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Decision making in pest management is a challenging task. While pest dynamics are often quite uncertain, such decisions are often based on tenuous assumptions of certainty (economic injury levels and marginal utility approximations). To overcome such assumptions and adequately consider uncertainty, we apply decision analysis to evaluate management strategies used by farmers in the Colombian Caribbean against the boll weevil (BW). We represent the decision to protect the crop using partial budget analysis. This allows us to capture key properties of BW control strategies, while accounting for uncertainty about pest infestation pressure, control effectiveness and cotton yield and price. Our results indicate that proactive pest management is more efficient than reactive control given the current BW infestation pressure. However, farmers may prefer the reactive strategy, since they have experienced seasons with low infestation pressure where no insecticide applications were required. The proactive strategy, in contrast, requires scheduled pesticide applications in all years. Results show that in seasons with high infestation pressure the expected revenues of the reactive strategy tend to decrease, mainly because more spray applications are required when fields are heavily infested by the weevil. Value of information analysis revealed that uncertainties related to the start of the infestation, loss damage rate and attainable yield have the greatest influence on the decision recommendation for crop protection. Narrowing these key knowledge gaps may offer additional clarity on the performance of the current management strategies and provide guidance for the development of strategies to reduce insecticide use. This is particularly important for the promotion of the proactive strategy, which, under the current infestation pressure, has potential to reduce insecticide use. While economic injury levels can only be applied to responsive measures, our approach of partial budget analysis under uncertainty allows us to assess and compare both responsive and preventive measures in the same methodological framework. This framework can be extended to non-pesticide control measures.
Oscar Burbano-Figueroa; Alexandra Sierra-Monroy; Cory Whitney; Christian Borgemeister; Eike Luedeling. Profitability of farm-scale management strategies against the boll weevil in the tropics: case study from the Colombian Caribbean. Journal of Pest Science 2021, 1 -17.
AMA StyleOscar Burbano-Figueroa, Alexandra Sierra-Monroy, Cory Whitney, Christian Borgemeister, Eike Luedeling. Profitability of farm-scale management strategies against the boll weevil in the tropics: case study from the Colombian Caribbean. Journal of Pest Science. 2021; ():1-17.
Chicago/Turabian StyleOscar Burbano-Figueroa; Alexandra Sierra-Monroy; Cory Whitney; Christian Borgemeister; Eike Luedeling. 2021. "Profitability of farm-scale management strategies against the boll weevil in the tropics: case study from the Colombian Caribbean." Journal of Pest Science , no. : 1-17.
The promotion of edible insects, including saturniid caterpillars as potential food source is widely gaining momentum. They are adequately rich in nutrients such as proteins, amino acids, fatty acids, and micronutrients. Despite saturniids being a traditional food source with economic benefits, information on their diversity, host plants and their potential distribution in Africa are lacking, which this study seeks to address. Edible saturniids and their host plants were characterized using specific primers (LepF1/LepR1 and 3F_KIM_F/1R_KIM_R, respectively). Maximum entropy (MaxENT) and GARP (genetic algorithm for ruleset production) models were used to characterize the potential distribution of commonly consumed saturniids under current and future climate scenarios. Seven species of saturniids were recorded from 11 host plants in Kenya: Gonimbrasia zambesina, Gonimbrasia krucki, Bunaea alcinoe, Gonimbrasia cocaulti, Gonimbrasia belina, Gynanisa nigra and Cirina forda. Two morphotypes of G. zambesina and B. alcinoe were recorded. These saturniid caterpillars occur twice a year except for G. cocaulti. Predictive models revealed that tropical and subtropical regions were potentially suitable for B. alcinoe and C. forda. The information generated from this study would be important to guide conservation efforts and their sustainable utilization as food in Africa.
Elizabeth Kusia; Christian Borgemeister; Fathiya Khamis; Robert Copeland; Chrysantus Tanga; Fidelis Ombura; Sevgan Subramanian. Diversity, Host Plants and Potential Distribution of Edible Saturniid Caterpillars in Kenya. Insects 2021, 12, 600 .
AMA StyleElizabeth Kusia, Christian Borgemeister, Fathiya Khamis, Robert Copeland, Chrysantus Tanga, Fidelis Ombura, Sevgan Subramanian. Diversity, Host Plants and Potential Distribution of Edible Saturniid Caterpillars in Kenya. Insects. 2021; 12 (7):600.
Chicago/Turabian StyleElizabeth Kusia; Christian Borgemeister; Fathiya Khamis; Robert Copeland; Chrysantus Tanga; Fidelis Ombura; Sevgan Subramanian. 2021. "Diversity, Host Plants and Potential Distribution of Edible Saturniid Caterpillars in Kenya." Insects 12, no. 7: 600.
Whereas many researchers still approach Terra Preta (TP) as a soil category, new evidence suggests that TP refers to a directional grading of soil property changes (i.e., color, pH, nutrients, etc.) within human-made soils, originating from human activities in pre-Columbian times. Currently, most TP research focuses on the Brazilian part of the Amazon basin, but only little information is available on TP soils in the Colombian Amazon. Here, we sampled four TP and surrounding soils in the Colombian Amazon region at different soil depths and analyzed them for (i) general soil properties such as color, pH and texture, (ii) soil organic carbon and black carbon (BC) contents, the latter using benzene polycarboxylic acids as molecular marker, (iii) phosphorus availability based on sequential fractionation, and (iv) microbial residue contents using amino sugars. Our data from Colombia’s middle Caquetá River and Leticia confirmed that SOC, BC, and total P were present in significantly higher concentrations in the TP areas than the surrounding soils, while pH values and microbial residue contents were unchanged. The enrichment of P forms comprised both easily extractable and stable P pools, which both dominated to a different degree, both in TP and adjacent soils. The different degree of SOC, BC and P enrichment suggests different amounts of waste disposal by the ancient populations at different TP sites, now warranting further research for reconstructing ancient population sizes from TP chemical analyses.
Juan Orozco-Ortiz; Clara Peña-Venegas; Sara Bauke; Christian Borgemeister; Ramona Mörchen; Eva Lehndorff; Wulf Amelung. Terra Preta Properties in Northwestern Amazonia (Colombia). Sustainability 2021, 13, 7088 .
AMA StyleJuan Orozco-Ortiz, Clara Peña-Venegas, Sara Bauke, Christian Borgemeister, Ramona Mörchen, Eva Lehndorff, Wulf Amelung. Terra Preta Properties in Northwestern Amazonia (Colombia). Sustainability. 2021; 13 (13):7088.
Chicago/Turabian StyleJuan Orozco-Ortiz; Clara Peña-Venegas; Sara Bauke; Christian Borgemeister; Ramona Mörchen; Eva Lehndorff; Wulf Amelung. 2021. "Terra Preta Properties in Northwestern Amazonia (Colombia)." Sustainability 13, no. 13: 7088.
Flaviviruses include a great diversity of mosquito-borne arboviruses with epidemic potential and high global disease burden. Several flaviviruses are circulating in southern Africa affecting humans and livestock, among them West Nile virus (WNV) and Wesselsbron virus. Despite their high relevance, no arbovirus surveillance study has been conducted for more than 35 years in Namibia. In this study we assessed the diversity of flaviviruses circulating in mosquitoes in the densely populated, semi-tropical Zambezi region of north-eastern Namibia. In total, 10,206 mosquitoes were sampled in Bwabwata and Mudumu national parks and Mashi and Wuparo conservancies and screened for flavivirus infections. A high infection rate with insect-specific flaviviruses was found with 241 strains of two previously known and seven putative novel insect-specific flaviviruses. In addition, we identified ten strains of WNV in the main vector Cx. univittatus sampled in the Mashi conservancy. Surprisingly, the strains fell into two different clades of lineage 2, 2b and 2d. Further, three strains of Bagaza Virus (BAGV) were found in Cx. univittatus mosquitoes originating from Mudumu national park. Assessment of BAGV growth in different cell lines showed high replication rates in mosquito and duck cells and about 100,000fold lower replication in human, primate and rodent cells. We demonstrate a wide genetic diversity of flaviviruses is circulating in mosquitoes in the Zambezi region. Importantly, WNV and BAGV can cause outbreaks including severe disease and mortality in humans and birds, respectively. Future studies should focus on WNV and BAGV geographic distribution, as well as on their potential health impacts in and the associated social and economic implications for southern Africa.
Heiko D. Guggemos; Matthias Fendt; Christian Hieke; Verena Heyde; John K. E. Mfune; Christian Borgemeister; Sandra Junglen. Simultaneous circulation of two West Nile virus lineage 2 clades and Bagaza virus in the Zambezi region, Namibia. PLOS Neglected Tropical Diseases 2021, 15, e0009311 .
AMA StyleHeiko D. Guggemos, Matthias Fendt, Christian Hieke, Verena Heyde, John K. E. Mfune, Christian Borgemeister, Sandra Junglen. Simultaneous circulation of two West Nile virus lineage 2 clades and Bagaza virus in the Zambezi region, Namibia. PLOS Neglected Tropical Diseases. 2021; 15 (4):e0009311.
Chicago/Turabian StyleHeiko D. Guggemos; Matthias Fendt; Christian Hieke; Verena Heyde; John K. E. Mfune; Christian Borgemeister; Sandra Junglen. 2021. "Simultaneous circulation of two West Nile virus lineage 2 clades and Bagaza virus in the Zambezi region, Namibia." PLOS Neglected Tropical Diseases 15, no. 4: e0009311.
The goal to improve food security in sub-Saharan Africa (SSA) through domestic, resource efficient and low carbon agriculture is importance. Interventions to produce more food could impact the resource-base and lead to increase in greenhouse gas (GHG) emissions from agroecosystems. Unfortunately, existing methods are limited in analyzing small-scale agricultural systems, and this situation is an obstacle to decision making which aims at sustainable agriculture. In this paper, we showcase the recently developed Emergy-Data Envelopment Analysis (EM-DEA) approach to assess the resource use efficiency (RUE) and sustainability in maize production systems in Ghana, SSA. Using the Agricultural Production Systems sIMulator (APSIM), five land use and resource management scenarios were modeled to represent practices as decision making units (DMUs) in small-scale maize systems. The carbon footprint of the systems was assessed using an approach, which we adapted from the FAO Ex-Ante Carbon balance Tool (EX-ACT). The overall trend of the results showed that the yield, total emergy, GHG emissions and carbon footprint all increased with increase in urea application intensity. However, the relationship between the yield and urea intensity was not always linear. A system that used more renewable or fewer resources to produce a yield equal to that of its peer was considered more efficient and sustainable in relative terms. In particular, the business-as-usual scenario (12 kg/ha/yr NPK input to rainfed maize system, i.e. Extensive12) was inefficient when compared to the four contrasting scenarios. The ecological intensive scenario (20 kg/ha/yr urea input to rainfed maize-legume intercropping system, i.e. Intercrop20) achieved the greatest marginal yield, better RUE and sustainability. The high input scenario (100 kg/ha/yr urea input plus supplemental irrigation to maize monoculture, i.e. Intensive100) produced the greatest yield, but the demand for purchased inputs as well as GHG emissions and carbon footprint were greatest. The no external input scenario (0 kg/ha/yr urea input to rainfed maize system, i.e. Extensive0), and the moderate input scenario (50 kg/ha/yr urea input plus supplemental irrigation to maize monoculture, i.e. Intensive50) showed the greatest and least yield gaps relative to Intensive100, respectively. Based on these results and trade-off analysis, it was evident that Intercrop20 and Intensive50 were the two best case scenarios. As such, land use policy that aims at sustainable agriculture could recommend Intercrop20 and Intensive50 for implementation in low and high input maize production systems, respectively. Comparison between our results and other existing empirical studies revealed similarities that confirm our results. We conclude that the information derived using the EM-DEA and EX-ACT approaches could be useful when making informed decisions that aim at sustainable agriculture. Despite the limitation caused by scarcity of data, the use of the EM-DEA approach led to inclusive information on RUE and sustainability of the DMUs. Hence, the EM-DEA approach represents a way forward to better assess energy footprint in agricultural land use as a whole.
Francis Molua Mwambo; Christine Fürst; Christopher Martius; Marcos Jimenez-Martinez; Benjamin Kofi Nyarko; Christian Borgemeister. Combined application of the EM-DEA and EX-ACT approaches for integrated assessment of resource use efficiency, sustainability and carbon footprint of smallholder maize production practices in sub-Saharan Africa. Journal of Cleaner Production 2021, 302, 126132 .
AMA StyleFrancis Molua Mwambo, Christine Fürst, Christopher Martius, Marcos Jimenez-Martinez, Benjamin Kofi Nyarko, Christian Borgemeister. Combined application of the EM-DEA and EX-ACT approaches for integrated assessment of resource use efficiency, sustainability and carbon footprint of smallholder maize production practices in sub-Saharan Africa. Journal of Cleaner Production. 2021; 302 ():126132.
Chicago/Turabian StyleFrancis Molua Mwambo; Christine Fürst; Christopher Martius; Marcos Jimenez-Martinez; Benjamin Kofi Nyarko; Christian Borgemeister. 2021. "Combined application of the EM-DEA and EX-ACT approaches for integrated assessment of resource use efficiency, sustainability and carbon footprint of smallholder maize production practices in sub-Saharan Africa." Journal of Cleaner Production 302, no. : 126132.
Diarrhea, soil-transmitted helminth infection and malnutrition are leading causes of child mortality in low- and middle-income countries (LMICs). To reduce the prevalence of these diseases, effective interventions for adequate water, sanitation, and hygiene (WaSH) should be implemented. This paper describes the design of a cluster-randomized controlled trial that will compare the efficacy of four school-based WaSH interventions for improving children’s health literacy, handwashing, and nutrition. Interventions consisted of (1) WaSH policy reinforcement; (2) low-, medium-, or high-volume health education; (3) hygiene supplies; and (4) WaSH facilities (e.g., toilets, urinals, handwashing basins) improvements. We randomly allocated school clusters from the intervention arm to one of four groups to compare with schools from the control arm. Primary outcomes were: children’s health literacy, physical growth, nutrition status, and handwashing prevalence. Secondary outcomes were: children’s self-reported health status and history of extreme hunger, satisfaction with WaSH facilities, and school restrooms’ WaSH adequacy. We will measure differences in pre- and post-intervention outcomes and compare these differences between control and intervention arms. This research protocol can be a blueprint for future school-based WaSH intervention studies to be conducted in LMICs. Study protocols were approved by the ethics committees of the University of Bonn, Germany, and the University of the Philippines Manila. This trial was retroactively registered, ID number: DRKS00021623.
Stephanie Sangalang; Shelley Medina; Zheina Ottong; Allen Lemence; Donrey Totanes; John Valencia; Patricia Singson; Mikaela Olaguera; Nelissa Prado; Roezel Ocaña; Rovin Canja; Alfem Benolirao; Shyrill Mariano; Jergil Gavieres; Clarisse Aquino; Edison Latag; Maria Anglo; Christian Borgemeister; Thomas Kistemann. Protocol for a Trial Assessing the Impacts of School-Based WaSH Interventions on Children’s Health Literacy, Handwashing, and Nutrition Status in Low- and Middle-Income Countries. International Journal of Environmental Research and Public Health 2020, 18, 226 .
AMA StyleStephanie Sangalang, Shelley Medina, Zheina Ottong, Allen Lemence, Donrey Totanes, John Valencia, Patricia Singson, Mikaela Olaguera, Nelissa Prado, Roezel Ocaña, Rovin Canja, Alfem Benolirao, Shyrill Mariano, Jergil Gavieres, Clarisse Aquino, Edison Latag, Maria Anglo, Christian Borgemeister, Thomas Kistemann. Protocol for a Trial Assessing the Impacts of School-Based WaSH Interventions on Children’s Health Literacy, Handwashing, and Nutrition Status in Low- and Middle-Income Countries. International Journal of Environmental Research and Public Health. 2020; 18 (1):226.
Chicago/Turabian StyleStephanie Sangalang; Shelley Medina; Zheina Ottong; Allen Lemence; Donrey Totanes; John Valencia; Patricia Singson; Mikaela Olaguera; Nelissa Prado; Roezel Ocaña; Rovin Canja; Alfem Benolirao; Shyrill Mariano; Jergil Gavieres; Clarisse Aquino; Edison Latag; Maria Anglo; Christian Borgemeister; Thomas Kistemann. 2020. "Protocol for a Trial Assessing the Impacts of School-Based WaSH Interventions on Children’s Health Literacy, Handwashing, and Nutrition Status in Low- and Middle-Income Countries." International Journal of Environmental Research and Public Health 18, no. 1: 226.
The emergence of arthropod-borne viruses (arboviruses) as linked to land-use changes, especially the growing agricultural intensification and expansion efforts in rural parts of Africa, is of growing health concern. This places an additional burden on health systems as drugs, vaccines, and effective vector-control measures against arboviruses and their vectors remain lacking. An integrated One Health approach holds potential in the control and prevention of arboviruses. Land-use changes favour invasion by invasive alien plants (IAPs) and investigating their impact on mosquito populations may offer a new dimension to our understanding of arbovirus emergence. Of prime importance to understand is how IAPs influence mosquito life-history traits and how this may affect transmission of arboviruses to mammalian hosts, questions that we are exploring in this review. Potential effects of IAPs may be significant, including supporting the proliferation of immature and adult stages of mosquito vectors, providing additional nutrition and suitable microhabitats, and a possible interaction between ingested secondary plant metabolites and arboviruses. We conclude that aspects of vector biology are differentially affected by individual IAPs and that while some plants may have the potential to indirectly increase the risk of transmission of certain arboviruses by their direct interaction with the vectors, the reverse holds for other IAPs. In addition, we highlight priority research areas to improve our understanding of the potential health impacts of IAPs.
Sheila B. Agha; Miguel Alvarez; Mathias Becker; Eric M. Fèvre; Sandra Junglen; Christian Borgemeister. Invasive Alien Plants in Africa and the Potential Emergence of Mosquito-Borne Arboviral Diseases—A Review and Research Outlook. Viruses 2020, 13, 32 .
AMA StyleSheila B. Agha, Miguel Alvarez, Mathias Becker, Eric M. Fèvre, Sandra Junglen, Christian Borgemeister. Invasive Alien Plants in Africa and the Potential Emergence of Mosquito-Borne Arboviral Diseases—A Review and Research Outlook. Viruses. 2020; 13 (1):32.
Chicago/Turabian StyleSheila B. Agha; Miguel Alvarez; Mathias Becker; Eric M. Fèvre; Sandra Junglen; Christian Borgemeister. 2020. "Invasive Alien Plants in Africa and the Potential Emergence of Mosquito-Borne Arboviral Diseases—A Review and Research Outlook." Viruses 13, no. 1: 32.
To evaluate environmental impacts and financial profitability of producing 1 MJ energy of charcoal from bamboo - Bambusa balcooa in comparison with two commonly used local species - Anogeissus leiocarpa and Senna siamea were analyzed. Environmental impacts were assessed using the Life Cycle Analytical (LCA) approach while financial viability of the various systems was evaluated using the financial benefit cost ratio (FBCR) and net present value (NPV). Emissions from all the charcoal production stages were calculated using GaBi 4 LCA software and the Ecoinvent V3 and Idemat 2015 life cycle inventory databases. Emission contributions from all four stages in the charcoal production cycle were analyzed using the CML 2001 method. Environmental impacts were analyzed based on the potential for global warming, atmospheric acidification, eutrophication, depletion of abiotic resources, human toxicity, ozone layer depletion and eco-toxicity. The LCA revealed that compared with S. siamea and A. leiocarpus, production of charcoal from B. balcooa (bamboo) was the more environmentally friendly option after S. siamea, recording lower in five out of the seven (86%) impact categories used in the LCA. This was attributed to the relatively low use of chemical inputs (fertilizer, pesticides, fossil fuel etc.) in the bamboo charcoal production cycle. Nonetheless, the financial analysis revealed that despite recording the lowest production cost, charcoal production from B. balcooa was least profitable (FBCR = 1.1) compared with the two traditional species. This was primarily due to the low market price of bamboo charcoal in the study region. While bamboo charcoal may be encouraged for purposes of environmental sustainability, increased sensitization on the economic potential of bamboo charcoal and the environmental benefits it brings may improve local adoption and market value.
Daniel S. Akoto; Samuel T. Partey; Manfred Denich; Michael Kwaku; Christian Borgemeister; Christine B. Schmitt. Environmental and financial assessment of producing bioenergy from Bambusa balcooa, Anogeissus leiocarpa and Senna siamea in Ghana. Journal of Cleaner Production 2020, 275, 123147 .
AMA StyleDaniel S. Akoto, Samuel T. Partey, Manfred Denich, Michael Kwaku, Christian Borgemeister, Christine B. Schmitt. Environmental and financial assessment of producing bioenergy from Bambusa balcooa, Anogeissus leiocarpa and Senna siamea in Ghana. Journal of Cleaner Production. 2020; 275 ():123147.
Chicago/Turabian StyleDaniel S. Akoto; Samuel T. Partey; Manfred Denich; Michael Kwaku; Christian Borgemeister; Christine B. Schmitt. 2020. "Environmental and financial assessment of producing bioenergy from Bambusa balcooa, Anogeissus leiocarpa and Senna siamea in Ghana." Journal of Cleaner Production 275, no. : 123147.
Malaria elimination will be challenging in countries that currently continue to bear high malaria burden. Sex-ratio distorting gene drives, such as driving-Y, could play a role in an integrated elimination strategy if they can effectively suppress vector populations. Using a spatially explicit, agent-based model of malaria transmission in eight representative provinces of the Democratic Republic of the Congo, we predict the impact and cost-effectiveness of integrating driving-Y gene drive mosquitoes in malaria elimination strategies that include existing interventions such as insecticide-treated nets and case management of symptomatic malaria. Gene drive mosquitoes could eliminate malaria and were the most cost-effective intervention overall if the drive component was highly effective with at least 95% X-shredding and associated cost of deployment below 7.17 $int per person per year. Suppression gene drive could be a cost-effective supplemental intervention for malaria elimination, but tight constraints on drive effectiveness and cost ceilings may limit its feasibility.
Nawaphan Metchanun; Christian Borgemeister; Gaston Amzati; Joachim von Braun; Milen Nikolov; Prashanth Selvaraj; Jaline Gerardin. Modeling impact and cost-effectiveness of gene drives for malaria elimination in the Democratic Republic of the Congo. 2020, 1 .
AMA StyleNawaphan Metchanun, Christian Borgemeister, Gaston Amzati, Joachim von Braun, Milen Nikolov, Prashanth Selvaraj, Jaline Gerardin. Modeling impact and cost-effectiveness of gene drives for malaria elimination in the Democratic Republic of the Congo. . 2020; ():1.
Chicago/Turabian StyleNawaphan Metchanun; Christian Borgemeister; Gaston Amzati; Joachim von Braun; Milen Nikolov; Prashanth Selvaraj; Jaline Gerardin. 2020. "Modeling impact and cost-effectiveness of gene drives for malaria elimination in the Democratic Republic of the Congo." , no. : 1.
The process of moving from experimental data to modeling and characterizing the dynamics and interactions in natural processes is a challenging task. This paper proposes an interactive platform for fitting data derived from experiments to mathematical expressions and carrying out spatial visualization. The platform is designed using a component-based software architectural approach, implemented in R and the Java programming languages. It uses experimental data as input for model fitting, then applies the obtained model at the landscape level via a spatial temperature grid data to yield regional and continental maps. Different modules and functionalities of the tool are presented with a case study, in which the tool is used to establish a temperature-dependent virulence model and map the potential zone of efficacy of a fungal-based biopesticide. The decision support system (DSS) was developed in generic form, and it can be used by anyone interested in fitting mathematical equations to experimental data collected following the described protocol and, depending on the type of investigation, it offers the possibility of projecting the model at the landscape level.
Ritter A. Guimapi; Samira A. Mohamed; Lisa Biber-Freudenberger; Waweru Mwangi; Sunday Ekesi; Christian Borgemeister; Henri E. Z. Tonnang. Decision Support System for Fitting and Mapping Nonlinear Functions with Application to Insect Pest Management in the Biological Control Context. Algorithms 2020, 13, 104 .
AMA StyleRitter A. Guimapi, Samira A. Mohamed, Lisa Biber-Freudenberger, Waweru Mwangi, Sunday Ekesi, Christian Borgemeister, Henri E. Z. Tonnang. Decision Support System for Fitting and Mapping Nonlinear Functions with Application to Insect Pest Management in the Biological Control Context. Algorithms. 2020; 13 (4):104.
Chicago/Turabian StyleRitter A. Guimapi; Samira A. Mohamed; Lisa Biber-Freudenberger; Waweru Mwangi; Sunday Ekesi; Christian Borgemeister; Henri E. Z. Tonnang. 2020. "Decision Support System for Fitting and Mapping Nonlinear Functions with Application to Insect Pest Management in the Biological Control Context." Algorithms 13, no. 4: 104.
Northwest Algeria has experienced fluctuations in rainfall between the two decades 1940s and 1990s from positive to negative anomalies, which reflected a significant decline in rainfall during the mid-1970s. Therefore, further analyzing rainfall in this region is required for improving the strategies on water resource management. In this study, we complement previous studies by dealing with sub basins that were not previously addressed in Tafna basin (our study area located in Northwest Algeria), and by including additional statistical methods (Kruskal–Wallis test, Jonckheere-Terpstra test, and the Friedman test) that were not earlier reported on the large scale (Northwest Algeria). In order to analyse the homogeneity, trends, and stationarity in rainfall time series for nine rainfall stations over the period 1979–2011, we have used several statistical tests. The results showed an increasing trend for annual rainfall after the break detected in 2007 for Djbel Chouachi, Ouled Mimoun, Sidi Benkhala stations using Hubert, Pettitt, and Buishand tests. The Lee and Heghinian test has detected a break at the same year in 2007 for all stations except Sebdou, Beni Bahdel, and Hennaya stations, which have a break date in 1980. We have confirmed this increasing trend for rainfall with other trend detection methods such as Mann Kendall and Sen’s method that highlighted an upward trend for all the stations in the autumn season, which is mainly due to an increase in rainfall in September and October. On a monthly scale, the date of rupture is different from one station to another because the time series are not homogeneous. In addition, we have applied three tests enabling further results: (i) the Jonckheere-Terpstra test has detected an upward trend for two stations (Khemis and Hennaya), (ii) Friedman test has indicated the difference between the mean rank again with Khemis and Hennaya stations and the Merbeh station, (iii) according to the Kruskal-Wallis test, there have been no variance detected between all the rainfall stations. The increasing trend in rainfall may lead to a rise in stream flow and enhance potential floods risks in low-lying regions of the study area.
Hanane Bougara; Kamila Baba Hamed; Christian Borgemeister; Bernhard Tischbein; Navneet Kumar. Analyzing Trend and Variability of Rainfall in The Tafna Basin (Northwestern Algeria). Atmosphere 2020, 11, 347 .
AMA StyleHanane Bougara, Kamila Baba Hamed, Christian Borgemeister, Bernhard Tischbein, Navneet Kumar. Analyzing Trend and Variability of Rainfall in The Tafna Basin (Northwestern Algeria). Atmosphere. 2020; 11 (4):347.
Chicago/Turabian StyleHanane Bougara; Kamila Baba Hamed; Christian Borgemeister; Bernhard Tischbein; Navneet Kumar. 2020. "Analyzing Trend and Variability of Rainfall in The Tafna Basin (Northwestern Algeria)." Atmosphere 11, no. 4: 347.
Aleksandar Matković; Jakob Genser; Markus Kratzer; Daniel Lüftner; Zhongrui Chen; Olivier Siri; Peter Puschnig; Conrad Becker; Christian Teichert. Light‐Assisted Charge Propagation in Networks of Organic Semiconductor Crystallites on Hexagonal Boron Nitride. Advanced Functional Materials 2019, 29, 1 .
AMA StyleAleksandar Matković, Jakob Genser, Markus Kratzer, Daniel Lüftner, Zhongrui Chen, Olivier Siri, Peter Puschnig, Conrad Becker, Christian Teichert. Light‐Assisted Charge Propagation in Networks of Organic Semiconductor Crystallites on Hexagonal Boron Nitride. Advanced Functional Materials. 2019; 29 (43):1.
Chicago/Turabian StyleAleksandar Matković; Jakob Genser; Markus Kratzer; Daniel Lüftner; Zhongrui Chen; Olivier Siri; Peter Puschnig; Conrad Becker; Christian Teichert. 2019. "Light‐Assisted Charge Propagation in Networks of Organic Semiconductor Crystallites on Hexagonal Boron Nitride." Advanced Functional Materials 29, no. 43: 1.
In sub-Saharan Africa, urban populations are projected to increase by 115% in the coming 15 years. In addition, economic growth and dietary shifts towards animal source foods have put high pressure and demand on agricultural production. The high ecological footprint of meat and dairy production, as well as high feed costs, prevent the livestock sector from meeting the increasing demand in a sustainable manner. Insects such as the black soldier fly (BSF) have been identified as potential alternatives to the conventionally used protein sources in livestock feed due to their rich nutrient content and the fact that they can be reared on organic side streams. Substrates derived from organic byproducts are suitable for industrial large-scale production of insect meal. Although efficient in waste management and in feed production, BSF larvae are very sensitive to the external environment such as temperature and rearing medium. Therefore, we studied the effect of temperature and substrate type, i.e., brewers’ spent grain (SG) and cow dung (CD), on the development and survival of BSF larvae. Both organic substrates were readily available in Nairobi, Kenya, the location of the experiments. In our experiment, 100 3–5-day-old BSF larvae were placed into containers that contained either SG or CD and further treated at temperatures of 15 °C, 20 °C, 25 °C, 30 °C, and 35 °C. The duration of larval development was recorded, and the prepupae were removed, weighed, and placed individually in separate, labeled, 35-mL plastic cups filled with moist sawdust. After emergence, 10 2-day-old adults (5 males and 5 females) from every replica per substrate were transferred into a cage (40 × 40 × 40 cm) and allowed to mate for 24 h at their respective temperatures. The laid egg batches were collected and counted, and the adult flies’ longevity was recorded. The data were subjected to a two-way analysis of variance (ANOVA) using the general linear model procedure. BSF larvae reared on SG developed faster than those reared on CD; the former also favored higher temperatures for their larval development and emergence into adults. The optimum range was 25–30 °C. With increasing temperatures, the longevity of adult BSF decreased, while the fecundity of females increased. Thus, it is possible to take advantage of the readily available SG waste streams in the urban environments of Kenya to produce BSF larvae-derived livestock feed within a short duration of time and at relatively high temperatures.
Marwa Shumo; Fathiya M. Khamis; Chrysantus M. Tanga; Komi K. M. Fiaboe; Sevgan Subramanian; Sunday Ekesi; Arnold Van Huis; Christian Borgemeister. Influence of Temperature on Selected Life-History Traits of Black Soldier Fly (Hermetia illucens) Reared on Two Common Urban Organic Waste Streams in Kenya. Animals 2019, 9, 79 .
AMA StyleMarwa Shumo, Fathiya M. Khamis, Chrysantus M. Tanga, Komi K. M. Fiaboe, Sevgan Subramanian, Sunday Ekesi, Arnold Van Huis, Christian Borgemeister. Influence of Temperature on Selected Life-History Traits of Black Soldier Fly (Hermetia illucens) Reared on Two Common Urban Organic Waste Streams in Kenya. Animals. 2019; 9 (3):79.
Chicago/Turabian StyleMarwa Shumo; Fathiya M. Khamis; Chrysantus M. Tanga; Komi K. M. Fiaboe; Sevgan Subramanian; Sunday Ekesi; Arnold Van Huis; Christian Borgemeister. 2019. "Influence of Temperature on Selected Life-History Traits of Black Soldier Fly (Hermetia illucens) Reared on Two Common Urban Organic Waste Streams in Kenya." Animals 9, no. 3: 79.
Aleksandar Matković; Markus Kratzer; Benjamin Kaufmann; Anthony Thomas; Zhongrui Chen; Olivier Siri; Conrad Becker; Christian Teichert; Aydan ÇİÇek. Growth morphologies of dihydro-tetraaza-acenes on c-plane sapphire. Surface Science 2018, 678, 128 -135.
AMA StyleAleksandar Matković, Markus Kratzer, Benjamin Kaufmann, Anthony Thomas, Zhongrui Chen, Olivier Siri, Conrad Becker, Christian Teichert, Aydan ÇİÇek. Growth morphologies of dihydro-tetraaza-acenes on c-plane sapphire. Surface Science. 2018; 678 ():128-135.
Chicago/Turabian StyleAleksandar Matković; Markus Kratzer; Benjamin Kaufmann; Anthony Thomas; Zhongrui Chen; Olivier Siri; Conrad Becker; Christian Teichert; Aydan ÇİÇek. 2018. "Growth morphologies of dihydro-tetraaza-acenes on c-plane sapphire." Surface Science 678, no. : 128-135.
Citrus is considered one of the most important fruit crops globally due to its contribution to food and nutritional security. However, the production of citrus has recently been in decline due to many biological, environmental, and socio-economic constraints. Amongst the biological ones, pests and diseases play a major role in threatening citrus quantity and quality. The most damaging disease in Kenya, is the African citrus greening disease (ACGD) or Huanglongbing (HLB) which is transmitted by the African citrus triozid (ACT), Trioza erytreae. HLB in Kenya is reported to have had the greatest impact on citrus production in the highlands, causing yield losses of 25% to 100%. This study aimed at predicting the occurrence of ACT using an ecological habitat suitability modeling approach. Specifically, we tested the contribution of vegetation phenological variables derived from remotely-sensed (RS) data combined with bio-climatic and topographical variables (BCL) to accurately predict the distribution of ACT in citrus-growing areas in Kenya. A MaxEnt (maximum entropy) suitability modeling approach was used on ACT presence-only data. Forty-seven (47) ACT observations were collected while 23 BCL and 12 RS covariates were used as predictor variables in the MaxEnt modeling. The BCL variables were extracted from the WorldClim data set, while the RS variables were predicted from vegetation phenological time-series data (spanning the years 2014–2016) and annually-summed land surface temperature (LST) metrics (2014–2016). We developed two MaxEnt models; one including both the BCL and the RS variables (BCL-RS) and another with only the BCL variables. Further, we tested the relationship between ACT habitat suitability and the surrounding land use/land cover (LULC) proportions using a random forest regression model. The results showed that the combined BCL-RS model predicted the distribution and habitat suitability for ACT better than the BCL-only model. The overall accuracy for the BCL-RS model result was 92% (true skills statistic: TSS = 0.83), whereas the BCL-only model had an accuracy of 85% (TSS = 0.57). Also, the results revealed that the proportion of shrub cover surrounding citrus orchards positively influenced the suitability probability of the ACT. These results provide a resourceful tool for precise, timely, and site-specific implementation of ACGD control strategies.
Kyalo Richard; Elfatih M. Abdel-Rahman; Samira A. Mohamed; Sunday Ekesi; Christian Borgemeister; Tobias Landmann. Importance of Remotely-Sensed Vegetation Variables for Predicting the Spatial Distribution of African Citrus Triozid (Trioza erytreae) in Kenya. ISPRS International Journal of Geo-Information 2018, 7, 429 .
AMA StyleKyalo Richard, Elfatih M. Abdel-Rahman, Samira A. Mohamed, Sunday Ekesi, Christian Borgemeister, Tobias Landmann. Importance of Remotely-Sensed Vegetation Variables for Predicting the Spatial Distribution of African Citrus Triozid (Trioza erytreae) in Kenya. ISPRS International Journal of Geo-Information. 2018; 7 (11):429.
Chicago/Turabian StyleKyalo Richard; Elfatih M. Abdel-Rahman; Samira A. Mohamed; Sunday Ekesi; Christian Borgemeister; Tobias Landmann. 2018. "Importance of Remotely-Sensed Vegetation Variables for Predicting the Spatial Distribution of African Citrus Triozid (Trioza erytreae) in Kenya." ISPRS International Journal of Geo-Information 7, no. 11: 429.
A transdisciplinary research approach requires that different scientists with their discipline-specific theories, concepts and methods find ways to work together with other societal players to address a real-life problem. In this study, the push–pull technology (PPT) was used as a boundary object to enable interactions among stakeholders across science-practice boundaries engaged in the control of stemborer pest in maize crops in Bako Tibe, Jimma Arjo and Yayu Woredas in Ethiopia between August 2014 and April 2015. The PPT is a biological mechanism developed by researchers for the control of stemborer pests and Striga weed in maize crop. It involves inter-cropping maize with a stemborer moth-repellent silverleaf or greenleaf Desmodium (push), and planting an attractive trap crop, Napier or Brachiaria grass (pull), around it. The on-farm implementation of PPT was used to provide an opportunity for collaboration, interaction and learning among stakeholders including researchers from the Ethiopian Institute of Agricultural Research and practitioners from the Ministry of Agriculture and smallholder farmers/traders. The research was implemented following the transdisciplinary action research and the data collected using mixed methods approach, including key informant interviews, focus group discussions, workshops, on-farm practical demonstrations and participant observations. The findings show that collaborative leadership provides a chance for the stakeholders to participate in the technology learning and decision making, by enabling them to jointly contribute skills towards development, refinement and adaptation of the PPT. In situations where there are conflicts, they are embraced and converted to opportunities for in-depth learning, finding solutions and adaptation of the innovation processes rather than being sources of contradictions or misunderstandings. The leadership roles of the farmers enabled them to reflect on their own practices and draw on scientific explanations from researchers. It also enabled them to take the lead in new technology implementation and information sharing with fellow farmers and other stakeholders in a free and easy manner. Although the perennial nature of the companion crops in the PPT provides opportunities for continuous stakeholder interaction and learning, it requires a personally committed leadership and formal institutional engagements for the sustainability of the activities, which span several cropping seasons. Market forces and the involvement of the private sector also play a role as shown from the involvement of individual farmers and traders in Desmodium and Brachiaria seed production, collection and distribution during the PPT implementation.
Isaac Mbeche Nyang’Au; Girma Kelboro; Anna-Katharina Hornidge; Charles A. O. Midega; Christian Borgemeister. Transdisciplinary Research: Collaborative Leadership and Empowerment Towards Sustainability of Push–Pull Technology. Sustainability 2018, 10, 2378 .
AMA StyleIsaac Mbeche Nyang’Au, Girma Kelboro, Anna-Katharina Hornidge, Charles A. O. Midega, Christian Borgemeister. Transdisciplinary Research: Collaborative Leadership and Empowerment Towards Sustainability of Push–Pull Technology. Sustainability. 2018; 10 (7):2378.
Chicago/Turabian StyleIsaac Mbeche Nyang’Au; Girma Kelboro; Anna-Katharina Hornidge; Charles A. O. Midega; Christian Borgemeister. 2018. "Transdisciplinary Research: Collaborative Leadership and Empowerment Towards Sustainability of Push–Pull Technology." Sustainability 10, no. 7: 2378.
Bamboo agroforestry is currently being promoted in Ghana as a viable land use option to reduce dependence on natural forest for wood fuels. To align the design and introduction of bamboo agroforestry to the needs of farmers, information on the determinants of bamboo acceptability and adoption is necessary. It is, therefore, the aim of this study to determine how socioeconomic factors, local farming practices and local knowledge on bamboo may influence its acceptability and adoption as a component of local farming systems. Data were collected from 200 farmers in the dry semi-deciduous forest zone of Ghana using semi-structured questionnaire interviews. The results show that farmers’ traditional knowledge on bamboo including its use for charcoal production and leaves for fodder are influential determinants of bamboo adoption. Among the demographic characteristics of farmers, age and gender are the most significant predictors. It is also evident that the regular practice of leaving trees on farmlands and type of cropping system may influence bamboo integration into traditional farming systems.
Daniel S. Akoto; Manfred Denich; Samuel T. Partey; Oliver Frith; Michael Kwaku; Alex A. Mensah; Christian Borgemeister. Socioeconomic Indicators of Bamboo Use for Agroforestry Development in the Dry Semi-Deciduous Forest Zone of Ghana. Sustainability 2018, 10, 2324 .
AMA StyleDaniel S. Akoto, Manfred Denich, Samuel T. Partey, Oliver Frith, Michael Kwaku, Alex A. Mensah, Christian Borgemeister. Socioeconomic Indicators of Bamboo Use for Agroforestry Development in the Dry Semi-Deciduous Forest Zone of Ghana. Sustainability. 2018; 10 (7):2324.
Chicago/Turabian StyleDaniel S. Akoto; Manfred Denich; Samuel T. Partey; Oliver Frith; Michael Kwaku; Alex A. Mensah; Christian Borgemeister. 2018. "Socioeconomic Indicators of Bamboo Use for Agroforestry Development in the Dry Semi-Deciduous Forest Zone of Ghana." Sustainability 10, no. 7: 2324.
The combined characterization of structural and optical properties of organic interfaces adsorbed on inorganic solid substrates down to the molecular scale is crucial from a fundamental point of view, but also if one tackles efficient applied devices. In this work, a set of joint structural and optical analyses of self-assemblies of π-conjugated bis-pyrene derivatives upon adsorption on two alkali halides bulk insulators is reported. The structural analysis is performed by means of noncontact atomic force microscopy in ultrahigh vacuum either at room or at the liquid-nitrogen temperature with molecular resolution. The surface coverage ranges from the submonolayer (ML) regime up to 5 ML. In situ optical spectroscopy is performed by means of differential reflectance (DR) spectroscopy. A thorough fitting methodology of the DR spectra allows us to derive the complete dielectric function of the molecular adlayers treated in an anisotropic formalism, albeit restricted to an uniaxial approximation. Conclusions regarding the process of condensation of the molecules into H aggregates from its early stages up to the solid molecular phase are drawn. This work highlights three main reasons to bridge high-resolution structural and optical characterization of the molecular layers, which all point towards the necessity to constrain the fitting process, namely, (i) characterizing the growth mode of the molecules, (ii) identifying the structural order of the resulting assemblies, and (iii) discriminating their constitutive phases by means of molecular resolution imaging.
Franck Bocquet; Laurent Nony; Franck Para; Philipda Luangprasert; Jean-Valère Naubron; Christian Loppacher; Thomas Leoni; Anthony Thomas; Alain Ranguis; Anthony D'Aléo; Frédéric Fages; Conrad Becker. Noncontact AFM and differential reflectance spectroscopy joint analyses of bis-pyrenyl thin films on bulk insulators: Relationship between structural and optical properties. Physical Review B 2018, 97, 235434 .
AMA StyleFranck Bocquet, Laurent Nony, Franck Para, Philipda Luangprasert, Jean-Valère Naubron, Christian Loppacher, Thomas Leoni, Anthony Thomas, Alain Ranguis, Anthony D'Aléo, Frédéric Fages, Conrad Becker. Noncontact AFM and differential reflectance spectroscopy joint analyses of bis-pyrenyl thin films on bulk insulators: Relationship between structural and optical properties. Physical Review B. 2018; 97 (23):235434.
Chicago/Turabian StyleFranck Bocquet; Laurent Nony; Franck Para; Philipda Luangprasert; Jean-Valère Naubron; Christian Loppacher; Thomas Leoni; Anthony Thomas; Alain Ranguis; Anthony D'Aléo; Frédéric Fages; Conrad Becker. 2018. "Noncontact AFM and differential reflectance spectroscopy joint analyses of bis-pyrenyl thin films on bulk insulators: Relationship between structural and optical properties." Physical Review B 97, no. 23: 235434.
The adsorption of 5,14-dihydro-5,7,12,14-tetraazapentacene (DHTAP) on Cu(110) has been investigated at different temperatures and coverages by means of scanning tunneling microscopy (STM) and low-energy diffraction (LEED). Our results show that the interaction of DHTAP with the Cu(110) surface differs considerably from that of pentacene on the same surface. The DHTAP molecules are chemisorbed on the surface via strong Cu-N bonds with an adsorption energy of roughly 3eV per molecule twice as high as the value for pentacene. We could identify three different ordered superstructures, which are commensurate with the substrate and characterized by the matrices (6 -1 | 1 2), (7 0 | 1 2) and (6 0 | 1 2), respectively.
Anthony Thomas; Walter Malone; Thomas Leoni; Alain Ranguis; Zhongrui Chen; Olivier Siri; Abdelkader Kara; Peter Zeppenfeld; Conrad Becker. Growth of Dihydrotetraazapentacene Layers on Cu(110). The Journal of Physical Chemistry C 2018, 122, 10828 -10834.
AMA StyleAnthony Thomas, Walter Malone, Thomas Leoni, Alain Ranguis, Zhongrui Chen, Olivier Siri, Abdelkader Kara, Peter Zeppenfeld, Conrad Becker. Growth of Dihydrotetraazapentacene Layers on Cu(110). The Journal of Physical Chemistry C. 2018; 122 (20):10828-10834.
Chicago/Turabian StyleAnthony Thomas; Walter Malone; Thomas Leoni; Alain Ranguis; Zhongrui Chen; Olivier Siri; Abdelkader Kara; Peter Zeppenfeld; Conrad Becker. 2018. "Growth of Dihydrotetraazapentacene Layers on Cu(110)." The Journal of Physical Chemistry C 122, no. 20: 10828-10834.
Conrad Becker. From Langmuir to Ertl: The “Nobel” History of the Surface Science Approach to Heterogeneous Catalysis. Encyclopedia of Interfacial Chemistry 2018, 99 -106.
AMA StyleConrad Becker. From Langmuir to Ertl: The “Nobel” History of the Surface Science Approach to Heterogeneous Catalysis. Encyclopedia of Interfacial Chemistry. 2018; ():99-106.
Chicago/Turabian StyleConrad Becker. 2018. "From Langmuir to Ertl: The “Nobel” History of the Surface Science Approach to Heterogeneous Catalysis." Encyclopedia of Interfacial Chemistry , no. : 99-106.