Influence of agronomic practices on yield and profitability in kenaf (Hibiscus cannabinus L.) fibre cultivation

Field trials were conducted in 2003 and 2004 at the Institute of Agricultural Research and Training, Ibadan (7o 38’ N 3o 84’ E), Nigeria to determine the influence of some agronomic practices on yield andprofitability in kenaf bast fibre production. Three kenaf varieties, Cuba 108, Ifeken 400 and Ibadan local, were subjected to three agronomic practices in a split-plot experiment. The agronomic practicesinclude the farmers’ practice where no input was used and two levels of improved management practices (IMP) where the influence of pests and soil nutrition were ameliorated. The results showed that total dry matter, fibre and core yields increased by 150 – 170%, incidence of nematode reduced by 50% and severity scores of insects attack on foliage reduced by 83% in the improved management practice (IMP). The three kenaf varieties differ significantly in their leaf biomass, reaction to nematode and foliage pests attack. In the control treatment, Ibadan local had more leaf biomass and was tolerantto pests attack while other varieties were susceptible. Economic analysis showed that net return was higher in the local cultivar than in the improved varieties under the farmers’ practice. However,economic returns and marginal rate of returns were higher under IMP’s than the control in Cuba 108 and Ifeken 100 varieties than the local cultivar

Studies on seed yield potential of some selected kenaf (Hibiscus cannabinus L.) genotypes

Kenaf seed yield depends on morpho-physiological traits between varieties, and the interaction between genotype and the environment. Studies were conducted in Ibadan, Ilora and Kisi stations of the Institute of Agricultural Research and Training (IAR&T), Obafemi Awolowo University, Moor Plantation, Ibadan, Oyo State, Nigeria during 2009 and 2010 cropping seasons to determine the influence of location and genotypes on seed yield potentials in 20 kenaf genotypes. The experiment was carried out using Randomized Complete Block Design (RCBD). Result shows that, kenaf plants had tallest average capsule height in Ilora in both years, while higher numbers of capsule/plant and seed number/capsule were recorded in Kishi. There were no significant differences among all the genotypes planted irrespective of the location on seed weight/plant, 100 seed weight and seed yield/ha. Average highest capsule height was recorded in 2009 across genotypes. However, average number of capsule/plant, seed number/capsule, seed weight/plant and seed yield/ha were higher in 2010. Local kenaf had highest number of capsules (55.04) with about the least seeds per capsule (9.45) and least weight of seed per plant (3.30 g). While BS-1 had the least capsule number (18.86) and highest seeds per capsule (15.74) was recorded in SF-549. AU-75 recorded the highest seed weight/plant. The 100 seed weight ranged from 3.37 to 2.19 g. Seed yield/ha across genotypes ranged from 660 kg/ha in Local line 36 to 1454.3 kg/ha in AU-75.Keywords: Kenaf, capsule height, capsule number, seed number, seed weight/capsule, 100 seed weight and seed yield/ha.African Journal of Biotechnology, Vol 13(24) 2420-242

Examiner performance in calibration exercises compared with field conditions when scoring caries experience

The objective of this study was to verify how valid misclassification measurements obtained from a 'pre-survey' calibration exercise are by comparing them to validation scores obtained in 'field' conditions. Validation data were collected from the 'Smile for Life' project, an oral health intervention study in Flemish children. A calibration exercise was organized under 'pre-survey' conditions (32 age-matched children examined by eight examiners and the benchmark scorer). In addition, using a pre-determined sampling scheme blinded to the examiners, the benchmark scorer re-examined between six and 11 children screened by each of the dentists during the survey. Factors influencing sensitivity and specificity for scoring caries experience (CE) were investigated, including examiner, tooth type, surface type, tooth position (upper/lower jaw, right/left side) and validation setting (pre-survey versus field). In order to account for the clustering effect in the data, a generalized estimating equations approach was applied. Sensitivity scores were influenced not only by the calibration setting (lower sensitivity in field conditions, p < 0.01), but also by examiner, tooth type (lower sensitivity in molar teeth, p < 0.01) and tooth position (lower sensitivity in the lower jaw, p < 0.01). Factors influencing specificity were examiner, tooth type (lower specificity in molar teeth, p < 0.01) and surface type (the occlusal surface with a lower specificity than other surfaces) but not the validation setting. Misclassification measurements for scoring CE are influenced by several factors. In this study, the validation setting influenced sensitivity, with lower scores obtained when measuring data validity in 'field' conditions. Results obtained in a pre-survey calibration setting need to be interpreted with caution and do not (always) reflect the actual performance of examiners during the field work

Measurement, analysis and interpretation of examiner reliability in caries experience surveys: some methodological thoughts

Data obtained from calibration exercises are used to assess the level of agreement between examiners (and the benchmark examiner) and/or between repeated examinations by the same examiner in epidemiological surveys or large-scale clinical studies. Agreement can be measured using different techniques: kappa statistic, percentage agreement, dice coefficient, sensitivity and specificity. Each of these methods shows specific characteristics and has its own shortcomings. The aim of this contribution is to critically review techniques for the measurement and analysis of examiner agreement and to illustrate this using data from a recent survey in young children, the Smile for Life project. The above-mentioned agreement measures are influenced (in differing ways and extents) by the unit of analysis (subject, tooth, surface level) and the disease level in the validation sample. These effects are more pronounced for percentage agreement and kappa than for sensitivity and specificity. It is, therefore, important to include information on unit of analysis and disease level (in validation sample) when reporting agreement measures. Also, confidence intervals need to be included since they indicate the reliability of the estimate. When dependency among observations is present [as is the case in caries experience data sets with typical hierarchical structure (surface-tooth-subject)], this will influence the width of the confidence interval and should therefore not be ignored. In this situation, the use of multilevel modelling is necessary. This review clearly shows that there is a need for the development of guidelines for the measurement, interpretation and reporting of examiner reliability in caries experience surveys

Incidence and treatment of complications in patients who had third molars or other teeth extracted

The aim of this study was to compare the incidence of complications after extraction of third molars (M3) or other teeth, and to describe their management. We made a retrospective cohort study of patients having M3 or other teeth extracted, and recorded complications up to two years' follow-up. A total of 142 complications developed after 2355 procedures (6%) - 7% after extraction of M3 compared with 5% after extractions of other teeth (p=0.024). The three most common complications were wound infection (2%), pain without apparent cause (<1%), and oroantral communication (<1%). Patients who had M3 extracted were at increased risk of complications compared with those who had other teeth extracted (Odds ratio (OR) 1.5, p=0.024), particularly for infection (OR 5.9, p<0.001) and hypoaesthesia (OR 8.4, p=0.027). Half of all patients with a complication were treated with antibiotics orally. The incidence of postoperative bleeding was 0.6% as a result of suboptimal management of antithrombotic drugs in extractions of teeth other than M3. Finally, optimal treatment of the complications was compared with the available evidence. Prevention and treatment of these complications could reduce the incidence, particularly of bleeding.status: publishe

Long-term neurosensory disturbances after modified sagittal split osteotomy

We have investigated the long-term incidence of neurosensory disturbances after modified bilateral sagittal split osteotomy, and identified associated risk factors. We prospectively studied 376 patients, and their self-reported neurosensory disturbances were evaluated six months, and one, two, and three years postoperatively. The correlations between the following risk factors and neurosensory disturbances were investigated using univariate analysis and stepwise multivariate analysis: age at operation, sex, type of movement (advancement, setback, or rotation), concurrent genioplasty, type of detachment, iliac crest bone graft, and use of dicalcium phosphate synthetic bone graft. Probabilities of less than 0.05 were accepted as significant. Three years postoperatively, 57 patients (15%) reported altered sensation of the lower lip or chin. Older age correlated significantly with neurosensory disturbances (p<0.0001). Greater mandibular advancement correlated with postoperative "positive" neurosensory phenomena (right side p=0.08; left side p=0.03). Intraoperative surgical manipulation of the left inferior alveolar nerve was significantly associated with postoperative hypoaesthesia (p=0.014). Older age at surgery, extensive mandibular advancement, and surgical manipulation of the left inferior alveolar nerve, were associated with long-term neurosensory disturbances after modified bilateral sagittal split osteotomy. The modified operation seems to safeguard the inferior alveolar nerve from transection, without causing damage to other nerves.status: publishe