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961.
Khanitta Somtrakoon Sudarat Suanjit Prayad Pokethitiyook Maleeya Kruatrachue Hung Lee Suchart Upatham 《World journal of microbiology & biotechnology》2008,24(4):523-531
Pyrene and fluoranthene, when supplied as the sole carbon source, were not degraded by Burkholderia sp. VUN10013. However, when added in a mixture with phenanthrene, both pyrene and fluoranthene were degraded in liquid broth
and soil. The amounts of pyrene and fluoranthene in liquid media (initial concentrations of 50 mg l−1 each) decreased to 42.1% and 41.1%, respectively, after 21 days. The amounts of pyrene and fluoranthene in soil (initial
concentrations of 75 mg kg−1 dry soil each) decreased to 25.8% and 12.1%, respectively, after 60 days. None of the high molecular weight (HMW) polycylic
aromatic hydrocarbons (PAHs) tested adversely affected phenanthrene degradation by this bacterial strain and the amount of
phenanthrene decreased rapidly within 3 and 15 days of incubation in liquid broth and soil, respectively. Anthracene also
stimulated the degradation of pyrene or fluoranthene by Burkholderia sp. VUN10013, but to a lesser extent than phenanthrene. The extent of anthracene degradation decreased in the presence of
these HMW PAHs. 相似文献
962.
Background
Altered neuronal vulnerability underlies many diseases of the human nervous system, resulting in degeneration and loss of neurons. The neuroprotective slow Wallerian degeneration (Wld s ) mutation delays degeneration in axonal and synaptic compartments of neurons following a wide range of traumatic and disease-inducing stimuli, providing a powerful experimental tool with which to investigate modulation of neuronal vulnerability. Although the mechanisms through which Wld s confers neuroprotection remain unclear, a diverse range of downstream modifications, incorporating several genes/pathways, have been implicated. These include the following: elevated nicotinamide adenine dinucleotide (NAD) levels associated with nicotinamide mononucleotide adenylyltransferase 1 (Nmnat1; a part of the chimeric Wld s gene); altered mRNA expression levels of genes such as pituitary tumor transforming gene 1 (Pttg1); changes in the location/activity of the ubiquitin-proteasome machinery via binding to valosin-containing protein (VCP/p97); and modified synaptic expression of proteins such as ubiquitin-activating enzyme E1 (Ube1). 相似文献963.
Background
Dosage compensation in Drosophila is the epigenetic process by which the expression of genes located on the single X-chromosome of males is elevated to equal the expression of X-linked genes in females where there are two copies of the X-chromosome. While epigenetic mechanisms are hypothesized to have evolved originally to silence transposable elements, a connection between transposable elements and the evolution of dosage compensation has yet to be demonstrated. 相似文献964.
Tijen Talas-Oğraş 《Acta Physiologiae Plantarum》2011,33(3):647-657
Advances in recombinant DNA technology have created advantages for the development of plants with high agro-economical values.
Since the production of transgenic plants, some issues concerning the safe use of these plants and their products have been
under debate throughout the world. In this respect, the potential risks and benefits of transgenic plants need to be evaluated
objectively. Risk assessment of transgenic crops is a basic prerequisite for monitoring the possible risks that could arise
upon the release and use of transgenic plants. To get a meaningful tool for decision making, risk assessment needs to be carried
out in a scientific sound and transparent manner. There are specific governmental regulations in many countries for the safety
assessment of genetically modified (GM) crops. Furthermore, there are some international agreements, which regulate the cultivation
and commercialization of transgenic plants and their derivatives. Internationally accepted risk assessment strategies have
been performed to evaluate the safe use of a large variety of GM crops. The main objectives of these regulations and risk
assessment strategies are focused to protect human/animal health and the environment. 相似文献
965.
Current knowledge of microbial community structures in landfills and its cover soils 总被引:2,自引:0,他引:2
Semrau JD 《Applied microbiology and biotechnology》2011,89(4):961-969
Landfills are a vital component of our waste handling processes. Our lack of knowledge on the microbial processes in these
systems, however, hampers our ability to design the next generation of landfills that: (1) enhance the rate and extent of
waste decomposition, (2) produce byproducts of some value (e.g., methane that can be used for energy generation), and, (3)
minimize their overall impact on driving climate change through the emission of greenhouse gases. In this review, the current
state of knowledge the microbial community structure and activity in both the refuse and overlying cover soils is discussed,
and suggestions provided for future research in this critical aspect of our infrastructure. 相似文献
966.
Karina Vanessa Hmeljevski Ademir Reis Tiago Montagna Maurício Sedrez dos Reis 《Conservation Genetics》2011,12(3):761-769
Dyckia ibiramensis is a naturally rare, endemic and threatened bromeliad which occurs naturally on 4 km of rocky river outcroppings in Southern
Brazil. For this study, subpopulations of the species were characterized based on size and genetics, to compile information
for in situ and ex situ conservation strategies. A census of the rosettes was undertaken for each subpopulation and seven allozyme polymorphic loci
were used to estimate genetic diversity and structure of adults and offspring and assess the mating system. In general, the
subpopulations were small and most of the rosettes were aggregated into clumps. The species showed a high genetic diversity
([^(H)]e = 0.219 \hat{H}_{e} = 0.219 ) and significant fixation index ([^(f)] = 0.642, \hat{f} = 0.642,
P ≤ 0.05). The estimate of differentiation among all adult subpopulations indicate pronounced genetic structure ([^(G)]¢ST = 0.674 \hat{G}^{\prime}_{ST} = 0.674 ). D. ibiramensis has a mixed mating system and multilocus outcrossing rates [^(t)]m \hat{t}_{m} were variable between subpopulations. This study demonstrates the importance of in situ preservation of all subpopulations
for the maintenance of species diversity. For effective ex situ conservation, it would be necessary to collect seeds from 52 to 99 seed-rosettes, depending on the target population. 相似文献
967.
Brandt’s vole (Lasiopodomys brandtii) distribution is discontinuous in Inner Mongolia with some populations isolated from others. Recently, some isolated populations
have suffered extinction, and the factors responsible remain elusive. Genetic drift is one of the processes affecting population
genetic differentiation, and can play a substantial role in the divergence of small, isolated populations. Using seven microsatellite
markers, we genotyped four geographically isolated populations of Brandt’s vole, all of which exhibit episodic fluctuations
in population density. The results showed a strong genetic differentiation among the geographically distinct populations (total
F
ST = 0.124) and in particular, one population (Zhengxiangbaiqi) was isolated from all others (F
ST values were greatest between Zhengxiangbaiqi and other populations). Furthermore, high levels of inbreeding (F
IS values ranged from 0.205 to 0.290) within each distinct population suggest that inbreeding has and is likely occurring in
Brandt’s vole populations. These processes can decrease average individual fitness and consequently increase the risk of extinction
of the species. 相似文献
968.
Hojun Rim Masayoshi Uefune Rika Ozawa Kinuyo Yoneya Junji Takabayashi 《BioControl》2017,62(2):233-242
Nesidiocoris tenuis, an omnivorous arthropod, infests plants in either the absence or presence of prey arthropods. We studied whether plant-infestation experience of N. tenuis affected its subsequent prey-finding behavior. We used sesame plants and eggplants as food plants for N. tenuis, and common cutworm (CCW) (Spodoptera litura larvae) as prey. We focused on their olfactory response to CCW-infested sesame plants versus CCW-infested eggplants in a Y-tube olfactometer. When N. tenuis adults experienced the infestation of sesame plants for one day, they preferred volatiles from CCW-infested sesame plants to those from CCW-infested eggplants. By contrast, when N. tenuis experienced the infestation of eggplants for one day, they showed no difference in their preference between the two odor sources. When the duration of the infestation of plants was increased to four days, N. tenuis that had experienced sesame plants showed a reversed response: they preferred CCW-infested eggplant volatiles, while those that had infested eggplants again showed no difference in their preference. Next, we studied the olfactory preference of N. tenuis that had previously infested plants with moth (Ephestia kuehniella) eggs. We found that irrespective of plant species and of duration of experience (either one or four days), N. tenuis adults that had previously experienced one plant species showed a significant preference for volatiles from CCW-infested plants of the same species. The blends of the volatiles emitted from CCW-infested sesame plants and those from CCW-infested eggplants were qualitatively different. Possibility to control the olfactory response of N. tenuis to certain prey-infested plant volatiles by adjusting their feeding history is discussed. 相似文献
969.
Myla F. J. Aronson Manisha V. Patel Karen M. O’Neill Joan G. Ehrenfeld 《Biological invasions》2017,19(12):3645-3657
Riparian areas are often the only green areas left in urban and suburban landscapes, providing opportunities for conservation and connectivity of both aquatic and terrestrial organisms. While city planners and land managers often tout the importance of riparian networks for these uses, it is not well established if urban riparian plant communities are actually functioning as connected assemblages. Furthermore, urban riparian zones are well known to be highly invaded by non-native plant species and may be functioning to increase the spread of non-native species across the landscape. Here we examine connectivity of plant assemblages in riparian networks within an extensively urbanized landscape. We sampled riparian plant communities at 13 sites along three second-order streams of the Rahway River watershed, New Jersey. We also characterized propagule dispersal at each site by sampling litter packs on the river banks five times between March–October 2011 and identifying germinants from litter packs after cold stratification. Species turnover of both riparian and litter vegetation was more strongly associated with flow distance, particularly for native species, indicating that riverine systems are important for promoting connectivity of native plant assemblages in urban landscapes. However, non-native germinants significantly dominated propagule dispersal along the stream reaches, particularly early in the growing season, suggesting spread utilizing the river system and preemption may be an important mechanism for invasion success in this system. Our data show that management of invasive species should be planned and implemented at the watershed scale to reduce spread via the river system. 相似文献
970.
In order to identify the lower limb movements accurately and quickly, a recognition method based on extreme learning machine (ELM) is proposed. The recognizing target set is constructed by decomposing the daily actions into different segments. To get the recognition accuracy of seven movements based on the surface electromyography, the recognition feature vector space is established by integrating short-time statistical characteristics under time domain, and locally linear embedding algorithm is used to reduce the computational complexity and improve robustness of algorithm. Compared with BP, the overall recognition accuracy for each subject in the best dimension with ELM is above 95%. 相似文献