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Amsterdam-Zuidoost, Netherlands

Hounkonnou D.,CIRAD - Agricultural Research for Development | Kossou D.,University Abomey Calavi | Kuyper T.W.,Wageningen University | Leeuwis C.,Wageningen University | And 5 more authors.
Agricultural Systems | Year: 2012

Sustainable intensification of smallholder farming is a serious option for satisfying 2050 global cereal requirements and alleviating persistent poverty. That option seems far off for Sub-Sahara Africa (SSA) where technology-driven productivity growth has largely failed. The article revisits this issue from a number of angles: current approaches to enlisting SSA smallholders in agricultural development; the history of the phenomenal productivity growth in the USA, The Netherlands and Green Revolution Asia; and the current framework conditions for SSA productivity growth. This analysis shows that (1) the development of an enabling institutional context was a necessary condition that preceded the phenomenal productivity growth in industrial and Green Revolution countries; and that (2) such a context is also present for successful SSA export crop production, but that (3) the context is pervasively biased against SSA's smallholder food production. The article traces the origins of technology supply push (TSP) as a dominant paradigm that hinders recognition of the role of enabling institutions. The article then reviews the literature on institutional change and zooms in on Innovation Platforms (IPs) as a promising innovation system approach to such change. We describe the concrete experience with IP in the Sub-Sahara Challenge Program (SSA-CP) and in the Convergence of Sciences: Strengthening Innovation Systems (CoS-SIS) Program. The former has demonstrated proof of concept. The latter is designed to trace causal mechanisms. We describe its institutional experimentation and research methodology, including causal process tracing. © 2012 Elsevier Ltd. Source

Murray G.L.,Monash University | Srikram A.,Khon Kaen University | Srikram A.,Kasetsart University | Henry R.,Monash University | And 3 more authors.
Molecular Microbiology | Year: 2010

Leptospira interrogans is the causative agent of leptospirosis. Lipopolysaccharide (LPS) is the major outer membrane component of L. interrogans. It is the dominant antigen recognized during infection and the basis for serological classification. The structure of LPS and its role in pathogenesis are unknown. We describe two defined mutants of L. interrogans serovar Manilae with transposon insertions in the LPS locus. Mutant M895 was disrupted in gene la1641 encoding a protein with no known homologues. M1352 was disrupted in a gene unique to serovar Manilae also encoding a protein of unknown function. M895 produced truncated LPS while M1352 showed little or no change in LPS molecular mass. Both mutants showed altered agglutination titres against rabbit antiserum and against a panel of LPS-specific monoclonal antibodies. The mutants were severely attenuated in virulence via the intraperitoneal route of infection, and were cleared from the host animal by 3 days after infection. M895 was also highly attenuated via the mucosal infection route. Resistance to complement in human serum was unaltered for both mutants. While complementation of mutants was not possible, the attenuation of two independently derived LPS mutants demonstrates for the first time that LPS plays an essential role leptospiral virulence. © 2010 Blackwell Publishing Ltd. Source

Leprosy-related disability is a challenge to public health, and social and rehabilitation services in endemic countries. Disability is more than a mere physical dysfunction, and includes activity limitations, stigma, discrimination, and social participation restrictions. We assessed the extent of disability and its determinants among persons with leprosy-related disabilities after release from multi drug treatment. We conducted a survey on disability among persons affected by leprosy in Indonesia, using a Rapid Disability Appraisal toolkit based on the International Classification of Functioning, Disability and Health. The toolkit included the Screening of Activity Limitation and Safety Awareness (SALSA) scale, Participation Scale, Jacoby Stigma Scale (anticipated stigma), Explanatory Model Interview Catalogue (EMIC) stigma scale and Discrimination assessment. Community members were interviewed using a community version of the stigma scale. Multivariate linear regression was done to identify factors associated with social participation. Overall 1,358 persons with leprosy-related disability (PLD) and 931 community members were included. Seventy-seven percent of PLD had physical impairments. Impairment status deteriorated significantly after release from treatment (from 59% to 77%). Around 60% of people reported activity limitations and participation restrictions and 36% anticipated stigma. As for participation restrictions and stigma, shame, problems related to marriage and difficulties in employment were the most frequently reported problems. Major determinants of participation were severity of impairment and level of education, activity and stigma. Reported severity of community stigma correlated with severity of participation restrictions in the same districts. The majority of respondents reported problems in all components of disability. The reported physical impairment after release from treatment justifies ongoing monitoring to facilitate early prevention. Stigma was a major determinant of social participation, and therefore disability. Stigma reduction activities and socio-economic rehabilitation are urgently needed in addition to strategies to reduce the development of further physical impairment after release from treatment. Source

Creswell J.,Stop TB Partnership | Sahu S.,Stop TB Partnership | Blok L.,Royal Tropical Institute KIT | Bakker M.I.,Royal Tropical Institute KIT Biomedical Research | And 2 more authors.
PLoS ONE | Year: 2014

Background: Globally, TB notifications have stagnated since 2007, and sputum smear positive notifications have been declining despite policies to improve case detection. We evaluate results of 28 interventions focused on improving TB case detection. Methods: We measured additional sputum smear positive cases treated, defined as the intervention area's increase in case notification during the project compared to the previous year. Projects were encouraged to select control areas and collect historical notification data. We used time series negative binomial regression for over-dispersed cross-sectional data accounting for fixed and random effects to test the individual projects' effects on TB notification while controlling for trend and control populations. Results: Twenty-eight projects, 19 with control populations, completed at least four quarters of case finding activities, covering a population of 89.2 million. Among all projects sputum smear positive (SS+) TB notifications increased 24.9% and annualized notification rates increased from 69.1 to 86.2/100,000 (p = 0.0209) during interventions. Among the 19 projects with control populations, SS+TB case notifications increased 36.9% increase while in the control populations a 3.6% decrease was observed. Fourteen (74%) of the 19 projects' SS+TB notification rates in intervention areas increased from the baseline to intervention period when controlling for historical trends and notifications in control areas. Conclusions: Interventions were associated with large increases in TB notifications across many settings, using an array of interventions. Many people with TB are not reached using current approaches. Different methods and interventions tailored to local realities are urgently needed. © 2014 Creswell et al. Source

Roth J.M.,Royal Tropical Institute KIT | Mens P.F.,Royal Tropical Institute KIT | Mens P.F.,University of Amsterdam
Critical Reviews in Clinical Laboratory Sciences | Year: 2016

Accurate diagnosis of malaria is essential for identification and subsequent treatment of the disease. Currently, microscopy and rapid diagnostic tests are the most commonly used diagnostics, next to treatment based on clinical signs only. These tests are easy to deploy, but have a relatively high detection limit. With declining prevalence in many areas, there is an increasing need for more sensitive diagnostics. Molecular tools may be a suitable alternative, although costs and technical requirements currently hamper their implementation in resource limited settings. A range of (near) point-of-care diagnostics is therefore under development, including simplifications in sample preparation, amplification and/or read-out of the test. Accuracy data, in combination with technical characteristics, are essential in determining which molecular test, if any, would be the most promising to be deployed. This review presents a comprehensive overview of the currently available molecular malaria diagnostics, ranging from well-known tests to platforms in early stages of evaluation, and systematically evaluates their published accuracy. No important difference in accuracy was found between the most commonly used PCR-based assays (conventional, nested and real-time PCR), with most of them having high sensitivity and specificity, implying that there are no reasons other than practical ones to choose one technique over the other. Loop-mediated isothermal amplification and other (novel) diagnostics appear to be highly accurate as well, with some offering potential to be used in resource-limited settings. © 2015 Taylor and Francis. Source

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