A simplified PCR test for early detection of dwarf off-types in micropropagated Cavendish bananas (Musa spp. AAA)

The dwarf somaclonal variant is a major problem affecting micropropagation of the banana cultivar Williams (Musa spp. AAA; subgroup Cavendish). This problem arises from genetic changes that occur during the tissue culture process. Early identification of this problem is difficult and propagators must wait until plants are ex vitro in order to visualise the dwarfism phenotype. In this study, we have improved a SCAR-based molecular diagnostic technique, developed by Damasco et al. [Acta Hortic. 461 (1997) 157], for the early identification of dwarf off-types. We have included a positive internal control in a multiplex PCR and adapted the technique for use with small amounts of fresh in vitro leaf material as PCR template. The control product is a 500 bp fragment from 18S rRNA and is amplified in all tissues irrespective of phenotype. The use of small in vitro leaf material removing the need for genomic DNA extraction.

Characterisation and early detection of an offtype from micropropagated Lady Finger bananas

An offtype has been identified from micropropagated Lady Finger bananas (Musa spp., AAB group, Pome subgroup) that is characterised by its slow growth and poor bunch size. Bunch weights were approximately 25% those of normal Lady Finger plants and all of the fruit produced was unmarketable. This particular offtype is the most commonly encountered from micropropagated Lady Finger plants and, in 2 instances, blocks of 3000 and 1500 plants were entirely comprised of this single offtype. Detection of offtype plants was possible during establishment and growth of plants in the glasshouse by the presence of chlorotic streaks in the leaves. In more severe cases the streaks coalesced into chlorotic patches that developed thin, necrotic areas that eventually produced holes or splits in the leaves. Symptom expression was not ameliorated by the addition of fertiliser and even though symptoms were similar to severe Ca and B deficiency, both normal and offtype plants had similar levels of these elements in the leaves. The offtype plants were also slow growing in the glasshouse and produced significantly (P<0.05) smaller pseudostems and leaves than normal plants. Offtype plants could be readily detected after 4 weeks deflasking using the presence of chlorotic streaks in the leaves as the main selection criterion. Maximum discrimination was possible between weeks 5–7 and at the 6-leaf stage when all of the offtypes could be detected.

Early detection of type 2 diabetes mellitus in Chinese and Indian adult population

Objectives of this study were to determine secular trends of diabetes prevalence in China and develop simple risk assessment algorithms for screening individuals with high-risk for diabetes or with undiagnosed diabetes in Chinese and Indian adults. Two consecutive population based surveys in Chinese and a prospective study in Mauritian Indians were involved in this study. The Chinese surveys were conducted in randomly selected populations aged 20-74 years in 2001-2002 (n=14 592) and 35-74 years in 2006 (n=4416). A two-step screening strategy using fasting capillary plasma glucose (FCG) as first-line screening test followed by standard 2-hour 75g oral glucose tolerance tests (OGTTs) was applied to 12 436 individuals in 2001, while OGTTs were administrated to all participants together with FCG in 2006 and to 2156 subjects in 2002. In Mauritius, two consecutive population based surveys were conducted in Mauritian Indians aged 20-65 years in 1987 and 1992; 3094 Indians (1141 men), who were not diagnosed as diabetes at baseline, were reexamined with OGTTs in 1992 and/or 1998. Diabetes and pre-diabetes was defined following 2006 World Health Organization/ International Diabetes Federation Criteria. Age-standardized, as well as age- and sex-specific, prevalence of diabetes and pre-diabetes in adult Chinese was significantly increased from 12.2% and 15.4% in 2001 to 16.0% and 21.2% in 2006, respectively. A simple Chinese diabetes risk score was developed based on the data of Chinese survey 2001-2002 and validated in the population of survey 2006. The risk scores based on β coefficients derived from the final Logistic regression model ranged from 3 – 32. When the score was applied to the population of survey 2006, the area under operating characteristic curve (AUC) of the score for screening undiagnosed diabetes was 0.67 (95% CI, 0.65-0.70), which was lower than the AUC of FCG (0.76 [0.74-0.79]), but similar to that of HbA1c (0.68 [0.65-0.71]). At a cut-off point of 14, the sensitivity and specificity of the risk score in screening undiagnosed diabetes was 0.84 (0.81-0.88) and 0.40 (0.38-0.41). In Mauritian Indian, body mass index (BMI), waist girth, family history of diabetes (FH), and glucose was confirmed to be independent risk predictors for developing diabetes. Predicted probabilities for developing diabetes derived from a simple Cox regression model fitted with sex, FH, BMI and waist girth ranged from 0.05 to 0.64 in men and 0.03 to 0.49 in women. To predict the onset of diabetes, the AUC of the predicted probabilities was 0.62 (95% CI, 0.56-0.68) in men and 0.64(0.59-0.69) in women. At a cut-off point of 0.12, the sensitivity and specificity was 0.72(0.71-0.74) and 0.47(0.45-0.49) in men; and 0.77(0.75-0.78) and 0.50(0.48-0.52) in women, respectively. In conclusion, there was a rapid increase in prevalence of diabetes in Chinese adults from 2001 to 2006. The simple risk assessment algorithms based on age, obesity and family history of diabetes showed a moderate discrimination of diabetes from non-diabetes, which may be used as first line screening tool for diabetes and pre-diabetes, and for health promotion purpose in Chinese and Indians.

The Early Detection of Motion Boundaries

This thesis shows how to detect boundaries on the basis of motion information alone. The detection is performed in two stages: (i) the local estimation of motion discontinuities and of the visual flowsfield; (ii) the extraction of complete boundaries belonging to differently moving objects. For the first stage, three new methods are presented: the "Bimodality Tests,'' the "Bi-distribution Test,'' and the "Dynamic Occlusion Method.'' The second stage consists of applying the "Structural Saliency Method,'' by Sha'ashua and Ullman to extract complete and unique boundaries from the output of the first stage. The developed methods can successfully segment complex motion sequences.

Development of a planar waveguide microarray for the monitoring and early detection of five harmful algal toxins in water and cultures

A novel multiplex microarray has been developed for the detection of five groups of harmful algal and cyanobacterial toxins found in marine, brackish, and freshwater environments including domoic acid (DA), okadaic acid (OA, and analogues), saxitoxin (STX, and analogues), cylindrospermopsin (CYN) and microcystins (MC, and analogues). The sensitivity and specificity were determined and feasibility to be used as a screening tool investigated. Results for algal/cyanobacterial cultures (n = 12) and seawater samples (n = 33) were compared to conventional analytical methods, such as high performance liquid chromatography (HPLC) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Detection limits for the 15 min assay were 0.37, 0.44, 0.05, 0.08, and 0.40 ng/mL for DA, OA, STX, CYN, and MC, respectively. The correlation of data obtained from the microarray compared to conventional analysis for the 12 cultures was r(2) = 0.83. Analysis of seawater samples showed that 82, 82, 70, 82, and 12% of samples were positive (>IC20) compared to 67, 55, 36, 0, and 0% for DA, OA, STX, CYN, and MC, respectively, for conventional analytical methods. The discrepancies in results can be attributed to the enhanced sensitivity and cross-reactivity profiles of the antibodies in the MBio microarray. The feasibility of the microarray as a rapid, easy to use, and highly sensitive screening tool has been illustrated for the five-plex detection of biotoxins. The research demonstrates an early warning screening assay to support national monitoring agencies by providing a faster and more accurate means of identifying and quantifying harmful toxins in water samples.

Early detection of leukaemic relapse after bone marrow transplantation using the polymerase chain reaction

We report a case of acute lymphoblastic leukaemia relapsing after allogeneic bone marrow transplantation in which the polymerase chain reaction (PCR) was used to assess chimeric status. This technique demonstrated the progressive reappearance of host cells prior to clinical relapse. The relapse was of host cell origin as shown by the presence of female (recipient) metaphases containing an abnormal chromosomal marker (iso 9q) which had also been present at initial diagnosis. The emergence of host cells in this case, detected only by PCR techniques but not by cytogenetic methods, appeared to herald overt relapse. PCR analysis provides a sensitive tool for detecting a progressive rise in host cell numbers which may predict clinical relapse.

Evaluation and early detection of problematic Internet use in adolescents

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The early detection of postpartum depression: midwives and nurses trial a checklist

Objective: To evaluate the use of a standard pen-and-paper test versus the use of a checklist for the early identification of women at risk of postpartum depression and to investigate the experiences of nurses in using the checklist.

Design: A prospective cohort design using repeated measures.

Setting: The booking-in prenatal clinic at a regional hospital in Victoria, Australia, and the community-based postpartum maternal and child health service.

Participants: 107 pregnant women over 20 years of age.

Main Measures: Postpartum Depression Prediction Inventory (PDPI), Postpartum Depression Screening Scale (PDSS), Edinburgh Postnatal Depression Scale (EPDS), demographic questionnaire, and data on the outcome from the midwives and nurses.

Results: The PDPI identified 45% of the women at risk of depression during pregnancy and 30% postpartum. The PDSS and EPDS both identified the same 8 women (10%), who scored highly for depression at the 8-week postpartum health visit. Nurses provided 80% of the women with anticipatory guidance on postpartum depression in the prenatal period and 46% of women at the 8-week postpartum health visit. Nurse counseling or anticipatory guidance was provided for 60% of the women in the prenatal period.

Conclusion: The PDPI was found to be a valuable checklist by many nurses involved in this research, particularly as a way of initiating open discussion with women about postpartum depression. It correlated strongly with both the PDSS and the EPDS, suggesting that it is useful as an inventory to identify women at risk of postpartum depression.

Early detection of depression and associated risk factors in adults with mild/moderate intellectual disability

The aim of this study was to determine the presentation and risk factors for depression in adults with mild/moderate intellectual disability (ID). A sample of 151 adults (83 males and 68 females) participated in a semi-structured interview. According to results on the Beck Depression Inventory II, 39.1% of participants evinced symptoms of depression (2 severe, 14 moderate, and 43 mild). Sadness, self-criticism, loss of energy, crying, and tiredness appeared to be the most frequent indicators of depression or risk for depression. A significant difference was found between individuals with and without symptoms of depression on levels of automatic negative thoughts, downward social comparison and self-esteem. Automatic negative thoughts, quality and frequency of social support, self-esteem, and disruptive life events significantly predicted depression scores in people with mild/moderate ID, accounting for 58.1% of the variance.

Early detection of emotional and behavioural problems in children with diabetes: the validity of the child health questionnaire as a screening instrument

Aims: To assess the validity of the Child Health Questionnaire (CHQ) as a screening tool for detecting 'at risk' emotional and behavioural  maladjustment in children with diabetes, using the Behaviour Assessment System for Children (BASC) as a gold standard measure. Methods: CHQ and BASC were administered to 103 parents of children with Type 1 diabetes, aged 7–12 years. Sub-scales of the two measures were compared using Pearson's bivariate correlations. CHQ sensitivity and specificity cut-points were optimized against the BASC borderline category using receiver operating characteristic curves. Results: The BASC Externalizing Problems scale correlated strongly with CHQ Behaviour, Global Behaviour, Mental Health, Family Activities and Family Cohesion scales (r-values −0.68, −0.54, −0.51, −0.59, and −0.42, respectively). BASC Internalizing Problems scale correlated strongly with CHQ Behaviour, Mental Health and Family Cohesion scales (r-values −0.40, −0.43 and −0.45, respectively). Using receiver operating characteristic curve analysis, the CHQ Mental Health scale most effectively identified children classified as borderline on the BASC Internalizing Problems scale (sensitivity 87%, specificity 78%), while the CHQ Global Behaviour scale most effectively identified children classified as borderline on the BASC Externalizing Problems scale (sensitivity 73%, specificity 82%). Conclusions: Significant correlations were seen between the CHQ Global Behaviour and Mental Health scales and the BASC Externalizing and Internalizing scales, respectively. Sequential use of the CHQ, as a screening tool, followed by an established mental health measure such as the BASC, may help identify children with diabetes 'at risk' for chronic maladjustment and poor health outcomes.