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1.
Llorenç Milà i Canals Christian Bauer Jochen Depestele Alain Dubreuil Ruth Freiermuth Knuchel Gérard Gaillard Ottar Michelsen Ruedi Müller-Wenk Bernt Rydgren 《The International Journal of Life Cycle Assessment》2007,12(1):5-15
Background, Aim and Scope
Land use by agriculture, forestry, mining, house-building or industry leads to substantial impacts, particularly on biodiversity
and on soil quality as a supplier of life support functions. Unfortunately there is no widely accepted assessment method so
far for land use impacts. This paper presents an attempt, within the UNEP-SETAC Life Cycle Initiative, to provide a framework
for the Life Cycle Impact Assessment (LCIA) of land use.
Materials and Methods:
This framework builds from previous documents, particularly the SETAC book on LCIA (Lindeijer et al. 2002), developing essential
issues such as the reference for occupation impacts; the impact pathways to be included in the analysis; the units of measure
in the impact mechanism (land use interventions to impacts); the ways to deal with impacts in the future; and bio-geographical
differentiation.
Results:
The paper describes the selected impact pathways, linking the land use elementary flows (occupation; transformation) and parameters
(intensity) registered in the inventory (LCI) to the midpoint impact indicators and to the relevant damage categories (natural
environment and natural resources). An impact occurs when the land properties are modified (transformation) and also when
the current man-made properties are maintained (occupation).
Discussion:
The size of impact is the difference between the effect on land quality from the studied case of land use and a suitable reference
land use on the same area (dynamic reference situation). The impact depends not only on the type of land use (including coverage
and intensity) but is also heavily influenced by the bio-geographical conditions of the area. The time lag between the land
use intervention and the impact may be large; thus land use impacts should be calculated over a reasonable time period after
the actual land use finishes, at least until a new steady state in land quality is reached.
Conclusions:
Guidance is provided on the definition of the dynamic reference situation and on methods and time frame to assess the impacts
occurring after the actual land use. Including the occupation impacts acknowledges that humans are not the sole users of land.
Recommendations and Perspectives:
The main damages affected by land use that should be considered by any method to assess land use impacts in LCIA are: biodiversity
(existence value); biotic production potential (including soil fertility and use value of biodiversity); ecological soil quality
(including life support functions of soil other than biotic production potential). Bio-geographical differentiation is required
for land use impacts, because the same intervention may have different consequences depending on the sensitivity and inherent
land quality of the environment where it occurs. For the moment, an indication of how such task could be done and likely bio-geographical
parameters to be considered are suggested. The recommendation of indicators for the suggested impact categories is a matter
of future research. 相似文献
2.
Rasmus Froberg Br?ndum Bernt Guldbrandtsen Goutam Sahana Mogens Sand? Lund Guosheng Su 《BMC genomics》2014,15(1)
Background
The advent of low cost next generation sequencing has made it possible to sequence a large number of dairy and beef bulls which can be used as a reference for imputation of whole genome sequence data. The aim of this study was to investigate the accuracy and speed of imputation from a high density SNP marker panel to whole genome sequence level. Data contained 132 Holstein, 42 Jersey, 52 Nordic Red and 16 Brown Swiss bulls with whole genome sequence data; 16 Holstein, 27 Jersey and 29 Nordic Reds had previously been typed with the bovine high density SNP panel and were used for validation. We investigated the effect of enlarging the reference population by combining data across breeds on the accuracy of imputation, and the accuracy and speed of both IMPUTE2 and BEAGLE using either genotype probability reference data or pre-phased reference data. All analyses were done on Bovine autosome 29 using 387,436 bi-allelic variants and 13,612 SNP markers from the bovine HD panel.Results
A combined breed reference population led to higher imputation accuracies than did a single breed reference. The highest accuracy of imputation for all three test breeds was achieved when using BEAGLE with un-phased reference data (mean genotype correlations of 0.90, 0.89 and 0.87 for Holstein, Jersey and Nordic Red respectively) but IMPUTE2 with un-phased reference data gave similar accuracies for Holsteins and Nordic Red. Pre-phasing the reference data only lead to a minor decrease in the imputation accuracy, but gave a large improvement in computation time. Pre-phasing with BEAGLE was substantially faster than pre-phasing with SHAPEIT2 (2.5 hours vs. 52 hours for 242 individuals), and imputation with pre-phased data was faster in IMPUTE2 than in BEAGLE (5 minutes vs. 50 minutes per individual).Conclusion
Combining reference populations across breeds is a good option to increase the size of the reference data and in turn the accuracy of imputation when only few animals are available. Pre-phasing the reference data only slightly decreases the accuracy but gives substantial improvements in speed. Using BEAGLE for pre-phasing and IMPUTE2 for imputation is a fast and accurate strategy. 相似文献3.
Here we examine the efficiency of different immobilized cell gradients applied to immobilized Saccharomyces cerevisiae fermenting glucose to ethanol. We developed a simulation model to fully study the competing effects of mass transfer hindrance and kinetics. It is based on a diffusion-reaction model and can be used to analyze the different cell concentration profiles inside an immobilized gel bead, in terms of effectiveness factors, productivity, and mass flux. The internal diffusion coefficient, which varies with the local cell concentration, as well as the external mass transfer, is taken into account when describing the efficiency. Although the diffusion hindrance is greater at higher cell concentrations, high cell concentration is still advantageous in the present case because the increase in reaction rate outweighs the diffusion hindrance. Thus, high cell concentrations contribute to increased productivity. The influence of the cell concentration gradient on the efficiency of the beads is negligible. Within the range of cell profiles studied it has been established that the location of the cells within the bead is of lesser importance. However, a steep cell gradient increases the importance of the external mass transfer. 相似文献
4.
Pragl B Koschak A Trieb M Obermair G Kaufmann WA Gerster U Blanc E Hahn C Prinz H Schütz G Darbon H Gruber HJ Knaus HG 《Bioconjugate chemistry》2002,13(3):416-425
Hongotoxin(1) (HgTX(1)), a 39-residue peptide recently isolated from the venom of Centruroides limbatus, blocks the voltage-gated K+ channels K(v)1.1, K(v)1.2, and K(v)1.3 at picomolar toxin concentrations (Koschak, A., Bugianesi, R. M., Mitterdorfer, J., Kaczorowski, G. J., Garcia, M. L., and Knaus, H. G. (1998) J. Biol. Chem. 273, 2639-2644). In this report, we determine the three-dimensional structure of HgTX(1) using NMR spectroscopy (PDB-code: 1HLY). HgTX(1) was found to possess a structure similar to previously characterized K+ channel toxins (e.g. margatoxin) consisting of a three-stranded antiparallel beta-sheet (residues 2-4, 26-30, and 33-37) and a helical conformation (part 3(10) helix and part alpha helix; residues 10-20). Due to the importance of residue Lys-28 for high-affinity interaction with the respective channels, lysine-reactive fluorescence dyes cannot be used to label wild-type HgTX(1). On the basis of previous studies (see above) and our NMR data, a HgTX(1) mutant (HgTX(1)-A19C) was engineered, expressed, and purified. HgTX(1)-A19C-SH was labeled using sulfhydryl-reactive Cy3-, Cy5-, and Alexa-dyes. Pharmacological characterization of fluorescently labeled HgTX(1)-A19C in radioligand binding studies indicated that these hongotoxin(1) analogues retain high-affinity for voltage-gated K+ channels and a respective pharmacological profile. Cy3- and Alexa-dye-labeled hongotoxin(1) analogues were used to investigate the localization of K+ channels in brain sections. The distribution of toxin binding closely follows the distribution of K(v)1.2 immunoreactivity with the highest expression levels in the cerebellar Purkinje cell layer. Taken together, these results demonstrate that fluorescently labeled HgTX(1) analogues comprise novel probes to characterize a subset of voltage-gated K+ channels. 相似文献
5.
Steinar Engen Thomas Kvalnes Bernt‐Erik Sæther 《Evolution; international journal of organic evolution》2014,68(9):2509-2523
An extension of the selection differential in the Robertson–Price equation for the mean phenotype in an age‐structured population is provided. Temporal changes in the mean phenotype caused by transient fluctuations in the age‐distribution and variation in mean phenotype among age classes, which can mistakenly be interpreted as selection, will disappear if reproductive value weighting is applied. Changes in any weighted mean phenotype in an age‐structured population may be decomposed into between‐ and within‐age class components. Using reproductive value weighting the between‐age class component becomes pure noise, generated by previous genetic drift or fluctuating selection. This component, which we call transient quasi‐selection, can therefore be omitted when estimating age‐specific selection on fecundity or viability within age classes. The final response can be computed at the time of selection, but can not be observed until lifetime reproduction is realized unless the heritability is one. The generality of these results is illustrated further by our derivation of the selection differential for the continuous time age‐structured model with general age‐dependent weights. A simple simulation example as well as estimation of selection components in a house sparrow population illustrates the applicability of the theory to analyze selection on the mean phenotype in fluctuating age‐structured populations. 相似文献
6.
Thomas Kvalnes Thor Harald Ringsby Henrik Jensen Ingerid Julie Hagen Bernt Rønning Henrik Pärn Håkon Holand Steinar Engen Bernt‐Erik Sæther 《Evolution; international journal of organic evolution》2017,71(8):2062-2079
A general assumption in quantitative genetics is the existence of an intermediate phenotype with higher mean individual fitness in the average environment than more extreme phenotypes. Here, we investigate the evolvability and presence of such a phenotype in wild bird populations from an eleven‐year experiment with four years of artificial selection for long and short tarsus length, a proxy for body size. The experiment resulted in strong selection in the imposed directions. However, artificial selection was counteracted by reduced production of recruits in offspring of artificially selected parents. This resulted in weak natural selection against extreme trait values. Significant responses to artificial selection were observed at both the phenotypic and genetic level, followed by a significant return toward preexperimental means. During artificial selection, the annual observed phenotypic response closely followed the predicted response from quantitative genetic theory ( = 0.96, = 0.56). The rapid return to preexperimental means was induced by three interacting mechanisms: selection for an intermediate phenotype, immigration, and recombination between selected and unselected individuals. The results of this study demonstrates the evolvability of phenotypes and that selection may favor an intermediate phenotype in wild populations. 相似文献
7.
Naess SN Sliwka HR Partali V Melø TB Razi Naqvi K Jackson HL Lockwood SF 《Chemistry and physics of lipids》2007,148(2):63-69
The surface and aggregation properties of a synthetic, highly water-soluble carotenoid, the tetracationic astaxanthin-lysine conjugate (Asly), have been examined through measurements of surface tension, optical absorption and dynamic light scattering. The following parameters were determined: critical aggregation concentration c(M), surface concentration Gamma, molecular area a(m), free energy of adsorption and aggregation (DeltaG(ad) degrees and DeltaG(M) degrees , respectively), and the aggregate size r(H). The compound forms true monomolecular solutions in water below c(M); aggregates emerge only at rather high concentrations (> or =2.18 mM). 相似文献
8.
Background
An elevated plasma glucose concentration has been considered to be a potential risk factor in the pathogenesis of left-displaced abomasums (DA). Therefore the present study was performed to investigate if spontaneous disease (parturient paresis, metritis, ketosis etc) in dairy cows results in elevated concentrations of glucose and cortisol in blood as cortisol is the major regulator of glucose in ruminants. 相似文献9.
Barbro Lindmark Pramod Kumar Rompikuntal Karolis Vaitkevicius Tianyan Song Yoshimitsu Mizunoe Bernt Eric Uhlin Patricia Guerry Sun Nyunt Wai 《BMC microbiology》2009,9(1):220
Background
Background: Cytolethal distending toxin (CDT) is one of the well-characterized virulence factors of Campylobacter jejuni, but it is unknown how CDT becomes surface-exposed or is released from the bacterium to the surrounding environment. 相似文献10.