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University of Life science

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Houck L.,University of Life science | Aurlien T.,University of Life science
Structures and Architecture - Proceedings of the 3rd International Conference on Structures and Architecture, ICSA 2016 | Year: 2016

This paper examines the fresh building engineering students’ outcome of a practical introduction task. The task is to build real bridges, starting with a model and then a full scale version. The article assesses the students’ practical background prior to the building engineering study, the design and building process, and the outcome in terms of learning and motivation. The method used is a questionnaire and observations. The conclusion is that there is a significant difference in building experience related to gender for the fresh students. The results of this research shows that about half of the female students have no building experience what so ever, not even simple building as children. The students answer they learned a lot from the task, both from the work within their own group and also through the work of other groups. The students answers in the questionnaire that they feel highly motivated for their study after the accomplishment of the task. The building of a bridge model and a one to one bridge allows to the student to study how structures may fail. More than 90% of the students answer they feel more motivated for the further study after the practical task. Students and teachers experience construction deficiencies together both demonstrated in models and in full-scale bridges - which creates common references useful in later theory teaching. © 2016 Taylor & Francis Group, London.

Wang Y.,Arizona State University | Brent C.S.,U.S. Department of Agriculture | Fennern E.,Arizona State University | Fennern E.,Oregon Health And Science University | And 2 more authors.
PLoS Genetics | Year: 2012

Honey bees (Apis mellifera) provide a system for studying social and food-related behavior. A caste of workers performs age-related tasks: young bees (nurses) usually feed the brood and other adult bees inside the nest, while older bees (foragers) forage outside for pollen, a protein/lipid source, or nectar, a carbohydrate source. The workers' transition from nursing to foraging and their foraging preferences correlate with differences in gustatory perception, metabolic gene expression, and endocrine physiology including the endocrine factors vitellogenin (Vg) and juvenile hormone (JH). However, the understanding of connections among social behavior, energy metabolism, and endocrine factors is incomplete. We used RNA interference (RNAi) to perturb the gene network of Vg and JH to learn more about these connections through effects on gustation, gene transcripts, and physiology. The RNAi perturbation was achieved by single and double knockdown of the genes ultraspiracle (usp) and vg, which encode a putative JH receptor and Vg, respectively. The double knockdown enhanced gustatory perception and elevated hemolymph glucose, trehalose, and JH. We also observed transcriptional responses in insulin like peptide 1 (ilp1), the adipokinetic hormone receptor (AKHR), and cGMP-dependent protein kinase (PKG, or "foraging gene" Amfor). Our study demonstrates that the Vg-JH regulatory module controls changes in carbohydrate metabolism, but not lipid metabolism, when worker bees shift from nursing to foraging. The module is also placed upstream of ilp1, AKHR, and PKG for the first time. As insulin, adipokinetic hormone (AKH), and PKG pathways influence metabolism and gustation in many animals, we propose that honey bees have conserved pathways in carbohydrate metabolism and conserved connections between energy metabolism and gustatory perception. Thus, perhaps the bee can make general contributions to the understanding of food-related behavior and metabolic disorders. © 2012 Wang et al.

Oleszczuk P.,Norwegian Geotechnical Institute | Oleszczuk P.,Lublin University of Life Sciences | Hale S.E.,Norwegian Geotechnical Institute | Lehmann J.,Cornell University | And 3 more authors.
Bioresource Technology | Year: 2012

The aim of the research was to determine the influence of biochar and activated carbon (AC) on the freely dissolved concentration of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge. Two different biochars (MSB and PMW) and two ACs (CP1 and BP2) were used in the present experiment. Addition of AC/biochar to sewage sludge caused significant decrease of freely dissolved PAHs concentration. Depending on the dose, the reduction of freely dissolved PAHs ranged from 56% to 95% (ACs) and from 0% to 57% (biochars). Only for the biochars was there a significant difference between short 7-d and long 30/60-d mixing time. It is concluded that both AC and biochar are effective at reducing PAH pore-water concentrations, the more expensive and non-carbon negative AC having the greatest effect. © 2012 Elsevier Ltd.

Yakovlev I.A.,Norwegian Forest And Landscape Institute | Fossdal C.G.,Norwegian Forest And Landscape Institute | Johnsen O.,University of Life science
New Phytologist | Year: 2010

•Norway spruce expresses a temperature-dependent epigenetic memory from the time of embryo development, which thereafter influences the timing bud phenology. MicroRNAs (miRNAs)are endogenous small RNAs, exerting epigenetic gene regulatory impacts. We have tested for their presence and differential expression.•We prepared concatemerized small RNA libraries from seedlings of two full-sib families, originated from seeds developed in a cold and warm environment. One family expressed distinct epigenetic effects while the other not. We used available plant miRNA query sequences to search for conserved miRNAs and from the sequencing we found novel ones; the miRNAs were monitored using relative real time-PCR.•Sequencing identified 24 novel and four conserved miRNAs. Further screening of the conserved miRNAs confirmed the presence of 16 additional miRNAs. Most of the miRNAs were targeted to unknown genes. The expression of seven conserved and nine novel miRNAs showed significant differences in transcript levels in the full-sib family showing distinct epigenetic difference in bud set, but not in the nonresponding full-sib family. Putative miRNA targets were studied.•Norway spruce contains a set of conserved miRNAs as well as a large proportion of novel nonconserved miRNAs. The differentially expression of specific miRNAs indicate their putative participation in the epigenetic regulation. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Andersen T.,University of Life science | Andersen T.,Fisheries and Aquaculture Research
Marine Genomics | Year: 2012

Hemoglobin is one of the most studied proteins in nature, and evolutionary modifications of the interacting subunits seem to have refined the oxygen binding properties in the wide range of land- and/or water-living vertebrates. The adaptation of fish to varying environments seems to involve multiple hemoglobins, and polymorphic variants may further increase the diversity of functional properties. The pioneering study of Knud Sick on the hemoglobin polymorphisms in Atlantic cod fifty years ago was accompanied by multiple population genetic, physiological and behavioral studies before the recent identification of the genetic basis of the protein variants. The Met-Lys and Val-Ala substitutions in the cod β1 globin subunit provided the link between genotype and physiological functions, and the geographical distribution of the variants in temperate and Arctic waters strongly indicate that hemoglobin is under adaptive evolution in Atlantic cod. The structural and regulatory polymorphisms of the cod β1 globin highlight the relationship between temperature and functional molecular variation in the hemoglobin system. © 2012 Elsevier B.V.

Amstaetter K.,Norwegian Geotechnical Institute | Eek E.,Norwegian Geotechnical Institute | Cornelissen G.,Norwegian Geotechnical Institute | Cornelissen G.,University of Life science | Cornelissen G.,University of Stockholm
Chemosphere | Year: 2012

The addition of activated carbon (AC) is an increasingly popular method for pollutant immobilization, and the AC material can be made of biomass or coal/fossil feedstock. The aim of the present study was to investigate whether there are differences between pollutant sorption to biomass and coal-based AC in the presence and absence of sediment. Through N 2 and CO 2 adsorption to probe surface area and pore size it was shown that the biomass-based AC had a stronger dominance of narrow pores in the size range 3.5-15å than the anthracite-based material. In the absence of sediment, sorption isotherms for the probe compounds pyrene and PCB-101 showed stronger sorption for the biomass-based AC (logarithmic Freundlich coefficients 8.15 for pyrene; 9.91 for PCB-101) than for the anthracite-based one (logarithmic Freundlich coefficients 7.20 and 9.70, respectively). In the presence of sediment, the opposite trend was observed, with the stronger sorption for anthracite-based AC. Thus, the presence of competing and/or pore-blocking sediment constituents reduces sorption to a larger extent for biomass-derived AC (factor of 5 for pyrene to almost 100 for PCB-101) than for anthracite-based AC (no reduction for pyrene to factor of 5 for PCB-101). This difference is tentatively attributed to the difference in pore size distribution, narrow pores being more prone to clogging, and could have implications for remediation feasibility with AC from different sources. © 2012 Elsevier Ltd.

Nadeem S.,University of Life science | Almas T.R.,University of Life science | Dorsch P.,University of Life science | Bakken L.R.,University of Life science
Soil Biology and Biochemistry | Year: 2013

Soil denitrifier communities (DC) have been studied intensively because their phenotypic characteristics may influence the emission of NO and N2O. In the present study, we challenge the concept of soil DC as one assemblage of organisms, and propose that DCs are functionally stratified based on their position within the soil matrix. We hypothesize that the soils contain "inner" and "outer" habitats; the inner meaning sites within crevices and cavities of the soil mineral material, structured organic materials and strong biofilms, the outer meaning exposed surfaces and macropores of the soil. We used sequential dispersion/density gradient centrifugation (DGC), to obtain two contrasting fractions of cells differing in the strength of attachment to soil particles. We define loosely attached cells (LAC) as those which are liberated from soil particles by moderate dispersion of the soils. LAC were harvested by DGC, and the pellets at the bottom of the gradients were then re-dispersed with higher shear force to release more strongly attached cells (SAC) which were again harvested by DGC. We hypothesized that SAC are cells situated deeper into biofilms and structures than LAC, hence SAC would experience more frequent and/or longer anoxic spells than LAC. For this reason, we hypothesized 1) that the relative frequency of denitrifying organisms is higher in SAC than LAC and 2) that N2O-reductase is expressed earlier and stronger in SAC than in LAC. The results suggest a rejection of the first hypothesis but lend strong support for the second: In response to oxygen depletion, the two fractions (LAC and SAC) expressed similar rates of denitrification, both produced a mixture of NO, N2O and N2, but the relative amount of N2O produced was much higher for LAC than SAC. The soils' matrix appears to contain strata which select for specific denitrification phenotypes, with implications for N2O-emission. © 2013 The Authors.

Nadeem S.,University of Life science | Dorsch P.,University of Life science | Bakken L.R.,University of Life science
Soil Biology and Biochemistry | Year: 2013

Nitric oxide (NO) is known to induce denitrification in model organisms, but the quantitative effect of NO and its concentration dependency has not been assessed for denitrification in soils. NO is chemically unstable in the presence of oxygen due to autoxidation, and the oxidation of NO is accelerated by acetylene (C2H2) which is commonly used as an inhibitor of N2O reductase in denitrification studies. As a first step to experimentally explore the role of NO in soil denitrification, we investigated NO oxidation kinetics for a closed " two phase" system (i.e. liquid phase + headspace) typically used for denitrification experiments with soil slurries, both with and without acetylene present. Models were developed to adequately predict autoxidation and acetylene-accelerated oxidation. The minimum oxygen concentration in the headspace ([O2]min, mL L-1) for acetylene-accelerated NO oxidation was found to increase linearly with the NO concentration ([NO], mL L-1); [O2]min = 0.192 + [NO] 0.1 (r2 = 0.978). The models for NO oxidation were then used to assess NO oxidation rates in denitrification experiments with batches of bacterial cells extracted from soil. The batches were exposed to low initial oxygen concentrations in gas tight serum flasks (with and without C2H2), and monitored for O2, NO, N2O and N2 production while depleting the oxygen and switching to anoxic respiration. Acetylene effectively scavenged NO from the cultures until oxygen concentration reached below ~0.19 mL L-1, and the estimated rate of acetylene-accelerated NO oxidation was more than sufficient to explain an observed reduction of the N2O production induced by acetylene. When [O2] reached below 0.19 mL L-1, the NO concentrations increased and stabilized at the same level as in the treatments without acetylene, but the rate of denitrification was much lower than without acetylene. The results indicate that the early accumulation of 10-20 nM NO during oxygen depletion has a significant effect on the expression of denitrification in soil communities. This warrants a greater interest in NO as a regulator of denitrification in soils and shows that the acetylene inhibition method may be problematic even for intentionally anoxic incubations, unless precautions are taken to secure initial O2 concentrations below 0.19 mL O2 L-1. © 2012 Elsevier Ltd.

Woolliams J.A.,University of Life science | Woolliams J.A.,Roslin Institute | Meuwissen T.H.E.,University of Life science
Genetics Selection Evolution | Year: 2012

Background: In the past, pedigree relationships were used to control and monitor inbreeding because genomic relationships among selection candidates were not available until recently. The aim of this study was to understand the consequences for genetic variability across the genome when genomic information is used to estimate breeding values and in managing the inbreeding generated in the course of selection on genome-enhanced estimated breeding values. Methods. These consequences were measured by genetic gain, pedigree- and genome-based rates of inbreeding, and local inbreeding across the genome. Breeding schemes were compared by simulating truncation selection or optimum contribution selection with a restriction on pedigree- or genome-based inbreeding, and with selection using estimated breeding values based on genome- or pedigree-based BLUP. Trait information was recorded on full-sibs of the candidates. Results: When the information used to estimate breeding values and to constrain rates of inbreeding were either both pedigree-based or both genome-based, rates of genomic inbreeding were close to the desired values and the identical-by-descent profiles were reasonably uniform across the genome. However, with a pedigree-based inbreeding constraint and genome-based estimated breeding values, genomic rates of inbreeding were much higher than expected. With pedigree-instead of genome-based estimated breeding values, the impact of the largest QTL on the breeding values was much smaller, resulting in a more uniform genome-wide identical-by-descent profile but genomic rates of inbreeding were still higher than expected based on pedigree relationships, because they measure the inbreeding at a neutral locus not linked to any QTL. Neutral loci did not exist here, where there were 100 QTL on each chromosome. With a pedigree-based inbreeding constraint and genome-based estimated breeding values, genomic rates of inbreeding substantially exceeded the value of its constraint. In contrast, with a genome-based inbreeding constraint and genome-based estimated breeding values, marker frequencies changed, but this change was limited by the inbreeding constraint at the marker position. Conclusions: To control inbreeding, it is necessary to account for it on the same basis as what is used to estimate breeding values, i.e. pedigree-based inbreeding control with traditional pedigree-based BLUP estimated breeding values and genome-based inbreeding control with genome-based estimated breeding values. © 2012 Sonesson et al.; licensee BioMed Central Ltd.

Nadeem S.,University of Life science | Hansen S.,Norwegian Institute for Agricultural And Environmental Research Bioforsk | Azzaroli Bleken M.,University of Life science | Dorsch P.,University of Life science
Biogeosciences | Year: 2012

Legumes are an important source of nitrogen in stockless organic cereal production. However, substantial amounts of N can be lost from legume-grass leys prior to or after incorporation as green manure (GM). Here we report N 2O emissions from a field experiment in SE Norway exploring different green manure management strategies: mulching versus removal of grass-clover herbage during a whole growing season and return as biogas residue to a subsequent barley crop. Grass-clover ley had small but significantly higher N2O emissions as compared with a non-fertilised cereal reference during the year of green manure (GM) production in 2009. Mulching of herbage induced significantly more N2O emission (+0.37 kg N2O-N ha-1) throughout the growing season than removing herbage. In spring 2010, all plots were ploughed (with and without GM) and sown with barley, resulting in generally higher N2O emissions than during the previous year. Application of biogas residue (60 kg NH4 +-N + 50 kg organic N ha-1) before sowing did not increase emissions neither when applied to previous ley plots nor when applied to previously unfertilised cereal plots. Ley management (mulching vs. removing biomass in 2009) had no effect on N2O emissions during barley production in 2010. In general, GM ley (mulched or harvested) increased N2O emissions relative to a cereal reference with low mineral N fertilisation (80 kg N ha-1). Based on measurements covering the growing season 2010, organic cereal production emitted 95 g N2O-N kg-1 N yield in barley grain, which was substantially higher than in the cereal reference treatment with 80 kg mineral N fertilisation (47 g N2O-N kg-1 N yield in barley grain). © 2012 Author(s). CC Attribution 3.0 License.

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