Time filter

Source Type

Sogstad A.M.,431 As | Osteras O.,431 As
Livestock Science | Year: 2012

This cross-sectional study was part of a large project on free-stall housing. The aim was to assess the use of locomotion score (LocS) performed by 15 professional claw trimmers and the relation to claw disorders at claw trimming, to see if LocS recordings could be used to screen herds for claw problems. The claw trimmers scored locomotion, trimmed and recorded claw disorders in 2569 cows in 61 dairy herds. The relation between LocS and hind-claw disorders was identified by three multivariable models with binomial outcomes; model 1: LocS > 1 vs. LocS = 1, model 2: LocS > 2 vs ≤ 2 and model 3: LocS > 3 vs ≤ 3. Input variables were different claw disorders, type of alley floor, days in milk and parity. Significant claw disorders from separate models were put into the same model. Herd and claw trimmer were included in the model as random effects. The results were as follows: there were more heel-horn erosions in cows with LocS > 1 vs. cows with LocS = 1 with OR = 1.6 (1.4/1.9) and in cows with LocS > 2 vs. cows with LocS ≤ 2 with OR = 1.6 (1.2/2.2). There were more sole ulcers in cows with LocS > 1 vs. cows with LocS = 1 with OR = 1.8 (0.9/3.4), in cows with LocS > 2 vs. cows with LocS ≤ 2 with OR = 3.3 (1.8/5.9) and LocS > 3 vs. LocS ≤ 3 with OR = 3.1 (1.5/6.3). There were more separations (white line fissure and/or double sole in cows with LocS > 1 vs. cows with LocS = 1 with OR = 1.7 1.4/2.2), in cows with LocS > 2 vs. cows with LocS ≤ 2 with OR = 2.1 (1.3/3.4) and LocS > 3 vs. LocS ≤ 3 with OR = 3.1 (1.8/5.2). There were more corkscrewed claws in cows with LocS > 2 vs. cows with LocS ≤ 2 with OR = 1.8 (1.0/3.2). © 2011 Elsevier B.V.

Cavicchi B.,431 AS | Cavicchi B.,University of Oslo
Environmental Innovation and Societal Transitions | Year: 2016

The development of a low carbon society does not always deliver sustainable outcomes at local level, as in the case of bioenergy. This paper analyses the impacts of biogas development in Emilia Romagna (Italy) from a social, economic and environmental perspective (triple bottom line). Since 2009, the number of biogas plants has exponentially increased here, following the introduction of the feed-in tariff. Social opposition has been rising since. Therefore, the goal of the study is to investigate the causal processes of biogas development in order to understand what endangered its triple bottom line sustainability. The study does so by employing qualitative system dynamics (i.e. causal loop diagram). Results show that sustainability is threatened by weak local synergies, plants management and equipment deficiencies and agriculture related issues. The analysis suggests that policy interventions should focus on biomass supply and outputs diversification, governance, and social participation. © 2016 Elsevier B.V.

Robinson N.,431 As | Robinson N.,Flinders University | Winberg P.,University of Wollongong | Kirkendale L.,University of Wollongong
Journal of Applied Phycology | Year: 2013

Marine macroalgae (seaweeds) consist of a diverse range of species with diverse morphology and bioactive properties. The potential for genetic improvement to increase the value of the production of such molecules and other economically important traits is likely to be high as procedures for cultivation of many species are well established, genetic diversity is often high, sexual propagation is often possible and seaweeds generally have a short generation time that allows rapid transition from one selected generation to the next. The need for genetic improvement has been voiced by industry for many years. Despite this, there is little published research describing seaweed genetic improvement methodology, results or impact. This review draws on knowledge from other groups of species and describes options, benefits and knowledge needed for the genetic improvement of macroalgae. In conclusion, the review highlights how a well-designed genetic improvement program, which targets one or a few select economically valuable traits whilst limiting inbreeding, could provide potentially large benefits for industries reliant on the culture of seaweeds. Progress will, to a large extent, rely on the magnitude of genetic variation for the trait in question. © 2012 Springer Science+Business Media Dordrecht.

Liu H.,University of Aarhus | Sorensen A.C.,University of Aarhus | Meuwissen T.H.E.,Norwegian University of Life Sciences | Berg P.,University of Aarhus | Berg P.,431 As
Genetics Selection Evolution | Year: 2014

Background: Genomic selection makes it possible to reduce pedigree-based inbreeding over best linear unbiased prediction (BLUP) by increasing emphasis on own rather than family information. However, pedigree inbreeding might not accurately reflect loss of genetic variation and the true level of inbreeding due to changes in allele frequencies and hitch-hiking. This study aimed at understanding the impact of using long-term genomic selection on changes in allele frequencies, genetic variation and level of inbreeding. Methods. Selection was performed in simulated scenarios with a population of 400 animals for 25 consecutive generations. Six genetic models were considered with different heritabilities and numbers of QTL (quantitative trait loci) affecting the trait. Four selection criteria were used, including selection on own phenotype and on estimated breeding values (EBV) derived using phenotype-BLUP, genomic BLUP and Bayesian Lasso. Changes in allele frequencies at QTL, markers and linked neutral loci were investigated for the different selection criteria and different scenarios, along with the loss of favourable alleles and the rate of inbreeding measured by pedigree and runs of homozygosity. Results: For each selection criterion, hitch-hiking in the vicinity of the QTL appeared more extensive when accuracy of selection was higher and the number of QTL was lower. When inbreeding was measured by pedigree information, selection on genomic BLUP EBV resulted in lower levels of inbreeding than selection on phenotype BLUP EBV, but this did not always apply when inbreeding was measured by runs of homozygosity. Compared to genomic BLUP, selection on EBV from Bayesian Lasso led to less genetic drift, reduced loss of favourable alleles and more effectively controlled the rate of both pedigree and genomic inbreeding in all simulated scenarios. In addition, selection on EBV from Bayesian Lasso showed a higher selection differential for mendelian sampling terms than selection on genomic BLUP EBV. Conclusions: Neutral variation can be shaped to a great extent by the hitch-hiking effects associated with selection, rather than just by genetic drift. When implementing long-term genomic selection, strategies for genomic control of inbreeding are essential, due to a considerable hitch-hiking effect, regardless of the method that is used for prediction of EBV. © 2014 Liu et al.; licensee BioMed Central Ltd.

Almli V.L.,431 As | Van Wezemael L.,Ghent University | Verbeke W.,Ghent University | Ueland T.,431 As
Meat Science | Year: 2013

New production technologies can help the beef sector to improve eating quality, in particular the tenderness, of low-value meat cuts. This paper aims at profiling potential consumers for unprocessed tenderloin M. Psoas major, muscle profiled M. Infraspinatus and marinated by injection M. Semitendinosus in Belgium (n= 108) and Norway (n= 110). Consumers' hedonic expectations for the three beef cuts, along with their general attitudes towards beef and food technology, were collected in central location tests. Results show that tenderloin triggers the highest hedonic expectations and best appeals to consumers profiled with high beef involvement in both countries. Consumers' expectations for steaks from novel technologies vary with consumers' attitudes towards beef, food technology and food risks and their country of residence, resulting in three additional consumer profiles. Furthermore, general attitudinal profiles of beef consumers also differ between the two countries. The results are useful for the positioning of novel beef products within the two national markets. © 2012 Elsevier Ltd.

Bogner C.,University of Bayreuth | Trancon y Widemann B.,University of Bayreuth | Trancon y Widemann B.,TU Ilmenau | Lange H.,431 As
Ecological Informatics | Year: 2013

The quality of surface water and groundwater is closely related to flow paths in the vadose zone. Therefore, dye tracer studies are often carried out to visualise flow patterns in soils. These experiments provide images of stained soil profiles and their evaluation demands knowledge in hydrology as well as in image analysis and statistics. The classical analysis consists of image classification in stained and non-stained parts and calculation of the dye coverage (i.e. the proportion of staining). The variation of this quantity with depth is interpreted to identify dominant flow types. While some feature extraction from images of dye-stained profiles is necessary, restricting the analysis to the dye coverage alone might miss important information. In our study we propose to use several index functions to extract different (ideally complementary) features. We associate each image row with a feature vector (i.e. a certain number of image function values) and use these features to cluster the image rows to identify similar image areas. Because images of stained profiles might have different reasonable clusterings, we calculate multiple consensus clusterings. Experts can explore these different solutions and base their interpretation of predominant flow type on quantitative (objective) criteria. © 2013 Elsevier B.V.

Ducey M.J.,University of New Hampshire | Astrup R.,431 As
Canadian Journal of Remote Sensing | Year: 2013

Nondetection of trees is a serious problem for the use of terrestrial laser scanning (TLS) in forest inventory applications. The use of multiple coregistered scans can reduce nondetection but may not eliminate it, and it carries substantial field and post-processing costs. We examined and extended previously developed theoretical approaches to modeling nondetection. The results suggested that tree size as well as multiple stand structural characteristics may be factors, but the theoretical models do not lend themselves to empirical estimation. We then used distance sampling techniques to identify detection probabilities and develop adjusted estimates for trees per hectare and basal area in nine forest stands in southern Norway. The results compared favorably with field estimates based on fixed-area plots. The estimated detection probabilities indicate that correction for nondetection is needed unless the search for trees is limited to very small distances from the scanner. Distance sampling appears promising when TLS is used in the context of temporary-plot forest inventories. © 2013 Government of Canada.

Breidenbach J.,431 As | McRoberts R.E.,U.S. Department of Agriculture | Astrup R.,431 As
Remote Sensing of Environment | Year: 2015

Due to the availability of good and reasonably priced auxiliary data, the use of model-based regression-synthetic estimators for small area estimation is popular in operational settings. Examples are forest management inventories, where a linking model is used in combination with airborne laser scanning data to estimate stand-level forest parameters where no or too few observations are collected within the stand. This paper focuses on different approaches to estimating the variances of those estimates. We compared a variance estimator which is based on the estimation of superpopulation parameters with variance estimators which are based on predictions of finite population values. One of the latter variance estimators considered the spatial autocorrelation of the residuals whereas the other one did not. The estimators were applied using timber volume on stand level as the variable of interest and photogrammetric image matching data as auxiliary information. Norwegian National Forest Inventory (NFI) data were used for model calibration and independent data clustered within stands were used for validation. The empirical coverage proportion (ECP) of confidence intervals (CIs) of the variance estimators which are based on predictions of finite population values was considerably higher than the ECP of the CI of the variance estimator which is based on the estimation of superpopulation parameters. The ECP further increased when considering the spatial autocorrelation of the residuals. The study also explores the link between confidence intervals that are based on variance estimates as well as the well-known confidence and prediction intervals of regression models. © 2015.

Breidenbach J.,Norwegian University of Life Sciences | Naesset E.,Norwegian University of Life Sciences | Lien V.,Norwegian University of Life Sciences | Gobakken T.,Norwegian University of Life Sciences | Solberg S.,431 As
Remote Sensing of Environment | Year: 2010

While forest inventories based on airborne laser scanning data (ALS) using the area based approach (ABA) have reached operational status, methods using the individual tree crown approach (ITC) have basically remained a research issue. One of the main obstacles for operational applications of ITC is biased results often experienced due to segmentation errors. In this article, we propose a new method, called "semi-ITC" that overcomes the main problems related to ITC by imputing ground truth data within crown segments from the nearest neighboring segment. This may be none, one, or several trees. The distances between segments were derived based on a set of explanatory variables using two nonparametric methods, i.e., most similar neighbor inference (MSN) and random forest (RF). RF favored the imputation of common observations in the data set which resulted in significant biases. Main conclusions are therefore based on MSN. The explanatory variables were calculated by means of small footprint ALS and multispectral data. When testing with empirical data the new method compared favorably to the well-known ABA. Another advantage of the new method over the ABA is that it allowed for the modeling of rare tree species. The results of predicting timber volume with the semi-ITC method were unbiased and the root mean squared error (RMSE) on plot level was smaller than the standard deviation of the observed response variables. The relative RMSEs after cross validation using semi-ITC for total volume and volume of the individual species pine, spruce, birch, and aspen on plot level were 17, 38, 40, 101, and 222%, respectively. Due to the unbiasedness of the estimation, this study is a showcase for how to use crown segments resulting from ITC algorithms in a forest inventory context. © 2009 Elsevier Inc. All rights reserved.

Dalsgaard L.,Copenhagen University | Dalsgaard L.,431 As | Mikkelsen T.N.,Technical University of Denmark | Bastrup-Birk A.,Copenhagen University
Journal of Plant Ecology | Year: 2011

Aims Beech (Fagus sylvatica L.) is an important species in natural and managed forests in Europe. This drought-sensitive species dominates even-aged stands as well more natural stands composed of a mixture of tree species, age and size classes. This study evaluates the extent that heterogeneity in spacing and tree diameter affect the seasonal availability and use of water. Methods Two stands were evaluated: (i) a heterogeneous forest remnant (NAT) with trees up to ∼300 years old, a mean top height of 28.4 m and a total of 733 stems ha-1with stem diameters averaging 18 cm and (ii) an even-aged 80-year old stand (MAN), with a height of 25 m, and a total of 283 stems ha -1 with diameters averaging 38 cm. Stem sap flow, Js (g m -2 s-1), was continuously measured in 12 (MAN) and 13 (NAT) trees using 20-mm long heat dissipation sensors. Individual tree measures of sap flow were correlated using non-linear statistical methods with air vapour pressure deficit (D, hPa) and global radiation (Rg, J m-2 day -1), along with constraints imposed by reductions in soil water content (SWC). SWC was measured as volumetric % using time domain reflectometry. Important Findings The daily integrated Js (Js-sum) for trees growing in the evenly spaced MAN stand and trees in canopy and closed forest positions in NAT stand decreased as the availability of soil moisture was reduced. In the heterogeneous NAT stand, SWC in a recently formed canopy gap remained high throughout the vegetation period. Based on regression models, the predicted relative decrease in Js-sum for dry relative to moist soil water conditions in the closed forest (at mean daily D = 10 hPa) was 7-11% for trees near the gap and 39-42% for trees in the closed forest. In MAN, the reduction in Js-sum was 29% in dry relative to moist conditions. Js-sum in the outer 20 mm of the xylem in NAT was lower than that in MAN and the rate of decline in Js with xylem depth was less in NAT than in MAN. In MAN, Js-sum in deep and outer xylem was negatively affected at low soil moisture availability; in NAT, this was the case for only the outer xylem indicating that deep roots could be important in supplying water at times of low soil moisture in the upper soil. © The Author 2011. Published by Oxford University Press on behalf of the Institute of Botany, Chinese Academy of Sciences and the Botanical Society of China.

Loading 431 As collaborators
Loading 431 As collaborators