The economic cost of weeds in dryland cotton production systems of Australia

Economic losses and costs associated with weeds in dryland cotton production are important, both for growers and for industry bodies when making decisions about research priorities and research and development funding. A survey was conducted to provide information on weed types, control strategies and estimated costs to growers. We used information from the survey to estimate conventional financial losses due to weeds, and as a basis for evaluating aggregate economic (society) impacts. An economic surplus model was used to estimate the aggregate societal impact of weeds for three production regions in north-eastern Australia. The annual economic costs associated with weeds were estimated to be $41 million, and the on-farm financial costs were$25 million. While these are past (sunk) costs, and based on a total removal of weeds, the approach outlined here can be used to begin evaluating likely future returns from technologies or management improvements for different agricultural problems.Weeds, Dryland Cotton, and Economics, Crop Production/Industries, Environmental Economics and Policy,

Impact of Principals' Managerial Roles Under School-based Management on School Improvement at Urban Secondary Schools of Bangladesh

This article aims al observing the relationship between principals' managerial roles and the improvement of schools and the impacts of principals' managerial roles toward school improvement based on the school-based management. This research uses 127 principals and 694 teachers of urban secondary schools of Bangladesh as the sample. Schools are becoming better when the principals give more emphasizing on strategic plan, supportive and comprehensive roles but less emphasizing on shared decision making. The findings of this study offer valuable information for policy makers and educational managers, especially the principals and teachers. Key words: Principals managerial roles, school-based management, teachers' Professional development activities, school improvement &nbsp

Anisotropic nonlinear elasticity in a spherical bead pack: influence of the fabric anisotropy

Stress-strain measurements and ultrasound propagation experiments in glass bead packs have been simultaneously conducted to characterize the stress-induced anisotropy under uniaxial loading. These measurements, realized respectively with finite and incremental deformations of the granular assembly, are analyzed within the framework of the effective medium theory based on the Hertz-Mindlin contact theory. Our work shows that both compressional and shear wave velocities and consequently the incremental elastic moduli agree fairly well with the effective medium model by Johnson et al. [J. Appl. Mech. 65, 380 (1998)], but the anisotropic stress ratio resulting from finite deformation does not at all. As indicated by numerical simulations, the discrepancy may arise from the fact that the model doesn't properly allow the grains to relax from the affine motion approximation. Here we find that the interaction nature at the grain contact could also play a crucial role for the relevant prediction by the model; indeed, such discrepancy can be significantly reduced if the frictional resistance between grains is removed. Another main experimental finding is the influence of the inherent anisotropy of granular packs, realized by different protocols of the sample preparation. Our results reveal that compressional waves are more sensitive to the stress-induced anisotropy, whereas the shear waves are more sensitive to the fabric anisotropy, not being accounted in analytical effective medium models.Comment: 9 pages, 8 figure

Solid behavior of anisotropic rigid frictionless bead assemblies

We investigate the structure and mechanical behavior of assemblies of frictionless, nearly rigid equal-sized beads, in the quasistatic limit, by numerical simulation. Three different loading paths are explored: triaxial compression, triaxial extension and simple shear. Generalizing recent results [1], we show that the material, despite rather strong finite sample size effects, is able to sustain a finite deviator stress in the macroscopic limit, along all three paths, without dilatancy. The shape of the yield surface is adequately described by a Lade-Duncan (rather than Mohr-Coulomb) criterion. While scalar state variables keep the same values as in isotropic systems, fabric and force anisotropies are each characterized by one parameter and are in one-to-one correspondence with principal stress ratio along all three loading paths.The anisotropy of the pair correlation function extends to a distance between bead surfaces on the order of 10% of the diameter. The tensor of elastic moduli is shown to possess a nearly singular, uniaxial structure related to stress anisotropy. Possible stress-strain relations in monotonic loading paths are also discussed

Risk Factors for Anaemia in Pregnancy in Rural KwaZulu-Natal – South Africa: Implication for Health Education and Health Promotion

Background: Anaemia in pregnancy is a major public health problem in developing countries. It is associated with an increased risk of maternal and perinatal morbidity and mortality. A high rate of anaemia in pregnancy in the rural population of KwaZulu-Natal (30% according to national and 57% according to the World Health Organization [WHO] definition of anaemia in pregnancy) is observed. The risk factors for anaemia, particularly during pregnancy, are multiple and complex and their relative contributions are known to vary by geographic areas and by seasons. In order to design an intervention for treatment and prevention of anaemia in pregnancy, studies to assess the aetiological factors are necessary. The aim of this study was to evaluate the strength of association between intestinal helminthiasis, urinary schistosomiasis and HIV infection on anaemia in pregnancy.Methods: A retrospective case-control study design was used in a rural district hospital of South Africa. A total of 300 pregnant women, 100 of them with anaemia (haemoglobin less than 10 gm/dL according to the national definition of anaemia in pregnancy) referred as cases and 200 controls were studied from Empangeni Hospital. Both cases and controls were matched for age, parity and gestational age. Data were collected from the antenatal clinic and prevention of mother-to-child transmission of HIV (PMTCT) programme registers for cases and controls at their booking visit during the months of May, June and July of 2004. Univariate and multiple logistic regression were performed to analyse the data.Results: Of the cases, 48% and 1% among the controls had intestinal helminthiasis, resulting in the odds ratio of 42 (p = 0,000 and 95% CI 9,96 – 176.59). The risk of anaemia was related to urinary schistosomiasis, as 27% of the cases compared to 1% of controls was found with anaemia. The odds ratio was 12 (p = 0,000 and 95% CI 3.58 – 41.02). These parasitic infestations are known to cause chronic haemorrhage and iron deficiency resulting in the development of anaemia in pregnancy. Transmissions of intestinal parasitic infestation occur through the faecal-oral route. Personal hygiene and other environmental factors are therefore an important factor for the transmission of the disease. To reduce the transmission of faecaloral diseases (e.g. intestinal helminthiasis and urinary schistosomiasis) key interventions recommended are: 1) safe disposal of human excreta, 2) hand-washing practices with soap after defecation, and 3) maintenance of drinking water free from faecal contamination. Similarly, HIV infection increased the chance of developing anaemia in pregnancy twofold as HIV infection was more common among cases (56%) than among controls (37%), resulting in an odds ratio of 2.11 (p = 0,003 and 95% CI 1.123 – 3.21). The prevention of HIV infection and transmission can be achieved through the improvement of knowledge of these conditions. These can be achieved through health education and health promotion.Conclusion: These findings confirm and conform to other studies on the association between anaemia in pregnancy and parasitic and HIV  infections. Antenatal care should promote de-worming and education on personal hygiene and HIV (risk factors, mode of transmission, etc.). The provision of safe water supply and toilet facilities for the rural communities should be considered urgently to prevent and promote better health for all, including pregnant women

Teenage Pregnancy and Perinatal Outcomes: Experience from Rural South Africa

Context: Teenage pregnancy is known as a risk factor for preterm birth, low birth weight and perinatal deaths, thus considered public health problem. In South Africa, most teenage pregnancy is found within the context of unstable relationship and unplanned or unwanted pregnancies. A high rate of teenage pregnancy is also an indicator of problems with the sexual and reproductive health of a country's youth.Objectives: To estimate the extent of and measure adverse perinatal outcome of teenage pregnancy and compare.Study-Design, Setting and Subjects: A retrospective comparative study was conducted targeting pregnant women delivered at Empangeni hospital from April to December 2004. All pregnant women who were less than 19 years (teenage) were chosen as cases and those who were 19 years or more were selected as controls. Data were collected from the labour warddelivery registry.Main Outcome Measures: Prevalence of teenage pregnancy, Pre-term delivery, low-birthweight and still-birth rates.Results: There were 7836 deliveries of which 1236 (16%) were teenage mothers. The pre-term delivery rate of 12% and low-birth-weight delivery rate of 14% were similar for teenage and older mothers respectively. Cesarean delivery rate was significantly lower (p < 0.05) in teenagers (20%) compared to older women (26%). Macerated stillbirth rate was significantly lower (1.1%) for teenage compared to older women of 2.1% (p < 0.05).Conclusion: Although there was a higher rate of teenage pregnancy, it did not appear that it was associated with extra perinatal outcome

Audit of Antenatal Care at a Rural District of KZN, South Africa

Background: Maternal and perinatal mortality remain a big challenge in developing countries, including South Africa, where the figures are amongst the highest in the world. Provision of adequate antenatal care is regarded as a cornerstone of maternal and perinatal health care and is expected to have a considerable impact on achieving the Millennium Development Goals. The detection of high-risk pregnancies through antenatal care has been advocated as a good tool to reduce maternal mortality in developing coun- tries. The South African Government\'s response in terms of providing free maternal care in public health facilities is commendable but access to quality antenatal care is still questionable. We conducted this audit to evaluate the quality of antenatal care/services provided against the set national standards at the first (booking) visit, and visits at 28 and 36 weeks of gestation, as part of a quality improvement initiative.Methods: A retrospective cross-sectional descriptive study was undertaken, targeting women who attended public health institutions for antenatal care in the Empangeni sub-district of Uthungulu, which is a health district in KwaZulu-Natal province. Data were collected from 244 pregnant mothers\' antenatal care records after delivery, and a random selection from a total of 5 109 women who delivered in Empangeni hospital during July to December 2004. Frequency tables were produced on the predetermined selective antenatal care indicators. A Pearson correlation test was conducted to determine the significant relations, if any, among variables. Results: The majority of the pregnant mothers were unemployed and poor. Virtually all of them (99.6%) had attended public healthcare (PHC) facilities for antenatal care (88% attended PHC clinics and the rest attended hospitals) and each woman had, on average, six antenatal visits. One quarter did not enrol for a prevention of mother-to-child transmission (PMTCT) programme. Only 9% of pregnant women booked a visit during their first trimester period but most of them (two-thirds) booked a visit during the second trimester of pregnancy. History-taking was done for every woman. Recording of haemoglobin (Hb) estimation was high at the first visit (95%) but low at 28 and 36 weeks (46% and 30% respectively). Recording of syphilis screening was very low (18%) at the first visit and only 2% was screened at 36 weeks. Only 16% received adequate treatment in cases where the results were positive. At 36 weeks, only 2% had a Wasserman reaction (WR) test done to screen syphilis at term. Over half (55%) of the pregnant women received three doses of tetanus toxoid vaccination before delivery. Conclusion: The study showed that the standard of antenatal care offered in the Empangeni sub-district fell short of the required level. This lack of proper care represents missed opportunities to impact optimally on maternal and perinatal health outcomes. Thus strategies are urgently needed to improve antenatal care through a quality improving initiative. South African Family Practice Vol. 50 (3) 2008: pp. 66-66