The Swedish liming programme

To mitigate the acidification problem in surface waters the Swedish government is funding a liming programme. Limestone or dolomite powder has been applied to acidified waters since 1976 and on a large scale since 1982. In most projects, limestone is applied directly to the lake, but in several cases supplementary liming is carried out on wetlands and in streams using dosers or other techniques. At present 7,500 Swedish lakes and more than 11,000 kilometers of streams are limed repeatedly with a total of some 200,000 tonne of limestone every year. In 1994 about US$ 25 million was invested by the Swedish government in the liming programme. The biological objective of the liming operations is to detoxify the water so that the natural fauna and flora can survive or recolonize. The chemical aim is to raise the pH above 6.0 and the alkalinity above 0.1 meq/l, which gives an acceptable buffering capacity. In addition, dissolved metals will be deposited after liming, thus reducing their toxicity. Overdosing must be avoided, with natural softwater characteristics being the objective. The chemical and biological effects in water of the liming operations are encouraging. The Swedish liming programme has so far resulted in restoration in 80–90% of the limed surface waters. The fauna often shows an initial dominance by a few species but diversity increases with time, In general, flora and fauna in limed waters show a great resemblance to those in waters not acidified. An undesired effect of liming is significant changes in mosses and lichens after wetland liming.     

Increasing activity and improving nutrition through a schools-based programme: Project Energize. 1. Design, programme, randomisation and evaluation methodology

Project Energize is a through-school nutrition and activity programme that is being evaluated in a 2-year, cluster-randomised, longitudinal study. The present paper describes the background of the programme and study, the programme development and delivery, the study methodology including randomisation, measurement and analysis tools and techniques, and the mix of the study population. The programme is being delivered to sixty-two primary schools with sixty-two control schools, each limb containing about 11 000 students. The children in the evaluation cohort are 5 or 10 years old at enrolment; the randomisation protocol has achieved post-consent enrolment of 3000 evaluation participants, who are comparable by age, sex and school decile. End-point measures include body composition and associated physical characteristics, fitness, home and school environment and practice.     

An evaluation of the impact of a school nutrition programme in Vietnam

OBJECTIVE: To evaluate the effectiveness of a school nutrition programme on the weight gain and growth of Vietnamese schoolchildren. DESIGN: A proximate cluster evaluation of children in seven schools, in which fortified milk and biscuits supplying 300 kcal of energy were being given on school days, compared with children in 14 nearby schools with no feeding. All children were dewormed. SETTING: Twenty-one primary schools in Dong Thap Province, Vietnam. SUBJECTS: A cohort of 1080 children in grade 1 of 21 primary schools, and a cross-sectional interview of 400 children in grade 3. RESULTS: The programme gave children the equivalent of 90 kcal day- 1 over 17 months. t-Tests showed a small but statistically significant difference between groups in their average gain in weight and height: 3.19 versus 2.95 kg (P < 0.001) and 8.15 versus 7.88 cm (P = 0.008). A multiple-level model showed that the programme was statistically significant after controlling for clustering of children in schools, sex, age and initial underweight (P = 0.024). A significant impact on height was also seen in a regression model, but not when controlling for school. The most undernourished children tended to gain the least weight. There was no evidence of substitution. CONCLUSION: The programme had a small but significant effect on weight gain, but the most undernourished children benefited the least. Methods need to be developed to target them. This design may offer a means of estimating the impact of school feeding on growth in other programme settings.     

Mt. Brocken,a site for a cloud chemistry measurement programme in Central Europe

We present results from the Brocken Cloud Chemistry Measurement Project (BROCCMON) which started in 1991. Since 1992 the full programme is running, based on continuous measurements (e.g. trace gases, meteorology, liquid water content), cloud water sampling and analysis and intensive measurement campaigns. The observed high variability of cloud water composition we explain with cloud dynamic and microphysical behaviour of clouds and differences in the air mass characteristics. During the measurement period 1992–1994 we observed an increase in cloud water acidity (by a factor of 3) and we found photochemical conditions typically for summersmog situations. Our preliminary data also show that an understanding of tropospheric ozone balance would be incomplete without consideration of chemical processes within clouds. A long-term goal of our programme is to establish a cloud chemistry climatology which is representative for the region.     

The process of establishing, implementing and maintaining a social support infant feeding programme

OBJECTIVE: To describe the process of establishing and implementing a social support infant feeding intervention. DESIGN: This paper outlines the initial stages of a randomised controlled trial which assessed the effectiveness of a social support intervention on a range of infant feeding outcomes. Details are presented of the processes involved in recruiting, training and supporting a group of volunteers who provided support to the study sample. SETTING: Camden and Islington, London, UK. RESULTS: Initial networking with local agencies and organisations provided invaluable information and contacts. Employing a dedicated volunteer co-ordinator is vitally important in the recruitment, training and support of volunteers. Providing child care and travel expenses is an essential incentive for volunteers with young children. Advertisements placed in local newspapers were the most successful means of recruiting volunteers. Appropriate training is needed to equip volunteers with the necessary knowledge and skills to provide effective support. Particular emphasis in the training focused upon developing the necessary interpersonal skills and self-confidence. The evaluation of the training programme demonstrated that it improved volunteers' knowledge and reported confidence. The provision of ongoing support is also essential to maintain volunteers' interest and enthusiasm. The retention of volunteers is, however, a key challenge. CONCLUSIONS: The processes outlined in this paper have demonstrated the feasibility of successfully establishing, implementing and maintaining a community-based social support infant feeding programme. The experiences described provide useful insights into the practical issues that need to be addressed in setting up a social support intervention.     

The United Kingdom national materials exposure programme

In 1986, the National Materials Exposure Programme was set up within the United Kingdom to investigate the effects of acid deposition on buildings and building materials. Thirty sites were chosen, which represented a range of geographical and pollution climates. Each site met a minimum meteorological and pollution monitoring regime (including SO₂, NO₂). After four years, other sites were included (with less frequent data collection) and some sites removed. At each site, samples of 3 types of stone, mild steel, painted steel, Cu, Al and galvanised steel were exposed, with some of the stone sheltered from direct precipitation. Samples were removed periodically for analysis and dose-response relations derived for different materials. The empirical relationships derived are in the form of: decay rate=a [SO₊] + b [H₂] + c [rainfall] + d These dose response relations have been used to develop critical load maps for materials for the United Kingdom. Eight years of data have been collected, some for the UNECE task force programme. Laboratory tests using an Atmospheric Flow Chamber were also undertaken. Since the beginning of the programme addition materials have been exposed on some sites including mortars. A further set of eight sites has been used to assess the effects of ozone on a range of organic materials (for example polyvinyl chloride, polycarbonate, sealants). The paper presents up-to-date findings for the programme and confirms the dominance of dry deposition of sulphur dioxide as the main decay process for sensitive materials in areas of significant pollution.     

The solar radiation network of the AGRHYMET programme

This communication presents details on the solar radiation network of the AGRHYMET Programme, its stations, equipment and the availability of the data collected.     

C语言程序设计教学方法探索

C语言程序设计教学不应局限于使学生单纯地了解和掌握C语言的基本语法规范，而是要致力于培养学生运用C语言解决实际问题的编程能力。C语言程序设计教学方法的改革让学生从多角度、以多方式去了解和掌握C语言以及程序设计的精髓，着重培养学生无论以后在学习、工作中使用什么语言编程，都能灵活应用这些思想和方法的能力。     

A programme to exterminate introduced plants on Raoul Island

Raoul, the sole subtropical island possession of New Zealand, is jointly administered by the Ministry of Transport (meteorological station) and Department of Lands and Survey (nature reserve). Since abandonment of attempts at settlement many species of cultivated exotic plants have become pernicious weeds threatening the indigenous vegetation. The methods and results of trials aimed at eradication of some of these weed species are discussed.     

Man and the biosphere: An international research programme

A new international research programme entitled Man and the Biosphere (MAB) has just been launched by the General Conference of UNESCO. This programme is to focus on the structure and functioning of the biosphere and its ecological regions, on the changes brought about by Man in the biosphere and its resources, on the overall effects of these changes upon the human species itself, and on the education and information which needs to be provided on these matters. The need for the programme and the history of its development are briefly analysed. The scope and the proposed scientific content of MAB are described, including a list of the 31 research themes that are being considered on natural environments little modified by Man, on rural environments, on urban-industrial environments, and on pollution and related phenomena affecting the biosphere. An indication is given of the type of basic operations needed for such an international programme which is to include networks of observation and research stations and utilization of modern methodologies; also indicated are the education and training activities contemplated as a support to the programme, particularly in developing countries. It is emphasized that the MAB programme, which constitutes in many respects a follow-up and extension at the intergovernmental level of the International Biological Programme (IBP), will be carried out under the guidance of a 25-countries coordinating council in close cooperation with the other United Nations agencies and non-governmental organizations concerned. Each country has been invited to set up a National Committee through which individual scientists can influence the content of the programme.     

C语言程序设计教学改革初探

提高C语言程序设计教学效果的方法和手段是教师关注的问题。在教学中让学生充分认识到该课程的重要作用,掌握正确的学习方法,提高课堂教学的效率和质量,提高学生的编程能力,提高学生的动手实践能力,加强各个教学环节的互动。使学习C语言的目的不再局限于使学生单纯地了解和掌握C语言的基本语法规范,而是要致力于培养学生运用C语言解决实际问题的编程能力。     

Community-based assessment of infant feeding practices within a programme for prevention of mother-to-child HIV transmission in rural Zimbabwe

OBJECTIVE: To describe the infant feeding practices and attitudes of women who used prevention of mother-to-child transmission of HIV (PMTCT) services in rural Zimbabwe. DESIGN: A cross-sectional study including structured interviews and focus group discussions was conducted between June 2003 and February 2004. SETTING: The study took place in Murambinda Mission Hospital (Buhera District, Manicaland Province), the first site offering PMTCT services in rural Zimbabwe. SUBJECTS: The interviews targeted HIV-infected and HIV-negative women who received prenatal HIV counselling and testing and minimal infant feeding counselling, and who delivered between 15 August 2001 and 15 February 2003. The focus groups were conducted among young and elderly men and women. RESULTS: Overall, 71 HIV-infected and 93 HIV-negative mothers were interviewed in clinics or at home. Most infants (97%) had ever been breast-fed. HIV-negative mothers introduced fluids/foods other than breast milk significantly sooner than HIV-infected mothers (median 4.0 vs. 6.0 months, P = 0.005). Infants born to HIV-negative mothers were weaned significantly later than HIV-exposed infants (median 19.0 vs. 6.0 months, P = 10(-5)). More than 90% of mothers reported that breast-feeding their infant was a personal decision, a third of whom also mentioned having taken into account health workers' messages. CONCLUSION: The HIV-infected mothers interviewed were gradually implementing infant feeding practices recommended in the context of HIV. Increased infant feeding support capacity in resource-limited rural populations is required, i.e. training of counselling staff, decentralised follow-up and weaning support.