Collaborative weed modelling with Universal Simulator

Universal Simulator is • open-source • modular • extendible • re-usable Universal Simulator includes • the INTERCOM model of plant growh • the Conductance model of plant growth • an annual weed demographic model • an insect demographic model • options to extend with any model and combine with the abov

Concepts and tools for collaborative weed demographic modeling

Weed demography is the study of the long-term dynamics of weed populations. Weed demography is an essential part of weed science, yet, its complexity makes scientific progress slow. Generalities remain obscure while the accumulation of specific data continues unhindered. In this talk, I introduce some modelling concepts and tools that I hope will help us disinter general principles from this heap of data, we are adding to every day

Domain-specific languages for ecological modelling

The primary concern of an ecological modeller is to construct a model that is mathematically correct and that correctly represents the essence of a natural system. When models are published as software, it is moreover in the hope of capturing an audience who will use and appreciate the model. For that purpose, the model software must be provided with an intuitive, flexible and expressive user interface. A graphical user interface (GUI) is the commonly accepted norm but in this review we suggest, that a domain-specific language (DSL) in many cases would provide as good an interface as a GUI, or even better. We identified only 13 DSLs that have been used in ecological modelling, revealing a general ignorance of DSLs in the ecological modelling community. Moreover, most of these DSLs were not formulated for the ecological modelling domain but for the broader, generic modelling domain. We discuss how DSLs could possibly fill out a vacant niche in the dominant paradigm for ecological modelling, which is modular, object-oriented and often component-based. We conclude that ecological modelling would benefit from a wider appreciation of DSL methodology. Especially, there is a scope for new DSLs operating in the rich concepts of ecology, rather than in the bland concepts of modelling generics

Tolerance of four spring barley (Hordeum vulgare L.) varieties to weed harrowing

We investigated the tolerance to weed harrowing of four spring barley varieties and examined the possible interactions between varietal weed suppressive ability and two nutrient levels. Tolerance was defined as the combined effect of crop resistance (ability to resist soil covering) and crop recovery (the ability to recover in terms of yield). The weed harrowing strategy was a combination of one pre- and one post-emergence weed harrowing. In terms of yield, the four varieties responded significantly differently to weed harrowing and the response depended on nutrient level. At the lower nutrient level, weed harrowing caused an increase in yield of 4.4 hkg ha-1 for a strong competitor (cv. Otira), while there was no effect on yield at the higher nutrient level. For a weaker competitor (cv. Brazil), weed harrowing caused no change in yield at the lower nutrient level, whereas yield decreased by 6.0 hkg ha-1 at the higher nutrient level. There were marked differences between the weed suppressive ability of the four varieties when not harrowed, with less pronounced but significant differences when harrowed. Weed harrowing did not change the weed suppressive ability of a variety. Varieties that are tall at post-emergence harrowing and have increased density after pre-emergence harrowing, are the ones that benefit most from weed harrowing

Ikke-kemisk ukrudtsbekæmpelse - mekanisk og termisk

Gennemgang af de mest almindelige ikke-kemiske bekæmpelsesmetoder. Tidligere tiders erfaringer såvel som nye forsøgsresultater

Disruption som konkurrencestatsideal: Udbredelsen af disruptionideen i Danmark

På baggrund af et bredt kildemateriale bestående af rapporter, avisartikler og bøger analyserer denne artikel disruptionideens udbredelse i Danmark. Artiklen bidrager til konkurrencestatens idéhistorie ved at vise, hvordan disruptionideen i det seneste årti er blevet et nyt buzzword inden for innovations-, udviklings- og entreprenørskabstænkningen, som rummer løfter om vækst og konkurrencedygtighed i fremtiden. Mere konkret viser artiklen med udgangspunkt i Michael Freedens ideologiforståelse, hvordan disruption er blevet mobiliseret som et ideal, der skal hjælpe erhvervslivet, den offentlige sektor og individet på den rette vej ind i fremtiden

The intensity of physical activity influences bone mineral accrual in childhood:the childhood health, activity and motor performance school (the CHAMPS) study, Denmark

BACKGROUND: Studies indicate genetic and lifestyle factors can contribute to optimal bone development. In particular, the intensity level of physical activity may have an impact on bone health. This study aims to assess the relationship between physical activity at different intensities and Bone Mineral Content (BMC), Bone Mineral Density (BMD) and Bone Area (BA) accretion. METHODS: This longitudinal study is a part of The CHAMPS study-DK. Whole-body DXA scans were performed at baseline and after two years follows up. BMC, BMD, and BA were measured. The total body less head (TBLH) values were used. Physical activity (PA) was recorded by accelerometers (ActiGraph, model GT3X). Percentages of different PA intensity levels were calculated and log odds of two intensity levels of activity relative to the third level were calculated. Multilevel regression analyses were used to assess the relationship between the categories of physical activity and bone traits. RESULTS: Of 800 invited children, 742 (93%) accepted to participate. Of these, 682/742 (92%) participated at follow up. Complete datasets were obtained in 602/742 (81%) children. Mean (range) of age was 11.5 years (9.7-13.9). PA at different intensity levels was for boys and girls respectively, sedentary 62% and 64%, low 29% for both genders and moderate to high 9% and 7% of the total time. Mean (range) BMC, BMD, and BA was 1179 g (563–2326), 0.84 g/cm(2) (0.64-1.15) and 1393 cm(2) (851–2164), respectively. Valid accelerometer data were obtained for a mean of 6.1 days, 13 hours per day. CONCLUSIONS: There 7was a positive relationship between the log odds of moderate to high-level PA versus low level activity and BMC, BMD and BA. Children with an increased proportion of time in moderate to high-level activity as opposed to sedentary and low-level activity achieved positive effects on BMC, BMD and BA