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Contains fulltext : 167328.pdf (Publisher’s version ) (Open Access) Larger serving sizes and more frequent eating episodes have been implicated in the rising prevalence of obesity at a population level. This study examines the relative contributions of meal size and frequency to weight gain in a large sample of British children. Using 3-day diet diaries from 1939 children aged 21 months from the Gemini twin cohort, we assessed prospective associations between meal size, meal frequency and weight gain from two to five years. Separate longitudinal analyses demonstrated that every 10 kcal increase in meal size was associated with 1.5 g/wk or 4% (p = 0.005) faster growth rate, while meal frequency was not independently associated with growth (beta = 0.3 g/wk p = 0.20). Including both meal parameters in the model strengthened associations (meal size: beta = 2.6 g/wk, p < 0.001; meal frequency: beta = 1.0 g/wk, p = 0.001). Taken together, the implication is that meal size promotes faster growth regardless of frequency, but meal frequency has a significant effect only if meal size is assumed to be held constant. Clearer advice on meal size and frequency, especially advice on appropriate meal size, may help prevent excess weight gain.

DNA was extracted from tomato plants showing symptoms of tomato yellow leaf curl disease. Using degenerate primers PAC1v1978 and PAV1c715, a putative viral fragment of ∼1.2 kb was amplified from the extracted DNA. The amplified viral DNA was isolated, cloned into PstI-digested pBluescript KS + plasmid and sequenced. Sequence comparison indicated that the virus causing tomato yellow leaf curl disease in Tanzania was genetically homologous (97% identity in the coat protein) to Tomato leaf curl Tanzania virus. There were no significant differences in DNA sequences among the field isolates from Tanzania.

Field experiments were conducted for two seasons (2001 and 2002) to determine the reaction of tomato genotypes to Tomato yellow leaf curl Tanzania virus. Tomato plants at the first leaf stage were inoculated with the virus in insect-proof cages in the screenhouse following 48-h and 72-h acquisition and inoculation feeding times by Bemisia tabaci, respectively. After inoculation, the whiteflies were killed with Karate 5EC (a.i 50 g/l λ-cylohalothrin). Test plants were transplanted to the field 4 weeks after inoculation in paired inoculated and non-inoculated plots replicated three times. The plants were maintained insect-free for the duration of the experiment by spraying weekly with Karate 5EC. Disease severity was scored weekly on a scale of 0 – 4 (0 = no symptoms and 4 = very severe symptoms). Average fresh plant weight after harvest (without roots), fruit number per plant, fruit weight and average total yield were recorded. There were significant differences in the effect of disease on yield components...

An investigation of the biological properties of the virus causing tomato yellow leaf curl disease in Tanzania was initiated to compare it with other known tomato yellow leaf curl viruses. Properties relating to acquisition and inoculation feeding time, persistence, mechanical inoculation, seed transmission and host range were studied. Results obtained indicate that the virus was transmitted persistently byBemisia tabaci Genn., but it was not mechanically, sap- or seed-transmissible. Minimum acquisition and inoculation feeding time was 30 min.Capsicum annuum, Datura stramonium, Nicotiana glutinosa, N. tabacum andLycopersicon esculentum were found to be hosts of the virus among the plant species tested, whereasPhaseolus vulgaris was not. It is concluded that the properties of the agent causing yellow leaf curl symptoms in tomato plants from different regions in Tanzania are similar to those ofTomato yellow leaf curl Sardinia virus species studied elsewhere.

Seed set in Musa spp. L. is known to vary greatly among seed-fertile cultivars, but germinate at an intractably low rate in soil thus making breeding of plantains and bananas difficult. This paper is a report on the influence and significance of fungicide treatments and other factors on the germination of hybrid plantain seeds. Bunches of hybrid plantain crosses were harvested 90–120 days after hand pollination, then ripened for 4 days in a room with acetylene. Fifty extruded air-dried seeds were planted in duplicate polyethylene bags containing moistened fungicide-drenched composted soil mix. Carbendazim applied as a soil drench at 5 ppm, yielded a peak germination of 24.8%. Mancozeb significantly increased seed germination in January 1996 (4.2 ppm) and February 1996 (1.8–1.3 ppm). Application of copper oxychloride resulted in significantly higher germination than control values only at a lower concentration (0.9–0.6 ppm) of fungicide applied in the February 1996. The time of seed treatment was also identified as a significant factor influencing the germination of the seeds. Percent germination in the control treatment positively correlated with average weather measurements: sunshine r = 0.995, p < 0.01; air temperature r = 0.986, p < 0.05). These results confirm the potential of the relevant fungicides as germination stimulators of plantain hybrid seeds in soil when applied at the appropriate concentration. A favorable environmental condition may also be crucial to meet optimum requirements for specific critical metabolic processes.

Tomato samples with typical symptoms of tomato yellow leaf curl virus (TYLCV) infection were collected from six tomato growing regions in Tanzania and dot-blotted on nylon membranes. The membranes were hybridised with nucleic acid probes synthesized to detect TYLCV from Israel and Sardinia. Viral DNA was extracted from the samples by phenol-chloform procedure and amplified by polymerase chain reaction using a primer pair (OTY 2 and OTY 6) designed to amplify a 1.2kb fragment containing the coat protein, intergenic region and replication-associated protein. The amplified DNA was ligated to pBluescript II KS+ and transformed into Esherichia coli strain JM 83 cells by electroporation. Colonies containing the insert were sequenced using a Li-Cor DNA Semi-automatic Sequencer. The BLAST programme was used to search for viruses with similar sequences. Phylogenetic relationships with 20 geminiviruses were established using the CLUSTAL function of the Vector NT1.5 software. Amplified DNA was digested with Alu I an...

A survey was initiated to detect tomato yellow leaf curl virus (TYLCV) and identify its reservoir weed hosts in six regions (Arusha, Morogoro, Dodoma, Iringa, Kilimanjaro and Dar es Salaam) in Tanzania. Three farms were randomly selected in each region. Assessment of TYLCV incidence was done by relating the number of infected tomato plants to the total number of plants assessed along a diagonal in five quadrants measuring 4m ‐ 4m in size (one at each corner of the farm and one at the centre). Disease severity was scored on a scale of 0 to 4 (where 0 = no symptoms and 4 = very severe symptoms). Within and outside each farm, weeds showing TYLCV-like symptoms were collected and either squash-blotted, dot-blotted or both on nylon membranes. The membranes were hybridized with DIG-labelled probe synthesized for the detection of TYLCV from Sardinia (TYLCV-Sar) following standard protocols. Selected plant species were experimentally inoculated with screenhouse cultures of TYLCV representative isolates from the si...

Objective: To assess developmental trends in physical activity and sedentary behaviour in British adolescents in relation to sex, ethnicity and socioeconomic status (SES).Design: A 5-year longitudinal study of a diverse cohort of students aged 11 - 12 years at baseline in 1999.Setting: 36 London schools sampled using a stratified random sampling procedure.Participants: A total of 5863 students categorised as white, black or Asian, and stratified for SES using the Townsend Index.Main outcome measures: Number of days per week of vigorous activity leading to sweating and breathing hard. Hours of sedentary behaviour, including watching television and playing video games. Data were analysed using multilevel, linear, mixed models.Results: Marked reductions in physical activity and increases in sedentary behaviour were noticed between ages 11 - 12 and 15 - 16 years. Boys were more active than girls, and the decline in physical activity was greater in girls (46% reduction) than in boys (23%). Asian students were less active than whites, and this was also true of black girls but not boys. Black students were more sedentary than white students. Levels of sedentary behaviour were greater in respondents from lower SES. Most differences between ethnic and SES groups were present at age 11 years, and did not evolve over the teenage years.Conclusions: Physical activity declines and sedentary behaviour becomes more common during adolescence. Ethnic and SES differences are observed in physical activity and sedentary behaviour in British youth that anticipate adult variations in adiposity and cardiovascular disease risk. These are largely established by age 11 - 12 years, so reversing these patterns requires earlier intervention.

BackgroundThere are wide international differences in one-year cancer survival. The UK and Denmark perform poorly compared with other high income countries with similar health care systems: Australia, Canada and Sweden have good cancer survival rates, Norway intermediate survival rates. The objective of this study was to examine the pattern of differences in cancer awareness and beliefs across these countries to identify where these might contribute to the pattern of survival.MethodsWe carried out a population-based telephone interview survey of 19,079 men and women aged 50 and older in Australia, Canada, Denmark, Norway, Sweden and the UK using the Awareness and Beliefs about Cancer measure.ResultsAwareness that the risk of cancer was greater in older people varied significantly across the countries, being lowest in the UK (14%), Canada (13%) and Australia (16%) and highest in Denmark (25%), Norway (29%) and Sweden (38%). Barriers to symptomatic presentation were highest in the UK, in particular being worried about wasting the doctor’s time (UK 34%; Canada 21%; Australia 14%; Denmark 12%; Norway 11%; Sweden 9%). There were small differences between the countries in cancer symptom awareness and beliefs about cancer outcomes.ConclusionsThe UK had the lowest awareness of age-related risk and most negative beliefs about barriers to symptomatic presentation although it did not differ from other countries in symptom awareness or beliefs about cancer. However, Denmark had high levels of knowledge about age-related risk and few negative beliefs about barriers to symptomatic presentation. Lack of awareness that the risk of cancer increases with age and barriers to presentation may contribute to later cancer diagnosis in the UK, but other factors must explain poor cancer survival in Denmark. In the UK, interventions to promote early symptomatic presentation should focus on addressing awareness of risk of cancer and understanding and improving the interaction between patient and primary care to encourage prompt presentation with cancer symptoms.

Objective: To explore predictors of programme adherence and weight loss in patients participating in a weight management programme using meal replacements (MR).Design: One hundred and fifty healthy obese women, age 48.5 years (s.d. = 8.3); weight, 97.6 kg (13.4); body mass index (BMI) 36.5 (3.7), participated in a longitudinal study with a 16-week acute weight loss phase (Phase 1) followed by 1 year of a trial of weight-loss maintenance (Phase 2). Energy intake during Phase 1 totaled 900 kcal (3.7 MJ) a day from a diet including two MR. Energy intake during Phase 2 consisted of either MR or a low-fat diet with a calculated energy deficit of 600 kcal/day (2.5 MJ).Methods: Weight, height and waist circumference were measured and body composition assessed by air plethysmography (Bodpod). Glucose and insulin were measured by standard immunoassays and insulin sensitivity assessed by homeostatic model assessment.Results: At the end of 16 weeks, 114 subjects (76%) completed Phase 1 and achieved a mean weight loss of 8.95 kg (3.38). Adherence to Phase 1 was predicted by weight loss over the first 2 weeks (p < 0.001). Weight loss during Phase 1 was predicted by initial weight and initial systolic blood pressure. Adherence to Phase 2 was not predicted by physiological measures. Weight loss maintenance in Phase 2 (not gaining more than 3% of the weight at start of phase 2) was predicted by cholesterol and triglyceride measured at the start of Phase 2 but otherwise was not predicted by the physiological measures. Initial insulin sensitivity did not predict weight loss in either phase.Conclusion: Participants whose weight loss over the first 2 weeks falls in the bottom third may need additional intervention if they are to continue in this type of programme. A battery of physiological measures at entry to a MR weight loss and maintenance programme explains only a very small proportion of the variation in weight loss.