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11.
Heritability of the backtest response in piglets and its genetic correlations with production traits
《Animal : an international journal of animal bioscience》2017,11(4):556-563
The backtest response of a pig gives an indication of its coping style, that is, its preferred strategy to cope with stressful situations, which may in turn be related to production traits. The objective of this study was therefore to estimate the heritability of the backtest response and estimate genetic correlations with production traits (birth weight, growth, fat depth and loin depth). The backtest was performed by placing the piglet on its back for 60 s and the number of struggles (NrS) and vocalizations (NrV), and the latency to struggle and vocalize (LV) was recorded. In total, 992 piglets were subjected to the backtest. Heritability estimates for backtest traits were statistically moderate (although high for behavioral traits), with LV having the highest heritability estimate (0.56±0.10, P<0.001) and NrS having the lowest estimate (0.37±0.09, P<0.001). Backtest traits also had high genetic correlations with each other, with vocalization traits (NrV and LV) having the highest (−0.94±0.03, P<0.001), and NrS with NrV the lowest correlation (0.70±0.09, P<0.001). No significant correlations were found between backtest traits and production traits, but correlations between NrS and birth weight (−0.38±0.25), and NrV and loin depth (−0.28±0.19) approached significance (P=0.07). More research into genotype-by-environment interactions may be needed to assess possible connections between backtest traits and production traits, as this may depend on the circumstances (environment, experiences, etc.). In conclusion, heritability estimates of backtest traits are high and it would therefore be possible to select for them. The high genetic correlations between backtest traits indicate that it may be possible to only consider one or two traits for characterization and selection purposes. There were no significant genetic correlations found between backtest traits and production traits, although some of the correlations approached significance and hence warrant further research. 相似文献
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Fire can cause severe nitrogen (N) losses from grassland, chaparral, and temperate and boreal forest ecosystems. Paradoxically,
soil ammonium levels are markedly increased by fire, resulting in high rates of primary production in re-establishing plant
communities. In a manipulative experiment, we examined the influence of wild-fire ash residues on soil, microbial and plant
N pools in a recently burned Californian bishop pine (Pinus muricata D. Don) forest. Ash stimulated post-fire primary production and ecosystem N retention through direct N inputs from ash to
soils, as well as indirect ash effects on soil N availability to plants. These results suggest that redistribution of surface
ash after fire by wind or water may cause substantial heterogeneity in soil N availability to plants, and could be an important
mechanism contributing to vegetation patchiness in fire-prone ecosystems. In addition, we investigated the impact of fire
on ecosystem N cycling by comparing 15N natural abundance values from recently burned and nearby unburned P. muricata forest communities. At the burned site, 15N natural abundance in recolonising species was similar to that in bulk soil organic matter. By contrast, there was a marked
15N depletion in the same species relative to the total soil N pool at the unburned site. These results suggest that plant uptake
of nitrate (which tends to be strongly depleted in 15N because of fractionation during nitrification) is low in recently burned forest communities but could be an important component
of eco- system N cycling in mature conifer stands.
Received: 29 June 1999 / Accepted: 24 October 1999 相似文献
16.
《Critical reviews in biotechnology》2013,33(1):32-52
The exponentially growing human population and the emergence of new diseases are clear indications that the world can no longer depend solely on conventional vaccine technologies and production schemes. The race to find a new vaccine technology is crucial to help speed up and complement the World Health Organization (WHO) disease elimination program. The ultimate goal is to uncover fast and efficient production schemes in the event of a pandemic, and also to effectively fight deadly diseases such as malaria, bird flu, hepatitis, and human immunodeficiency virus (HIV). Plasmid DNA vaccines, if properly formulated, offer specific priming of the immune system and similar or even better prophylactic effects than conventional vaccines. This article discusses many of the critical issues that need to be considered when developing fast, effective, and reliable plasmid DNA vaccine manufacturing processes. Different modes of plasmid production via bacterial fermentation are compared. Plasmid purification by chromatography is specifically discussed as it is the most commercially viable bioprocess engineering technique for continuous purification of supercoiled plasmid DNA. Current techniques and progress covering the area of plasmid DNA vaccine design, formulation, and delivery are also put forward. 相似文献
17.
Per-Anders Hansson Berit Mattsson 《The International Journal of Life Cycle Assessment》1999,4(4):202-206
The shortage of data for emissions from agricultural tractors contributes to LCA results on environmental load from modern
crop production possibly having high error levels and high uncertainties.
The first part of this work describes measurements and calculations made in order to obtain operation-specific agricultural
emission data. Calculations are based on emission data measured on a standard 70 kW tractor of a widely available make. In
the second part, results from an LCI on wheat production based on traditionally used emission data are calculated and compared
with results obtained when using the emission data for specific working operations derived in part one.
One conclusion of the study is that the emission values, when related to the energy in the used fuel, show very large variations
between different driving operations. Another conclusion is that the use of the new data results in a marked reduction of
the total air emissions produced in the wheat production chain, especially for CO and HC, but also for NOx and SO2. 相似文献
18.
Promotion of indole alkaloid production in Catharanthus roseus cell cultures by rare earth elements 总被引:3,自引:0,他引:3
Production of the indole alkaloids, ajmalicine or catharanthine, in cell suspension cultures of Catharanthus roseus was enhanced by cerium (CeO2 and CeCl3), yttrium (Y2O3) and neodymium (NdCl3). The yield of ajmalicine in these treated-cultures reached 51 mg l–1 (CeO2), 40 mg l–1 (CeCl3), 41 mg l–1 (Y2O3) and 49 mg l–1 (NdCl3) while catharanthine production reached to 36 mg l–1 (CeO2) and 31 mg l–1 (CeCl3). A major portion of increased alkaloids was released into medium in these treatments. But Sm2O3, SmCl3, La2O3, LaCl3, complex of chromium (III)-titanium (IV) and NaSeO4 treatments had little effect on alkaloid production of C. roseus cell cultures. 相似文献
19.
Ting‐Hang Liu Chia‐Lin Chyan Feng‐Yin Li Ying‐Jie Chen Jason T. C. Tzen 《Biotechnology progress》2011,27(6):1760-1767
It has been demonstrated that caleosin alone is sufficient to stabilize artificial oil bodies. A series of recombinant caleosins, mutated with 3, 5, 8, 11, 13, 15, and 17 extra Lys residues and over‐expressed in Escherichia coli, were used as carrier proteins to render biotin as a hapten on the surface of artificial oil bodies for antibody production. Biotinylation levels of the recombinant caleosins were step‐wisely elevated as the number of extra Lys residues increased, and the biotinylated Lys residues were identified by mass spectrometric analysis. Polyclonal antibodies against biotin were successfully generated in rats injected with artificial oil bodies constituted with each of the biotinylated caleosins. Moreover, those generated via the biotinylated caleosins with eight or more extra Lys residues no longer recognized caleosin. It appears that engineered Lys‐rich caleosins are suitable carrier proteins for the production of antibodies against small molecules. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011 相似文献
20.
G. Pellegrino D. Caimi M. E. Noce A. Musacchio 《Plant Systematics and Evolution》2005,251(2-4):119-129
The rewardless orchid Dactylorhiza sambucina shows a stable flower colour polymorphism, with both yellow- and red-flowered morphs growing sympatrically. Pollination biology and breeding system were investigated to examine the effects of density of plants, colour polymorphism, inflorescence dimension, and flower position within inflorescence on male and female reproductive success in three natural populations of D. sambucina. There were significant differences among sites in the number of pollinia removed and in fruit set per inflorescence. Number of removed pollinia and capsule production in D. sambucina were independent from flower and inflorescence size or flower position. As a whole, the red morphs showed the highest number of capsules produced, while the yellow morphs had the greatest male success. The relative male and female reproductive success were independent from plant density but were significantly correlated with the yellow morph frequency at the population level. Overall, our findings show that the contribution to the total reproductive success deriving from the two colour morphs does not conform with the predictions of negative frequency-dependent selection. 相似文献