46 research outputs found

    Structural variation and introgression from wild populations in East Asian cattle genomes confer adaptation to local environment

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    BACKGROUND: Structural variations (SVs) in individual genomes are major determinants of complex traits, including adaptability to environmental variables. The Mongolian and Hainan cattle breeds in East Asia are of taurine and indicine origins that have evolved to adapt to cold and hot environments, respectively. However, few studies have investigated SVs in East Asian cattle genomes and their roles in environmental adaptation, and little is known about adaptively introgressed SVs in East Asian cattle. RESULTS: In this study, we examine the roles of SVs in the climate adaptation of these two cattle lineages by generating highly contiguous chromosome-scale genome assemblies. Comparison of the two assemblies along with 18 Mongolian and Hainan cattle genomes obtained by long-read sequencing data provides a catalog of 123,898 nonredundant SVs. Several SVs detected from long reads are in exons of genes associated with epidermal differentiation, skin barrier, and bovine tuberculosis resistance. Functional investigations show that a 108-bp exonic insertion in SPN may affect the uptake of Mycobacterium tuberculosis by macrophages, which might contribute to the low susceptibility of Hainan cattle to bovine tuberculosis. Genotyping of 373 whole genomes from 39 breeds identifies 2610 SVs that are differentiated along a "north-south" gradient in China and overlap with 862 related genes that are enriched in pathways related to environmental adaptation. We identify 1457 Chinese indicine-stratified SVs that possibly originate from banteng and are frequent in Chinese indicine cattle. CONCLUSIONS: Our findings highlight the unique contribution of SVs in East Asian cattle to environmental adaptation and disease resistance

    Experimental Investigation of the Influence of Freeze–Thaw Mode on Damage Characteristics of Sandstone

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    The influence of rock weathering caused by freezing–thawing on stone cultural relics cannot be ignored. For immovable stone cultural relics, different parts under different environmental conditions will be under different freeze–thaw actions and suffer different degrees of damage. In this paper, three typical freeze–thaw cycle tests of sandstone are designed, namely immersion test, capillary action test, and periodic saturation test. The macroscopic and microscopic morphologies of rock samples under different freeze–thaw cycles were analyzed. Weathering indicators such as porosity, water content, wave velocity, and surface hardness were tested, as well as uniaxial compressive strength. The variation law of weathering index and uniaxial compressive strength under different freezing–thawing cycles was obtained, and the quantitative relationship between each index parameter was further analyzed. The results show that under different freezing–thawing conditions, the apparent morphology of rock samples is different, and the trend of weathering indexes is similar, but the rate of change is different. The water content of rock has a great influence on the test results of wave velocity but has little influence on the surface hardness. The function relationship between weathering index and compressive strength under different freezing–thawing modes is similar, but the fitting parameters are different. Finally, the strength and wave velocity damage factors were used to quantitatively evaluate the degree of rock weathering. The results show that the immersion freeze–thaw damage is the highest, the periodic saturated freeze–thaw damage is the second highest, and the capillary freeze–thaw damage is the least highest. This is consistent with the field observation results. The conclusion of this paper can provide reference for the detection of stone cultural relics and provides a scientific basis for the anti-weathering protection of stone cultural relics

    Study on SO42−/Cl− Erosion Resistance and Mechanism of Recycled Concrete Containing Municipal Solid Waste Incineration (MSWI) Powder

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    In this paper, the strength characteristics and erosion resistance of solid waste incineration (MSWI) powder were studied. Firstly, the optimum process for the preparation of regenerated powder from MSWI bottom slag by ball milling was determined as follows: rotational speed 350 r/min, time 45 min. The strength activity index of regenerated powder reached the maximum when the substitute content of powder was 30%. Secondly, the semi-erosion method was used to study the strength variation rule of mortar with different content of MSWI powder in semi-immersion of salt solution. It was found that the higher the content of MSWI powder, the greater the anti-erosion coefficient of mortar specimen. Finally, the capillary rise test, crystallization test and capillary pore water absorption test were used to study the total porosity, coarse capillary-pore porosity and fine-capillary pore porosity of concrete containing MSWI powder. The results showed that, with the increase in MSWI powder content, the above pore structure properties were improved. The results revealed the transport and crystallization process of salt solution in concrete mixed with MSWI powder and the mechanism of corrosion resistance

    Influence of Ground Motion Parameters on the Seismic Response of an Anchored Rock Slope

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    The seismic response of rock slopes is closely related to the dynamic characteristics of earthquakes. In this study, based on a numerical model of rock slopes with bolt support, the seismic responses of both anchored and unanchored rock slopes under different seismic waves are calculated. The results show that a “cumulative effect” of the relative permanent displacement of the slope is generated during seismic action, and it is found that the permanent displacement of the slope is caused by larger earthquake accelerations. The dynamic responses of an anchored slope are analyzed in terms of the wave type, frequency, amplitude, and duration and are compared with those of an unanchored rock slope. This comparison suggests that the nominal shear strain increases with the amplitude and duration, which decreases as frequency increases. The axial force is directly related to the surrounding rock strain. The maximum axial force of the bolt is near the rock interface, which shows that the structural plane of the slope plays a dominant role in the seismic response. The seismic waves are random, whereas the structural plane of the rock slope is certain. The seismic response characteristics of the slope under different earthquake conditions are similar, and the dynamic stability of the slope can be attributed to the structural analysis of the rock slope

    Differentiation Study of the Damage Characteristics of Rock Cultural Heritage Sites Due to the Sulfate Weathering Process

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    Salt crystallization represents one of the primary forms of weathering encountered in rock cultural heritage sites, with sulfate weathering having particularly notable destructive effects. This study focuses on sandstone and limestone, using them as test materials to conduct simulation experiments on sulfate weathering under specific environmental conditions. The experimental process involved documenting the surface morphology of the rock samples and analyzing changes in indicators such as wave velocity, hardness, composition, and pore size distribution. The degree of damage to the two types of rock was evaluated using the entropy weight–TOPSIS method, and the sensitivity of different weathering indicators in assessing the weathering of the two rocks was also discussed. The results revealed that sandstone exhibited obvious surface damage under sulfate erosion, with dissolution holes and pits surrounding the rock samples, while limestone primarily suffered damage at its edges. There were notable differences in the rate of attenuation observed in the macro and micro indicators between the two rock types. The wave velocity of both types of rocks exhibits linear attenuation while the intensity undergoes exponential change. It is worth noting that sandstone hardness demonstrates a pattern of “fast–rapid–slow–stable” decline characteristics, whereas limestone follows an exponential trend with an initial fast decline followed by a slower decline. Additionally, sandstone exhibited significantly greater damage and weathering thickness compared to limestone, owing to the involvement of complex and diverse physical and chemical reactions. The pore damage factor and macro-level indicators of the rock samples could be fitted using exponential and linear functions, respectively, although the fitting curves differed distinctly. The sensitivity indicators reflecting the weathering state of sandstone and limestone under sulfate erosion varied, with mass loss applicable to sandstone and porosity to limestone. Overall, with our research findings, we aim to provide a theoretical foundation for the anti-salination and precision protection of rock cultural heritage sites

    Study on the Seismic Performance of Small-Diameter Bolts Reinforced in Grottoes

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    The Yungang Grottoes, a World Heritage Site in Datong, consist of 252 caves that are noted for their collection of 5th- and 6th-century Buddhist grotto sculptures and reliefs. Various diseases have appeared in the grottoes under the general influence of natural and artificial factors. Bolt support is a commonly employed method for grotto reinforcement and has been widely applied in many projects. Small-diameter bolts have also been used in the reinforcement projects at the Yungang Grottoes, but the corresponding effect on the seismic performance of grottoes is still unclear. In this paper, a dynamic analysis via the numerical modelling of an ear grotto of the 19th grotto in Yungang is established, and the rock displacement, acceleration, and bolt axial force responses under a seismic wave are analyzed. The results show that the seismic dynamic responses of grottoes are greatly affected by the cliff structure. The displacement and acceleration responses of the cliff body vary greatly within the abrupt transition of the cliff structure. Based on this variation, the seismic capacity of small-diameter bolts in the vertical direction is greater than that in the horizontal direction. The axial force of a bolt is small at both ends of the bolt, large in the middle of the bolt, small on the top of a cliff, and large at the bottom of the cliff. Although the axial force is small, the upper rock mass of the grotto has a tendency to undergo relative movement compared with the outer rock mass. The results also indicate that based on the structural defects in the vertical direction of the cliff body caused by grotto excavation, the inclined angle of the bolt should be increased as far as possible or vertical support should be adopted to enhance the stability of the rock mass at the top of the grotto

    A Noise-Immune Kalman Filter and Modelling forPedestrian Traffic Loads

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    The definition of design load with walking crowd excitation on these slender structures is a significant problem to human-induced vibration. To capture the characteristics of walking crowd loads, this article researches both the ground reaction force and ground reaction moment for 36 healthy adults. Firstly, a oscillate system modeling walking leg is used to build a governing equation, which further transformed into the discrete state space. Then the Kalman method is applied to filter the noises for the measured ground reaction force, which can well remove the noises hiding in the measured signals. In addition, the Fourier series are used to model the ground reaction force and ground reaction moment, and the first six corresponding coefficients are obtained and analyzed. This work comprehensively explores the excitation force and moment from walking pedestrian feet. The result of this study provides the reference of load design for these slender structures such as footbridges, grandstands, or stations under crowd excitation

    A Retrospective Study of 52 Patients With Primary Small Cell Carcinoma of the Esophagus Treated With Radical Surgery

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    Background: Primary small cell carcinoma of the esophagus (SCCE) is a rare and extremely fatal disease. We aim to evaluate the efficacy of radical surgery for resectable SCCE and to explore potential prognostic factors. Methods: We retrospectively reviewed 52 consecutive SCCE patients who underwent radical surgery from February 1993 to November 2014 at a single institution. The Kaplan-Meier estimator with log-rank test was used to assess overall survival (OS), disease-free survival (DFS) and median survival time. Univariate and multivariable analyses were used to evaluate prognostic factors through Cox proportional hazard regression model. Results: Twenty-five (48.1%) patients were treated with surgery alone, whereas 27 (51.9%) patients underwent adjuvant therapy after surgery. The median OS time was 17.4 months (95% CI: 13.5-21.3). The median DFS time was 13.4 months (95% CI: 7.7-19.0). Patients whose tumors were located in the lower part of thoracic esophagus and the esophagogastric junction showed significantly better OS (27.0 vs. 13.2 months, P = 0.016) and DFS (27.0 vs. 11.3 months, P = 0.017) than those located in the upper and middle parts. Patients with N0 status experienced significantly better OS (21.4 vs. 11.6 months, P = 0.012) and DFS (21.4 vs. 8.6 months, P = 0.012) than those with N+ status. Patients whose tumor lengths were shorter than 5 cm had a better OS (17.4 vs. 5.7 months, P = 0.035) than those longer than 5 cm. Patients who underwent chemotherapy experienced a significantly improved OS (21.0 vs. 14.1 months, P = 0.032) compared to surgery alone. Multivariable analysis showed that lower tumor location, shorter tumor length, pN0 status and chemotherapy independently predicted better OS; lower tumor location and pN0 status independently predicted better DFS. Conclusions: Radical surgery in combination with chemotherapy has better outcomes than surgery alone for resectable SCCE. Higher tumor location, longer tumor length, lymph node metastasis and not undergoing chemotherapy independently predict worse prognoses

    Experimental study on salt weathering of sandstone with different weathering degrees

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    Due to lithological and environmental differences, the weathering degree of stone heritage varies even within the same area. Various factors dominate the weathering process at different stages. Implementing preventive measures has reduced the impact of controllable factors such as human activities. However, salt weathering caused by atmospheric pollutants, water, and salt migration in rock formations has emerged as a major contributor to the deterioration of stone heritage. Understanding the re-weathering characteristics of stone cultural heritage at different weathering degrees is crucial for preventive protection. This study investigated the weathering status of Nanshiku Temple and designed an experimental scheme based on field monitoring data. By controlling the number of freeze-thaw cycles, stones with different weathering degrees were prepared, and sulfate weathering simulations were conducted. The results revealed severe damage to sandstone due to Na2SO4 crystallization. Higher initial weathering degrees resulted in more pronounced deterioration and faster weathering rates. Surface hardness analysis approximated the decay process using a logarithmic function within a certain range but could not fully capture the overall weathering of the stone. Uniaxial compressive strength showed a strong correlation with weathering indices like p-wave velocity. These findings provide a theoretical basis for preventive protection efforts in stone cultural heritage

    Experimental Investigation of the Influence of Freeze–Thaw Mode on Damage Characteristics of Sandstone

    No full text
    The influence of rock weathering caused by freezing–thawing on stone cultural relics cannot be ignored. For immovable stone cultural relics, different parts under different environmental conditions will be under different freeze–thaw actions and suffer different degrees of damage. In this paper, three typical freeze–thaw cycle tests of sandstone are designed, namely immersion test, capillary action test, and periodic saturation test. The macroscopic and microscopic morphologies of rock samples under different freeze–thaw cycles were analyzed. Weathering indicators such as porosity, water content, wave velocity, and surface hardness were tested, as well as uniaxial compressive strength. The variation law of weathering index and uniaxial compressive strength under different freezing–thawing cycles was obtained, and the quantitative relationship between each index parameter was further analyzed. The results show that under different freezing–thawing conditions, the apparent morphology of rock samples is different, and the trend of weathering indexes is similar, but the rate of change is different. The water content of rock has a great influence on the test results of wave velocity but has little influence on the surface hardness. The function relationship between weathering index and compressive strength under different freezing–thawing modes is similar, but the fitting parameters are different. Finally, the strength and wave velocity damage factors were used to quantitatively evaluate the degree of rock weathering. The results show that the immersion freeze–thaw damage is the highest, the periodic saturated freeze–thaw damage is the second highest, and the capillary freeze–thaw damage is the least highest. This is consistent with the field observation results. The conclusion of this paper can provide reference for the detection of stone cultural relics and provides a scientific basis for the anti-weathering protection of stone cultural relics
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