Research on deformation monitoring of surrounding rock based on weak fiber grating sensing technology

The prominent contradiction between high ground stress and low strength of surrounding rock in deep strata of coal mine leads to large deformation and instability disaster after roadway excavation. In order to grasp the internal deformation of surrounding rock before and after roadway excavation and support in time, this study developed a quasi-distributed large-range strain sensor cable based on weak fiber grating sensing technology, and realized the 1 m-level spacing arrangement of deformation measuring points in surrounding rock. The test performance of the sensor cable is mastered through the indoor calibration test. The test results show that the strain range of the developed strain sensing cable is not less than 0.04, the sensitivity is 1.23 pm/με, and the accuracy level is 0.5. It belongs to the high-precision sensor and has good repeatability and linearity. Field industrial test was carried out in deep rock roadway of No. 4 Coal Mine of Pingdingshan Tian’an Coal Shares The results show that: The strain value of surrounding rock decreases with the increase of hole depth. The strain value of surrounding rock within 4 m is larger, and the strain value outside 7 m is smaller and tends to be stable. The strain of roadway surrounding rock mainly occurs within 30 days after roadway repair, and then the strain increase of roadway surrounding rock gradually decreases and tends to be stable. Taking the rapid convergence position of strain rate to 0 as the boundary of surrounding rock loose zone, the boundary of roadway side and top loose zone is 5 m, and the boundary of shoulder loose zone is 4 m. Through the comprehensive application of weak fiber grating technology and time division multiplexing technology, the strain optical cable greatly improves the multiplexing capacity of optical fiber sensing network and meets the large range and fine online monitoring requirements of surrounding rock deformation monitoring in deep roadway of coal mine. Through technical application, the internal deformation characteristics of surrounding rock of deep roadway in coal mine and the spatio-temporal evolution law of loose circle can be mastered in time, which provides scientific basic data for the stability control decision of surrounding rock of deep roadway

Differential Responses of Net N Mineralization and Nitrification to Throughfall Reduction in a Castanopsis Hystrix Plantation in Southern China

Background Many regions in the world are experiencing changes in precipitation pattern, which likely impact soil nitrogen cycling and availability. However, we know little about how soil nitrogen processes respond to drought stress under climate change. Methods A continuous 5-year experiment of throughfall reduction treatment (TRT) was conducted in a Castanopsis hystrix plantation in subtropical China to assess how soil nitrogen processes responded to a change in precipitation. Net nitrogen transformation, soil properties, microbial biomass carbon (MBC) and nitrogen (MBN), and microbial community phospholipid fatty acids (PLFAs as bacteria, fungi and arbuscular mycorrhizal fungi (AMF)) were investigated in the wet and dry seasons over the period of the manipulation experiment. Results TRT had no significant effects on net ammonification rate (NAR) and nitrogen mineralization rate (NMR), and the unchanged NAR and NMR were mainly caused by the no change of soil nitrogen availability (i.e. NH4+-N, NO3−-N and dissolved organic nitrogen). However, TRT significantly increased net nitrification rate (NNR) in the wet season primarily due to the increase in NO3− concentration, and might be further caused by reduced NO3− leaching, denitrification or NO3−-N uptake in the TRT. Differently, TRT significantly decreased the NNR in the dry season, which might be linked to the limited SWC that resulted in greater microbial nitrate immobilization than gross nitrate mineralization. In addition, TRT significantly influenced the soil microbial community composition in 0–10 cm soil layer in the wet season, primarily due to the variations in NO3−-N, DOC and DON. Conclusions Precipitation reduction affected the NNR rather than NAR and NMR, and consequently, further affected soil N availability and N uptake by Castanopsis hystrix

Earthquake Trauma, Overgeneral Autobiographical Memory, and Depression Among Adolescent Survivors of the Wenchuan Earthquake

Trauma has a profound impact on overgeneral autobiographical memory (OGM), which is a risk factor for depression. Violent earthquakes can cause tremendous trauma in survivors. We examined the relationship between earthquake trauma, OGM and depression in adolescent survivors of the Wenchuan earthquake in this study. OGM was assessed using the autobiographical memory test in a sample of adolescent participants who experienced the violent earthquakes in Wenchuan, China, in 2008 and control participants who had never experienced a destructive earthquake. Depression was measured using the Beck Depression Inventory-II in all participants. The results showed that compared with the adolescents with no earthquake trauma, the adolescents with earthquake trauma reported significantly more depression (d = 0.49) and overgeneral autobiographical memories (d = 0.55). Moreover, when they experienced earthquake trauma, the adolescents with low OGM did not experience more depression, but the adolescents with average and high OGM experienced more depression than the adolescents with no earthquake trauma. This finding indicated that in a non-Western cultural context, adolescents’ propensity toward OGM made them vulnerable to depression after experiencing an earthquake trauma

Complete Genome Sequence of Industrial Biocontrol Strain Paenibacillus polymyxa HY96-2 and Further Analysis of Its Biocontrol Mechanism

Paenibacillus polymyxa (formerly known as Bacillus polymyxa) has been extensively studied for agricultural applications as a plant-growth-promoting rhizobacterium and is also an important biocontrol agent. Our team has developed the P. polymyxa strain HY96-2 from the tomato rhizosphere as the first microbial biopesticide based on P. polymyxa for controlling plant diseases around the world, leading to the commercialization of this microbial biopesticide in China. However, further research is essential for understanding its precise biocontrol mechanisms. In this paper, we report the complete genome sequence of HY96-2 and the results of a comparative genomic analysis between different P. polymyxa strains. The complete genome size of HY96-2 was found to be 5.75 Mb and 5207 coding sequences were predicted. HY96-2 was compared with seven other P. polymyxa strains for which complete genome sequences have been published, using phylogenetic tree, pan-genome, and nucleic acid co-linearity analysis. In addition, the genes and gene clusters involved in biofilm formation, antibiotic synthesis, and systemic resistance inducer production were compared between strain HY96-2 and two other strains, namely, SC2 and E681. The results revealed that all three of the P. polymyxa strains have the ability to control plant diseases via the mechanisms of colonization (biofilm formation), antagonism (antibiotic production), and induced resistance (systemic resistance inducer production). However, the variation of the corresponding genes or gene clusters between the three strains may lead to different antimicrobial spectra and biocontrol efficacies. Two possible pathways of biofilm formation in P. polymyxa were reported for the first time after searching the KEGG database. This study provides a scientific basis for the further optimization of the field applications and quality standards of industrial microbial biopesticides based on HY96-2. It may also serve as a reference for studying the differences in antimicrobial spectra and biocontrol capability between different biocontrol agents

Precision of Corneal Thickness Measurements Obtained Using the Scheimpflug-Placido Imaging and Agreement with Ultrasound Pachymetry

Purpose. To assess the reliability and comparability of measuring central corneal thickness (CCT) and thinnest corneal thickness (TCT) using a new Scheimpflug-Placido analyzer (TMS-5, Japan) and ultrasound (US) pachymetry. Methods. Seventy-six healthy subjects were prospectively measured 3 times by 1 operator using the TMS-5, 3 additional consecutive scans were performed by a second operator, and ultrasound (US) pachymetry measurements were taken. The test-retest repeatability (TRT), coefficient of variation (CoV), and intraclass correlation coefficient (ICC) were calculated to evaluate intraoperator repeatability and interoperator reproducibility. Agreement among the devices was assessed using Bland-Altman plots and 95% limits of agreement (LoA). Results. The intraoperators TRT and CoV were <19 μm and 2.0%, respectively. The interoperators TRT and CoV were <12 μm and 1.0%, respectively, and ICC was >0.90. The mean CCT and TCT measurements using the TMS-5 were 15.97 μm (95% LoA from −26.42 to −5.52 μm) and 20.32 μm (95% LoA from −30.67 to −9.97 μm) smaller, respectively, than those using US pachymetry. Conclusions. The TMS-5 shows good repeatability and reproducibility for measuring CCT and TCT in normal subjects but only moderate agreement with US pachymetry results. Caution is warranted before using these techniques interchangeably

Choosing legumes and perennial grasses

Many letters are received annually by the Iowa Agricultural Experiment Station requesting information on the different legumes and grasses. This publication has been prepared to answer the more important questions pertaining to the choice of legumes and grasses for different uses and conditions.2 Legumes of greatest value for different uses or soil conditions in Iowa are (1) alfalfa, (2) medium red clover, (3) mammoth red clover, (4) alsike clover, (5) white clover, (6) the biennial white and yellow sweet clovers, (7) hubam clover, (the annual white sweet clover) (8) Korean lespedeza, (9) dalea and (10) soybeans. A discussion of soybeans is largely omitted in this publication since the growing of this crop is entirely different from that of the others.

MSC-Derived Exosomes for Tissue Engineering and Disease Intervention

Mesenchymal stem cells (MSCs), also known as mesenchymal stromal cells or medicinal signaling cells or multipotent stem cells, are heterogeneous cell populations with unique immunomodulatory feature and hematopoietic-supporting capacity. MSCs function through a variety of approaches including paracrine and autocrine, direct- or trans-differentiation, bidirectional immunomodulation, and serving as constitutive microenvironment. Of them, exosomes and microvesicles function as the pivotal vehicle for mediating the ameliorative and therapeutic effect of MSCs toward various recurrent and refractory diseases, such as xerophthalmia, radioactive nasal mucosa injury, acute-on-chronic liver failure (ACLF), dermal chronic ulcers, and intrauterine adhesions. State-of-the-art renewal has also highlighted the promising prospective of MSC-derived exosomes (MSC-exo) and diverse biomaterial composites in regenerative medicine. In this book chapter, we mainly focus on the concept, biological phenotypes, preclinical research, and clinical practice of MSC-derived exosomes (MSC-Exos) and/or biomaterials, which will collectively supply overwhelming new references for the further development of MSC-Exos-based biotherapy and disease diagnosis in future