Dual-labelled (13C/15N) green manure to differentiate between plant uptake of organic and inorganic N

Experimental data is still lacking for determining whether plant uptake of organic nitrogen in agricultural soils contributes substantially to the total N uptake. Pulseinjection studies with dual-labelled amino acids have confirmed that non-mycorrhizal crops possess the capacity to take up organic N but failed to quantify the uptake relative to total N uptake

SDU Campus Kolding

https://openscholarship.wustl.edu/bcs/1328/thumbnail.jp

Harpa Concert Hall and Conference Centre

https://openscholarship.wustl.edu/bcs/1399/thumbnail.jp

Harpa Concert Hall and Conference Centre

https://openscholarship.wustl.edu/bcs/1463/thumbnail.jp

Agricultural Risk Management - Experiences from an Action Research Approach

A new model for risk management in agriculture is described in the paper. The risk model is constructed as a context dependent process, which includes four main phases. The model is aimed at agricultural advisors, who wish to facilitate and disseminate risk management to farmers. It is developed and tested by an action research approach in an attempt to make risk management more applicable on family farms. Our obtained experiences indicate that farmers don't apply probabilistic thinking and other concepts according to formal decision theory.Risk management, consulting, action research, farm families, Risk and Uncertainty,

Collembola’s role in regulating mass fluxes in soil and the effects of contrasting life histories

The study determined metabolic rates and elemental pools for two Collembola species with contrasting life histories. The fittest of the two species, P. minuta, excreted the equivalent of 10–12% of the elemental body content per day, and P. armata 7–10%. Most elements are lost to excretion (CO2 and N-waste). These figures in combination with stoichiometry and life histories indicate that the cost of P. minuta’s better fitness is a requirement for a higher quality diet than P. armata. The data produced in this study can be used to estimate the collembolan contribution to C and N fluxes in the soil

Nutrient allocations and metabolism in two collembolans with contrasting reproduction and growth strategies

Physiological mechanisms such as allocation and release of nutrients are keys to understanding an animal\u27s adaptation to a particular habitat. This study investigated how two detrivores with contrasting life‐history traits allocated carbon (C) and nitrogen (N) to growth, reproduction and metabolism. As model organisms we used the collembolans, Proisotoma minuta (Tullberg 1871) and Protaphorura fimata (Gisin 1952). To estimate allocations of C and N in tissue, we changed the isotopic composition of the animal\u27s yeast diets when they became sexually mature and followed isotope turnover in tissue, growth and reproduction for 28 days. In addition, we measured the composition of C, N and phosphorus (P) to gain complementary information on the stoichiometry underlying life‐history traits and nutrient allocation. For P. minuta, the smallest and most fecund of the two species, the tissue turnover of C and N were 13% and 11% day−1, respectively. For P. fimata, the equivalent rates were 5% and 4% d−1, respectively. Protaphorura fimata had the lowest metabolic rate relative to total body mass but the highest metabolic rates relative to reproductive investment. Adult P. fimata retained approximately 17% of the nutrient reserves acquired while a juvenile and adult P. minuta about 11%. N and P contents of total tissue were significantly higher in P. minuta than in P. fimata, suggesting that tissue turnover was correlated with high protein‐N and RNA‐P. Our results suggest that the lower metabolism and nutritional requirements by P. fimata than P. minuta is an adaptation to the generally low availability and quality of food in its natural habitat. The methodological approach we implemented tracking mass balance, isotope turnover and elemental composition is promising for linking nutrient budgets and life‐history traits in small invertebrates such as Collembola

Betydningen av sosial klasse for elevers motivasjon for og karakterer i kroppsøving: En kvantitativ studie av 854 ungdommer i Norge

Sosial klasse som begrep har gjennom historien utviklet seg til å bli mer komplekst og uklart enn det Karl Marx (1818-1883) og etterhvert Max Weber (1864-1920) først antok. Denne studien har sett på sosial klasse og dens betydning for elevers motivasjon for og karakter i kroppsøving. For å fange opp eventuelle nyanser i bildet, ble det lagt inn en medierende variabel (aktivitetsstøtte fra foreldre) som i andre studier har vist effekt på barn og unges involvering i fysisk aktivitet. Problemstillinger og hypoteser er utarbeidet ut i fra Pierre Bourdieus (1930-2002) samfunnsteori som får frem den sosiale klassens kompleksitet på en tydeligere måte en Marx og Weber. 854 ungdommer fra ungdoms- og videregående skole ble inkludert i analysen. Deltakerne er fra studien ”Moderne ungdom på fritiden” (MUF)

Physical activity monitors to enhance the daily amount of physical activity in elderly-a protocol for a systematic review and meta-analysis

Abstract Background To investigate the use of physical activity monitors (PAMs) for the elderly, the scientific literature should be systematically reviewed and the effect quantified, as the evidence seems inconclusive. Methods and design Randomized controlled trials and randomized crossover trials, with participants with a mean age above 65 years, comparing any PAM intervention with other control interventions or no intervention, will be included. This protocol is detailed according to the recommendations of the Cochrane Handbook, and it is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols statement. Results We will present results from the search in a flow diagram. The results from the analyses will include regular meta-analyses, stratified analyses, and meta-regressions. The results on each outcome of interest will be presented in a summary of findings table. Discussion This paper will explore and analyze the heterogeneity of the results and try to identify variables that will enhance the effect of PAMs in elderly. The results will be useful to researchers working with elderly and/or PAMs, health care professionals working with elderly, and relatives together with the elderly themselves. Systematic review registration PROSPERO CRD42018083648