Influence of Cereal-Legume Rotation on Striga Control and Maize Grain Yield in Farmers’ Fields in the Northern Guinea Savanna of Nigeria

On-farm trials were conducted in 2001, 2002, and 2003 in the northern Guinea savanna of Nigeria to evaluate integrated Striga hermonthica control measures under farmermanaged conditions. These included intercropping a Striga-resistant maize variety with cowpea for 3 years and also cropping this maize in rotation with legume trap crops - soybean and cowpea for 1-2 two years. Intercropping Striga-tolerant maize variety, Acr. 97TZL Comp. 1-W, with cowpea (Vigna unguiculata L.) consistently reduced Striga infestation in maize relative to continuously cropped sole maize over the threeyear period. Maize grain yield was lower in the intercrop than in the sole maize plot probably due to competition from cowpea. However, because of the high value of cowpea in the intercrop, crop value for this system was higher than sole cropped maize. Legume-maize rotation reduced Striga infestation by 35% after one year of legumes in the rotation and by 76% after two years of legumes in the rotation. Soybean was more effective in reducing Striga infestation and also gave higher maize grain yield than cowpea. The rotation of these two legumes with maize had clear advantage over continuously cropped maize. Farmers should therefore be encouraged to adopt the introduction of grain legumes into the cereal cropping systems of the Nigerian savanna

Intensive cereal-legume–livestock systems in West African dry Savannas.

The dry savannas of West Africa are undergoing rapid transformation of agricultural practices owing to the rapid human and livestock population growth, increase in agricultural intensification and accelerated climate change which has increased the incidence and severity of diseases, pests and drought. The major constraints to agricultural production in the savanna include poor soil fertility, pests and diseases of crops and livestock, parasitic weeds such as Striga hermonthica, drought, and competition between crops and livestock for resources, Inadequate policies, weak institutional mechanisms, and poor linkages among farmers, and researchers prevent adoption of improved agricultural technologies that can combat these constraints. The risk of continuous cultivation on these poor and fragile soils is huge. Integrating crop and livestock production offers ways to increase production while protecting the environment. Over the years, research and development institutions have generated several agricultural technologies to alleviate the majority of the production constraints in the West African savannas. However, most development organizations use traditional extension methods that result in poor adoption of the improved technologies. The integration of crop and livestock production is particularly desirable in intensively farmed and densely populated areas with access to urban markets. Proper integration of these practices will diversify smallholder income and increase food security. Integrated genetic and natural resource management provides the keys improved eco-efficiency. This includes integrating pesticide use with cultural practices such as modified planting date and disease control; rotating/ intercropping cereals and legumes; use of pest resistant\tolerant cultivars to increase the effectiveness of pest control and reduce the need for pesticides; and improving soil fertility restoration/maintenance. Government and national institutions in West Africa are encouraged to scale-out these technologies to wider areas for increased benefit to farmers through the use of proven extension methods

Performance of semideterminate and indeterminate cowpeas relaycropped into maize in Northeast Nigeria

Field trials were conducted in 2005 and 2006 in Tilla (northern Guinea savanna) and Sabon-Gari (Sudan savanna) in northeast Nigeria to determine the performance of two improved cowpea varieties when relay-intercropped with early and late maize, 6 and 8 weeks after planting the maize. Grain yield, number of branches and number of pods per plant were higher for the variety IT89KD-288 than for IT97K-499-35, whether planted sole or relay-intercropped with maize. Grain yield was lower for IT97K-499-35 than for IT89KD-288 when relay-intercropped with maize irrespective of the maturity period of the companion maize crop. This may be due to the indeterminate growth habit and shade tolerance of IT89KD-288 which allowed a higher pod load than IT97K-499-35. However, relay-intercropping with early maize gave higher yield than relay-intercropping into late maize. Also relay-intercropping at 6 weeks after planting maize (WAP) gave a higher yield than relay-intercropping at 8 WAP. This therefore, suggests that introducing cowpea into short statured early maize may mean less competition for light and soil resources compared to taller late maize. Also introducing the cowpea earlier may allow the crop to make full use of soil moisture during the cropping season

Bringing the social into vaccination research: Community-led ethnography and trust-building in immunization programs in Sierra Leone

Background Vaccine hesitancy is a complex, contested social phenomenon and existing research highlights the multifaceted role of trust in strengthening vaccine confidence. However, understanding public engagement with vaccination through the lens of (mis)trust requires more contextual evidence on trust's qualitative determinants. This includes expanding the geographic focus beyond current studies' focus on High Income Countries. Furthermore, obstacles remain in effectively integrating social science findings in the design of vaccine deployment strategies, and in ensuring that those who implement interventions and are affected by them are directly involved in producing knowledge about vaccination challenges. Methods We piloted a community-led ethnographic approach, training Community Health Workers (CHWs) in Kambia District, Sierra Leone, in qualitative social science methods. Methods included participant observation, participatory power mapping and rumour tracking, focus group discussions and key stakeholder interviews. CHWs, with the support of public health officials and professional social scientists, conducted research on vaccination challenges, analysed data, tested new community engagement strategies based on their findings and elicited local perspectives on these approaches. Results Our findings on vaccine confidence in five border communities highlighted three key themes: the impact of prior experiences with the health system on (mis)trust; relevance of livelihood strategies and power dynamics for vaccine uptake and access; and the contextual nature of knowledge around vaccines. Across these themes, we show how expressions of trust centered on social proximity, reliability and respect and the role of structural issues affecting both vaccine access and confidence. The pilot also highlighted the value and practical challenges to meaningfully co-designed research. Conclusion There is scope for broader application of a community-led ethnographic approach will help redesign programming that is responsive to local knowledge and experience. Involving communities and low-cadre service providers in generating knowledge and solutions can strengthen relationships and sustain dialogue to bolster vaccine confidence

Lower Bounds for Encrypted Multi-Maps and Searchable Encryption in the Leakage Cell Probe Model

Encrypted multi-maps (EMMs) enable clients to outsource the storage of a multi-map to a potentially untrusted server while maintaining the ability to perform operations in a privacy-preserving manner. EMMs are an important primitive as they are an integral building block for many practical applications such as searchable encryption and encrypted databases. In this work, we formally examine the tradeoffs between privacy and efficiency for EMMs. Currently, all known dynamic EMMs with constant overhead reveal if two operations are performed on the same key or not that we denote as the $\mathit{global\ key\text{-}equality\ pattern}$. In our main result, we present strong evidence that the leakage of the global key-equality pattern is inherent for any dynamic EMM construction with $O(1)$ efficiency. In particular, we consider the slightly smaller leakage of $\mathit{decoupled\ key\text{-}equality\ pattern}$ where leakage of key-equality between update and query operations is decoupled and the adversary only learns whether two operations of the $\mathit{same\ type}$ are performed on the same key or not. We show that any EMM with at most decoupled key-equality pattern leakage incurs $\Omega(\log n)$ overhead in the $\mathit{leakage\ cell\ probe\ model}$. This is tight as there exist ORAM-based constructions of EMMs with logarithmic slowdown that leak no more than the decoupled key-equality pattern (and actually, much less). Furthermore, we present stronger lower bounds that encrypted multi-maps leaking at most the decoupled key-equality pattern but are able to perform one of either the update or query operations in the plaintext still require $\Omega(\log n)$ overhead. Finally, we extend our lower bounds to show that dynamic, $\mathit{response\text{-}hiding}$ searchable encryption schemes must also incur $\Omega(\log n)$ overhead even when one of either the document updates or searches may be performed in the plaintext

An intra-COVID-19 assessment of hand hygiene facility, policy and staff compliance in two hospitals in Sierra Leone: is there a difference between regional and capital city hospitals?

Although hand hygiene (HH) is the most effective intervention to reduce the spread of infections, there are limited data on HH facilities, policy, and compliance in sub-Saharan Africa. This cross-sectional study is aimed at assessing HH using the WHO HH self-assessment framework, HH technical reference manual, and a modified infection control self-assessment tool in two hospitals in Sierra Leone. Only 10% and 9% of regional and capital city hospitals had running tap water, respectively. Veronica buckets were the resources for HH in 89% of units in the regional hospital and 92% of units in capital city hospital. Constant supply of soap and alcohol-based hand rub was available in 82% and 68%; and 74% and 79% of units in the capital city and regional hospitals, respectively. Only 10% of the units in both hospitals had hand-drying facilities and functional sinks. Overall HH compliance for the two hospitals was 18.6% and was higher in the regional (20.8%) than the capital city (17.0%) hospitals. The HH levels for the capital city and regional hospitals were 277.5 and 262.5 respectively. Despite the COVID-19 pandemic, there are still challenges with HH compliance in Sierra Leone. It is, therefore, necessary to strengthen the HH multi-modal strategy

Lower Limb Amputation at the 34 Military Hospital in Freetown, Sierra Leone: Causes and Indications.

The global prevalence of diabetes mellitus is increasing substantially. This overall increment leads to the growth in the number of individuals with diabetic complications including lower limb amputation. In low-income countries like Sierra Leone, lack of access to adequate health care, poverty and social stigma attached to “amputation” all prevent people from seeking early medical treatment for diabetic foot.The purpose of this study was to document the causes and indications of lower limb amputations and to make appropriate recommendations to the health sector of Sierra Leone.This retrospective study was conducted at 34 Military Hospital, one of the major referral hospitals in Freetown, between January 2011 and December 2014. A team of medical staff was trained to extract data. The operating theatre and ward case records were searched for information (age, gender, cause and indication for amputation) of all the patients who underwent amputation during this period. The findings were statistically documented in tables.Twenty-seven patients (24 males and 3 females) were involved in the study. The age distribution was 15-65 years (Mean 43). Majority (77.7%) of the patients presented with gangrenous and infected diabetic feet, 18.5 % was due to Road Traffic Accident and 3.8% due to complication of HIV infection. The commonest level was transtibial amputation 85% and 67% was right sided. Hospital stay was 20-50 days (average 35). There was no postoperative mortality.As most amputations were done for diabetic feet, there is need for diabetes sensitization and prevention campaigns for the general public and improvement of diabetic care for individual patients including proper glycemic control and risk factors prevention. Increased funding is required by the health sector of Sierra Leone to implement these measures. Prevention of road traffic accidents by training/educating the drivers should also be considered by Sierra Leone Road Transport Authority.