131 research outputs found
C-4. Current situation and challenge of beef cattle industry in China(Abstracts of the International Symposium on Recent Advances in Animal Science(IS-RAAS),Joint meeting of 2^<nd> IS-AS and 3^<rd> IS-IFS)
Comprehensive Evaluation of Emergency Shelters in Wuhan City Based on GIS
Emergency shelters, which reflect the city's ability to respond to and deal
with major public emergencies to a certain extent, are essential to a modern
urban emergency management system. This paper is based on spatial analysis
methods, using Analytic Hierarchy Process to analyze the suitability of the 28
emergency shelters in Wuhan City. The Technique for Order Preference by
Similarity to an Ideal Solution is further used to evaluate the accommodation
capacity of emergency shelters in central urban areas, which provides a
reference for the optimization of existing shelters and the site selection of
new shelters, and provides a basis for improving the service capacity of
shelters. The results show that the overall situation of emergency shelters in
Wuhan is good, with 96\% of the places reaching the medium level or above, but
the suitability level needs to be further improved, especially the
effectiveness and accessibility. Among the seven central urban areas in Wuhan,
Hongshan District has the strongest accommodation capacity while Jianghan
District has the weakest, with noticeable differences.Comment: the 29th International Conference on Geoinformatics, E
Optimized Design Method for Satellite Constellation Configuration Based on Real-time Coverage Area Evaluation
When using constellation synergy to image large areas for reconnaissance, it
is required to achieve the coverage capability requirements with minimal
consumption of observation resources to obtain the most optimal constellation
observation scheme. With the minimum number of satellites and meeting the
real-time ground coverage requirements as the optimization objectives, this
paper proposes an optimized design of satellite constellation configuration for
full coverage of large-scale regional imaging by using an improved simulated
annealing algorithm combined with the real-time coverage evaluation method of
hexagonal discretization. The algorithm can adapt to experimental conditions,
has good efficiency, and can meet industrial accuracy requirements. The
effectiveness and adaptability of the algorithm are tested in simulation
applications.Comment: the 29th International Conference on Geoinformatics, E
Effects of water content change path on laboratory and field compaction of lime stabilized expansive soil
Generally, the soil requires to be compacted in highway construction. The expansive soil is a special type of soil that is highly susceptible to variations in water content, which affects the degree of compaction at the same compaction energy. In the present study, a series of wet compaction tests and dry compaction tests were carried out in the laboratory. Laboratory test results show that dry compaction will produce a higher optimum water content and a higher maximum dry unit weight compared to wet compaction, because its matric suction is smaller. Field compaction tests were also conducted, the results showed that there might be a risk of under-compacting soils during construction caused by different water content change path in actual field conditions
Curvelet-Based Joint Waveform and Envelope Inversion of Early-Arrival Imaging Shallow Geological Structure
AbstractNear-surface imaging structures often plays a significant role in the field of environmental and engineering geophysics. Early-arrival waveform inversion (EWI) is state-of-the-art method to imaging near-surface structures due to its high resolution. However, the method faces with cycle-skipping issue which might lead to an unexpected local minimum. Envelope inversion (EI) could deal with this issue which contributes to the ultralow-frequency information extracted from the envelope but has a low resolution. We have developed a curvelet-based joint waveform and envelope inversion (CJWEI) method for inverting imaging near-surface velocity structures. By inverting two types of data, we are able to recover the low- and high-wavenumber structures and mitigate the cycle-skipping problem. Curvelet transform was used to decompose seismic data into different scales and provide a multiscale inversion strategy to further reduce non-uniqueness of waveform inversion efficiently. With synthetic test and real data application, we demonstrate that our method can constrain the anomalies and hidden layers in the shallow structure more efficiently as well as is robust in terms of noise. The proposed multiscale joint inversion offers a computational efficiency and high precision to imaging fine-scale shallow underground structures
Assessment of Ruminal Bacterial and Archaeal Community Structure in Yak (Bos grunniens)
The aim of this study was to determine the microbial community composition in the rumen of yaks under different feeding regimes. Microbial communities were assessed by sequencing bacterial and archaeal 16S ribosomal RNA gene fragments obtained from yaks (Bos grunniens) from Qinghai-Tibetan Plateau, China. Samples were obtained from 14 animals allocated to either pasture grazing (Graze), a grazing and supplementary feeding regime (GSF), or an indoor feeding regime (Feed). The predominant bacterial phyla across feeding regimes were Bacteroidetes (51.06%) and Firmicutes (32.73%). At genus level, 25 genera were shared across all samples. The relative abundance of Prevotella in the graze and GSF regime group were significantly higher than that in the feed regime group. Meanwhile, the relative abundance of Ruminococcus was lower in the graze group than the feed and GSF regime groups. The most abundant archaeal phylum was Euryarchaeota, which accounted for 99.67% of the sequences. Ten genera were detected across feeding regimes, seven genera were shared by all samples, and the most abundant was genus Methanobrevibacter (91.60%). The relative abundance of the most detected genera were similar across feeding regime groups. Our results suggest that the ruminal bacterial community structure differs across yak feeding regimes while the archaeal community structures are largely similar
Dynamic Alterations in Yak Rumen Bacteria Community and Metabolome Characteristics in Response to Feed Type
Current knowledge about the relationships between ruminal bacterial communities and metabolite profiles in the yak rumen is limited. This is due to differences in the nutritional and metabolic features between yak and other ordinary cattle combined with difficulties associated with farm-based research and a lack of technical guidance. A comprehensive analysis of the composition and alterations in ruminal metabolites is required to advance the development of modern yak husbandry. In the current study, we characterized the effect of feed type on the ruminal fluid microbiota and metabolites in yak using 16S rRNA gene sequencing and liquid chromatography-mass spectrometry (LC-MS). Bacteroidetes and Firmicutes were the predominant bacterial phyla in the yak rumen. At the genus level, the relative abundance of Bacteroidales BS11 gut group, Prevotellaceae UCG-003, Ruminococcaceae UCG-011, Bacteroidales RF16 group and Ruminococcaceae UCG-010 was significantly (P < 0.01) higher in the forage group compared to that in the concentrate group, while the concentrate group harbored higher proportions of Bacteroidales S24-7 group, Ruminococcaceae NK4A214, Succiniclasticum and Ruminococcus 2. Yak rumen metabolomics analysis combined with enrichment analysis revealed that feed type altered the concentrations of ruminal metabolites as well as the metabolic pattern, and significantly (P < 0.01) affected the concentrations of ruminal metabolites involved in protein digestion and absorption (e.g., L-arginine, ornithine, L-threonine, L-proline and β-alanine), purine metabolism (e.g., xanthine, hypoxanthine, deoxyadenosine and deoxyadenosine monophosphate) and fatty acid biosynthesis (e.g., stearic acid, myristic acid and arachidonic acid). Correlation analysis of the association of microorganisms with metabolite features provides us with a comprehensive understanding of the composition and function of microbial communities. Associations between utilization or production were widely identified between affected microbiota and certain metabolites, and these findings will contribute to the direction of future research in yak
Additional Serine/Threonine Phosphorylation Reduces Binding Affinity but Preserves Interface Topography of Substrate Proteins to the c-Cbl TKB Domain
The E3-ubiquitin ligase, c-Cbl, is a multi-functional scaffolding protein that plays a pivotal role in controlling cell phenotype. As part of the ubiquitination and downregulation process, c-Cbl recognizes targets, such as tyrosine kinases and the Sprouty proteins, by binding to a conserved (NX/R)pY(S/T)XXP motif via its uniquely embedded SH2 domain (TKB domain). We previously outlined the mode of binding between the TKB domain and various substrate peptide motifs, including epidermal growth factor receptor (EGFR) and Sprouty2 (Spry2), and demonstrated that an intrapetidyl hydrogen bond forms between the (pY-1) arginine or (pY-2) asparagine and the phosphorylated tyrosine, which is crucial for binding. Recent reports demonstrated that, under certain types of stimulation, the serine/threonine residues at the pY+1 and/or pY+2 positions within this recognition motif of EGFR and Sprouty2 may be endogenously phosphorylated. Using structural and binding studies, we sought to determine whether this additional phosphorylation could affect the binding of the TKB domain to these peptides and consequently, whether the type of stimulation can dictate the degree to which substrates bind to c-Cbl. Here, we show that additional phosphorylation significantly reduces the binding affinity between the TKB domain and its target proteins, EGFR and Sprouty2, as compared to peptides bearing a single tyrosine phosphorylation. The crystal structure indicates that this is accomplished with minimal changes to the essential intrapeptidyl bond and that the reduced strength of the interaction is due to the charge repulsion between c-Cbl and the additional phosphate group. This obvious reduction in binding affinity, however, indicates that Cbl's interactions with its TKB-centered binding partners may be more favorable in the absence of Ser/Thr phosphorylation, which is stimulation and context specific in vivo. These results demonstrate the importance of understanding the environment in which certain residues are phosphorylated, and the necessity of including this in structural investigations
GPU-Accelerated Anisotropic Random Field and Its Application in the Modeling of a Diversion Tunnel
In this paper, a GPU-accelerated Cholesky decomposition technique and a coupled anisotropic random field are suggested for use in the modeling of diversion tunnels. Combining the advantages of GPU and CPU processing with MATLAB programming control yields the most efficient method for creating large numerical model random fields. Based on the geological structural characteristics of red-bedded soft rocks in central Yunnan, anisotropic rock random fields and tunnel excavation with various rotation degrees are simulated. In the comparison of anisotropic random fields specifically, the relationship between the anisotropic rotation angle and the plastic zone, as well as the multiple measurements for the overall safety factor, are analyzed. The distribution of the plastic zone after excavation has a significant relationship with the random parameters of the anisotropic random field. When the stronger or weaker random parameters are located in the surrounding rock of the cavern, they will cause a change in the radius of the plastic zone. The overall safety factor of the anisotropic random field is relatively stable, with an average value of about 2, which mainly depends on the strength of the random parameter of the rock mass. Based on the random fluctuation of the suggested value in the engineering report, the simulation result is safe. This study can provide theoretical and technical support for the design and construction of relevant rock engineering in the red-bedded soft rock region of central Yunnan
A Dynamic Strain-Rate-Dependent Contact Model and Its Application in Hongshiyan Landslide
An earthquake-induced landslide, mainly affected by seismic movement, is a frequent large-scale geological hazard in hydraulic engineering. This paper proposed a rate-dependent strain-softened micromechanical contact model and implemented it in discrete element method code, namely, PFC. Using the PFC-FLAC coupling scheme, the Hongshiyan earthquake landslide is analyzed as a case study. The influence of the strain rate, damping, and topographic effect is discussed. The results indicate that the rate-dependent micromechanical model can give a reasonable seismic-induced failure process compared with the in situ situation and provide a numerical technique for earthquake-induced landslide analysis and rockfall hazard prediction
- …