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991.
The vegetation of the aquatic and marshland habitats of the Orava region (north of Slovakia) was studied in 2009, using traditional phytosociological methods. Sixteen aquatic and eighteen marsh plant communities were described within 96 phytosociological relevés by using TWINSPAN with the application of the dominance principle. Three associations, Potametum alpini, Potametum zizii and Ranunculo-Juncetum bulbosi, were found as new communities for Slovakia. Myriophylletum verticillati, Potametum nodosi, Potametum graminei and Alisma gramineum community were recorded in the northernmost localities in Slovakia. Among marsh communities, Calletum palustris is very rare, both in the Orava region and in Slovakia as a whole. According to Ellenberg’s indicator values (EIV), moisture was evaluated as the main ecological gradient. Plant communities are ordered along the first Detrended Correspodence Analysis (DCA) axis in a typical hydroseries (Potametea → Lemnetea → Phragmition communis → Phalaridion arundinaceae, Oenanthion aquaticae and Sparganio-Glycerion → Magnocaricion elatae). The second DCA axis was most correlated with EIV for nutrients. Among the five directly measured ecological characteristics (temperature, pH and conductivity of water, water depth, and substrate type), conductivity of water (0.44, P < 0.01) and substrate type (0.32, P < 0.05) were the statistically significant variables explaining the variability along the first DCA axis. 相似文献
992.
Li H Jin G Qin J Tian M Shi J Yang W Tan X Zhang X Zou L 《Histochemistry and cell biology》2011,136(5):515-526
During the central nervous system (CNS) development, radial glia cells (RGCs) play at least two essential roles, they contribute
to neuronal production and the subsequent guidance of neuronal migration, whereas its precise distribution and contribution
to cerebral cortex remains less understood. In this research, we used Vimentin as an astroglial marker and Sox2 as a neural
progenitor marker to identify and investigate RGCs in rat cerebral cortex at embryonic day (E) 16.5. We found that the Sox2+
progenitor cells localized in the germinal zone (GZ) of E16.5 cerebral cortex, ~95% Sox2+ cells co-localized with Vimentin+
or Nestin+ radial processes which extended to the pial surface across the cortical plate (CP). In vitro, we obtained RG-like
cells from E16.5 cerebral cortex on adherent conditions, these Sox2+ Radial glia (RG)-like cells shared some properties with
RGCs in vivo, and these Sox2+ RG-like cells could differentiate into astrocytes, oligodendrocytes and presented the radial
glia—neuron lineage differentiation ability. Taken together, we identified and investigated some characterizations and properties
of Sox2+ RGCs derived from E16.5 cerebral cortex, we suggested that the embryonic Sox2+ progenitor cells which located in
the cortical GZ were mainly composed of Sox2+ RGCs, and the cortex-derived Sox2+ RG-like cells displayed the radial glia—neuron
lineage differentiation ability as neuronal progenitors in vitro. 相似文献
993.
Phillip A. Wadl Adam J. Dattilo Lisa M. Vito Robert N. Trigiano 《Plant Cell, Tissue and Organ Culture》2011,106(3):513-516
Pityopsis ruthii is an endangered herbaceous perennial species from the United States. In vitro multiplication of this species can be valuable
for germplasm conservation. Flower receptacles of P. ruthii were cultured on Murashige and Skoog medium (MS) supplemented with 11.4 μM indole-3-acetic acid (IAA) in combination with
2.2, 4.4 or 8.8 μM 6-benzyladenine (BA). Shoots were visible within 14–28 days and three plants were successfully rooted on
MS medium supplemented with 5.7 μM IAA. A two tailed t-test for paired-variates revealed that shoot regeneration on MS medium
amended with 11.4 μM IAA and 2.2 μM BA was significantly higher (P < 0.05) than on other treatments. Leaf explants were also cultured on MS not supplemented with growth regulators or supplemented
with 11.4 μM IAA in combination with 0, 2.2, 4.4 or 8.8 μM BA. Shoots were visible within 21–35 days and one plant was successfully
rooted on MS medium supplemented with 5.4 μM NAA. Shoot regeneration on MS medium augmented with 11.4 μM IAA and 2.2 μM BA
was significantly higher (P < 0.05) than the other treatments according to analysis of variance (ANOVA) with a rank transformation. Hyperhydricity and
rooting of shoots was problematic for explants derived from flower receptacles and leaf tissue, but viable plants were regenerated
using both explants sources indicating the potential role for micropropagation in the ex situ conservation of the species. 相似文献
994.
Kwek Yan Chong Richard T. Corlett Darren C. J. Yeo Hugh T. W. Tan 《Biological invasions》2011,13(7):1571-1577
Worldwide spread and establishment of alien plant species continues to accelerate and damage ecological and agricultural systems.
Early warning and prevention of high-risk introductions is the most cost-effective approach to minimise losses while maximising
benefits, and the Australian Weed Risk Assessment (A-WRA) system has been the most well-developed and successful predictive
scheme. However, any system would be limited if the results or scores were confined to the locality of assessment. We compiled
A-WRA scores conducted in four tropical to sub-tropical regions and tested the accuracy of these scores for predicting naturalisations
for a separate well-documented, equatorial, exotic flora where weed risk assessments have never been conducted. Receiver Operating
Characteristic (ROC) curves reflect high accuracies of predictions, comparable to those in other studies. No significant differences
in accuracy were found between each regional subset and the compiled set of scores. Our results show that A-WRA scores assessed
at one locality can be used for others of similar climate, increasing the utility of every species’ assessment. A global database
of A-WRA scores would enable rapid local decision-making in border controls on imported plant species. A growing record of
species assessments would also facilitate monitoring evolutionary and ecological aspects of invasive species. 相似文献
995.
Amandine Berthoud Pauline Maupu Camille Huet Antoine Poupart 《The International Journal of Life Cycle Assessment》2011,16(8):841-847
Purpose
A life cycle assessment (LCA) was conducted on winter wheat, based on real agricultural practices databases, on a sample divided into four production scenarios. The main objectives of this study are (1) to assess the environmental impact of winter wheat, using an LCA covering field practices, and the transport and storage of grain until it is sold to a miller; (2) to use the USEtox model (Rosenbaum et al. in Int J Life Cycle Assess 13:532–546, 2008) to assess the part of the total freshwater ecotoxicity impact due to pesticide use, its variability among plots, and to identify the active ingredients with the strongest impact; (3) and with the help of fungicide, insecticide, herbicide experts, to identify active ingredients to replace these high-impact pesticides and estimate the effect of such a substitution on total freshwater ecotoxicity. 相似文献996.
Pseudomonas putida E41 was isolated from oil-contaminated soil and showed its ability to grow on ethyl-benzene as the sole carbon and energy
source. Moreover, P. putida E41 show the activity of biodegradation of ethylbenzene in the batch culture. E41 showed high efficiency of biodegradation
of ethylbenzene with the optimum conditions (a cell concentration of 0.1 g wet cell weight/L, pH 7.0, 25°C, and ethylbenzene
concentration of 50 mg/L) from the results of the batch culture. The maximum degradation rate and specific growth rate (μmax) under the optimum conditions were 0.19+0.03 mg/mg-DCW (Dry Cell Weight)/h and 0.87+0.13 h−1, respectively. Benzene, toluene and ethylbenzene were degraded when these compounds were provided together; however, xylene
isomers persisted during degradation by P. putida E41. When using a bioreactor batch system with a binary culture with P. putida BJ10, which was isolated previously in our lab, the degradation rate for benzene and toluene was improved in BTE mixed medium
(each initial concentration: 50 mg/L). Almost all of the BTE was degraded within 4 h and 70–80% of m-, p-, and o-xylenes within 11 h in a BTEX mixture (initial concentration: 50 mg/L each). In summary, we found a valuable new strain of
P. putida, determined the optimal degradation conditions for this isolate and tested a mixed culture of E41 and BJ10 for its ability
to degrade a common sample of mixed contaminants containing benzene, toluene, and xylene. 相似文献
997.
NMR structural determination of large multi-domain proteins is a challenging task due to significant spectral overlap with
a particular difficulty in unambiguous identification of domain–domain interactions. Segmental labeling is a NMR strategy
that allows for isotopically labeling one domain and leaves the other domain unlabeled. This significantly simplifies spectral
overlaps and allows for quick identification of domain–domain interaction. Here, a novel segmental labeling strategy is presented
for detection of inter-domain NOEs. To identify domain–domain interactions in human apolipoprotein E (apoE), a multi-domain,
299-residues α-helical protein, on-column expressed protein ligation was utilized to generate a segmental-labeled apoE samples
in which the N-terminal (NT-) domain was 2H(99%)/15N-labeled whereas the C-terminal (CT-) domain was either 15N- or 15N/13C-labeled. 3-D 15N-edited NOESY spectra of these segmental-labeled apoE samples allow for direct observation of the inter-domain NOEs between
the backbone amide protons of the NT-domain and the aliphatic protons of the CT-domain. This straightforward approach permits
unambiguous identification of 78 inter-domain NOEs, enabling accurate definition of the relative positions of both the NT-
and the CT-domains and determination of the NMR structure of apoE. 相似文献
998.
Despite improved national censuses and “micro-demographic” studies, demographic processes and health conditions among indigenous populations in Amazonia and elsewhere in lowland Latin America are not well understood. A new source of demographic and health data has emerged in the past decade, namely meso-scale surveys initiated and administered by indigenous organizations. These surveys offer the potential for filling information gaps, shedding light on culturally specific factors that shape demographic processes and health, and empowering indigenous organizations with data that could inform health initiatives. This article assesses the indigenous-run survey “2005 Health Analysis of the Shuar and Achuar Nations” of eastern Ecuador in which the authors were involved, which reached 1,943 households in 257 communities in Morona-Santiago Province. We present findings on fertility, migration, sanitation, and health, and assess the strengths and weaknesses of the survey. We argue that despite flaws in the survey design and implementation, this survey revealed important linkages among fertility, migration, and health. Such surveys have the potential to provide much needed detail, representativeness, and cultural specificity that macro and micro data sources cannot provide. We conclude with recommendations to improve surveys of this type. 相似文献
999.
Haishan Tian Lu Tang Yi Wang Xiaojie Wang Lili Guan Jian Zhang Xiaoping Wu Xiaokun Li 《International journal of peptide research and therapeutics》2011,17(2):123-129
Recombinant human keratinocyte growth factor-2 (rhKGF-2) has previously been expressed in Escherichia coli using isopropyl-β-d-thiogalactopyranoside (IPTG), a non-metabolizable and expensive compound, as the inducer. In order to determine whether IPTG
could be replaced with the cheap and natural lactose to induce rhKGF-2 expression, we examined the expression of rhKGF-2 in
flask culture and 30-l fermentation using lactose as the inducer. The optimized fermentation induced with lactose resulted
in 1,382 g of cell mass, corresponding to a 84% enhancement in cell mass compared with IPTG induction. While the expression
level of rhKGF-2 induced with lactose was comparable to that induced with IPTG, the solubility of target protein was increased
by lactose induction than by IPTG induction. The recombinant protein was further purified by cation exchange and heparin-affinity
chromatography. 255 milligrams of pure rhKGF-2 was achieved per liter culture by lactose induction, 52% higher than that obtained
by IPTG induction. A preliminary biochemical characterization of purified rhKGF-2 was performed by Western blotting and mitogenic
activity analysis, and the results demonstrated that the purified lactose-induced rhKGF-2 could react with anti-human KGF-2
antibody and stimulate the proliferation of FGFR2-IIIb-transfected mouse BaF3 cells as IPTG-induced rhKGF-2 could do. 相似文献
1000.
Karen F Chambers Joanna F Pearson Davide Pellacani Naveed Aziz Miodrag Gužvić Christoph A Klein Shona H Lang 《Journal of biomedical science》2011,18(1):45