37 research outputs found

    Genetic analysis of Ethiopian mustard genotypes using amplified fragment length polymorphism (AFLP) markers

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    Genetic diversity within Brassica carinata A. Braun has not been extensively examined with molecular markers. The objective of this study was to investigate the genetic relationships among 39 B. carinata genotypes using amplified fragment length polymorphisms (AFLPs). Thirty-nine genotypes of B.carinata were analyzed using six AFLP primer combinations. A total of 189 polymorphic fragments were scored, with an average of 32 fragments per primer combination. Genetic distance estimates (GDEs) based on AFLPs was calculated and found to range from 0.346 to 0.639 with a mean of 0.504 ± 0.002. Polymorphic rates ranged from 50 to 80%. The unweighted pair group method of arithmetic averages (UPGMA) cluster analysis group these genotypes into seven distinct clusters. These data demonstrate that AFLP is a reliable tool and permits greater insights into the genetic diversity of B. carinata

    Detection of GMO in food products in South Africa: Implications of GMO labelling

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    Genetically modified (GM) crops currently account for 29% of crop production worldwide. South Africa is currently the only country in Africa to commercially grow GM crops. Despite a lack of regulations to provide for food labelling that allows for consumer preference, many products carry negative or positive labels with regard to genetic modification. The aim of this study was to test different maize and soy products to determine the uptake of GM food into the human food chain as well as the validity of “non-GMO” (genetically modified organisms), “GMO free” or “organic” labels, on local as well as imported products. Of the 58 products selected and sampled randomly, 44 tested positive for the presence of GM. Furthermore, of the 20 products with a GM related label, 14 tested positive for GM. These results demonstrate the extent of GM in the human food chain in South Africa and highlight the need for effective regulations to protect consumers against misleading claims.Keywords: Genetically modified organisms (GMOs), genetic modification (GM), food, labellin

    Analysis of genetic diversity in linseed using AFLP markers

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    Linseed (Linum usitatissimum L.) is the second most important oilseed crop in the highlands of Ethiopia where it has been cultivated for its valuable seed-oil since antiquity. Sixty accessions of linseed predominantly from Ethiopia were analysed using amplified fragment length polymorphism (AFLP) markers to assess their genetic diversity. Out of seven pairs of AFLP primers screened, Eco-ACA/ Mse-CAT and Eco-ACA/ Mse-CTT resulted in a greater number of amplification products. The estimated genetic distance for pairwise accessions significantly (P < 0.001) varied from 0.29 to 0.71, indicating the prevalence of genetic diversity in both exotic and local collections. Introductions from Canada and collections from different parts of Ethiopia, especially those from central and northwest regions revealed considerable variations between and within their geographic locations and thus can be used to create genetic variations. Cluster analysis categorized the 60 accessions into 13 classes, each consisting of one to 14 accessions. Two introduced accession were individually clustered, showing their greater divergence. AFLP analysis was found effective in discriminating the accessions and in selecting suitable parents for future genetic improvement. It was also useful for efficient management of genetic resources, eliminating unnecessary duplications. Key words/phrases: AFLP, DNA markers, genetic diversity, linseed SINET: Ethiopian Journal of Science Vol. 28 (1) 2005: 41–5

    Substance abuse, treatment needs and access among female sex workers and non-sex workers in Pretoria, South Africa

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    <p>Abstract</p> <p>Background</p> <p>This study examined cross-sectional data collected from substance-using female sex workers (FSW) and non-sex workers (non-SW) in Pretoria, South Africa, who entered a randomized controlled trial.</p> <p>Methods</p> <p>Women who reported alcohol use and recently engaging in sex work or unprotected sex were recruited for a randomized study. The study sample (N = 506) comprised 335 FSW and 171 female non-SW from Pretoria and surrounding areas. Self-reported data about alcohol and other drug use as well as treatment needs and access were collected from participants before they entered a brief intervention.</p> <p>Results</p> <p>As compared with female non-SW, FSW were found to have a greater likelihood of having a past year diagnosis of alcohol or other drug abuse or dependence, having a family member with a history of alcohol or other drug abuse, having been physically abused, having used alcohol before age 18, and having a history of marijuana use. In addition, the FSW were more likely to perceive that they had alcohol or other drug problems, and that they had a need for treatment and a desire to go for treatment. Less than 20% of participants in either group had any awareness of alcohol and drug treatment programs, with only 3% of the FSW and 2% of the non-SW reporting that they tried but were unable to enter treatment in the past year.</p> <p>Conclusion</p> <p>FSW need and want substance abuse treatment services but they often have difficulty accessing services. The study findings suggest that barriers within the South African treatment system need to be addressed to facilitate access for substance-using FSW. Ongoing research is needed to inform policy change that fosters widespread educational efforts and sustainable, accessible, woman-sensitive services to ultimately break the cycle for current and future generations of at-risk South African women.</p

    Use of pJANUS™-02-001 as a calibrator plasmid for Roundup Ready soybean event GTS-40-3-2 detection: an interlaboratory trial assessment

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    Owing to the labelling requirements of food and feed products containing materials derived from genetically modified organisms, quantitative detection methods have to be developed for this purpose, including the necessary certified reference materials and calibrator standards. To date, for most genetically modified organisms authorized in the European Union, certified reference materials derived from seed powders are being developed. Here, an assessment has been made on the feasibility of using plasmid DNA as an alternative calibrator for the quantitative detection of genetically modified organisms. For this, a dual-target plasmid, designated as pJANUS™-02-001, comprising part of a junction region of genetically modified soybean event GTS-40-3-2 and the endogenous soybean-specific lectin gene was constructed. The dynamic range, efficiency and limit of detection for the soybean event GTS-40-3-2 real-time quantitative polymerase chain reaction (Q-PCR) system described by Terry et al. (J AOAC Int 85(4):938–944, 2002) were shown to be similar for in house produced homozygous genomic DNA from leaf tissue of soybean event GTS-40-3-2 and for plasmid pJANUS™-02-001 DNA backgrounds. The performance of this real-time Q-PCR system using both types of DNA templates as calibrator standards in quantitative DNA analysis was further assessed in an interlaboratory trial. Statistical analysis and fuzzy-logic-based interpretation were performed on critical method parameters (as defined by the European Network of GMO Laboratories and the Community Reference Laboratory for GM Food and Feed guidelines) and demonstrated that the plasmid pJANUS™-02-001 DNA represents a valuable alternative to genomic DNA as a calibrator for the quantification of soybean event GTS-40-3-2 in food and feed products

    Animal Perception of Seasonal Thresholds: Changes in Elephant Movement in Relation to Rainfall Patterns

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    Background: The identification of temporal thresholds or shifts in animal movement informs ecologists of changes in an animal\u2019s behaviour, which contributes to an understanding of species\u2019 responses in different environments. In African savannas, rainfall, temperature and primary productivity influence the movements of large herbivores and drive changes at different scales. Here, we developed a novel approach to define seasonal shifts in movement behaviour by examining the movements of a highly mobile herbivore (elephant; Loxodonta africana), in relation to local and regional rainfall patterns. Methodology/Principal Findings: We used speed to determine movement changes of between 8 and 14 GPS-collared elephant cows, grouped into five spatial clusters, in Kruger National Park, South Africa. To detect broad-scale patterns of movement, we ran a three-year daily time-series model for each individual (2007\u20132009). Piecewise regression models provided the best fit for elephant movement, which exhibited a segmented, waveform pattern over time. Major breakpoints in speed occurred at the end of the dry and wet seasons of each year. During the dry season, female elephant are constrained by limited forage and thus the distances they cover are shorter and less variable. Despite the inter-annual variability of rainfall, speed breakpoints were strongly correlated with both local and regional rainfall breakpoints across all three years. Thus, at a multi-year scale, rainfall patterns significantly affect the movements of elephant. The variability of both speed and rainfall breakpoints across different years highlights the need for an objective definition of seasonal boundaries. Conclusions/Significance: By using objective criteria to determine behavioural shifts, we identified a biologically meaningful indicator of major changes in animal behaviour in different years. We recommend the use of such criteria, from an animal\u2019s perspective, for delineating seasons or other extrinsic shifts in ecological studies, rather than arbitrarily fixed definitions based on convention or common practice

    A Novel Approach to Determining Violence Risk in Schizophrenia: Developing a Stepped Strategy in 13,806 Discharged Patients

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    Clinical guidelines recommend that violence risk be assessed in schizophrenia. Current approaches are resource-intensive as they employ detailed clinical assessments of dangerousness for most patients. An alternative approach would be to first screen out patients at very low risk of future violence prior to more costly and time-consuming assessments. In order to implement such a stepped strategy, we developed a simple tool to screen out individuals with schizophrenia at very low risk of violent offending. We merged high quality Swedish national registers containing information on psychiatric diagnoses, socio-demographic factors, and violent crime. A cohort of 13,806 individuals with hospital discharge diagnoses of schizophrenia was identified and followed for up to 33 years for violent crime. Cox regression was used to determine risk factors for violent crime and construct the screening tool, the predictive validity of which was measured using four outcome statistics. The instrument was calibrated on 6,903 participants and cross-validated using three independent replication samples of 2,301 participants each. Regression analyses resulted in a tool composed of five items: male sex, previous criminal conviction, young age at assessment, comorbid alcohol abuse, and comorbid drug abuse. At 5 years after discharge, the instrument had a negative predictive value of 0.99 (95% CI = 0.98–0.99), meaning that very few individuals who the tool screened out (n = 2,359 out of original sample of 6,903) were subsequently convicted of a violent offence. Screening out patients who are at very low risk of violence prior to more detailed clinical assessment may assist the risk assessment process in schizophrenia
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