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Systemic vulnerability is an internal and essential factor that influences environmental sustainable development capability. Optimizing adjustments on systemic vulnerability significantly contributes to improved function, decreased disturbance, and guaranteed scientific evolution of environmental sustainable development capability. The connotation of systemic vulnerability of environmental sustainable development capability is defined and demonstrated. Measuring indexes, which reflect three aspects such as economic, ecological, and social subsystems, are established. With the application of the entropy-topsis model, statistical data from 1993 to 2012 in China are collected to carry out empirical research. The measuring values on systemic vulnerability are significantly below the standard values. On the basis of further analysis, adjustment strategy can be constituted for decreasing systemic vulnerability and improving environmentally sustainable development capability.
Antibiotics, as special pollutants in piggery wastewater, have negative effects on wastewater treatment processes. However, it is difficult to obtain a clear understanding of the toxic potency of antibiotics using the common inhibitory experiments of wastewater because of their low concentrations. Therefore, this study for the first time reports research on examining the toxic strength of piggery wastewater containing antibiotics by acute toxicity experiments using luminescent bacteria. Also reported herein for the first time were the mixed toxic effects of different antibiotics on luminescent bacteria using orthogonal experimental designs. Results showed that piggery wastewater had high ecotoxicity equal to 24.6 mg∙L⁻¹ HgCl₂, and the toxicity units (TU) of Chlortetracycline, amoxicillin, florfenicol, and sulfamethazine (SM₂) were 85.5, 64.72, 1.27, and 1.20, respectively, which fell under high or significant ecotoxicity according to the Toxicity Classification System (TCS). The IC₁₀ values indicated that the antibiotics could impose single or mixed toxic effects on luminescent bacteria even in trace concentrations. Among these antibiotics, Chlortetracycline was the most significant one needing more attention in the treatment of wastewater-containing antibiotics.
Knowledge about the impact of nitrogen (N) addition on soil respiration (Rs) is critical for understanding soil carbon (C) balance and its responses to climate change. We conducted a long-term field experiment to evaluate the response of Rs to N addition in a larch (Larix principis-rupprechtii) plantation during the growing season in northern China. We applied four N (in the form of NH₄NO₃) levels, i.e., control (N0: 0 g N m⁻² year⁻¹), low-N (N1: 5 g N m⁻² year⁻¹), medium-N (N2: 10 g N m⁻² year⁻¹), and high-N (N3: 15 g N m⁻² year⁻¹) monthly starting in June 2015. The results showed that N addition – especially N2 and N3 levels – significantly stimulated Rs. N1 and N2 levels resulted in the increase of Rs in a short time, whereas the duration of N3 level can last across the whole month or at least 10 days. The results highlight the need for improving the Rs sampling interval after N addition to ensure more accurate evaluation of C emission. Soil temperature and soil moisture together explained more variations of Rs. N addition exhibited a slight increase in the sensitivity of Rs to temperature (Q₁₀), but no significant differences were found for the Q₁₀ among N levels.
ASYMMETRIC LEAVES2-LIKE38/LBD41 gene of Arabidopsis is a member of the ASYMMETRIC LEAVES2 (AS2)/LATERAL ORGAN BOUNDARIES (LOB) domain gene family. To explore ASL38 function, we transformed 35S:ASL38 constructs into cockscomb (Celosia plumosus) plants via Agrobacterium tumefaciens and obtained T1 35S:ASL38 plants. The extremely folded or crinkly leaves were seen in these T1 cockscomb plants. The anatomical analysis of these malformed leaf blades indicated that adaxial cells revealed abaxialized traits, which were never seen in those of wild-type plants. These results suggested that ectopic expression of ASL38 might lead to alternations of dorsoventrality in folded or crinkly leaves of 35S:ASL38 cockscomb. In general, all data showed that ASL38 might be involved in dorsoventral determination in lateral organ development of plants.
ASYMMERTIC LEAVES2-LIKE38 (ASL38/ LBD41), isolated from Arabidopsis, is a member of the LATERAL ORGAN BOUNDARY DOMAIN gene family. We reported that ASL38 might be involved in the dorsoventral determination in extremely folded or crinkly leaves of 35S:ASL38.cockscomb plants; suggesting ASL38 is a transcript factor, and regulates a number of genes that are involved in the morphogenesis and development of plants. To verify this speculation, in this work, we constructed the binary vector pBI121–pMD-18T, which contained the GFP and coding sequences of ASL38, and introduced them into cockscomb via Agrobacterium tumefaciens. We found that ASL38-GFP fusion protein was localized in discrete subnuclear bodies, indicating ASL38 might be a nuclear protein and function as a transcription factor. In modification of flowering plants, many potentially useful genes that are involved in the pathways associated with flower and plant morphology have been cloned. Transcription factors regulating plant development and biosynthetic or regulatory genes involved in plant hormones are common candidates. If 35S:ASL38 cockscomb plants are altered in morphology, these morphological modifications could pave the foundation for the selection of novel flower varieties. As it was speculated by us, in this work, we showed that these 35S:ASL38 cockscomb flowered earlier and their flowers were turned into multiple column patterns, when compared with wild-type cockscomb. Moreover, leaves of some 35S:ASL38 plants revealed lobed and dissected patterns, and extremely, two leaf blades were developed on the same petiole; which was never found in wild-type cockscomb. Together, these morphological modifications of cockscomb indicate that we have successfully attained some novel lines of cockscombs. These lines can have potential practical applications.
The conotoxin-like (ctx) gene encodes a small cysteine-rich polypeptide in various baculoviruses. Previous research has demonstrated that the product of the ctx gene could be purified from insect cells infected by Autographa californica nuclear polyhedrosis virus (AcMNPV), but its function was unknown. In this paper, we compared the conserved cysteine motif structure (CX3GX2CX5CCX3CX6C) of the ctx gene in baculoviruses and generated recombinant Bombyx mori nuclear polyhedrosis virus (BmNPV) with the BmNPV bacmid system. !e recombinant BmNPV contained the ctx gene from AcMNPV or a fusion gene of ctx with eGFP, respectively. Fluorescence in CTX-eGFPpositive cells was mainly observed on the cell membrane. To gain insight into CTX function, two methods were used to elucidate the affect CTX had on hemolymph melanization in vivo and in vitro in insect larvae and pupae. The results indicated that CTX abrogates hemolymph melanization; however, the mechanisms require further evaluation.
Grazing exclusion with fencing has been widely implemented to rehabilitate degraded grasslands in China. However, the response of grassland ecosystems has remained controversial among sites and vegetation types. In this study, characteristics of vegetation and soil properties under degradation gradients (light and middle) and grazing exclusion were examined in the Maqin alpine meadow in August 2013. The results showed that grazing exclusion resulted in a significant recovery in vegetation with higher above- and below-ground biomasses, which reached 459.29 g·m⁻² and 5,657.93 g·m-2 in comparison with 132.53 g·m⁻² and 1,494.37 g·m⁻² in middle degraded plots, respectively. Soil bulk density in grazing exclusion decreased especially obviously in the 0-10 cm layer. Soil capillary and saturated water in grazing exclusion increased to 1,075.2 g·kg⁻¹ and 1,072.4 g·kg⁻¹, respectively, in the 0-10 cm layer. They also increased a little in the 10-20 cm layer. Grazing exclusion had significant positive effects on soil organic carbon and total nitrogen content, especially in the 0-10 cm layer. The results above indicated that grazing exclusion was an effective restoration approach to rehabilitate degraded alpine meadow in Maqin.
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