evidence supporting that contested elections with strong oppositions as well as effective policy implementing institutions may act as intervening institutional mechanisms that explain a part of democracy's association with rural electricity provision. Higher income per capita, national savings and population densities may further foster rural electrification, while high foreign aid shares of GDP and rural population percentages may pose challenges to access equality.
•Democracy helps to understand sub-Saharan African rural electrification variations.•Democracy is furthermore associated with decreasing electrification inequality.•Strong oppositions and effective institutions may be intervening mechanisms.•Favourable economic and demographic factors seem to foster rural electrification.
The study sought to identify the extent to which Advance Care Planning (ACP) is practised by palliative care health professionals providing care to patients with advanced cancer and their families in ...Uganda.
A mixed methods study design using qualitative and quantitative methods was used for the assessment. In-depth interviews with a group of nine highly experienced health professionals were conducted using a semi-structured interview guide. Quantitative data were retrieved and analysed from a survey administered to 124 health professionals of whom only 57 (45.9%) responded. The qualitative data were analysed using inductive thematic analysis and descriptive analysis was used for the quantitative data.
Of the 57 health professionals who participated in the survey, 87% were aware of ACP and 55% reported regular practice. Fifty-five (55%) percent reported regular provision of ACP for their patients and 46% reported engaging in informal ACP practices. However, 58.5% resp. 37.5% reported that they routinely provide ACP to more than 50% resp. 75% of their patients. A group of nine highly experienced palliative care professionals had a pooled ACP prevalence of only 1.2%. There was a generally good attitude towards ACP with 98.2% acknowledging that patients should be able to determine their future care. However, 32% reported being uncomfortable withholding or withdrawing life sustaining treatment. There are a number of socio-cultural beliefs and barriers, for instance that discussing death and dying is a “taboo”, as well as witchcraft, family influence in decision-making, religious beliefs that do not agree with palliative care practices and a preference to use aggressive treatment like chemotherapy for terminally ill, etc. Institutional barriers like lack of a legal framework for ACP, limited time for health professionals to engage in ACP and other patient factors such as denial of diagnosis and collusion to withhold information from patients were reported by 78.2% resp. 84% of the respondents.
Despite the good awareness and attitude to ACP, there is a range of barriers that are affecting the implementation of ACP in Uganda. There is need for development of a legal framework for ACP, more research to understand the contextual barriers and develop appropriate education and public sensitisation programs.
Ziel der Studie war es zu ermitteln, inwieweit Palliativmedizinerinnen und -mediziner, die Patientinnen und Patienten mit fortgeschrittenen Krebserkrankungen und deren Familien in Uganda betreuen, Advance Care Planning (ACP) praktizieren.
Für die Bewertung wurde ein Mixed-Methods-Design mit qualitativen und quantitativen Methoden verwendet. Mit einer Gruppe von neun sehr erfahrenen Gesundheitsfachkräften wurden anhand eines semistrukturierten Interviewleitfadens ausführliche Interviews geführt. Aus einer Umfrage unter 124 Gesundheitsfachkräften, auf die jedoch nur 57 (45,9%) antworteten, wurden quantitative Daten gewonnen und ausgewertet. Die qualitativen Daten wurden induktiv mit der Methode der thematischen Analyse und die quantitativen Daten mittels deskriptiver Analyse ausgewertet.
Von den 57 Gesundheitsfachkräften, die an der Umfrage teilnahmen, hatten 87% Kenntnis von ACP, und 55% gaben an, ACP regelmäßig zu praktizieren. 55% gaben an, ihren Patientinnen und Patienten regelmäßig ACP anzubieten, und 46% berichteten von der Durchführung informeller ACP-Praktiken. Allerdings gaben nur 58,5% bzw. 37,5% an, mehr als 50% bzw. 75% ihrer Patientinnen und Patienten routinemäßig ein ACP-Angebot zu machen. In einer Gruppe von neun sehr erfahrenen Palliativmedizinerinnen und -medizinern fand sich jedoch eine gepoolte ACP-Prävalenz von nur 1,2%. Die Einstellung zu ACP war generell positiv, wobei 98,2% der Befragten die Meinung vertraten, dass Patientinnen und Patienten über ihre zukünftige Versorgung selbst entscheiden können sollten. 32% der Befragten gaben jedoch an, dass es ihnen schwerfiele, den Betroffenen lebenserhaltende Maßnahmen vorzuenthalten oder diese abzubrechen. Hindernisse auf soziokultureller Ebene sind zum Beispiel der Glaube, dass Gespräche über Tod und Sterben ein Tabu darstellen, Hexenglauben, der Einfluss der Familie auf die Entscheidungsfindung, religiöse Überzeugungen, die nicht mit palliativmedizinischen Maßnahmen vereinbar sind, sowie die Bevorzugung aggressiver Behandlungen wie Chemotherapie für unheilbar Kranke etc. Weiterhin benannten 78,2% bzw. 84% der Befragten institutionelle Barrieren wie das Fehlen eines gesetzlichen Rahmenwerks für ACP, die begrenzte Zeit, die Gesundheitsfachkräften zur Verfügung steht, um sich mit ACP zu befassen, und sonstige Patientenfaktoren wie die Leugnung der Diagnose und heimliche Absprachen mit dem Ziel, der erkrankten Person Informationen vorzuenthalten.
Ungeachtet der vorhandenen Kenntnisse und der positiven Einstellung gegenüber ACP gibt es eine Reihe von Hindernissen, welche die Implementierung von ACP in Uganda beeinträchtigen. Es muss ein Rechtsrahmen für ACP geschaffen werden, es muss mehr geforscht werden, um die kontextuellen Hindernisse zu verstehen, und es müssen geeignete Aufklärungsangebote und Programme zur Sensibilisierung der Öffentlichkeit entwickelt werden.
Wetlands are valuable ecosystems providing a variety of important ecosystem services such as food supply and flood control. Due to increasing anthropogenic influences and the impact of climate ...change, wetlands are increasingly threatened and degraded. An effective monitoring of wetlands is therefore necessary to preserve and restore these endangered ecosystems. Earth Observation (EO) data offer a great potential to support cost-effective and large-scale monitoring of wetlands. Current state-of-the-art methods for wetland mapping, however, require large training data and manual effort and can therefore only be locally applied. The focus of this study is to evaluate a methodology for large-scale and highly automated wetland mapping based on current EO data streams. For this purpose, an algorithm for water and wetness detection based on multi-temporal optical imagery and topographic data is presented. Suitable spectral indices sensitive to water and wetness were identified using feature selection methods based on mutual information between optical indices and occurrence of water and wetness. In combination with the Topographic Wetness Index (TWI), these were used to derive monthly water and wetness masks using a dynamic thresholding approach. Aggregating all observations corrected for seasonal bias yielded flooding and wetness frequencies and the Water Wetness Presence (or Probability) Index (WWPI) as an indicator for wetland occurrence or a pre-inventory. To demonstrate the applicability of the proposed method, the algorithm is demonstrated at three study sites with different wetland types in Kenya/Uganda, Algeria, and Austria using Sentinel-2 MultiSpectral Instrument (MSI) imagery. For all sites, the overall accuracy was above 92%. User's and producer's accuracies were higher for water (>96%) than for wetness (>75%). Due to the high degree of automation and low processing time, the proposed method is applicable on a large scale and has already been applied during the production of the Copernicus High Resolution Water-Wetness Layer and within the European Space Agency (ESA) project GlobWetland Africa.
•A highly automated algorithm for water and wetness detection is proposed.•Tile-based image thresholding is applied to spectral and topographic indices.•Water is automatically detected with very high accuracy across different regions.•The Water and Wetness Probability Index provides a basic wetland inventory.
This article analyses the contingent factors which influence the relationship between entrepreneurial passion and venture profit. While research on entrepreneurial passion is burgeoning, studies that ...analyse contingent factors and boundary conditions surrounding entrepreneurial passion theory are sparse. Moreover, we know very little about how the influence of entrepreneurial passion on venture outcomes might vary in emerging markets, typically characterised by higher levels of bureaucratic involvement and institutional deficiencies. We extend entrepreneurial passion theory by testing a contingent model that evaluates the influence of political connections and environmental dynamism on the relationship between entrepreneurial passion and venture profit. More specifically, we examine the role of passion on venture profit and the moderating impact of political connections and perceived environmental dynamism. Using time-lagged data from 231 small businesses in Ghana, we find that political connections amplify the potency of passion as a driver of venture profit. In addition, we find that this interaction is conditioned by environmental dynamism; specifically, the moderating effect of political connections on the relationship between entrepreneurial passion and venture profit is stronger when dynamism is high. Our fine-grained analysis increases the conceptual scope and generalisability of entrepreneurial passion to non-Western contexts.
This study attempts to provide some understanding about SMEs' access to finance within theWest African sub-region with particular interest in establishing whether there are similarities and/or ...differences in the determinants of SMEs access to finance across countries in SSA. For robustness sake, we developed both subjective and objective measures of access to finance. Using data from World Bank's Enterprise Survey data set, we examine the determinants of access to finance both at the sub-regional level and at the country-level. We found that, generally, at the sub-regional level, access to finance is strongly determined by factors such as firm size, ownership, strength of legal rights, and depth of credit information, firm's export orientation and the experience of the top manager. However, we found important differences in the correlates of firms' access to finance at the country level. The findings of this study therefore have important implications for policy.
Resilience in the global food system Seekell, David; Carr, Joel; Dell'Angelo, Jampel ...
Environmental research letters,
02/2017, Letnik:
12, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Ensuring food security requires food production and distribution systems function throughout disruptions. Understanding the factors that contribute to the global food system's ability to respond and ...adapt to such disruptions (i.e. resilience) is critical for understanding the long-term sustainability of human populations. Variable impacts of production shocks on food supply between countries indicate a need for national-scale resilience indicators that can provide global comparisons. However, methods for tracking changes in resilience have had limited application to food systems. We developed an indicator-based analysis of food systems resilience for the years 1992-2011. Our approach is based on three dimensions of resilience: socio-economic access to food in terms of income of the poorest quintile relative to food prices, biophysical capacity to intensify or extensify food production, and the magnitude and diversity of current domestic food production. The socio-economic indicator has a large variability, but with low values concentrated in Africa and Asia. The biophysical capacity indicator is highest in Africa and Eastern Europe, in part because of a high potential for extensification of cropland and for yield gap closure in cultivated areas. However, the biophysical capacity indicator has declined globally in recent years. The production diversity indicator has increased slightly, with a relatively even geographic distribution. Few countries had exclusively high or low values for all indicators. Collectively, these results are the basis for global comparisons of resilience between countries, and provide necessary context for developing generalizations about resilience in the global food system.
Despite its epidemiological importance, the time Plasmodium parasites take to achieve development in the vector mosquito (the extrinsic incubation period, EIP) remains poorly characterized. A novel ...non-destructive assay designed to estimate EIP in single mosquitoes, and more broadly to study Plasmodium-Anopheles vectors interactions, is presented. The assay uses small pieces of cotton wool soaked in sugar solution to collect malaria sporozoites from individual mosquitoes during sugar feeding to monitor infection status over time. This technique has been tested across four natural malaria mosquito species of Africa and Asia, infected with Plasmodium falciparum (six field isolates from gametocyte-infected patients in Burkina Faso and the NF54 strain) and across a range of temperatures relevant to malaria transmission in field conditions. Monitoring individual infectious mosquitoes was feasible. The estimated median EIP of P. falciparum at 27 °C was 11 to 14 days depending on mosquito species and parasite isolate. Long-term individual tracking revealed that sporozoites transfer onto cotton wool can occur at least until day 40 post-infection. Short individual EIP were associated with short mosquito lifespan. Correlations between mosquito/parasite traits often reveal trade-offs and constraints and have important implications for understanding the evolution of parasite transmission strategies.
This article examines the role of institutional structures in the relationship between trade openness and financial development in sub‐Saharan economies. The study is based on empirical data from ...sampled sub‐Saharan African countries for a period of 1996–2017. The system generalized method of moment was employed to estimate the models. The findings suggest that, even though trade openness has a positive significant influence on the level of financial development in sub‐Saharan African economies, this relationship is enhanced through the presence of good institutions in these economies. Thus, for these economies to realize the full benefit of the effect of trade openness on financial development, they need to strengthen their institutions.
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