A new species of forest hedgehog (Mesechinus, Erinaceidae, Eulipotyphla, Mammalia) from eastern China

The hedgehog genus Mesechinus (Erinaceidae, Eulipotyphla) is currently comprised of four species, M. dauuricus, M. hughi, M. miodon, and M. wangi. Except for M. wangi, which is found in southwestern China, the other three species are mainly distributed in northern China and adjacent Mongolia and Russia. From 2018 to 2023, we collected seven Mesechinus specimens from Anhui and Zhejiang provinces, eastern China. Here, we evaluate the taxonomic and phylogenetic status of these specimens by integrating molecular, morphometric, and karyotypic approaches. Our results indicate that the Anhui and Zhejiang specimens are distinct from the four previously recognized species and are a new species. We formally described it here as Mesechinus orientalis sp. nov. It is the only Mesechinus species occurring in eastern China and is geographically distant from all known congeners. Morphologically, the new species is most similar to M. hughi, but it is distinguishable from that species by the combination of its smaller size, shorter spines, and several cranial characteristics. Mesechinus orientalis sp. nov. is a sister to the lineage composed of M. hughi and M. wangi from which it diverged approximately 1.10 Ma

DNA repair proteins Metnase and PARP1 regulate DNA integration

2015 Spring.Includes bibliographical references.DNA integration occurs naturally in various formats and plays important roles in evolution. DNA integration also affects human and animal health. Various genome-editing tools have been developed based on site-specific DNA integration. In mammalian cells, DNA integration is largely random. The mechanism of random DNA integration is not fully understood but has close association with repair of double-strand DNA damage. There are two major pathways to repair double-strand breaks (DSBs), homologous recombination (HR) and non-homologous end joining (NHEJ). In mammalian cells, NHEJ occurs more frequently than HR, possibly explains why random integration is more efficient than homology-directed integration or gene targeting. Proteins function in DSB repair pathways often engage in DNA integration. Metnase is a fusion protein that only expresses in higher primates, including humans. Metnase contains a SET methyltransferase domain and a transposase domain. Metnase promotes efficiency and accuracy of NHEJ and promotes DNA integration. The SET domain dimethylates histone H3K36 at DSB sites, and the transposase domain binds to the human Mariner transposon Hsmar1 terminal inverted repeat (TIR) sequence specifically. Both domains have been shown to be important for the role of Metnase in NHEJ. In this study, we tested the role of Metnase in promoting plasmid integration. We hypothesized that Metnase promotes plasmid integration through its functions in the NHEJ pathway. Metnase enhances the efficiency and accuracy of NHEJ, we predict that overexpression of Metnase can prevent integrating plasmid and genomic DNA at integration sites from large deletions. Besides, if the specific TIR binding of Metnase can direct more DNA integration into the TIR sequence in the human genome, overexpression of Metnase would increase the ratio of DNA integration found at or nearby TIR region. To test this hypothesis, we mapped plasmid integration in the human cell line HEK293T at low and high levels of Metnase expression. Our results demonstrated that Metnase promotes plasmid DNA integration independently of TIR sequence in the human genome. Overexpression of Metnase suppressed microhomology-mediated DNA integration, supporting our hypothesis that Metnase promotes DNA integration through classical NHEJ (cNHEJ). In contrast to cNHEJ, alternative NHEJ (aNHEJ) utilizes a different set of core proteins to rejoin broken ends. Compared to cNHEJ, aNHEJ is more error-prone and considered as the major generator of chromosomal translocations. Initiation of aNHEJ requires end resection. PARP1 plays an important role in initiating aNHEJ by recruiting end resection factors to DSBs. PARP1 has also been shown to promote DSB-induced chromosomal translocations. Based on the structural similarity between chromosomal translocations and DNA integration, we hypothesized that PARP1 may promote a sub-set of DNA integration, possibly through aNHEJ. We tested the effects of two PARP1 inhibitors PJ34 and Olaparib on DNA integration. Surprisingly, the two inhibitors showed opposite effects on DNA integration. PJ34 suppressed DNA integration, while Olaparib promoted DNA integration. We then confirmed PARP1 promoted DNA integration in a stable PARP1 knockdown cell line. Future studies are needed to understand the engagement of PARP1 in DNA integration and interpret the result where Olaparib promotes DNA integration

Experimental Study on Active Control of Surge in a Centrifugal Compression System

An experimental study has been carried out on the active control of surge in a centrifugal compression system. With a computerized on-line control scheme, the surge phenomenon is suppressed and the stable operating range of the system is extended. In order to design the active control scheme and choose the desired parameters of the control system inputs, special emphases have been placed on the development of surge inception and the nonlinear interaction between the system and the actuator. By use of the method designed in the present work, the results of active control onsurge have been demonstrated for the different B parameters, different prescribed criteria and different control frequencies

An Ionization-Driven Air Plasma Jet

Non-thermal atmospheric pressure plasma jets (NAPPJs) using ambient air as the inducer are of particular and desirable interest but with significant challenges. In this study, we report an air APPJ driven by ionization in the afterglow region, resembling noble gas APPJs. A pin-to-nozzle electrode is used for the air plasma jet with a nanosecond-pulsed DC high voltage as the power supply. Results show that the nozzle diameter plays an essential role in forming the air plasma jet. When the nozzle diameter is 3 mm, the air APPJ is driven by ionization in the afterglow region which is proved by the following three phenomena. First, with an exposure time of 0.1 s, an obvious shiny line (the narrow channel plasma) formed by electron accumulation is observed in the jet. The narrow channel becomes much brighter with a grounding pin approaching the nozzle vertically. In comparison, there is no such phenomenon with a 1-mm diameter nozzle. Second, the afterglow region discharge current of the ionization-driven processes is hundreds of mA distinguished from airflow-driven processes, the afterglow region current of which is typically zero. By using E-FISH to measure the electric field in the afterglow region, it can detect the electric field which has a maximum value of 10.5 kV/cm. Third, the intensity of the N2+ band is much stronger with a 3-mm diameter nozzle than with a 1-mm diameter nozzle, indicating that the local electric field plays an important role in the discharge. We expect this study can offer useful guidelines on the design and understanding of ionization-driven air plasma jets.</p

Understanding the Corrective Effect of the Urban Growth Boundary Policy on Land Finance Dependence of Local Governments in China

The preference for land urbanization of local governments promotes urban sprawl, which leads to the dilemma of land finance dependence (LFD) of local governments and the negative constraints on the ecosystem of urban areas in China. However, how the urban growth boundary (UGB) policy corrects local governments&rsquo; reliance on land finance has not been discussed in depth. In July 2014, the UGB policy began to be piloted in fourteen cities in China, providing a setting to further reveal the effectiveness of the UGB policy. By constructing an evolutionary game simulation model to clarify the behavioral strategies that local governments tend to adopt in the context of the UGB policy implementation, this study proves that the effective implementation of the UGB policy, by controlling the urban land capacity, can help solve local governments&rsquo; LFD dilemma in China. The UGB policy consists of a set of technical means and policy tools that controls urban sprawl. It breaks the &ldquo;unlimited land capacity&rdquo; situation faced by local governments in China by limiting the urban land capacity within a given period of time, and has become a new solution to the dilemma of LFD. The implementation of the UGB policy highlighted the shortage of urban land, which has led to the increasing cost of land finance for local governments and constraints on local governments&rsquo; LFD behavior. The shortage has also forced local governments to adjust and optimize their fiscal revenue structure. The UGB policy induced ongoing evolution in the benefit distribution among relevant entities in land finance, motivated local governments and other entities to adjust their primary strategies, and made it possible to address the dilemma of LFD in China

A Novel CGM Metric-Gradient and Combining Mean Sensor Glucose Enable to Improve the Prediction of Nocturnal Hypoglycemic Events in Patients with Diabetes

Nocturnal hypoglycemia is a serious complication of insulin-treated diabetes, and it is often asymptomatic. A novel CGM metric-gradient was proposed in this paper, and a method of combining mean sensor glucose (MSG) and gradient was presented for the prediction of nocturnal hypoglycemia. For this purpose, the data from continuous glucose monitoring (CGM) encompassing 1,921 patients with diabetes were analyzed, and a total of 302 nocturnal hypoglycemic events were recorded. The MSG and gradient values were calculated, respectively, and then combined as a new metric (i.e., MSG+gradient). In addition, the prediction was conducted by four algorithms, namely, logistic regression, support vector machine, random forest, and long short-term memory. The results revealed that the gradient of CGM showed a downward trend before hypoglycemic events happened. Additionally, the results indicated that the specificity and sensitivity based on the proposed method were better than the conventional metrics of low blood glucose index (LBGI), coefficient of variation (CV), mean absolute glucose (MAG), lability index (LI), etc., and the complex metrics of MSG+LBGI, MSG+CV, MSG+MAG, and MSG+LI, etc. Specifically, the specificity and sensitivity were greater than 96.07% and 96.03% at the prediction horizon of 15 minutes and greater than 87.79% and 90.07% at the prediction horizon of 30 minutes when the proposed method was adopted to predict nocturnal hypoglycemic events in the aforementioned four algorithms. Therefore, the proposed method of combining MSG and gradient may enable to improve the prediction of nocturnal hypoglycemic events. Future studies are warranted to confirm the validity of this metric