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991.
992.
Mervi Laaksonen Kaisa Murdoch Juha Siitonen Gergely Várkonyi 《Journal of Insect Conservation》2010,14(1):89-98
The beetle genus Agathidium is the largest insect group documented that principally feeds on slime moulds. Agathidium pulchellum, one of the rarest Agathidium species in Europe, is listed in the EU’s Habitats Directive. We studied the habitat associations of A. pulchellum in 44 sites located in old-growth and managed forests in eastern Finland. Agathidium pulchellum occurred exclusively on the slime-mould species Trichia decipiens. The host was associated with mid-decayed aspen, spruce and birch logs, and its incidence grew with both increasing log diameter
and stand-level log density of spruce and aspen. We also observed that even if its host was present, the beetle was absent
from sites with less than 80 aspen and spruce logs per hectare. All sites with A. pulchellum were natural forests of high conservation value. Our results show that it is possible to systematically survey the occurrence
of A. pulchellum. 相似文献
993.
Morinda citrifolia adventitious roots were cultured in shake flasks using Murashige and Skoog medium with different types and concentrations
of auxin and cytokinin. Root (fresh weight and dry weight) accumulation was enhanced at 5 mg l−1 indole butyric acid (IBA) and at 7 and 9 mg l−1 naphthalene acetic acid (NAA). On the other hand, 9 mg l−1 NAA decreased the anthraquinone, phenolic and flavonoid contents more severely than 9 mg l−1 IBA. When adventitious roots were treated with kinetin (0.1, 0.3 and 0.5 mg l−1) and thidiazuron (TDZ; 0.1, 0.3 and 0.5 mg l−1) in combination with 5 mg l−1 IBA, fresh weight and dry weight decreased but secondary metabolite content increased. The secondary metabolite content (including
1,1-diphenyl-2-picrylhydrazyl activity) increased more in TDZ-treated than in kinetin-treated roots. Antioxidative enzymes
such as catalase (CAT) and guaiacol peroxidase (G-POD), which play important roles in plant defense, also increased. A strong
decrease in ascorbate peroxidase activity resulted in a high accumulation of hydrogen peroxide. This indicates that adventitious
roots can grow under stress conditions with induced CAT and G-POD activities and higher accumulations of secondary metabolites.
These results suggest that 5 mg l−1 IBA supplementation is useful for growth and secondary metabolite production in adventitious roots of M. citrifolia. 相似文献
994.
Ho Nam Chang Nag-Jong Kim Jongwon Kang Chang Moon Jeong 《Biotechnology and Bioprocess Engineering》2010,15(1):1-10
The typical biorefinery platforms are sugar, thermochemical (syngas), carbon-rich chains, and biogas platforms, each offering
unique advantages and disadvantages. The sugar platform uses hexose and pentose sugars extracted or converted from plant body
mass. The thermochemical (syngas) platform entails a chemical or biological conversion process using pyrolysis or gasification
of plants to produce biofuels. The carbon-rich chains platform is used to produce biodiesel from long-chain fatty acids or
glycerides. In the present work, we suggest a new platform using volatile fatty acids (VFAs) for the production of biofuels
and biochemicals production. The VFAs are short-chain fatty acids composed mainly of acetate and butyrate in the anaerobic
digestion (AD) process, which does not need sterilization, additional hydrolysis enzymes (cellulose or xylanase), or a high
cost pretreatment step. VFAs are easily produced from almost all kinds of biomass with low lignin content (terrestrial, aquatic,
and marine biomass) by the AD process. Considering that raw material alone constitutes 40∼80% of biofuel production costs,
biofuels made from VFAs derived from waste organic biomass potentially offer significant economical advantage. 相似文献
995.
Lyme disease risk is increasing in the United States due in part to the spread of blacklegged ticks Ixodes
scapularis, the principal vector of the spirochetal pathogen Borrelia
burgdorferi. A 5-year study was undertaken to investigate hypothesized coinvasion of I. scapularis and B. burgdorferi in Lower Michigan. We tracked the spatial and temporal dynamics of the tick and spirochete using mammal, bird, and vegetation
drag sampling at eight field sites along coastal and inland transects originating in a zone of recent I.
scapularis establishment. We document northward invasion of these ticks along Michigan’s west coast during the study period; this pattern
was most evident in ticks removed from rodents. B.
burgdorferi infection prevalences in I.
scapularis sampled from vegetation in the invasion zone were 9.3% and 36.6% in nymphs and adults, respectively, with the majority of
infection (95.1%) found at the most endemic site. There was no evidence of I. scapularis invasion along the inland transect; however, low-prevalence B.
burgdorferi infection was detected in other tick species and in wildlife at inland sites, and at northern coastal sites in years before
the arrival of I.
scapularis. These infections suggest that cryptic B.
burgdorferi transmission by other vector-competent tick species is occurring in the absence of I.
scapularis. Other Borrelia spirochetes, including those that group with B. miyamotoi and B. andersonii, were present at a low prevalence within invading ticks and local wildlife. Reports of Lyme disease have increased significantly
in the invasion zone in recent years. This rapid blacklegged tick invasion—measurable within 5 years—in combination with cryptic
pathogen maintenance suggests a complex ecology of Lyme disease emergence in which wildlife sentinels can provide an early
warning of disease emergence. 相似文献
996.
Volatility of oil prices along with major concerns about climate change, oil supply security and depleting reserves have sparked
renewed interest in the production of fuels from renewable resources. Recent advances in synthetic biology provide new tools
for metabolic engineers to direct their strategies and construct optimal biocatalysts for the sustainable production of biofuels.
Metabolic engineering and synthetic biology efforts entailing the engineering of native and de novo pathways for conversion of biomass constituents to short-chain alcohols and advanced biofuels are herewith reviewed. In the
foreseeable future, formal integration of functional genomics and systems biology with synthetic biology and metabolic engineering
will undoubtedly support the discovery, characterization, and engineering of new metabolic routes and more efficient microbial
systems for the production of biofuels. 相似文献
997.
Development and characterization of an oat TILLING-population and identification of mutations in lignin and β-glucan biosynthesis genes 总被引:1,自引:0,他引:1
Aakash Chawade Per Sikora Marcus Bräutigam Mikael Larsson Vivekanand Vivekanand Montedar All Nakash Tingsu Chen Olof Olsson 《BMC plant biology》2010,10(1):86
Background
Oat, Avena sativa is the sixth most important cereal in the world. Presently oat is mostly used as feed for animals. However, oat also has special properties that make it beneficial for human consumption and has seen a growing importance as a food crop in recent decades. Increased demand for novel oat products has also put pressure on oat breeders to produce new oat varieties with specific properties such as increased or improved β-glucan-, antioxidant- and omega-3 fatty acid levels, as well as modified starch and protein content. To facilitate this development we have produced a TILLING (Targeting Induced Local Lesions IN Genomes) population of the spring oat cultivar SW Belinda. 相似文献998.
Andreas Jørgensen Lufanna C. H. Lai Michael Z. Hauschild 《The International Journal of Life Cycle Assessment》2010,15(1):5-16
Background, aim and scope
Assuming that the goal of social life cycle assessment (SLCA) is to assess damage and benefits on its ‘area of protection’ (AoP) as accurately as possible, it follows that the impact pathways, describing the cause effect relationship between indicator and the AoP, should have a consistent theoretical foundation so the inventory results can be associated with a predictable damage or benefit to the AoP. This article uses two concrete examples from the work on SLCA to analyse to what extent this is the case in current practice. One considers whether indicators included in SLCA approaches can validly assess impacts on the well-being of the stakeholder, whereas the other example addresses whether the ‘incidence of child labour’ is a valid measure for impacts on the AoPs. 相似文献999.
In this study, we examined the response of glioma C6 cells to 2′,3′-O-(4-benzoylbenzoyl)-ATP (BzATP) and showed that the BzATP-induced calcium signaling does not involve the P2X7 receptor activity. We show here that in the absence of extracellular Ca2+, BzATP-generated increase in [Ca2+]i
via Ca2+ release from intracellular stores. In the presence of calcium ions, BzATP established a biphasic Ca2+ response, in a manner typical for P2Y receptors. Brilliant Blue G, a selective antagonist of the rat P2X7 receptor, did not reduce any of the two components of the Ca2+ response elicited by BzATP. Periodate-oxidized ATP blocked not only BzATP- but also UTP-induced Ca2+ elevation. Moreover, BzATP did not open large transmembrane pores. What is more, a cross-desensitization between UTP and
BzATP occurred, which clearly shows that in glioma C6 cells BzATP activates most likely the P2Y2 but not the P2X7 receptors. 相似文献
1000.
Mesorhizobium huakuii strain 7653R harbored two indigenous plasmids named pMH7653Ra and pMH7653Rb. The larger plasmid pMH7653Rb (symbiotic plasmid)
was transferred to M. huakuii HN308SR harboring three plasmids: pMHHN308a, pMHHN308b and pMHHN308c, and HN3015SR harboring three plasmids: pMHHN3015a,
pMHHN3015b and pMHHN3015c by tri-parent mating. Two stable indigenous plasmids, pMHHN308b and pMHHN308c of HN308SR, were co-eliminated
due to the introduction of pMH7653Rb, and the transconjugant was named HN308SRN14. The results implied that pMH7653Rb and
pMHHN308b, pMHHN308c were incompatible and might have been ascribed to the same incompatible group. The plasmid profiles of
transconjugant HN3015SRN14 showed that the second largest plasmid pMHHN3015b of HN3015SR was cured due to the introduction
of pMH7653Rb. The results also implied that pMH7653Rb and pMHHN3015b were incompatible. Results from plant nodulation tests
showed that pMH7653Rb could only maintain the nodulation ability in transconjugant HN308SRN14 and its nodule number was more
than that of wild strain HN308SR, but could not replace the nitrogen fixation effect of pMHHN308b and pMHHN308c. The plasmid
cured mutant HN308SRN14D harboring only pMHHN308a formed null nodules that demonstrated pMHHN308a was relevant to nodulation
ability. HN3015SRN14 harboring pMH7653Rb, pMHHN3015a and pMHHN3015c formed null nodules while HN3015SRN14D containing pMHHN3015a
and pMHHN3015c lost the nodulation ability. The plasmid replication repC-like gene sequences were detected by a polymerase chain reaction from 7653R, HN308, HN3015, HN308SRN14 and HN3015SRN14. The
repC gene sequence similarities of the strains tested attained 99%. 相似文献