•Phragmites australis was used as a bioindicator for wetland delimitation.•Modeling benefits from optimizing the selection of variables and resolution.•Wetlands are predicted to experience net loss ...in the future.•Wetlands expand towards areas with more rainfall and higher altitude under warming.•Priority areas for wetland restoration in the Songnen Plain were delimited.
Species distribution models (SDMs) are an effective tool in ecological restoration, but the application of SDMs in wetland restoration is rare owing to limited survey data. Based on field survey of the iconic, widespread wetland species Phragmites australis (Poaceae), we built maximum entropy (MaxEnt) models to study the current and future delimitation of wetlands in the Songnen Plain in Northeast China. In building the model, we evaluated the selection of environmental predictors and data resolutions. The evaluation showed the addition of soil and topo-hydrological (e.g. slope, Topographic Wetness Index, water table depth) variables significantly improved model performance in comparison with climate-only models, and the best model performance was under spatial resolution of 250 m. This study found that wetlands of the Songnen Plain are facing threats from climate change and anthropogenic expansion. The selected models predicted approximately a 15% net loss in suitable habitats, as well as expansion trends towards more humid and higher altitude areas in the future. Based on the modeling results, we delimited 1.51 × 103 km2 and 1.48 × 103 km2 of potential wetland restoration areas under RCP 4.5 and RCP 8.5 scenarios, respectively. Our study highlighted the importance of optimizing the selection of variables and spatial resolution in the application of SDMs in wetlands, and illuminated priority areas of the Songnen Plain for consideration in future wetland restoration efforts.
Based on sensor input, a robot arm should dynamically adjust its trajectory while maintaining stability to react to a sudden change in the target point in an unknown environment. To solve this ...problem, in this study, a time-optimized online trajectory generation (OTG) method is proposed using an S-curve velocity profile, which can generate trajectories in response to external sensor signals. The generated trajectory has characteristics that can guarantee the synchronization of multijoints according to an arbitrary initial state and a desired target state under velocity, acceleration, and jerk constraints. For multijoints time synchronization, two different characteristics are considered according to different application scenarios: minimum velocity or peak acceleration, which correspond to two sub-methods. The first one can be used to calculate with a minimum velocity peak, which can quickly adjust the trajectory according to the signal feedback. The second can be used to calculate the minimization of the acceleration peak, which can reduce the vibration of the robot arm due to a change in the motion. Compared with other OTG methods, the second proposed sub-method can effectively reduce the acceleration peak of the planned motion with the same synchronization time and parameters. Additionally, both sub-methods have the advantage of a rapid calculation and can generate time synchronization motion trajectories for 6 axes in 0.21 ms on a personal computer, fully satisfying the requirements of online motion planning. Finally, the effectiveness of the algorithm is verified by simulations and experiments with a lab-developed robot arm.
•A time-optimized and jerk-limited online trajectory generation algorithm that can be used to compute with either minimum velocity or acceleration peak is proposed.•The proposed algorithm can generate trajectories according to arbitrary initial motion state and generate a trajectory within 0.21ms for a 6-axis robot.•The minimum velocity peak OTG sub-method can change the current motion state with its maximum ability.•The minimum acceleration peak OTG sub-method applies to the occasions that require high motion smoothness and softness.
Periprosthetic joint infections (PJIs) have become the most catastrophic complication for patients after arthroplasty. Although previous studies have found that many biomarkers have good performance ...for diagnosing PJI, early diagnosis remains challenging and a gold standard is lacking. This study aimed to investigate the diagnostic accuracy of plasma fibrinogen (FIB) in detecting PJI compared to other traditional biomarks (CRP, WBC and ESR). A total of 156 patients (including 57 PJI and 99 non-PJI patients) who underwent revision arthroplasty were retrospectively reviewed from 01/2014 to 01/2020. The diagnostic criteria of PJI were mainly based on the definition from the evidence-based definition for periprosthetic joint infection in 2018. The optimal plasma FIB predictive cutoff was 4.20 g/L, the sensitivity of the plasma fibrinogen was 0.860, the specificity was 0.900, the positive predictive value (PPV) was 0.831, and the negative predictive value (NPV) was 0.908. The area under the curve (AUC) value of plasma fibrinogen was 0.916 (95% CI 0.869-0.964), and the CRP, ESR and WBC levels had AUCs of 0.901, 0.822 and 0.647, respectively. Plasma FIB demonstrated better diagnostic strength compared with that of other serum biomarkers before revision arthroplasty. It represents a new horizon for the diagnosis of PJI due to the diagnosis values and cost-effective features.
The flavonoid xanthohumol is an important flavor substance in the brewing industry that has a wide variety of bioactivities. However, its unstable structure results in its low content in beer. ...Microbial biosynthesis is considered a sustainable and economically viable alternative. Here, we harness the yeast Saccharomyces cerevisiae for the de novo biosynthesis of xanthohumol from glucose by balancing the three parallel biosynthetic pathways, prenyltransferase engineering, enhancing precursor supply, constructing enzyme fusion, and peroxisomal engineering. These strategies improve the production of the key xanthohumol precursor demethylxanthohumol (DMX) by 83-fold and achieve the de novo biosynthesis of xanthohumol in yeast. We also reveal that prenylation is the key limiting step in DMX biosynthesis and develop tailored metabolic regulation strategies to enhance the DMAPP availability and prenylation efficiency. Our work provides feasible approaches for systematically engineering yeast cell factories for the de novo biosynthesis of complex natural products.
The molecular composition of polycarbosilane (PCS) and its evolution in the synthesis process, as well as the contribution of each component to the spinnability of PCS, were explored by combining ...distillation separation with gel permeation chromatogram peak-splitting. The results show that PCS is composed of four kinds of molecules with different structures, namely M
, M
, M
, and M
(number-average molecular weights of 531, 1207, 2731, and 10 977, respectively). In the synthesis process, PCS changed from containing two components to three components, and finally to four components. The PCS can be spun when it is composed of M
, M
, and M
, but is not suitable for spinning when it is composed of one, two, or four components. For a PCS having three components, increasing the amount of M
and restricting M
to within a certain range can enhance the spinnability of PCS. The underlying mechanism is controlled by the linear structure of M
and its low melting point by there being an appropriate M
content, which ensures melting, de-foaming, and stability in spinning. The final optimum ratio is found to be an M
content of 30-45%, an M
content of 30-51%, and an M
content of 18-25%.
Programmed cell death (PCD) is a fundamental biological process. Deficiency in MOSAIC DEATH 1 (MOD1), a plastid-localized enoyl-ACP reductase, leads to the accumulation of reactive oxygen species ...(ROS) and PCD, which can be suppressed by mitochondrial complex I mutations, indicating a signal from chloroplasts to mitochondria. However, this signal remains to be elucidated. In this study, through cloning and analyzing a series of mod1 suppressors, we reveal a comprehensive organelle communication pathway that regulates the generation of mitochondrial ROS and triggers PCD. We show that mutations in PLASTIDIAL NAD-DEPENDENT MALATE DEHYDROGENASE (plNAD-MDH), chloroplastic DICARBOXYLATE TRANSPORTER 1 (DiT1) and MITOCHONDRIAL MALATE DEHYDROGENASE 1 (mMDH1) can each rescue the ROS accumulation and PCD phenotypes in mod1, demonstrating a direct communication from chloroplasts to mitochondria via the malate shuttle. Further studies demonstrate that these elements play critical roles in the redox homeostasis and plant growth under different photoperiod conditions. Moreover, we reveal that the ROS level and PCD are significantly increased in malate-treated HeLa cells, which can be dramatically attenuated by knockdown of the human gene MDH2, an ortholog of Arabidopsis mMDH1. These results uncover a conserved malate-induced PCD pathway in plant and animal systems, revolutionizing our understanding of the communication between organelles.
DnaJ proteins, which are molecular chaperones that are widely present in plants, can respond to various environmental stresses. At present, the function of DnaJ proteins was studied in many plant ...species, but only a few studies were conducted in tomato. Here, we examined the functions of a novel tomato (
) DnaJ protein (SlDnaJ20) in heat tolerance using sense and antisense transgenic tomatoes. Transient conversion assays of
protoplasts showed that SlDnaJ20 was targeted to chloroplasts. Expression analysis showed that
expression was induced by chilling, NaCl, polyethylene glycol, and H₂O₂, especially via heat stress. Under heat stress, sense plants showed higher fresh weights, chlorophyll content, fluorescence (Fv/Fm), and D1 protein levels, and a lower accumulation of reactive oxygen species (ROS) than antisense plants. These results suggest that
overexpression can reduce the photoinhibition of photosystem II (PSII) by relieving ROS accumulation. Moreover, higher expression levels of
and
were observed under heat stress in sense plants, indicating that
overexpression contributes to
expression. The yeast two-hybrid system proved that SlDnaJ20 can interact with the chloroplast heat-shock protein 70. Our results indicate that
overexpression enhances the thermotolerance of transgenic tomatoes, whereas suppression of
increases the heat sensitivity of transgenic tomatoes.
As a typical Information Centric Networking, Named Data Networking (NDN) has attracted wide research attentions in recent years. NDN evolves today's host-centric network architecture TCP/IP to a ...data-centric network architecture. It turns the end-to-end connection-oriented transport of TCP/IP into receiver-driven connectionless transport. Compared with the traditional TCP/IP networking, the transport in NDN has new characteristics: Receiver-driven, One-Interest-one-Data, Multi-Source, and Multi-Path. These distinguished features pose new challenges to NDN congestion control mechanisms. This paper presents a comprehensive survey of state-of-art techniques aiming to address these issues, with particular focus on improving the effectiveness of congestion detection and the efficiency of Interest rate shaping. As a new research area, this paper also points out research challenges and open issues in this subject.
In recent years, ultrawide bandgap semiconductor materials represented by aluminum nitride (AlN) have attracted worldwide attention due to their excellent high-frequency power characteristics, stable ...high-temperature performance, low energy loss, and good ultraviolet (UV) transmittance. They have great application prospects in the fields of high-efficiency optoelectronic devices, high-power and high-frequency electronic devices, ultra-high voltage power electronic devices, deep UV warning and guidance, and deep UV-LED disinfection. The physical vapor transport (PVT) method has the advantages of a simple growth process, fast growth rate, and high crystal integrity, and has gradually become one of the most effective methods for growing bulk AlN crystals. This review systematically summarizes the latest research progress in AlN crystals grown by the PVT method in recent years, and introduces their applications in deep UV-LEDs, UV lasers and Schottky barrier diodes (SBDs). Finally, the challenges and application prospects of AlN crystals are discussed. As an important new type of direct bandgap ultrawide bandgap semiconductor material, AlN crystals have shown extremely important strategic application value. The output power of deep UV-LED devices meets practical requirements, and high-power electronic power devices are still in the verification stage. From the perspective of material superiority, they have considerable development potential.
This review systematically summarizes the latest research advances of AlN crystals grown by the PVT method and their applications.
In the process of walking, attentional resources are flexibly allocated to deal with varying environmental constraints correlated with attentional control (AC). A dual-task paradigm was used to ...investigate the effects of AC on gait and inter-joint coordination. Fifty students volunteered to participate in this study. Based on the reaction time (RT) in the Stroop task, the top 15 participants were assigned to the High Attentional Control (HAC) group, while the last 15 participants were assigned to the Low Attentional Control (LAC) group. The participants in the two groups were randomly asked to perform three tasks: (i) single 2-back working memory task (ST 2-back); (ii) single walking task (ST walking); and (iii) dual task (DT). Cognitive outcomes and gait spatiotemporal parameters were measured. Continuous relative phase (CRP), derived from phase angles of two adjacent joints, was used to assess inter-joint coordination. The LAC group exhibited significant task effects regarding RT, correct rate (CR), step width, gait cycle, step time, forefoot contact times, heel-forefoot times, hip-knee mean absolute relative phase (MARP), and deviation phase (DP) in the stance and swing phases (
p
< 0.05). In the HAC group, significant task effects were only detected in RT and foot progression angle of the left foot (
p
< 0.05). Under the three task conditions, the LAC group exhibited a higher CR in ST, longer heel contact times, and longer heel-forefoot times when compared with the LAC group (
p
< 0.05). Compared with the LAC group, the HAC group exhibited significantly smaller (closer to zero) MARP and weaker hip-knee DP values in the swing phase across all gait conditions (
p
< 0.05). In the stance phase, the HAC group had smaller MARP (closer to zero) values when compared with the LAC group (
p
< 0.05). In conclusion, the ability to maintain gait control and modulate inter-joint coordination patterns in young adults is affected by the level of attentional control in accommodating gait disturbances. AC is correlated with the performance of motor control, which theoretically supports the competitive selection of athletes and fall prevention strategies for a specific population.
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