Segmentation and classification of individual tree crowns

By segmentation and classification of individual tree crowns in high spatial resolution aerial images, information about the forest can be automatically extracted. Segmentation is about finding the individual tree crowns and giving each of them a unique label. Classification, on the other hand, is about recognising the species of the tree. The information of each individual tree in the forest increases the knowledge about the forest which can be useful for managements, biodiversity assessment, etc. Different algorithms for segmenting individual tree crowns are presented and also compared to each other in order to find their strengths and weaknesses. All segmentation algorithms developed in this thesis focus on preserving the shape of the tree crown. Regions, representing the segmented tree crowns, grow according to certain rules from seed points. One method starts from many regions for each tree crown and searches for the region that fits the tree crown best. The other methods start from a set of seed points, representing the locations of the tree crowns, to create the regions. The segmentation result varies from 73 to 95 % correctly segmented visual tree crowns depending on the type of forest and the method. The former value is for a naturally generated mixed forest and the latter for a non-mixed forest. The classification method presented uses shape information of the segments and colour information of the corresponding tree crown in order to decide the species. The classification method classifies 77 % of the visual trees correctly in a naturally generated mixed forest, but on a forest stand level the classification is over 90 %

A conditional marker gene allowing both positive and negative selection in plants

Selectable markers enable transgenic plants or cells to be identified after transformation. They can be divided into positive and negative markers conferring a selective advantage or disadvantage, respectively. We present a marker gene, dao1, encoding D-amino acid oxidase (DAAO, EC 1.4.3.3) that can be used for either positive or negative selection, depending on the substrate. DAAO catalyzes the oxidative deamination of a range of D-amino acids. Selection is based on differences in the toxicity of different D-amino acids and their metabolites to plants. Thus, D-alanine and D-serine are toxic to plants, but are metabolized by DAAO into nontoxic products, whereas D-isoleucine and D-valine have low toxicity, but are metabolized by DAAO into the toxic keto acids 3-methyl-2-oxopentanoate and 3-methyl-2-oxobutanoate, respectively. Hence, both positive and negative selection is possible with the same marker gene. The marker has been successfully established in Arabidopsis thaliana, and proven to be versatile, rapidly yielding unambiguous results, and allowing selection immediately after germination

Marital Partner and Mortality: The Effects of the Social Positions of Both Spouses

Background Individual education, social class, social status and income are all associated with mortality, and this is likewise the case for the position of the marital partner. We investigate the combined effect on mortality of own and partner’s positions regarding these four factors. Methods Prospective follow-up of information in the 1990 Census of the Swedish population aged 30-59 (N=1 502 148). Data on all-cause mortality and deaths from cancer and circulatory disease for the period 1991-2003 were collected from the Cause of Death Register. Relative mortality risks were estimated by Cox regression. Results All-cause mortality of both men and women differs by women’s education and status and by men’s social class and income. Men’s education has an effect on their own mortality but not on their partner’s, when other factors are included in the models. Women’s education and men’s social class are particularly important for women’s deaths from circulatory diseases. Conclusions The partner’s social position has a clear effect on individual mortality, and women’s education seems to be particularly important. The results appear above all to support hypotheses about the importance of lifestyle and economic resources for socio-economic differences in mortality.-

"Stratification and Mortality - A Comparison of Education, Class, Status and Income"

In many analyses of social inequality in health, different dimensions of social stratification have been used more or less interchangeably as measures of the individual’s general social standing. This procedure, however, has been questioned in previous studies, most of them comparing education, class and/or income. In the present article, the importance of education and income as well as two aspects of occupation – class and status – are examined. The results are based on register data and refer to all Swedish employees in the age range 35-59 years. There are clear gradients in total death risk for all socioeconomic factors except for income from work among women. The size of the independent effects of education, class, status and income differ between men and women. For both sexes, there are clear net associations between education and mortality. Class and income show independent effects on mortality only for men and status shows an independent effect only for women. While different stratification dimensions – education, social class, income, status – all can be used to show a “social gradient” with mortality, each of them seems to have a specific effect in addition to the general effect related to the stratification of society for either men or women.-

McIntosh and Munk's Supposed Test of the Validity of the E-G Class Schema: A Comment

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Wage Differentials in Italy: Market Forces, Institutions, and Inflation

During the 1970s, Italy experienced an extreme compression of wage differentials, similar to the better-known situation in Sweden. Most evidence suggests that this compression came to a stop around 1982-83, coincident with a major institutional change (in the form of the escalator clause in Italian union contracts), a major economic change (the slowdown in inflation), a major technological change (industrial restructuring and the computer revolution), and a major political change (the loss of support for unions and their egalitarian pay policies). While we cannot definitively distinguish among the relative influences of institutions, market forces, technology and politics on the evolution of earnings inequality in Italy, our analysis of skill level wage differentials and our comparisons at the individual level with the more laissez-faire system of the United States suggest that both inflation and egalitarian wage-setting institutions have importantly influenced Italian wage compression in the regular sector of the economy. Yet, this very compression may well have contributed to the flight away from the regular sector of the economy at both ends of the skill distribution, plausibly leading to a greater overall degree of inequality for the whole economy than is apparent from our analysis of wage differentials in the regular sector.

A Comparison Of Characteristics Of Forest and Farm Cooperative Members

The forest owner cooperatives in Sweden were established almost a century ago with the aim to improve the private forest owners’ bargaining situation and improve silviculture (the study, cultivation, and management of forest trees). The characteristics of today’s private forest owners and forest industry are changing, something which should encourage the forest owner cooperatives to consider adaptations of their organizations. The aims of this paper are, first, to describe characteristics of forest owner cooperative members and second, to probe the applicability of farm cooperative research in this venture. The statements that are tested are based on characteristics established in farm cooperative research and refer to (i) a negative relation between forest cooperative member’s age and property size, (ii) a positive relation between member’s age and proportion of trade accomplished through the cooperative, (iii) a positive relation between member’s age and membership in cooperative boards and committees, and, finally, (iv) a positive relation between property size and resignation from the forest cooperative. The hypotheses were tested on data from Norra Skogsägarna, a forest cooperative in northern Sweden. None of the propositions found support in the data. The results thus indicate that forest cooperative members may differ from farm cooperative members in several respects. The premise is put forward that this may be due to differences between forest and farm owners’ situations with respect to market characteristics and investment intensity, something that can affect membership expectations.Private forest owners, cooperative theory, statistical analysis, member’s age, property size, transaction, Agribusiness,

Implementation of the National SAM Innovation Project: A Comparison of Project Designs

Compares increases in principals' instructional time and other benefits of hiring school administration managers specifically for the position to help principals with time management and of assigning the task to those who hold other school positions

Environmental impacts of grazed clover/grass pastures

peer-reviwedGrazed clover/grass pastures are important for animal production systems and the clover component is critical for its contribution to N inputs via biological fixation of atmospheric N2. The resource efficiency and environmental emissions for clover/grass pastures can differ from that of N-fertilised grass-only pastures. Fixation of N2 by clover uses photosynthetically- fixed carbon, whereas fertiliser N production consumes fossil fuels and has net greenhouse gas (GHG) emissions. Clover has a higher phosphorus (P) requirement than grass and where extra P fertiliser is used for clover/grass pastures the risk of P loss to waterways is greater than for grass-only pastures. Nitrogen leaching from grazed pasture increases exponentially with increased N inputs and urinary-N contributes 70 to 90% of total N leaching. However, the few studies comparing clover/grass and N-fertilised grass-only pastures at similar total N inputs indicated similar N leaching losses. Nitrous oxide emissions from grazed pastures due to N-cycling of excreta are similar for clover/grass and N-fertilised grass-only pastures at similar total N inputs. However, grass-only pasture requires the application of N fertiliser, which will result in additional specific losses that don’t occur from clover-fixed N. Thus, total N2O emissions are generally higher for N-fertilised grass pastures than for clover/grass pastures. A summary of various whole-system and life cycle assessment analyses for dairy farms from various countries indicated that at similar total N inputs, clover/grass pasture systems can be more efficient than N-fertilised grass systems per kilogram of milk produced from an energy use and GHG perspective whereas results for nutrient losses to waterways were mixed and appear to be similar for both pasture types. In practice, other management practices on farm, such as crop integration, supplementary feeding strategy and winter management, can have a larger overall effect on environmental emissions than whether the N input is derived from fertiliser N or from N2 fixation