Masking in Central Visual Field Under a Variety of Temporal and Spatial Configurations

For over a century, visual maskingwhere one stimulus reduces the visibility of another stimulushas been used as a powerful tool to explore the visual system. Two major forms have emerged: backward masking and common onset masking. These two forms, which are characterized by the temporal properties of the stimuli, are often used to probe different underlying masking mechanisms, and the two forms typically employ a unique set of spatial characteristics of the mask. This clustering of stimulus properties makes it challenging to assess the effect of each stimulus property by itself. This dissertation describes an attempt to isolate the effects of these properties. In the first set of experiments various masking schedules are tested, including backward, common onset, and variations between, while keeping the spatial properties of the stimuli constant. In the second set of experiments four-dot common onset masking is explored in detail, and in one of the experiments, a single masking schedule is tested while varying the spatial properties of the mask. Across all experiments, target stimuli are presented foveally. A computational model is developed to account for data across both sets of experiments. Three important findings emerge. First, masking can be successfully obtained in central visual field using a variety of stimulus properties. Second, there is compelling evidence that persisting traces of these stimuli play an important role in masking. Third, there is strong evidence of both spatially local and global masking effects

Overcoming barriers to trust in agricultural biotechnology projects: a case study of Bt cowpea in Nigeria.

Background: Nigeria, Africa’s most populous country, has been the world’s largest cowpea importer since 2004. The country is currently in the early phases of confined field trials for two genetically modified crops: Bacillus thuringiensis (Bt) cowpea and nutritionally enhanced cassava (“BioCassava Plus”). Using the bio-safety guidelines process as a backdrop, we evaluate the role of trust in the operation of the Cowpea Productivity Improvement Project, which is an international agricultural biotechnology public-private partnership (PPP) aimed at providing pest-resistant cowpea varieties to Nigerian farmers. Methods: We reviewed the published literature and collected data through direct observations and semistructured, face-to-face interviews. Data were analyzed based on emergent themes to create a comprehensive narrative on how trust is understood and built among the partners and with the community. Results: Our findings highlight the importance of respecting mandates and eliminating conflicts of interest; holding community engagement initiatives early on; having on-going internal discussion and planning; and serving a locally-defined need. These four lessons could prove helpful to other agricultural biotechnology initiatives in which partners may face similar trust-related challenges. Conclusions: Overcoming challenges to building trust requires concerted effort throughout all stages of project implementation. Currently, plans are being made to backcross the cowpea strain into a local variety in Nigeria. The development and adoption of the Bt cowpea seed hinges on the adoption of a National Biosafety Law in Nigeria. For countries that have decided to adopt biotech crops, the Nigerian cowpea experiment can be used as a model for other West African nations, and is actually applied as such in Ghana and Burkina Faso, interested in developing a Bt cowpea

Trait stacking for biotech crops: an essential consideration for agbiotech development projects for building trust.

The development of agricultural biotechnology humanitarian projects for food security in the last five years has been rapid in developing countries and is expected to rise sharply over the coming years. An extremely critical issue in these projects involves building trust with the community and farmers they aim to serve. For the first time, our social audit engagement with one of these initiatives, the Water Efficient Maize for Africa project, has revealed that a critical but unrecognized component of building trust with farmers involves publicly addressing the concerns surrounding stacked trait crops. As a result, we argue in this article that it is critical to actively anticipate the concerns that could be raised over trait stacking by incorporating them into global access plans of such initiatives early in order to facilitate adoption, provide the best value to the small-scale farmer and gain trust with the community whom these projects aim to serve. This perspective, based on an actual international social audit, should be of value to scientists, funders and partners involved in biotech development initiatives for food securit

Building effective partnerships: the role of trust in the Virus Resistant Cassava for Africa project

Background: Virus Resistant Cassava for Africa (VIRCA) is an agricultural biotechnology public-private partnership (PPP) comprising the Donald Danforth Plant Sciences Center (DDPSC), National Agricultural Research Organization (NARO) of Uganda and Kenya Agricultural Research Institute (KARI). The project seeks to develop virus-resistant cassava for farmers in Kenya and Uganda. Yet, there is much public skepticism about the use of genetically modified (GM) crops and private sector involvement in Africa. This case study sought to understand the role of trust in the VIRCA partnership. Methods: We conducted semi-structured, face-to-face interviews to obtain stakeholders’ views on the challenges to, and practices for, building trust in the VIRCA partnership. Interviewee responses, together with relevant documents and articles, were analyzed to generate descriptions of how trust is operationalized in this evolving agbiotech PPP. Data were analyzed based on recurring and emergent themes from the interviewee responses. Results: Various factors undermine and build trust in agbiotech PPPs. Individual and institutional enthusiasm and detailed collaborative agreements stipulating partner roles and responsibilities are likely to enhance trust among partners. On the other hand, negative perceptions propagated by international partners about the capacities of African institutions and scientists, coupled with slow regulatory processes in Africa, are likely to be impediments to trust building. Conclusions: Based on the findings of this study, we have derived four key lessons. First, differences in the capacity of the partner institutions and individuals should be respected. Second, technical and infrastructural capacity support for regulatory processes in Africa must be built. Third, detailed agreements and open and transparent partner practices during project implementation are necessary to dispel perceptions of inequality among partners. Fourth, institutional and individual commitment to succeed is important in initiation of the project. These lessons can be used by other agbiotech PPPs as a guide for building trust among partners and with the community

Nanotechnology and the Developing World

How nanotechnology can be harnessed to address some of the world's most critical development problem

Strategies for building trust with farmers: the case of Bt maize in South Africa

<p>Abstract</p> <p>Background</p> <p>In 1999, South Africa became the first African country to approve commercial production of subsistence genetically modified (GM) maize. The introduction of GM crop technology is often met with skepticism by stakeholders including farmers. The involvement of the private sector in this process can further breed mistrust or misperceptions. To examine these issues more closely, the objective of this case study was to understand the role of trust in the public-private partnership (PPP) arrangement involved in the development of <it>Bacillus thuringiensis</it> (Bt) maize in South Africa.</p> <p>Methods</p> <p>We conducted semi-structured, face-to-face interviews to obtain stakeholders’ understanding of <it>trust</it> in general as well as in the context of agricultural biotechnology (agbiotech) PPPs. A thematic analysis of the interview transcripts, documents, reports and research articles was conducted to generate insights into the challenges to, and practices for, building trust among the partners and with the public.</p> <p>Results</p> <p>The findings of this study are organized into four main lessons on trust building. First, as the end users of GM technology, farmers must be engaged from the start of the project through field demonstrations and educational activities. Second, an effective technology (i.e., the seed) is key to the success of an agbiotech PPP. Third, open communication and full disclosure between private sector companies and government regulatory bodies will build trust and facilitate the regulatory processes. Fourth, enforcing good agronomic practices, including appropriate management of the refuge areas, will serve the interests of both the farmers and the seed companies.</p> <p>Conclusions</p> <p>Trust has proven to be a critical factor determining the success of the Bt maize project in South Africa. Distrust of the private sector and of GM technology were cited as major barriers to building trust. The trust-building practices described in this case study have often served to overcome these barriers; however, erosion of trust was also present. The success of the project has been, and will continue to be, dependent upon the concerted effort of the farmers, government, and private sector players in the establishment and maintenance of trust.</p

The value of trust in biotech crop development: a case study of Bt cotton in Burkina Faso

Background: Agricultural biotechnology public-private partnerships (PPPs) have been recognized as having great potential in improving agricultural productivity and increasing food production in sub-Saharan Africa. However, there is much public skepticism about the use of GM (genetically modified) crops and suspicion about private sector involvement in agbiotech projects. This case study sought to understand the role of trust in the Bacillus thuringiensis (Bt) cotton in Burkina Faso project by exploring practices and challenges associated with trust-building, and determining what makes these practices effective from the perspective of multiple stakeholders. Methods: We conducted semi-structured, face-to-face interviews to obtain stakeholders’ understanding of trust in general as well as in the context of agbiotech PPPs. Relevant documents and articles were analyzed to generate descriptions of how trust was operationalized in this evolving agbiotech PPP. Data was analyzed based on emergent themes to create a comprehensive narrative on how trust is understood and built among the partners and with the community. Results: We derived four key lessons from our findings. First, strong collaboration between research, industry and farmers greatly contributes to both the success of, and fostering of trust in, the partnership. Second, this case study also revealed the important, though often unrecognized, role of researchers as players in the communication strategy of the project. Third, effective and comprehensive communication takes into account issues such as illiteracy and diversity. Fourth, follow-up at the field level and the need for a multifaceted communications strategy is important for helping push the project forward. Conclusions: Burkina Faso’s well-established and effective cotton selling system laid the foundation for the implementation of the Bt cotton project – particularly, the strong dialogue and the receptivity to collaboration. Interviewees reported that establishing and maintaining trust among partners, researchers and the community in Burkina Faso greatly contributed to the success of the PPP. By addressing challenges to building trust and engaging in trust-building practices early on, improvements in the effectiveness of agbiotech PPPs are likely

Science-based health innovation in Tanzania: bednets and a base for invention

<p>Abstract</p> <p>Background</p> <p>Tanzania is East Africa’s largest country. Although it is socially diverse, it has experienced general political stability since independence in 1964. Despite gradual economic development and Tanzania’s status as one of the biggest recipients of aid in Africa, health status remains poor. This paper explores Tanzania’s science-based health innovation system, and highlights areas which can be strengthened.</p> <p>Methods</p> <p>Qualitative case study research methodology was used. Data were collected through reviews of academic literature and policy documents, and through open-ended, face-to-face interviews with 52 people from across the science-based health innovation system over two visits to Tanzania from July to October 2007.</p> <p>Results and discussion</p> <p>Tanzania has a rich but complex S&T governance landscape, with the public sector driving the innovation agenda through a series of different bodies which are not well-coordinated. It has some of the leading health research on the continent at the University of Dar es Salaam, Muhimbili University of Health and Applied Sciences, the National Institute for Medical Research and the Ifakara Medical Institute, with strong donor support. Tanzania has found developing an entrepreneurial culture difficult; nevertheless projects such as the clusters initiative at the University of Dar es Salaam are encouraging low-tech innovation and overcoming knowledge-sharing barriers. In the private sector, one generics company has developed a South-South collaboration to enable technology transfer and hence the local production of anti-retrovirals. Local textile company A to Z Textiles is now manufacturing 30 million insecticide impregnated bednets a year.</p> <p>Conclusions</p> <p>To have a coherent vision for innovation, Tanzania may wish to address some key issues: coordination across stakeholders involved with health research, increasing graduates in health-related disciplines, and building capabilities in biological testing, preclinical testing, formulation and standardization, and related areas important to moving from basic research to applications. The private sector can be encouraged to innovate through improved access to financing, and incentives for R&D. The diaspora community represents an untapped source for partnerships and access to other developing world markets and technology. The government may wish to set up mechanisms to encourage south-south collaborations, and to bring the public and private sector together around specific projects to help realize the country’s innovation potential.</p

Global health challenges: The need for an expanded discourse on bioethics

Although the 20th century saw a major expansion of the world economy, impressive military/security advances, and spectacular progress in science and technology, the grim reality in the first decade of the new millennium is that human life, health, and security remain under severe threat—but now from the adverse effects of inexorably widening disparities in wealth, health, and knowledge within and between nations. The gap between the income of the richest and poorest 20% of people in the world increased from a 9-fold difference at the beginning of the 20th century to 30-fold by 1960—and since then to over 80-fold by 2000 (Figure 1). Although life expectancy has improved dramatically worldwide during this century, this trend has been reversed in the poorest countries in recent years [1]. The challenge of achieving improved health for a greater proportion of the world's population is one of the most pressing problems of our time and is starkly illustrated by the threat of infectious diseases