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61.
Søren Ugilt Larsen Uffe Jørgensen Jens Bonderup Kjeldsen Poul Erik Lærke 《Bioenergy Research》2014,7(2):620-635
Long-term yield studies in perennial crops like miscanthus are important to determine mean annual energy yield and the farmer’s economy. In two Danish field trials, annual yield of two miscanthus genotypes was followed over a 20-year period. The trials were established in 1993 on loamy sand in Foulum and on coarse sand in Jyndevad. Effects of genotype, row distance and fertilization were investigated. In both trials, yield development over time was characterized by an increase during the first years, optimum yields after 7–8 years and a decrease to a lower level which remained relatively constant from year 11 to 20. Spring harvest reduced the yield by 34–42 % compared to autumn harvest. In Foulum annual fertilization with 75 kg ha?1 N increased the yield of the genotype Goliath (Miscanthus sinensis) by 26 %. Additional N fertilization only increased the yield of Goliath little, and the genotype Giganteus (Miscanthus?×?giganteus) did not respond to fertilization at all. The highest mean yield in Foulum for the period 1997–2012 was obtained with the shortest row distance (~18,000 rather than ~12,000 plants ha?1) and harvested in late autumn, namely 13.1 and 12.0 Mg ha?1 DM annually for Giganteus and Goliath, respectively. In Jyndevad, where only Goliath was studied, the highest yield during 1995–2001 was obtained by short row distance, autumn harvest and annual fertilization with 75 kg ha?1 N, with yield increasing up to 116 % in response to fertilization. A mean yield of 14.4 Mg ha?1 DM was achieved over the period 1995–2012. 相似文献
62.
Benjamin F Miller Mette Hansen Jens L Olesen Peter Schwarz John A Babraj Kenneth Smith Michael J Rennie Michael Kjaer 《Journal of applied physiology》2007,102(2):541-546
In general, there is a higher incidence of musculoskeletal injuries during physical activity in women than in men. We hypothesized that in women rates of tendon collagen synthesis would be lower than in men at rest and after exercise, especially in the later luteal phase when estrogen and progesterone concentrations are higher than the early follicular phase. We studied tendon collagen fractional synthesis rate (FSR) in 15 young, healthy female subjects in either the early follicular (n = 8) or the late luteal phase (n = 7) 72 h after an acute bout of one-legged exercise (60 min kicking at 67% workload maximum) (72 h) and compared the results with those previously obtained for men. Samples were taken from the patellar tendon in both the exercised and rested legs to determine collagen FSR by the incorporation of [15N]proline into tendon collagen hydroxyproline. There was no effect of menstrual phase on tendon collagen synthesis either at rest or after exercise. However, there was a significant difference between women and men at rest (women = 0.025 +/- 0.002%/h, men = 0.045 +/- 0.008%/h; P < 0.05) and 72 h after exercise (women = 0.027 +/- 0.005%/h; men = 0.058 +/- 0.008%/h). Furthermore, rest and 72-h tendon collagen synthesis were not different in women, whereas in men tendon collagen synthesis remained significantly elevated 72 h after exercise. It is concluded that both in the resting state and after exercise, tendon collagen FSR is lower in women than in men, which may contribute to a lower rate of tissue repair after exercise. 相似文献
63.
64.
Janine Bolliger Frank Hagedorn Jens Leifeld Jürgen Böhl Stephan Zimmermann Reto Soliva Felix Kienast 《Ecosystems》2008,11(6):895-907
We assessed how consequences of future land-use change may affect size and spatial shifts of C stocks under three potential
trends in policy—(a) business-as-usual: continuation of land-use trends observed during the past 15 years; (b) extensification:
full extensification of open-land; and (c) liberalization: full reforestation potential. The build-up times for the three
scenarios are estimated at 30, 80 and 100 years, respectively. Potential C-stock change rates are derived from the literature.
Whereas the business-as-usual scenario would cause marginal changes of 0.5%, liberalization would provoke a 13% increase in
C stocks (+62 MtC). Gains of 24% would be expected for forests (+95 MtC), whereas open-land C stock would decrease 27% (−33 MtC).
Extensification would lead to a C stock decrease of 3% (−12 MtC). Whereas forest C is expected to increase 12% (+36.5 MtC)
at high elevations, stocks of open-land C would decline 38.5% (−48.5 MtC). Most affected are unfavorable grasslands, which
increase in area (+59%) but contribute only 14.5% to the C stocks. C sinks would amount to 0.6 MtC y−1 assuming a build-up time of 100 years for the liberalization scenario. C stocks on the current forest area are increasing
by 1 MtC y−1. The maximal total C sink of 1.6 MtC might thus suffice to compensate for agricultural greenhouse gases (2004: 1.4 Mt CO2–C equivalents), but corresponds only to 11–13% of the anthropogenic greenhouse gas emission in Switzerland. Thus, even the
largest of the expected terrestrial C stocks under liberalization will be small in comparison with current emissions of anthropogenic
greenhouse gases. 相似文献
65.
Distribution and diversity of palms in a tropical biodiversity hotspot (Thailand) assessed by species distribution modeling
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Jantrararuk Tovaranonte Anne Blach‐Overgaard Ratchada Pongsattayapipat Jens‐Christian Svenning Anders S. Barfod 《Nordic Journal of Botany》2015,33(2):214-224
Species distribution modeling has been widely used to address questions related to ecology, biogeography and species conservation on global and regional scales. Here, we study palms (Arecaceae) in a tropical biodiversity hotspot (Thailand) using species distribution modeling to assess range‐limiting factors and estimate distribution and diversity patterns based on a comprehensive compilation of occurrence records. We focused on palms as a model group due to their key‐stone importance for ecosystem functioning and socio‐economics. Different combinations of climatic, non‐climatic environmental and spatial predictors were used. The most accurate models as indicated by the ‘area under the receiver operating characteristic curve’ (AUC) statistic were those that combined all predictors. The four strongest single predictors of palm species distributions were, in decreasing order of importance, 1) latitude, 2) precipitation of driest quarter, 3) annual precipitation, and 4) minimum temperature of the coldest month, suggesting rainfall patterns and latitudinal spatial constraints as the main range determinants. Overlaying the predicted distributions revealed that potential palm hotspots are situated in the provinces of Satun and Yala in southern Thailand where vast areas remain relatively open to the discovery of new palm records and perhaps even new species. 相似文献
66.
The generation of novel yeast cell factories for production of high-value industrial biotechnological products relies on three metabolic engineering principles: design, construction, and analysis. In the last two decades, strong efforts have been put on developing faster and more efficient strategies and/or technologies for each one of these principles. For design and construction, three major strategies are described in this review: (1) rational metabolic engineering; (2) inverse metabolic engineering; and (3) evolutionary strategies. Independent of the selected strategy, the process of designing yeast strains involves five decision points: (1) choice of product, (2) choice of chassis, (3) identification of target genes, (4) regulating the expression level of target genes, and (5) network balancing of the target genes. At the construction level, several molecular biology tools have been developed through the concept of synthetic biology and applied for the generation of novel, engineered yeast strains. For comprehensive and quantitative analysis of constructed strains, systems biology tools are commonly used and using a multi-omics approach. Key information about the biological system can be revealed, for example, identification of genetic regulatory mechanisms and competitive pathways, thereby assisting the in silico design of metabolic engineering strategies for improving strain performance. Examples on how systems and synthetic biology brought yeast metabolic engineering closer to industrial biotechnology are described in this review, and these examples should demonstrate the potential of a systems-level approach for fast and efficient generation of yeast cell factories. 相似文献
67.
Lactobacillus reuteri is both a gut symbiont and a stable member of sourdough microbiota. This study employed multilocus sequence analysis and an analysis of host-specific physiological and genetic traits to assign five sourdough isolates to rodent- or human-specific lineages. Comparative genome hybridization revealed that the model sourdough isolate LTH2584 had a genome content very similar to that of the model rodent isolate 100-23. These results demonstrate that sourdough isolates of L. reuteri are of intestinal origin. 相似文献
68.
69.
Christian Weiss Joanna Weiss Jens Boy Issi Iskandar Robert Mikutta Georg Guggenberger 《Ecology and evolution》2016,6(14):5043-5056
Mangroves play an important role in carbon sequestration, but soil organic carbon (SOC) stocks differ between marine and estuarine mangroves, suggesting differing processes and drivers of SOC accumulation. Here, we compared undegraded and degraded marine and estuarine mangroves in a regional approach across the Indonesian archipelago for their SOC stocks and evaluated possible drivers imposed by nutrient limitations along the land‐to‐sea gradients. SOC stocks in natural marine mangroves (271–572 Mg ha?1 m?1) were much higher than under estuarine mangroves (100–315 Mg ha?1 m?1) with a further decrease caused by degradation to 80–132 Mg ha?1 m?1. Soils differed in C/N ratio (marine: 29–64; estuarine: 9–28), δ15N (marine: ?0.6 to 0.7‰; estuarine: 2.5 to 7.2‰), and plant‐available P (marine: 2.3–6.3 mg kg?1; estuarine: 0.16–1.8 mg kg?1). We found N and P supply of sea‐oriented mangroves primarily met by dominating symbiotic N2 fixation from air and P import from sea, while mangroves on the landward gradient increasingly covered their demand in N and P from allochthonous sources and SOM recycling. Pioneer plants favored by degradation further increased nutrient recycling from soil resulting in smaller SOC stocks in the topsoil. These processes explained the differences in SOC stocks along the land‐to‐sea gradient in each mangrove type as well as the SOC stock differences observed between estuarine and marine mangrove ecosystems. This first large‐scale evaluation of drivers of SOC stocks under mangroves thus suggests a continuum in mangrove functioning across scales and ecotypes and additionally provides viable proxies for carbon stock estimations in PES or REDD schemes. 相似文献
70.
Sigurdsson V Fridriksdottir AJ Kjartansson J Jonasson JG Steinarsdottir M Petersen OW Ogmundsdottir HM Gudjonsson T 《In vitro cellular & developmental biology. Animal》2006,42(10):332-340
Summary Attempts to study endothelial-epithelial interactions in the human breast have been hampered by lack of protocols for long-term
cultivation of breast endothelial cells (BRENCs). The aim of this study was to establish long-term cultures of BRENCs and
to compare their phenotypic traits with the tissue of origin. Microvasculature was localized in situ by immunohistochemitry
in breast samples. From this tissue, collagen-rich stroma and adipose tissue were dissected mechanically and further disaggregated
to release microvessel organoids BRENCs were cultured from these organoids in endothelial specific medium and characterized
by staining for endothelial markers. Microvessels were a prominent feature of intralobular tissue as evidenced by immunostaining
against endothelial specific markers such as CD31, VE-cadherin, and von Willebrand factor (VWF). Double staining against VE-cadherin
and lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1) showed that blood and lymphatic vessels could be distinguished.
An antibody against CD31 was used to refine protocols for isolation of microvasculature from reduction mammoplasties. BRENCs
retained critical traits even at high passage, including uptake of low-density lipoprotein, and had E-selectin induced upon
treatment with tumor necrosis factor-α. The first signs of senescence in passage 14 were accompained by gain of trisomy 11.
At passage 18 cells showed chromosomal aberrations and growth arrest as revealed by β-galactosidase staining. We demonstrate
here that breast microvasculature may serve as a large-scale source for expansion of BRENCs with molecular and functional
traits preserved. These cells will form the basis for studies on the role of endothelial cells in breast morphogenesis. 相似文献