Delivery of Agricultural Technology to Resource-poor Farmers in Africa
Address for correspondence: Hodeba D. Mignouna, Ph.D., African Agricultural Technology Foundation, P.O. Box 30709, Nairobi, Kenya. Voice: +254-20-422-3736; fax: +254-20-422-3701. (For USA, voice: 650-833-6660, ext. 3736; fax: 650-833-6661.)
Recent developments in agricultural science and technology have the potential to transform the agricultural sector in the developing world. These technological advances constitute key drivers of economic growth and hold great promise for poverty reduction in sub-Saharan Africa (SSA). Agricultural research and development in Africa is undergoing a major paradigm shift. Until recently, public-sector institutions in Africa worked in isolation to create and disseminate agricultural technologies to smallholder farmers. However, they need access to improved proprietary technologies developed for the most part by the private sector in developed countries. These technologies are currently concentrated in the hands of a few large corporations and are protected by intellectual property rights. The African Agricultural Technology Foundation (AATF) is a new initiative addressing the challenges associated with the access, development, and deployment of agricultural technologies to smallholder farmers in SSA. This article describes the AATF model of facilitating the creation of partnership alliances dedicated to promote and support collaboration among a wide variety of public- and private-sector organizations around shared agricultural research and development goals for the public good. It explains AATF's public–private partnership framework for technology delivery in the light of market failures, institutional constraints, and systemic weaknesses, which impede public-sector organizations from accessing and delivering pro-poor knowledge and technology to farmers. The article provides policy makers, research managers, and business decision makers with an understanding of how access to, and delivery of, proprietary technologies could contribute to food security and the improvement of farmers' livelihoods in Africa.
African Agriculture and Constraints to Agricultural Productivity
Africa has an estimated land area of about 30 million km2, second only to that of the Asian continent. The population, which stood at 200 million 30 years ago, has increased more than fourfold to the current estimate of 930 million. At the current growth rate of 3.1%, the highest population growth rate in the world, it is projected that there will be 1.7 billion people living in sub-Saharan Africa (SSA). Agriculture remains the backbone of many African economies, representing an estimated 57% of total employment and 17% of the gross domestic product.1 Despite the importance of this sector, agricultural productivity of the continent is low, barely exceeding 1% annual growth.
SSA is the only region of the world where per capita food grain output has declined over the past four decades, requiring the continent to import 25% of its food grain requirements.2,3 Cereal crop yields in SSA have stagnated and remain at an average of about 1 ton per hectare (ha) over the last 40 years, while the meager produce from the land is subject to epidemics of pests and diseases. Farm inputs, such as chemical fertilizers and pesticides, are prohibitively expensive and, where used, carry attendant human and environmental health concerns as a result of poisoning and pollution. Although the proportion of malnourished individuals in SSA has remained in the range of 33%–35% since around 1970, the absolute number of malnourished people in Africa has increased substantially with population growth, from around 88 million in 1970 to an estimate of more than 200 million—a third of all Africans.1,4 This figure is even more alarming when one considers that four in 10 Africans live on less than US$1 per day.3
Agricultural market reforms in SSA have not properly transferred structural and institutional functions performed by the state to the private sector.5 Kherallah et al.5 argue that further progress in developing well-functioning markets will, among other things, require strengthened investment in public goods, such as infrastructure, and research and extension, as well as the development of competitive markets. The acquisition, development, and delivery of agricultural technologies to smallholder farmers, as well as timely public market information to help stabilize markets, are among the priorities of a new agenda for market development in Africa.5 Agricultural productivity gains brought about by research and new technology have been shown to lead directly to higher incomes for peasant farming and landless rural households, the two groups that make up most of the poor.4 Runge et al. cite a study of 35 countries by Peter C. Timmer that revealed that a 1% increase in agricultural gross domestic product led to a 1.6% increase in the per capita incomes of the poorest people.4 But agriculture in Africa is characterized by a dearth of new technologies, which would ensure increased agricultural productivity. Africa's competitiveness in traditional areas of its comparative advantage has been eroded by major advancements in technological innovations in the rest of the world and the effects of globalization.
To end hunger and prevent the recurrence of famine and starvation, Runge et al.4 called for a reform of public institutions and the creation of innovative funding and partnership agreements, as well as increased funding for scientific and technological research to boost agricultural production and efficiency. Throughout the 1990s, the budgets of African countries for agricultural research either declined or remained stagnant. Because scientific and technological advancement is so essential to the struggle against hunger, this slowdown in agricultural research and technology investments must be reversed. Addressing these constraints is a monumental challenge that warrants, among other things, technological interventions requiring use of new intensive production technologies (including adoption of genetically modified crops) to increase yields and reduce losses. National and regional institutions in Africa, in collaboration with their international partners, are responding to these challenges and developing innovative approaches to addressing Africa's agricultural malaise.
Need for, and Approaches to, Technological Interventions
Governments and regional organizations in Africa are committed to addressing the challenge of increasing agricultural productivity through using the Comprehensive Africa Agriculture Development Program as an engine for Africa's economic development.6,7 African leaders have set a target of increasing agricultural output by 6% per year over the next 20 years. However, to achieve even half this target, the New Partnership for Africa's Development states that the continent will require, among other factors, the following:
- • accelerated adoption of the most promising available technologies by linking research findings and extension services to producers in a more innovative and efficient way;
- • technology delivery systems that quickly bring innovations to farmers and agribusinesses;
- • enhancement of agricultural research systems' ability to generate, adapt, and integrate modern technologies, including biotechnologies; and
- • mechanisms that reduce the cost and risks of adopting new technologies.8
Thus, there is a clear recognition that the development and adoption of productivity-enhancing technologies is of paramount importance in this endeavor.
Because the critical mass of human resources and infrastructure for the development and delivery of new technologies may not be optimal in Africa currently, and in the immediate future, it is essential that creative approaches be adopted to enable access to appropriate technologies and to increase the necessary research and development (R&D) capability and expertise. But successful adoption of such pro-poor technologies will require partnership between the private sector, which has proven ability to bring technologies to farmers in the form of seeds and other agricultural inputs, and the public sector, which has agricultural research capability and a firm commitment to smallholder farmers' needs. The technology transfer continuum from research to farmers' fields has many prerequisites that go beyond successful technology development. Serious attention should be paid to important requirements, such as intellectual property (IP) management, regulatory compliance, and public awareness, which ultimately determine the success or failure of efforts to commercialize the products of agricultural technology. Barriers to technology adoption in Africa have led to the failure of many agricultural R&D efforts in the past and must be given thorough consideration in any scheme aimed at the development and delivery of agricultural technologies (including biotechnologies) to African farmers. Several key issues must be addressed to ensure successful adaptation and/or adoption by resource-poor farmers:
- • complexity and divisibility of the technology;
- • congruence of the technology with farmers' practices;
- • the cost, risk, and uncertainty associated with adoption;
- • effective information management to ensure that the public is well informed about the technology;
- • presence of a supportive social and physical infrastructure; and
- • the need for effective policies and institutions.
The understanding and effective management of IP, regulatory compliance, public awareness, and commercialization of the products of advanced technology are paramount to their adoption.9
Several institutions are experimenting with agricultural innovation models that bring together public- and private-sector institutions, nongovernmental organizations (NGOs), extension services, and farmers' associations to deal with these issues. One such institution is the African Agricultural Technology Foundation (AATF), a private, nonprofit foundation established to help resource-poor farmers in SSA gain access to proprietary technology. AATF is an Africa-based, Africa-led entity, officially launched in 2004 and registered as a charity under the laws of England and Wales. AATF has the specific objective of relieving poverty in Africa by facilitating public–private partnerships (PPPs) for the transfer and use of innovative agricultural technologies by smallholder farmers, particularly resource-poor farmers.9,10 The fundamental rationale for the creation of AATF was to establish links between private-sector and public-sector institutions (that own technological innovations) in developed nations and African stakeholders in agricultural development, such as the National Agricultural Research and Extension Systems, farmers' associations, NGOs, and national private-sector agribusinesses. AATF's goal is to realize the full potential of new technologies in Africa by facilitating access to advanced scientific and technological resources and promoting their adaptation for use in specific projects intended to increase the productivity of smallholder farmers in SSA. In doing so, AATF contributes to increased productivity, higher farm output, increased food security, and higher incomes.
This article highlights AATF's experience in the delivery of improved agricultural technology on the basis of its experience in western Kenya and argues that increasing agricultural productivity of smallholder farmers is feasible if appropriate mechanisms are put in place and implemented. The article specifically explores the model developed by AATF for technology transfer that incorporates the following:
- • managing PPPs that are organized into agricultural innovation platforms,
- • facilitating access to agricultural technologies and ensuring freedom to operate,
- • adapting agricultural technology to fit farmers' needs, and
- • deploying proven agricultural technologies in target areas.
Public–Private Partnerships and the Development and Delivery of Pro-poor Agricultural Technology
Science, technology, and innovation in developing-country agriculture are evolving in ways that necessitate new approaches to conducting R&D. In Africa, agricultural knowledge and technologies have traditionally been created by national public institutions.6 Recently, advances in molecular biology have led to the development of biotechnological tools and techniques of relevance to agriculture worldwide, and private-sector companies (particularly those in the developed countries) have invested heavily in agricultural research and technology, including biotechnology.11 However, the private sector has no commercial incentive to develop products of benefit to smallholder farmers. Because it is the public sector in Africa that plays the more prominent role in agricultural R&D, there is a need to capitalize on the strengths of both private and public institutions to develop products and technologies for the benefit of smallholder farmers. PPPs in agricultural R&D are increasingly viewed as an effective means of conducting advanced research, commercializing new technologies, and deploying new products for the benefit of small-scale, resource-poor farmers; food-insecure consumers; and other marginalized groups in developing countries.12
These partnerships represent efforts in which partners jointly plan and execute activities with a view to accomplishing mutually agreed-upon objectives while sharing the costs, risks, and benefits incurred in the process. Collaborations of this type can help overcome many of the impediments posed by market failure, institutional constraints, and systemic weaknesses in agricultural research and technology delivery by building on complementary factors, exploiting synergies, and distributing costs and risk between the public and private sectors. Different innovative PPP approaches have been adopted to improve the pace of research on, and delivery of, modern agricultural technologies in developing countries. One strategy is for the public sector to take a stronger public negotiation stance, advocate for greater private tax incentives, or promote other mechanisms to improve the willingness of firms to invest in or provide IP donations for research with a public-interest focus.13
Alternatively, researchers and policymakers have explored the use of “honest brokers,” or nonprofit, third-party organizations to facilitate interactions between the sectors. These honest brokers assume responsibility for the use of proprietary knowledge and technology, and they focus research priorities and execution toward pro-poor crops, traits, and technologies. These organizations are designed to reduce the costs and risks associated with transferring technologies and tools from the private sector to the public sector, typically for R&D undertakings that benefit the poor. Brokers include nonprofit organizations, such as AATF, the International Service for the Acquisition of Agri-biotech Applications, and the Public Intellectual Property Resource for Agriculture, as well as advanced research institutes such as the Donald Danforth Plant Science Center and CAMBIA (Center for the Application of Molecular Biology to International Agriculture). AATF is playing such a role in agricultural biotechnology and genetically modified crop management in Africa.9
PPPs managed by AATF for technology development and delivery in Africa rely on processes of knowledge sharing, resource pooling, cost minimization, scale economies, and joint learning to generate synergies for commercializing new technologies. These synergies are expected to result in enhanced prospects of success and improved cost effectiveness. Because the effort is strategically focused on the needs of marginalized social groups, outcomes are expected to ultimately translate into significant social and economic benefits. These model partnerships have already been developed by AATF to implement projects on cowpeas, maize, sorghum, bananas, and plantains.9,10
Constraints to Efficient Public–Private Partnerships in African Agriculture and the AATF Strategy
The challenges of successfully managing pro-poor PPPs have been thoroughly investigated, and several useful insights have been provided.9,13–15 Partnerships are constrained by conflicting incentive structures, high transaction and opportunity costs, competition and risk associated with proprietary assets, and mutually negative misperceptions. Competition and risk along with negative misperceptions, followed by conflicting incentives and high costs, were the most significant constraints cited by respondents.13
A common barrier to successful PPP collaboration results from the obvious differences in incentive structure: Private firms exist to maximize profits, whereas public agencies exist to address a wider scope of social mandates. The challenge for AATF is to find areas of common public–private interests and thereby increase the potential for collaboration and cooperation. Even where converging interests are identified or created, PPPs may face challenges arising from high transaction costs in contracting, coordinating, and enforcing rules of collaboration. Opportunity costs in PPPs may arise from the fact that organizations are ultimately accountable to their shareholders, and only a few African countries offer the large agricultural markets, strong IP protections, and/or adequate investment incentives that provide profitable opportunities for firms in the agricultural technology sector.
Perhaps the most significant barrier to partnership is associated with the risk and competition that comes with the use of proprietary knowledge and IP.9,13 The overriding concern is not access to patented tools or applications but rather concern over the use and misuse of the IP. For the private sector, PPPs involving IP run the risk that a public partner might advertently or inadvertently share the IP with the private partners' competitors or mishandle the stewardship of the IP, potentially allowing misuse or abuse by third parties. From the public-sector perspective, PPPs run the risk that a private partner might capitalize on technologies or genetic materials held in trust for the public good, appropriating any gains from its use for private gain.14 These risks can translate into significant financial and reputational liability for both public organizations and private firms.
To capture the technological advances made by the private and public sectors globally, and the strengths of the public agricultural research system in Africa, AATF has developed a strategy for the efficient management of partnerships for project formulation, product development, and deployment. This strategy aims at introducing innovative agricultural technologies to African farming systems. Doing so entails identification and development of partnerships with the most appropriate organizations for product development. Partnerships may also include investments for information provision (e.g., farm-level demonstrations). AATF ensures that IP management is addressed and assists its partners to comply with the relevant regulatory and biosafety procedures. It ensures that its partners are investing the required resources in product stewardship and develops workable liability arrangements. AATF acts as the principal and responsible party in targeting technologies, ensuring regulatory and legal compliance, and promoting good stewardship.9 The foundation works with, and responds to, an exceptionally wide range of private firms, public organizations, civil society, and smallholder farmer organizations—its stakeholders, as well as establishing well-defined relationships with particular organizations, which become its partners. On a case-by-case basis, and responding on a project-by-project basis to the expressed needs of African farmers, AATF facilitates PPPs mediated by agreements that define expectations for both parties and imply shared risks. It endeavors to assemble all the necessary components for each project, balancing related expenses, while ensuring simplicity and effectiveness. More specifically, AATF consults with African stakeholders to identify priority crops and key constraints for resource-poor farmers; consults with potential technology providers, in both the private and public sectors, to identify technologies that can address those constraints; negotiates with potential partners to develop a project business plan that specifies the role of each partner institution, and determines how and where the technology will be used.16
Facilitating Access to Agricultural Technologies and Freedom to Operate
Traditionally, progress in agriculture has been achieved through free access to germplasm, selection, and crossing of desirable crop land races on research stations, followed by extensive on-farm testing and release of improved varieties to farmers. This classical approach to crop improvement is increasingly complemented by the use of molecular biology tools with associated IP rights. The interdependence of biotechnological inventions means that multiple patented technologies can be required to make one product, and the need for cross-licensing or barriers to obtain even one commercial license can greatly delay or shut out new innovation. Despite these drawbacks, patents on genes or biotechnological tools and associated breeders' rights are necessary to serve as an incentive for the owners of these technologies. However, there is a need to strike a balance between protecting IP rights and providing benefit to the society by allowing access to improved germplasm especially for use by small, resource-poor farmers.16 Several initiatives have emerged in recent years aimed at addressing this challenge.17–19
Failure to invest in the capability needed to evaluate, access, and regulate the technologies being developed in the North is considered a far greater constraint than freedom to operate in developing countries.20 AATF focuses specifically on negotiating access to proprietary technologies and facilitating the delivery of the technologies to smallholder farmers through a platform of specialized institutions along the entire product value chain.9 Because of the high transaction cost associated with issues related to availability, complexity, licensing, testing, safety, and potential liability associated with new agricultural technologies, it is imperative to create a mechanism that permits smooth and easy delivery of the products to resource-poor farmers.17 This process has been carried out by AATF through a clearly defined strategy centered around the principle of a responsible party that brings together public and private partners on a case-by-case basis to develop, test, and deploy improved agricultural technologies. In particular, AATF identifies potential technologies that match specific farmers' needs, negotiates with potential partners for technology development and farm-level deployment, and enters into licensing agreements with IP holders to ensure freedom to operate for all the components of the technologies according to a well-established operating principle and strategy.9,16 This process comprises, among others, sublicensing of the technology to partner institutions, monitoring compliance with the requirements of sublicenses, facilitating the delivery of the product to farmers, and ensuring market access for farmers' surpluses. The nature of the licensing agreement is project specific and depends on AATF's involvement and the issues to be addressed in the project.16
AATF has, to date, negotiated for the right to use several technologies that could reduce several constraints faced by smallholder farmers. Moreover, it has established and is managing several project partnerships designed to develop and deliver products from such technologies to farmers. These licensing agreements have been negotiated under favorable terms that allow for fee-free and royalty-free access to proprietary technologies, as well as improved prospects for cost-effective deployment of the products developed using such technologies. A major goal of the foundation is to obtain freedom to operate for all technologies that it helps to access. Examples include the Bt (Bacillus Thuringensis)gene obtained under license from Monsanto and the pflp (plant ferrodoxin like protein) gene licensed to AATF by Academia Sinica for use in the cowpea and banana improvement projects, respectively.9,16
Knowledge Management and Agricultural Technology Adaptation to Meet Farmers' Needs
To produce relevant information to address African agricultural development needs, AATF established a knowledge and information management system to support technology identification and development while ensuring an enabling policy environment. This goal is achieved by putting in place a mechanism for access to information on production constraints in African agriculture; the technical characteristics of candidate technologies; and relevant regulatory, biosafety, and IP rights requirements. This information on product performance and potential is shared with relevant stakeholders. In negotiations to access a proprietary technology, critical feasibility studies are carried out to establish effective partnerships that can carry the technology forward, resulting in the development and deployment of a useful product for African farmers. In addition to establishing such partnerships, AATF ensures that product development is pursued only where there is an adequate enabling environment of laws, policies, and regulations. Successfully negotiating for access to proprietary technology does not guarantee that farmers can benefit from it; the technology must be incorporated into a product that can be used by farmers. AATF establishes effective partnerships for product development followed by effective and timely delivery.
AATF also pays careful attention to the enabling environment. An initial feasibility study provides AATF with enough confidence to proceed with supporting product development in a particular country, but constant monitoring and support for partners is also important. The most important elements of the enabling environment include IP rights procedures, regulations for input markets (particularly seed and chemicals), and biosafety regulations (for transgenic crops). AATF's development of partnerships for product development and deployment and its interactions with legal and regulatory bodies are all part of a strategy to promote effective product stewardship. To fulfill its role as the responsible party in technology delivery, AATF ensures that the companies, manufacturers, retailers, and government agencies that are involved in the development and delivery of the product are aware of their stewardship roles and responsibilities and can invest the required resources to ensure the safe and effective use of the innovation. AATF's experience in facilitating R&D of a biotechnology product involving public-sector institutions is illustrated by the banana project.9
AATF is therefore actively involved in the packaging of appropriate technologies into products or adapting the technology or product for use in target areas of SSA. This endeavor entails some adaptive research and testing on station and on farm. In this process, baseline studies, risk management, and effective communication strategies are implemented to avoid potential pitfalls. Issues of public acceptance of the product are critical at this stage. With a product in sight, it is important to identify strong partnerships that will support the dissemination of information to various critical targets/stakeholders who will affect the final release and use of the product. Other activities in this phase include the identification of partners for local product development, setting up structures to service the partnership, gathering information that will assist regulatory compliance, and monitoring public opinion.
Deploying Proven Agricultural Technologies in Target Areas
The facilitation role played by AATF is giving rise to the concept of agricultural innovation platforms, which entails fostering public- and private-sector partnerships along the agricultural technology value chain—from basic research to applied research, to field testing, to commercialization, including facilitating market access for farmers who produce surplus. All relevant partners are brought together such that each can provide the required input at the right time for successful project implementation. AATF also works with partners in providing stewardship as the product is developed and delivered to target farmers. Keeping all the partners engaged in the process is the single most important challenge to bringing technologies to farmers. This model constitutes, in our opinion, the necessary and appropriate mechanism for bringing products from gene technologies to African farmers, because it makes it possible to address issues such as IP management, regulatory compliance, and public-awareness management and stewardship for which traditional public research institutes and extension services do not have comparative advantage.
When a product has been developed, tested, and found to provide a satisfactory solution to the targeted farmers' constraints, relevant public or private institutions are identified to mass-produce and distribute the product. Deployment of the product will typically start in pilot locations. Preliminary adoption studies and farmer perception studies of the technology or product are conducted in this phase. Lessons learned in the pilot location are used to scale out the technology to other locations. Wide-scale deployment activities are conducted to reach as many farmers as possible. During this phase, AATF identifies and establishes strategies that will support the long-term availability of the products. Such strategies will include the private-sector entity commercializing the product, extension services, NGOs, and community-based organizations. An exit strategy is designed (often during the project formulation phase) to ensure that the product will continue to be accessible to farmers after AATF has disengaged from the project.
This technology delivery model has been tested and proven to be efficient and successful, as exemplified by the dissemination of imazapyr (a systemic herbicide)-resistant maize varieties to control a damaging parasitic weed (Striga) of maize. During 2004–2006, AATF was involved in partnership with BASF (Badische Anilin and Soda Fabrik—German Chemical products company) and the Centro Internacional de Mejoramiento De Maize y Trigo to deliver a technology, Strigaway, in an attempt to control the witchweed, Striga. Striga is a parasitic weed that destroys maize, millet, sorghum, upland rice, and napier grass throughout SSA, and it infests an estimated 20 million to 40 million ha of farmland cultivated by resource-poor farmers. Every year, Striga damage to crops accounts for an estimated US$7 billion in yield loss in SSA and affects the welfare and livelihood of more than 100 million people. In Kenya alone, it is estimated that 211,000 ha of farmland is infested with Striga, causing crop losses amounting to nearly 400,000 tons worth US$80 million per year. The Strigaway technology involves application of a low-dose of imazapyr seed coating to imazapyr-resistant maize seed. Small quantities of imazapyr (as little as 30 g per ha), delivered in this manner, act at the time of Striga attachment to the maize root and so prevent the exertion of the phytotoxic effect of Striga on the maize plant, thus enabling the plant to grow to its full potential. The low-dose herbicide seed dressing used in the Strigaway technology controls Striga without affecting sensitive intercrops when planted 10 cm or more away from the maize hills. Recent on-farm trials demonstrate that the herbicide coating adds about US$4 per ha to the cost of maize seeds. However, in a moderately Striga-infested field, the additional maize yield due to application of the Strigaway technology is estimated at US$52 per ha. The technology was commercially launched in Kenya in December 2006, and AATF is collaborating with partners and stakeholders in Tanzania and Uganda to facilitate delivery of the same technology in Striga-infested fields in those countries.
The precarious state of Africa's food security, the extent of the continent's rural poverty, and the failure of many conventional programs and projects to bring about meaningful progress21 call for a rethinking of the continent's agricultural R&D strategy in the 21st century.6,7,9,14 Although many different models of partnerships have promoted PPP in technology delivery, few have provided tangible results (improved farmers' livelihoods) in developing country agriculture. Many PPPs fail because of lack of crucially important skills (e.g., ability to identify opportunities, develop common interests, and negotiate commitments) among partnering agents and efforts to strengthen these skills. It therefore became evident that there was a need for an innovative PPP approach to technology delivery for improved agricultural productivity and poverty reduction in Africa. This mandate is carried out by AATF, whose mission is to broker PPPs that are specifically designed to deliver the products of advanced proprietary research to African farmers. AATF achieves its mission through mechanisms to ensure access to new proprietary technologies from around the world on a royalty-free basis; promote the development and deployment of useful products by local research organizations and commercial firms; support the growth of responsive and responsible regulatory, legal, and commercial institutions; and help build African agribusiness.
In summary, during the brief period (4 years) of its operations, AATF has demonstrated a clear proof of concept: The foundation has achieved remarkable success in negotiating access to technology owned by private multinational corporations (Monsanto, BASF) and public institutions from advanced countries (Academia Sinica, Taiwan). It has also demonstrated its ability to promote partnerships among technology donors, public- and private-sector institutions that adapt the technology, seed companies that bring the products of technology within farmers' reach, and NGOs and government extension agents that familiarize farmers with the technology. AATF has established itself as a trusted partner in agricultural development and is increasingly becoming a partner-of-choice institution for national and international institutions from the public and private sector interested in using science and technology to increase agricultural productivity in smallholder farms in SSA. AATF and its partners are poised to capitalize on these gains to deliver sustained beneficial outcomes in agricultural development on the continent.
Conflicts of Interest
The authors declare no conflicts of interest.