Pal Kraft

This paper describes use of contraception at first intercourse among Norwegian adolescents and sheds some light upon whether the HIV-epidemic has influenced the use of contraception. The data stem from a population-based survey of 3,000 17-, 18- and 19-year-olds. The response rate was 60.9%. A total of 1,172 persons had experienced intercourse and constitute the material. A total of 42.2% reported having used a condom, 8.5% the p-pill, 17.6% practiced withdrawal, and 31.0% did not use any contraception at their first experience of intercourse. Use/non-use of contraception was associated with educational aspirations, age at first intercourse and consumption of alcohol. Condom use was associated with age, educational aspirations, parental education, consumption of alcohol and discussing contraception with parents and peers. The higher proportion of condom use at first intercourse among the 17-year-olds (47.5%) as compared with the 19-year-olds (34.3%) can probably be ascribed to the HIV-epidemic.

A 6-year longitudinal panel study investigated the absolute and relative stability in depressed mood throughout adolescence by reporting data from a sample of 538 adolescents between 13 and 19 years of age. Results revealed the following. (1) Girls had on average higher depressed mood scores than boys at all ages. (2) Among boys there were no substantial changes in depressed mood mean scores, while among girls there was a slight tendency of a curvilinear trend, with a peak level reached in midadolescence. (3) There was a tendency for adolescents to retain their relative level in depressed mood, most pronounced for a period of 4 years, from age 15 to age 19 years. (4) Depressed mood was most stable in a subgroup of adolescents who had high initial depressed mood scores. (5) By applying structural equation modeling, it was shown that the stable (“trait”) component of depressed mood increased in importance with increasing age, while the temporal (“state”) component decreased with increased age.

A number of studies indicate that the prevalence of smoking declined among young Norwegian adults during the 1960s and 1970s. The present paper shows, however, that this decreasing trend seemed to level out during the 1980s. Hence the total prevalence of smoking in Norway decreased by only two percent units from 1980 to 1993, as compared with approximately 10% in many other European countries. Among persons aged 16-19 years an increased prevalence of smoking has been observed in most recent years. Consequently, in 1995 the smoking prevalences among young males and females were about the same as observed around 1980. These trends in smoking prevalence and use of snuff are discussed with particular reference to the lack of emphasis on preventive measures that has characterised the Norwegian tobacco policy during the last decades; especially that the funds allocated for tobacco-related health education and information were reduced by 90% during the 1980s.

This article presents data on nicotine dependence among daily smokers in Norway in terms of Fagerströms Test for Nicotine Dependence (FTND). Nicotine dependence was higher among those smoking hand-rolled cigarettes than among those smoking manufactured cigarettes, in spite of the fact that the average number of cigarettes smoked per day was the same for both groups. The dependence also increased the lower the age of starting to smoke daily. Nicotine dependence was higher among daily smokers with a low level of education than among smokers with a higher level of education. This difference was explained by a difference in the proportion of respondents who smoked hand-rolled cigarettes in the two groups. The data are discussed in light of Norwegian research showing that hand-rolled cigarettes can contain two to three times as much nicotine and tar as manufactured cigarettes. When smokers of hand-rolled cigarettes are less motivated to quit they are exposed to greater health injury than smokers of manufactured cigarettes. The price of (and tax on) a hand-rolled cigarette is about half the price of a manufactured cigarette. Raising the tax on rolling tobacco would be very effective in promoting health and would have the particularly precise effect of reducing the differences in occurrence of disease and premature death among different social groups.

The identification of storage dynamics in remote areas is limited by data scarcity. Both top-down and bottom up approaches to identify dominant hydrological processes often fail under these circumstances. In this study, we are combining both approaches in order to test several hypotheses concerning storage dynamics. The upper Xilin catchment, Inner Mongolia, China, is a primary example for such a

Current expectations in biochar products (BC) are numerous, e.g., including improved soil fertility & plant growth, support to combat desertification, and an increase in the carbon sequestration of soils. Costs for biochar production & application must be covered by a positive budget of benefits, which may crucially depend on the residence time (or half life T1/2, yr) of BC in soils. The objective of the present study was to assess the biodegradation rates of BC in different soils by means of a cost-efficient and standardized laboratory method. Investigated BC were from the source material of the C4 plant Miscanthus, and converted via (1) pyrolysis (pyrBC) and (2) hydrothermal carbonization (htcBC). The high-labelling of the educt allowed the quantification of degradation by measurement of the 13CO2 efflux. The pyrBC and htcBC were mixed with four different agricultural soils ranging in texture from sand to loam and in soil organic carbon (SOC) from 0.63% to 2.53%. Four samples of e...

The use of crop models as part of scientific research models or economic farm tools leads to a wide range of applications. On the one hand they need to be simple; on the other hand they should be complex enough to simulate a variety of growth mechanisms. The development of entirely new models for different questions requires a lot of coding and work such as changes in the model structure, the inclusion of alternative process descriptions or the implementation of additional functionality. Often, added model components do not really fit to the model philosophy of the originally developed base model. We therefore developed a flexible (modular, generic and mixed procedural object oriented) and integrative (replaceable, expandable, independent and interactive) software tool for the setup of adapted crop models. The Plant growth Modeling Framework (PMF) is based on the Unified Modeling Language and implemented in Python, a high level object-oriented programming language. PMF provides the ...

Today, crop models have a widespread application in natural sciences, because plant growth interacts and modifies the environment. Transport processes involve water and nutrient uptake from the saturated and unsaturated zone in the pedosphere. Turnover processes include the conversion of dead root biomass into organic matter. Transpiration and the interception of radiation influence the energy exchange between atmosphere and biosphere. But many more feedback mechanisms might be of interest, including erosion, soil compaction or trace gas exchanges. Most of the existing crop models have a closed structure and do not provide interfaces or code design elements for easy data transfer or process exchange with other models during runtime. Changes in the model structure, the inclusion of alternative process descriptions or the implementation of additional functionalities requires a lot of coding. The same is true if models are being upscaled from field to landscape or catchment scale. We t...

Modeling nutrient fluxes in a catchment is a complex and interdisciplinary task. Building and improving simulation tools for such complex systems is often constraint by the expertise of the engaged scientists: Since different fields of science are involved like vadose zone and ground water hydrology, plant growth, atmospheric exchange, soil chemistry, soil microbiology, stream physics and stream chemistry, a single work group cannot excel in all parts. As a result, either parts of the system, where no scientist involved is an expert, include rough simplifications, or a "complete" group is too big for maintaining the system over a longer period. However, many approaches exist to create complex models that integrate processes for all sub domains. But a tight integration bears the problem of freezing a specific state of science in the complex system. A model infrastructure, which takes the complex feedback loops across domain boundaries (e.g. soil moisture and plant growth) i...

Persuasive technologies pervade much of our everyday lives today in areas from marketing to public health. In the latter case, persuasive technology represents a promising area of application. However, we know much too little about how to design effective interventions to support sustained behaviour change and improved well-being. The purpose of the present paper was to contribute in two ways. First, we want to contribute to current practice in designing such interventions. Second, we try to identify key research questions that could be a point of departure for a more detailed and comprehensive future research program. We do this by means of expressing 28 propositions. In sum, the propositions reflect that the construction of digital interventions should be seen as an iterative process which should take into account both content and design factors. However, we argue that intervention research and practical design experience is not just something that follows basic research at a poli...

Any hydrological model designed to reflect our current process understanding implies a plethora of hypotheses concerning the water transport. Very recently, generic model frameworks, like the Catchment Modelling Framework (CMF) that we present in this study, are available to facilitate the formulation of hypotheses and implementation of processes. With such frameworks, the number of possible model structures, as well as the number of sensitive parameters is only limited by imagination and time of the scientist. But does this help to reject model structures as inappropriate, or is the freedom to create any model structure with its own parameter set just the next level of equifinality? Our study area, the upper Xilin catchment in Inner Mongolia, China, is a large, remote catchment that is poorly gauged. The available data sets are short, incomplete and have a low spatial resolution. Precipitation and other hydrological drivers are highly uncertain in space and time. To understand the ...

We know much too little about how to design effective digital interventions to support sustained behaviour change and improved well-being. The purpose of the present study is to explore whether characteristics and features from social network sites like Facebook, Twitter and MySpace can be used to facilitate digital interventions for Health Behaviour Change in order to enhance social support and

This paper reports on knowledge about sexually transmitted diseases in Norwegian adults. The sample (572 males and 601 females) was representative of Norwegians aged 15 and above. Data were collected by means of personal interviews and self-completed questionnaires. Out of ten respondents, seven did not know that sexually diseases are not transmitted via toilet seats; six that syphilis is not the most prevalent of the sexually transmitted diseases in Norway; five that both males and females can be infected by chlamydia; four that contraceptive pills do not protect against chlamydia infection; three that condoms protect against all sexually transmitted diseases; and two that condoms protect against gonorrhoea and that females infected by sexually transmitted diseases run higher risk of infertility. Knowledge about sexually transmitted diseases was lowest in the youngest and oldest age groups, and increased monotonously with increased education.

The present paper deals with three issues related to public opinion in Norway: 1) the importance and credibility of HIV/AIDS information sources; 2) changes or intended changes of sexual behaviour because of fear of HIV/AIDS and, 3) attitudes towards homosexuals and the integrity of HIV-infected persons. The data stem from a national interview survey conducted in 1986, and the sample is considered to be representative of the total adult Norwegian population. By far the most important sources of information related to HIV/AIDS are television, newspapers, and radio. The subgroup pattern clearly reflects the general pattern of media consumption in Norway. Only 2% regarded friends as important information sources, indicating that HIV/AIDS is not included in the agenda of interpersonal communication, either because of lack of personal interest in the issue or because HIV/AIDS is a taboo subject. The judgement of the credibility of the information sources corresponds to the judgement of t...

This paper studied different kinds of knowledge related to HIV/AIDS in the adult Norwegian population. The empirical basis stems from two national interview surveys conducted in 1986. Data were analysed using contingency table analysis and multiple classification analysis (MCA). Totally, 64% knew that HIV/AIDS is caused by a virus. Homosexuals, drug-users, prostitutes and bisexuals were mentioned most often as groups at high risk of becoming infected. As to knowledge about the transmission of the infection, 95% were aware that sex between men and blood transfusion may be channels of infection, 93% recognized contaminated needles, and 85% sexual contact with a person of the opposite sex as possible routes of transmission. A substantial number of respondents were uncertain whether the infection can be transmitted through social contact. Knowledge about HIV/AIDS increased with diminishing age and with increased level of income and education. The direct effect of age upon knowledge may ...

The purpose of the present study was to identify predictors of sexual promiscuity and use of condoms. The empirical data stem from a postal survey of a representative sample of persons aged 19-24 in a medium-sized Norwegian town (n = 565). Four selected predictors explained 28.1% and 17.8% of the variance in promiscuity among men and women, respectively. The strongest predictors of sexual promiscuity of men were "la dolce vita" (i.e. alcohol consumption and visits to discoteque/cinema) and marital status. For women the strongest predictors of sexual promiscuity were marital status and age at first intercourse. Knowledge of HIV/AIDS had no significant effect upon either female nor male promiscuity. Six predictors, including promiscuity and knowledge of HIV/AIDS, did not explain a substantial proportion of the variance of condom use neither among men nor women. Age at first intercourse was the only significant predictor upon use of condoms for both men and women.

This paper describes use of contraception at first intercourse among Norwegian adolescents and sheds some light upon whether the HIV-epidemic has influenced the use of contraception. The data stem from a population-based survey of 3,000 17-, 18- and 19-year-olds. The response rate was 60.9%. A total of 1,172 persons had experienced intercourse and constitute the material. A total of 42.2% reported having used a condom, 8.5% the p-pill, 17.6% practiced withdrawal, and 31.0% did not use any contraception at their first experience of intercourse. Use/non-use of contraception was associated with educational aspirations, age at first intercourse and consumption of alcohol. Condom use was associated with age, educational aspirations, parental education, consumption of alcohol and discussing contraception with parents and peers. The higher proportion of condom use at first intercourse among the 17-year-olds (47.5%) as compared with the 19-year-olds (34.3%) can probably be ascribed to the H...

The paper describes the use of contraception at the most recent intercourse and during casual sex among Norwegian adolescents. The empirical data stem from a population-based survey of 3,000 Norwegian adolescents aged 17-19. The response rate was 60.9%. A total of 17.7% did not use any contraception at the most recent intercourse, 9.0% practised withdrawal, 31.2% used a condom, and 39.0% used the p-pill. Among those who reported having experienced casual sex, no use of contraception was most frequent (38.0%) on the most recent occasion of casual sex, whereas 18.4% reported having used a condom on this occasion. 5.1% of the adolescents were characterized as consistently not using contraception.

ABSTRACT Knowledge about water flow paths is essential for understanding biogeochemical fluxes in developed agricultural landscapes, i.e., the input of nutrients into surface waters, soil erosion, or pesticide fate. Several methods are available to study rainfall-runoff processes and flux partitioning: hydrometric based approaches, chemical tracers, modeling, and stable isotope applications. In this study a multi-method approach was conducted to gain insights into the hydrological fluxes and process understanding within the complex anthropogenic-influenced catchment of the Vollnkirchener Bach, Germany. Our results indicate that the catchment responds differently to precipitation input signals and dominant runoff-generation processes change throughout the year. Rainfall-induced runoff events during dry periods are characterized by a temporarily active combined sewer overflow. During stormflow, a large contribution of fast event water is observed. At low flow conditions losing and gaining conditions occur in parallel. However, when catchment's moisture conditions are high, an ephemeral source from clay shale-graywacke dominated forested sites becomes active. The study reveals that the collection of detailed distributed hydrometric data combined with isotopic tracers, provides fundamental information on the complex catchment behavior, which can finally be utilized for conceptualizing water fluxes at a small catchment scale.

ABSTRACT Hydrological models are composed of hypotheses concerning the flow regime in the landscape. Classical model applications do not test these implicit hypotheses, but solely calibrate the parameter set of this single model structure. This more or less blind use of modeling systems has been critically disputed in the last decade, due to the lack of a hypotheses guided methodology. Modular frameworks can help to formulate, implement and test hypotheses. The Catchment Modelling Framework, CMF, is such a modular framework, designed to be openly accessible and operating system independent. CMF is implemented in C++ as a library of objects for the design of problem oriented, catchment specific model structures. The objects of the library are assembled with the programming language Python, utilizing the vast amount of available scientific libraries. The model domain is discretized following a finite volume approach. Models are created as a web of water fluxes, where the finite volumes (water storages) and boundary conditions form the nodes, and equations for water fluxes (flux connections) form the edges. Using these objects as a model toolkit, a large range of different models can be realized: from physics based one dimensional percolation models, over two dimensional hillslope models to large scale lumped or semi-distributed approaches. Distinct hydrological features, like irrigation or drainage measures can be included into the model as additional flux connections. Due to the open interface of CMF, high frequency exchange of data with additional models can be implemented. By coupling models in depth with this mechanism, driven by a shared steering script, new integrated approaches are rapidly developed. This model coupling has been shown for biogeochemical models, for integrated nutrient transport and turnover modeling, where CMF acts as a lateral distributor, and the biogeochemical model calculates the reactive flux. In another study, a regional, steady state groundwater flux model has been incorporated as a lower boundary condition of a fully distributed model of inter- and subsurface water flow. CMF is free software; the source code is available for download at http://www.uni-giessen.de/cms/fbz/fb09/institute/ilr/ilr-frede/download

A 6-year longitudinal panel study investigated the absolute and relative stability in depressed mood throughout adolescence by reporting data from a sample of 538 adolescents between 13 and 19 years of age. Results revealed the following. (1) Girls had on average higher depressed mood scores than boys at all ages. (2) Among boys there were no substantial changes in depressed mood mean scores, while among girls there was a slight tendency of a curvilinear trend, with a peak level reached in midadolescence. (3) There was a tendency for adolescents to retain their relative level in depressed mood, most pronounced for a period of 4 years, from age 15 to age 19 years. (4) Depressed mood was most stable in a subgroup of adolescents who had high initial depressed mood scores. (5) By applying structural equation modeling, it was shown that the stable (“trait”) component of depressed mood increased in importance with increasing age, while the temporal (“state”) component decreased with incre...

Ten to 15% of women experience postpartum depression. First-time mothers are particularly at risk. The present qualitative study aimed to gain insight in terms of why some women find the transition of becoming a mother to be so emotionally taxing that they feel some level of depressed mood, while others feel mostly content after having a baby. Semi-structured interviews were conducted with 12 self-selected first-time mothers. Participants described their pregnancy and birth experience, expectations and experiences with regard to the postpartum period, social support and what they considered important with regard to well-being and depression in the postpartum period. Data were analysed by means of thematic analyses. Ethical approval was granted by the Regional Ethics Committee. Two approaches to motherhood emerged, which we refer to as 'relaxed' and 'controlled'. These approaches influenced how the mothers had envisioned the postpartum period, their need for mastery and how they experienced it emotionally. Social support and managing breastfeeding stood out as important with regard to well-being and depressive symptoms. Frequent consultations with midwifes and public health nurses during the pregnancy and the postpartum period gives unique opportunities for preventive work. The consultations should to a greater extent focus on the woman's expectations and needs, and the partner should be present for an open discussion on how they best support each other in this vulnerable period.

ABSTRACT Purpose of the study: One of the most prevalent mental conditions in people with HIV is depression as uniquely characterized by low positive affect. This study examined the effect of a web-based intervention (Avanti) on overall mood and depressive symptoms among patients with HIV infection. Methods: Patients treated with effective antiretroviral treatment were included in a two-armed trial with substance abuse as an exclusion criterion and randomized to Avanti (n=36) or control (n=31). Patients were surveyed at baseline, as well as 1 and 3 months after the initiation of a 5-week intervention period. Outcomes were Center for Epidemiological Studies-Depression scale and the Positive and Negative Affect Schedule which was combined into an overall mood index. Changes within groups were tested by Wilcoxon matched pairs test and baseline differences between groups by chi-square and Mann-Whitney independent samples test. Summary of results: Baseline scores for both groups were similar. However, patients in the intervention group had an improvement in median (M) overall mood from baseline (M=67.6) to 1 month (M=71, p=0.02) which was also maintained from 1 to 3 months (M=71.9). Moreover, these patients had a favorable reduction in negative affect from 1 (M=24) to 3 months (M=22, p=0.01) and a transient improvement in positive affect from baseline (M=31.7) to 1 month after intervention onset (M=35, p<0.01) which almost returned to baseline levels at month 3 (M=32, p=0.01). In contrast, no significant changes were observed within the control group, except for a reduction in negative affect from 1 (M=23) to 3 months (M=21.6, p=0.05). Notably, symptoms of depression at baseline were low in both the Avanti (M=13) and control (M=12) groups, possibly explaining why no further reduction in depression was observed from baseline to 3 months in either of the two groups. Conclusions: The results of this study lend support to the promise of a web-based psychological intervention among patients with HIV and its ability to improve overall mood with favorable intervention-related changes in negative and positive affect. Avanti had no effect on depression but this was probably due to low initial symptoms of depression. The findings suggest that a prolonged web-based intervention with regular contact could maintain the positive effects on mood seen in this study. If so, Avanti could potentially provide an easily accessible and cost-effective adjunct to traditional psychotherapy.

Much research interest has been devoted to reveal the psychosocial processes associated with the development of depressive symptoms during adolescence. One of the important factors that has been studied is body image. In a 5-year longitudinal investigation, we revealed and discussed the relationship between body image and depressed mood in a cohort of adolescents at ages 13, 15 and 18. Girls reported on average higher depressed mood levels and more negative body image than boys at all ages. However, the correlations between the variables were nearly as strong for boys as for girls. Structural equation modelling revealed that body image predicted change in depressed mood both for boys and girls, but at different ages. In contrast, we did not find any support for the existence of causal effects of depressed mood upon body image.

To identify predictors of the adoption of safety measures by mothers of 2 year old children. 26 municipalities in the county of Sogn and Fjordane, and four municipalities in the county of Møre and Romsdal in Norway. Data was collected by questionnaires mailed to all mothers of 2 year olds in the 30 municipalities (response rate 70.7%, n = 1233). Information was obtained on socioeconomic variables, the child's injury history, adoption of safety measures, and variables describing mother's health related beliefs (parent health locus of control) and the value of health (health value). Income, municipality of residence, age of the mother, and marital status were significantly associated with the reported adoption of safety measures. High income and older, married mothers were positively associated with the adoption of safety measures. The significant effect of income on the adoption of safety measures, underlined by the fact that safety measures were less often adopted by young single mothers, may indicate that the implementation of structural measures such as loan schemes and subsidies, are necessary to increase the adoption of child safety measures. The lack of association between education and social cognitive beliefs, respectively, and the adoption of safety measures, offer less optimism for traditional health education initiatives.