Democratic Republic Of Congo Research Articles

Changing Rainfall Patterns in the Northeastern South Kivu Region, Democratic Republic of the Congo: A Detailed Analysis Using CHIRPS Rainfall Data (1981–2023)

AbstractUnderstanding changes in rainfall patterns is vital for effective water resource management and agricultural planning in climate-sensitive regions. In Northeastern South Kivu, Democratic Republic of the Congo, limited knowledge of rainfall dynamics poses challenges for local climate assessments. This study analyzed rainfall patterns using the Climate Hazards Group InfraRed Precipitation with Stations (CHIRPS) dataset from 1981 to 2023 to fill this knowledge gap. The findings revealed significant spatial and temporal changes in rainfall across the regions of Kabare, Bukavu, Kalehe, and Idjwi. Mean annual rainfall ranged from 1136.92 mm to 2048.85 mm, with coefficients of variation between 8.23% and 8.45%. Monthly rainfall fluctuations were substantial, ranging from 16 to 56.35%. Standardized rainfall anomalies indicated a shift from predominantly wet conditions in the 1980s to drier conditions in later decades, with over half the years from 1990 to 2023 recording below-average rainfall. Mann-Kendall trend analysis, supported by Innovative Trend Analysis (ITA), confirmed significant decreases in annual rainfall, with rates between − 3.53 to -5.72 mm/year. Additionally, rainfall intensity indices highlighted a decline in total annual precipitation, suggested fewer extreme events. Spatial variability was observed, with regions like Kalehe and Bukavu showed higher values for indices such as R95P and RX1day compared to Kabare and Idjwi. These results underscored the urgent need for adaptive strategies to mitigate water scarcity and manage changing rainfall patterns in the region.

Lessons from Recent Measles Post-Campaign Coverage Surveys Worldwide

Background: Measles elimination strategies include supplementary immunization activities (SIAs) to rapidly fill immunity gaps. Post-campaign coverage surveys (PCCSs) are recommended to assess SIA coverage. We characterized selected PCCSs performed following recent SIAs, highlighting specific challenges and strengths, and provide recommendations for improvement. Methods: We extracted national SIA data from the global measles/MR SIA database for the period of 2020–2023 and reviewed PCCS reports available at the World Health Organization headquarters. We extracted selected information on PCCS implementation, including information about the implementer, sampling, and main results. Results: Only 15 of 66 countries (23%) with a national-level SIA performed since 2020 had a PCCS report available. We reviewed those reports, plus six more, following three 2019 SIAs with a delayed PCCS and two PCCSs following large subnational SIAs (Kenya 2021 and Yemen 2023). All 24 PCCS reports available were from Gavi-eligible countries, with 15 from South Saharan Africa (Cameroon, the Democratic Republic of the Congo, and Ethiopia had two PCCSs). Eleven (45.8%) PCCSs were conducted within three months of the end of the SIA. All included sampling information and most had percentage of participation. Description of the interviewers’ profiles varied but was limited. PCCS coverage was lower than administrative data in all but two instances. All PCCSs collected data on previous measles vaccination status that would allow exploring indicators on the SIA reaching previously measles zero-dose children. Of the 12 PCCSs reporting coverage among previously measles zero-dose children, nine reported coverage among this group of more than 50% (range: 12% and 91.6%). Conclusion: Even though a PCCS following an SIA is recommended and a requirement in Gavi-supported countries, most SIAs are not followed by a PCCS and, when performed, the timeliness of survey implementation needs improvement. Recent PCCSs were independently conducted and reports included basic survey information, but analysis and presentation of survey results vary particularly for measles zero-dose-related indicators. More guidance and technical support on how to implement PCCSs, including standardization of reports and more in-depth PCCS analyses, may help improve reporting and use of available PCCS data.

Using spatial video and deep learning for automated mapping of ground-level context in relief camps

BackgroundThe creation of relief camps following a disaster, conflict or other form of externality often generates additional health problems. The density of people in a highly stressed environment with questionable safe food and water access presents the potential for infectious disease outbreaks. These camps are also not static data events but rather fluctuate in size, composition, and level and quality of service provision. While contextualized geospatial data collection and mapping are vital for understanding the nature of these camps, various challenges, including a lack of data at the required spatial or temporal granularity, as well as the issue of sustainability, can act as major impediments. Here, we present the first steps toward a deep learning-based solution for dynamic mapping using spatial video (SV).MethodsWe trained a convolutional neural network (CNN) model on a SV dataset collected from Goma, Democratic Republic of Congo (DRC) to identify relief camps from video imagery. We developed a spatial filtering approach to tackle the challenges associated with spatially tagging objects such as the accuracy of global positioning system and positioning of camera. The spatial filtering approach generates smooth surfaces of detection, which can further be used to capture changes in microenvironments by applying techniques such as raster math.ResultsThe initial results suggest that our model can detect temporary physical dwellings from SV imagery with a high level of precision, recall, and object localization. The spatial filtering approach helps to identify areas with higher concentrations of camps and the web-based tool helps to explore these areas. The longitudinal analysis based on applying raster math on the detection surfaces revealed locations, which had a considerable change in the distribution of tents over space and time.ConclusionsThe results lay the groundwork for automated mapping of spatial features from imagery data. We anticipate that this work is the building block for a future combination of SV, object identification and automatic mapping that could provide sustainable data generation possibilities for challenging environments such as relief camps or other informal settlements.

Conflict, Displacement and Overlapping Vulnerabilities: Understanding Risk Factors for Gender Based Violence Among Displaced Women in Eastern Democratic Republic of Congo

Eastern Democratic Republic of Congo (DRC) has been embroiled in decades-long conflict that has resulted in the forced displacement of millions of people and extremely high rates of gender-based violence (GBV). While much attention has understandably focused on conflict-related sexual violence, intimate partner violence (IPV) is in fact one of the most pervasive forms of GBV, including in conflict settings. This paper presents results of a large, randomised survey looking at both sexual and intimate partner violence. Formerly displaced women had 11 per cent greater odds of reporting past-year IPV (p < 0.05), and currently displaced women reported 20 per cent greater odds of IPV in the past-year (p < 0.001). Women who reported ever being displaced also reported 8.5 per cent greater odds (p < 0.001) of past-year sexual violence. Both displacement and war-related experiences are highly and significantly associated with lifetime and past-year IPV and sexual violence. By acknowledging and creating programs that explicitly address the high risk of violence faced by displaced women, we may more effectively break the cycles of violence in fragile settings.

Monkeypox 2024 outbreak: Fifty essential questions and answers.

As the world still vividly recalls the previous monkeypox (mpox) outbreak that impacted over 120 countries worldwide with more than 99,000 cases in 2022, we are now facing a second wave of infections from the monkeypox virus (MPXV), characterized by an exponential increase in cases. The current 2024 outbreak has already recorded more than 20,000 cases in Africa, marking a dramatic escalation compared to previous outbreaks. The predominance of the newly identified clade Ib variant, first detected in the Democratic Republic of the Congo (DRC) and now identified across multiple African nations and beyond, underscores its enhanced transmissibility and potential for international spread, evidenced by cases in Sweden and Thailand. The World Health Organization (WHO) declared on August 14, 2024, the current mpox outbreak a Public Health Emergency of International Concern (PHEIC), calling for heightened global public health measures. The ongoing pattern of unusual, frequent, and extensive outbreaks of mpox with potential global implications poses significant questions. This review addresses, in the format of 50 questions and answers, the 2024 mpox outbreak, detailing its characteristics, epidemiological data, and impact compared to previous outbreaks. It comprehensively explores critical questions related to MPXV virological characteristics, immunological response, clinical manifestations, epidemiology, diagnostics, and available treatments. The review also documents the significant and evolving challenges posed by the current mpox outbreak, highlighting its scale, spread, and public health response.

Compellence by denial against armed groups: UN peacekeeping in Ituri, the Democratic Republic of the Congo

Abstract Peace operations are often deployed to countries where conflicts are effectively ongoing, with mandates to protect civilians and provide security. With the authorisation to use force beyond self-defence, peacekeepers are expected to exert military pressure on armed groups to induce them to abandon violence and join peace processes. Such an approach falls in the domain of compellence. Given that peace operations struggle to adapt to this new expectation, it is imperative to find effective ways of compelling armed groups. While studies on compellence agree on the effectiveness of denial-type pressure, its specific forms are highly context-dependent. What is the most effective way to achieve denial against armed groups in the context of peace operations? There are four such approaches: attrition, stronghold neutralisation, decapitation, and counter-coercion negation. A case study of peacekeeping by the United Nation in Ituri reveals that stronghold neutralisation and counter-coercion negation were especially important for compelling rebels to disarm. As existing studies have not examined the effectiveness of specific forms of denial in peace operations, the finding contributes significantly to the literature on compellence and peace operations.

Introduction to the Symposium “The monusco Intervention Brigade at Ten” Ten Years of the monusco Intervention Brigade: International Law Concerns on the Future of Peacekeeping and the Protection of Civilians

Abstract This is an introduction on a special issue on ‘The monusco Intervention Brigade at Ten’. The special issue includes three articles that discuss the impact of ten years of practice of the monusco Intervention Brigade on peacekeeping in general and the protection of civilians in the Democratic Republic of the Congo in particular.

Mpox Vaccine Acceptance, Democratic Republic of the Congo.

We report general acceptance (61.0%) of an mpox vaccine in the Democratic Republic of the Congo among 5,226 survey respondents. Healthcare workers and respondents in historic mpox-endemic regions had higher acceptance rates. These data highlight the need for increased community engagement and sensitization before widespread deployment of mpox vaccines.

Diversity and availability of edible caterpillar host plants in the Luki Biosphere Reserve landscape in the Democratic Republic of the Congo

Edible caterpillars are an important food and economic resource for rural African people. However, they are subject to a number of threats; in particular, their host plants are threatened. The Luki Biosphere Reserve landscape is a region of the Democratic Republic of Congo where the practice of eating caterpillars is a recent phenomenon; however, rural communities have reported their scarcity. This study assessed the diversity and availability of host plants of the edible caterpillars in the Luki Biosphere Reserve (LBR) landscape. Botanical inventories were conducted in eleven ha plots of each of the following habitats: forest, savannah, fallow, and inhabited areas, covering an area of 44 ha. The coverage-based rarefaction and extrapolation method and the iNEXT online software were used to calculate the true diversity of edible caterpillar host plants. The diameter structure of the edible caterpillar host plant species was assessed by counting the number of individuals in each diameter class. The results revealed that in the Luki Biosphere Reserve landscape, edible caterpillars rely on 15 main plant host species (Spondias mombin L., Petersianthus macrocarpus (P.Beauv.) Liben, Croton sylvaticus Hochst. ex Krauss, Hymenocardia acida Tul., Lannea welwitschii (Hiern) Engl., Macaranga spinosa Müll.Arg., Celtis mildbraedii Engl., Coelocaryon botryoïdes Vermoesen, Albizia gummifera (J.F.Gmel.) C. A. Sm, Bridelia atroviridis Müll.Arg, Ficus mucuso Welw. ex Ficalho, Funtumia elastica (P.Preuss) Stapf, Lannea welwitschii (Hiern) Engl., Milicia excelsa (Welw.) C.C. Berg., and Terminalia superba Engl. & Diels). The habitats exhibited low species diversity of the edible caterpillar host plants. Moreover, several of these species are becoming scarce or are locally threatened with extinction. The trend in the diametric structure is similar to species evolving in a disturbed environment.The results of this study suggest potential habitat instability linked to human activities that could lead to biodiversity loss and, thus, a decline in edible caterpillars in the LBR landscape. A better understanding of the unfavourable conditions that influence the nutritional support for the edible caterpillars would help promote appropriate strategies that can be applied in local development plans for community lands at a landscape scale.

The Force Intervention Brigade in the drc, Civilian Security and Women Peace and Security

Abstract This article examines the UN Security Council (unsc) authorised Force Intervention Brigade (fib) in the Democratic Republic of the Congo (drc) and the component of the mandate that articulates civilian security as a rationale for justified force. In examining civilian protection (articulated as both civilian security and as the protection of civilians), we explore the parallels between the women, peace and security agenda and the image – versus the reality – of civilian vulnerability in the drc. In focusing on the narratives of civilian security we explore how the ten years of repeat authorisations for the fib replicate heteronormative and colonial tropes that have ultimately undermined security in the drc and, for international lawyers, undermine peacekeeping principles, authorisations of force, and understandings of consent. The contradictions between the Security Council’s commitments to addressing and preventing conflict-related sexual violence and the mobilisation of the fib are drawn on to demonstrate the ways in which gender simultaneously strengthens the Council’s legitimacy and yet produces few spaces of significant change from a feminist perspective. We conclude that not only is the legacy of the fib detrimental to women’s security in the drc given reports of sexual exploitation and abuse (sea) perpetrated by peacekeepers but that the fib has transformed peacekeeping away from peace, embedding militarised responses to a complex humanitarian crisis.

Inventory of the best-selling medicinal plants on the Lubumbashi markets (DR Congo) and authentication of samples from the 3 most popular species

Ethnopharmacological relevanceKnowledge of the high-sale medicinal plants and their authentication are essential parameters to ensure the safety of people using herbal medicine and to plan the safeguarding of medicinal species threatened with extinction. AimsThe present study, carried out in Lubumbashi, Democratic Republic of Congo, aimed to geolocate medicinal plant sales points, list the best-selling species, and authenticate samples of the most popular species on the market. MethodsA survey was conducted among the medicinal plant sellers in Lubumbashi’s markets and other public spaces, to identify the best-selling species. Samples of the species reported as the most sold were purchased for sales unit weight measurement, and authentication. For the 3 most popular plant species, the identity of 92 samples, purchased from some 25 herbalists, was assessed by combining the microscopic characteristics of powdered drugs with the HPTLC fingerprints of methanolic extracts; for each species, these samples were compared with 1 or 2 botanically authenticated reference samples. As abundant starch granules were detected by microscopy, some samples were suspected of heavy flour contamination, which was confirmed by an enzymatic determination of their starch content. ResultsA total of 108 herbalists (48.1 % women) with a median age of 37 years (range, 20 to 67 years), and a median seniority of 5 years (0.7 to 30) were interviewed. From a total of 514 purchased samples, 396 (77.0 %) corresponded to 56 species that could be identified, including 92 samples representing the 3 most frequently sold plant species. The identities of 118 samples (having 82 different vernacular names), could not be determined, due to the lack of voucher specimen Roots were the most sold organ (56.0 %; n = 514), mainly in powder form (78.7 %), and the median price was 21 USD/kg, at the time of the survey (01/2022). The identified specimens were, predominantly, the roots of Terminalia mollis M.A.Lawson (33.3 %), Securidaca longepedunculata Fresen (28.7 %), and stem barks of Nauclea pobeguinii Hua ex Pobég. (23.1 %); from the recorded sales figures, the amounts of material annually sold for these 3 species are estimated at about 5.7, 6.0, and 3.1 tons, respectively. Some sellers reported problems in identifying and/or preserving S. longepedonculata and T. mollis.Among the 92 samples analyzed for the three species, 18.5 % raised problems, including species substitutions (14/17), dilution with flour (1/17), dilution with flour and species substitution (1/17), and detection of a phytochemical variant (1/17), that could arise either from contamination by another species, a particular plant growth environment, or poor storage conditions. ConclusionThe confusion/adulteration rate measured here for highly popular species is quite alarming (18.5 %); but, indeed, roots, especially as powders, are often difficult to differentiate based on the coarse organoleptic examination practiced by herbal traders. Microscopic and phytochemical characteristics reported in this study, quite easy to obtain with basic laboratory equipment, should be systematically applied by the health products regulatory authorities to control the quality of herbals and ensure that patients get the drug desired for their treatment.

The Force Intervention Brigade: A Conscious Departure

Abstract This article examines lessons learned from the Force Intervention Brigade in relation to the fundamental principles of peacekeeping. Whilst the Security Council declared that the Brigade, deployed in the dr Congo in 2013, was created ‘without a precedent or any prejudice to the agreed principles of peacekeeping’ this article will consider how it has challenged our understanding of these principles and will question to what extent a precedent has been set within peacekeeping. As the UN’s peace operation in the Congo, monusco, is set to withdraw and regional actors involved in the creation of the Brigade seek to deploy forces, the article will argue that the Brigade expanded peacekeeping to its very limits, amounting to a ‘conscious departure’ from the peacekeeping principles which should be avoided in any future UN peace operations.

Process evaluation of an urban piped water supply infrastructure improvement programme in Uvira, Democratic Republic of the Congo

Major investments in water supply infrastructure will be required to achieve Sustainable Development Goal (SDG) 6. Safely managed water services are also central to global cholera and diarrhoeal diseases prevention strategies. However, evidence remains scarce on how to efficiently improve piped water services in complex settings where infrastructure investments are most needed. We conducted a process evaluation of a large-scale water supply infrastructure improvement programme in Uvira, Democratic Republic of the Congo, in parallel to a pragmatic trial. Considering three evaluation domains–context, implementation, and population response–, we assessed the validity of the programme’s theory of change and underlying assumptions. Information sources included construction works documentation, operational and billing records from the water utility, and household surveys. The evaluation covers the period 2014–2021. Trial results are not within the scope of this manuscript. The programme did not achieve expected improvements in the water supply service during the evaluation period. Out of 16 assumptions underlying the theory of change, six remained valid, seven partially valid, and three turned out to be invalid. Contextual challenges included extreme flooding in 2020 and the Covid-19 pandemic, which disrupted construction works. Issues related to electricity supply and the rise of Lake Tanganyika emphasise the need for cross-sectoral approaches and consideration of climate change in the planning of water supply infrastructure. Implementation challenges underlined the importance of capacity strengthening alongside infrastructure improvements. Population response elements suggest that affordability and informal practices such as tap sharing should be taken into account. The programme was a good example of early engagement with researchers and provides unique insights into the implementation of large-scale infrastructure improvements in a complex, low-income setting. Pragmatic evaluation approaches should be adopted for the generation of scientific evidence from complex programmes in order to optimise future infrastructure investments contributing to progress towards SDG6.

Cardiovascular Disease and Diabetes Are Among the Main Underlying Causes of Death in Twenty Healthcare Facilities Across Two Cities in the Democratic Republic of Congo

Introduction: The mortality rates associated with cardiovascular disease (CVD) and diabetes exhibit disparities by region, with Central Africa ranking fourth globally in terms of mortality rate. The Democratic Republic of Congo (DRC) does not possess mortality data pertaining to these specific underlying causes of death. This study aimed to determine the death rate attributable to CVD and diabetes in two cities in the DRC. Methodology: The data on CVD and diabetes utilized in this study were obtained from a pilot project and were registered in the National Health Information System (NHIS). Data quality was initially evaluated using an automated Digital Open Rule Integrated Selection (DORIS), followed by an assessment conducted manually by three assessors. Descriptive and comparative analyses were carried out to determine the proportion of mortality related to CVD and diabetes. Results: CVD accounted for 20.4% (95%CI: 17.7–23.4%) of deaths in the two cities (Kinshasa and Matadi), whereas diabetes accounted for 5.4% (95%CI: 3.9–7.2%). After adjusting for age and city, the proportional mortality from CVD and diabetes was higher for women than men and increased with age. This study recorded 4.4% of deaths among men and 7.0% among women as the proportional mortality from diabetes. Conclusions: Non-communicable diseases (NCDs) continue to be a major cause of death, and CVD and diabetes are among the leading causes of early mortality in adults in urban areas. The proportional mortality related to CVD and diabetes appears to be higher in women than in men. Special emphasis should be placed on women, particularly during adulthood, to ensure the prompt detection of diabetes and cardiovascular conditions.

Close female friendships and knowledge of recommended abortion methods in Nigeria and the Democratic Republic of the Congo among a representative sample of reproductive-aged women

IntroductionThere is a high incidence of unsafe abortion among women in Nigeria and the DRC. Low knowledge of recommended abortion methods [i.e., surgical and medication abortion (MA) pills] is a barrier for women accessing safe abortions. Women often rely on friends for information about abortion methods. Understanding characteristics of women with knowledge of recommended abortion methods, and MA specifically, and how it is influenced by close female friendships may help identify women most at risk of relying on unsafe abortion.MethodsWe used survey data from Performance Monitoring for Action from 11,106 women of reproductive age in Nigeria (April–May 2018) and 3,697 women in Kinshasa and Kongo Central, DRC, (December 2021–April 2022) to produce representative estimates of knowledge of abortion methods at the national and province levels, respectively. We performed bivariate and multivariate logistic regression to determine which characteristics were independently associated with knowing a recommended abortion method, with knowing of MA pills specifically, and to assess our hypothesis that having at least one female confidante would increase one's odds of knowing about these methods.ResultsA minority (26.9%) of women in Nigeria and the majority in Kinshasa (76.7%) and Kongo Central (58.1%) reported having knowledge of at least one recommended abortion method, while knowledge of MA pills was low in all sites. Having at least one close female confidante was associated with increased odds of knowing a recommend abortion method in Nigeria (aOR = 1.50, 95% CI 1.25–1.79) and in Kongo Central (aOR = 2.66, 95% CI 1.40–5.40), and with increased odds of knowing about MA specifically in Kinshasa (aOR = 1.44, 95% CI 1.08–1.93) and Kongo Central (aOR = 3.61, 95% CI 1.28–10.22), but not Nigeria.DiscussionIn legally restrictive contexts where knowledge of recommended abortion methods (particularly medication abortion) is low, having close female friends is related to increased knowledge of recommended abortion methods.

Anthropogenic Effects on Green Infrastructure Spatial Patterns in Kisangani City and Its Urban–Rural Gradient

Urban and peri-urban expansion significantly influences the spatial pattern of cities and surrounding zones. This study examines the spatial changes in green infrastructure components, specifically focusing on mature forests, short forests, and agricultural and grass lands from 1986 to 2021, using satellite imagery. Two landscape ecology indexes, the percentage of landscape (PLAND), and the largest patch index (LPI), were applied. PLAND provides insights into the proportion of habitat types, capturing overall extent, while LPI elucidates their spatial configuration. The research is conducted in a specific context of increasing urbanization and peri-urbanization in Kisangani city, DR Congo. The findings reveal a decline in both mature and short forests, respectively, from 1986 to 2021, and from 2006 to 2021 alongside a continuous expansion of agricultural and grass lands at the landscape scale. Moreover, the spatial pattern of mature and short forests exhibited significant variations across urban, peri-urban, and rural zones. In the context of 2021, in urban and peri-urban zones, mature forests account for less than 1% of the 2.25 km2 plots, against more than 35% in certain rural plots. Similarly, larger patches of mature forest in urban and peri-urban zones cover less than 0.5% of the 2.25 km2 plots, whereas they exceed 20% in rural zones. From 1986 to 2021, both mature and short forests experienced significant decline and fragmentation, particularly in urban and peri-urban zones, while agricultural and grass lands increased significantly in peri-urban and rural zones. These results raise concerns regarding the functions, services, and opportunities provided by mature and short forests in the context of global change. They also highlight the need for urban planning in Kisangani to prioritize green infrastructure preservation, focusing on maintaining forest connectivity and preventing further fragmentation. Policies should promote sustainable land use in peri-urban zones to achieve a balance between urban expansion and the provision of essential ecosystem services, thereby enhancing long-term resilience.

What do urban consumers want? Findings from a discrete choice experiment on the preference for locally produced staple food in Central Africa: Evidence from the Democratic Republic of Congo (DRC)

ABSTRACT A discrete choice experiment in Kinshasa (DRC) investigated urban consumers' preferences between imports and local options for five staple foods – cassava, rice, maize, sugar and cooking oil – under a random utility model. We also examined how distance, packaging and price influenced consumer choice. To assess whether preferences could be manipulated, we introduced two treatment groups – local, import – and a control group. We did not find support for a preference for imports. Instead, there is a statistically significant preference for local products, with the exception of sugar. Respondents are willing to pay 28% more for local food, a premium quantified at 1540 CF (.93 USD) per kg for maize and 1091CF (.66 USD) per litre for oil. Packaging is an attribute of influence as the willingness to pay (WTP) in full remains positive when products interact with packaging and with price. There is demand for local products for which consumers are willing to pay a premium. Yet, DRC imports 1.5 billion dollars of food yearly with only 10% of its arable land exploited. The increased urban consumption of imports does not signify a bias against local products, but rather points to structural issues undermining local supply. DRC needs to develop local value chains linking rural farmers to urban markets through the transformation of local foods to meet urban needs and to convert the WTP into a producer surplus benefiting rural livelihoods.

Prediction, modeling, and optimization studies of eco-friendly gold extraction using alpha-cyclodextrin and the RSM and CCD methods

In the Democratic Republic of the Congo, gold extraction from ore in South Kivu utilized alpha-cyclodextrin (α-CD) as an eco-friendly method to replace harmful methods. Analysis of variance and response surface methodology were employed for prediction, modeling, and optimization studies. Atomic absorption spectroscopy revealed a 0.06% gold content in a randomly taken ore sample. Leaching with modified aqua regia was optimized with the following parameters: 7.27 h, 50 g/L HBr concentration, pH 1, and 200 rpm stirring speed, resulting in 98.5% removal. Neutralization tests with potassium hydroxide (KOH) followed leaching to prepare the solution medium with appropriate pH for extraction test, by varying parameters such as time, KOH concentration, and pH. Following neutralization, extraction tests with α-CD were carried out and optimized with the following parameters: 40 min, α-CD concentration of 11.6166 g/L, and a pH of 5, resulting in a percent removal of 98.9%. α-CD’s eco-friendly nature, cost-effectiveness, and high percent removal make it a promising and sustainable alternative for gold recovery, appealing to the mining industry.

Light-demanding canopy tree species do not indicate past human disturbance in the Yangambi rainforest (Democratic Republic of the Congo)

Key messageIn a former paper, we investigated whether the presence of light-demanding tree species in the forest canopy of the Yangambi Biosphere Reserve (central Congo basin) might be a result of past human disturbances (Luambua et al., Ecol Evol 11:18691–18707, 2021). We focussed on the spatial distribution of the most abundant light demanders, but this approach did not yield conclusive results. In the present study, we focus on all species in the forest and conclude that light demanders are not a transient feature of successional tropical forests but an intrinsic component of old-growth forests in Yangambi.ContextCentral African rainforests are characterised by an abundance of light-demanding tree species, which are aggregated in the canopy but underrepresented in the understorey. A popular explanation is that these forests are recovering from slash-and-burn farming activities preceding the relocation of settlements during the colonial era. In a former paper, we showed that the abundance of light-demanding tree species in the Yangambi Biosphere Reserve (central Congo basin) cannot be unambiguously attributed to past human disturbances, using an approach that focused on the spatial distribution of the most abundant light demanders (Luambua et al., Ecol Evol 11:18691–18707, 2021).AimsAs the former study was inconclusive, the present study aims to further test the assumptions behind the ‘recovery from human disturbance hypothesis’, by considering all species in the forest of Yangambi. We addressed four specific research questions: (i) do light demanders occur in large ‘pockets’ occupying large areas of forest? (ii) Are light demanders abundant? (iii) Do they exhibit a regeneration deficit? (iv) Is species composition in pockets of light demanders different from the surrounding forests?MethodsWe identified the location and size of pockets of light demanders in several transects cumulating to 50 km. We installed permanent inventory plots within and outside these pockets and calculated the diameter and age distributions of light demanders within each pocket. We assessed whether pockets of light demanders are different from surrounding forests, using plot clustering analysis.ResultsOur results showed that light demanders were aggregated, but the pockets were small, scarce, and represent a minor fraction of the total forest area. Furthermore, light demanders were not abundant, even in pockets where they were aggregated. Their age distributions did not show a regeneration deficit. Finally, species composition in pockets of light demanders did not differ substantially from surrounding forests where they were scarce or absent.ConclusionsWe conclude that light-demanding canopy species do not indicate past human disturbance in Yangambi and that they are an intrinsic component of old-growth forests rather than a transient feature of successional forests. Our insights show that the large carbon sink observed in mature forests in this region is not driven by successional forest dynamics.

Microfinance Services and Women's Empowerment in the Democratic Republic of Congo: A Case Study of FINCA and Hekima Microfinance

Microfinance Services and Women's Empowerment in the Democratic Republic of Congo: A Case Study of FINCA and Hekima Microfinance