DRSNFuse: Deep Residual Shrinkage Network for Infrared and Visible Image Fusion.

Infrared images are robust against illumination variation and disguises, containing the sharp edge contours of objects. Visible images are enriched with texture details. Infrared and visible image fusion seeks to obtain high-quality images, keeping the advantages of source images. This paper proposes an object-aware image fusion method based on a deep residual shrinkage network, termed as DRSNFuse. DRSNFuse exploits residual shrinkage blocks for image fusion and introduces a deeper network in infrared and visible image fusion tasks than existing methods based on fully convolutional networks. The deeper network can effectively extract semantic information, while the residual shrinkage blocks maintain the texture information throughout the whole network. The residual shrinkage blocks adapt a channel-wise attention mechanism to the fusion task, enabling feature map channels to focus on objects and backgrounds separately. A novel image fusion loss function is proposed to obtain better fusion performance and suppress artifacts. DRSNFuse trained with the proposed loss function can generate fused images with fewer artifacts and more original textures, which also satisfy the human visual system. Experiments show that our method has better fusion results than mainstream methods through quantitative comparison and obtains fused images with brighter targets, sharper edge contours, richer details, and fewer artifacts.

Numerical Parametric Study of Coda Wave Interferometry Sensitivity to Microcrack Change in a Multiple Scattering Medium.

The expansion of cracks in 3D printing concrete materials may lead to structural failure, so it is essential to monitor crack propagation development. Coda wave interferometry (CWI) has been proven to be sensitive to microcracks, however, the evolution pattern of ultrasonic coda waves during crack growth is still not clear. This paper reports a numerical study of the sensitivity and feasibility of CWI for monitoring microcrack growth in heterogeneous materials. A two-phase concrete model, which contains microcracks with different angles and lengths, was developed using the finite element analysis software ABAQUS. The relative velocity change (Δv/v) and the decorrelation coefficient (Kd) at different crack increments were quantitatively analyzed. The numerical simulation results show that coda waves are sensitive to microcrack length as well as the crack angle. The Δv/v increases linearly with the increase of the length of a single microcrack, and the Kd could be linked to the crack length quadratically. Furthermore, a quantitative functional relationship between the CWI observations (Kd, Δv/v) and the angle of the crack to the source/receiver and the relative length growth of the crack are established. In addition, the nonlinear relationship between slope and angle can be fitted with a sinusoidal function. The reported results quantitatively assess the coda wave variation pattern during crack propagation, which is important for the promotion and application of CWI technology.

Are cognition and personality related in budgerigars?

In recent years, researchers have been attempting to relate differences in personality (e.g., boldness, aggressiveness, exploration tendency) to variation in cognition (performances in tasks that require learning, reasoning, attention, or memory, etc.) both theoretically and empirically. However, it is unclear on what basis personality and cognition might be associated with each other. Previous theory suggests a connection between fast-slow personality types and cognitive speed-accuracy tradeoffs. In this study, we tested this hypothesis in budgerigars and found that, in their 1st associative learning, birds with fast personality (less fearful of handling stress) were fast learners in the beginning, while slow personality individuals improved faster, but both types of birds did not differ in accuracy. However, these relationships were context-dependent. No significant relationship was found in subsequent learning tasks (reversal learning and a 2nd associative learning) in the familiar context (task setup and apparatus similar to the 1st associative learning). We then conducted a problem-solving experiment with novel setup and apparatus to test 1 possible explanation that the association between personality and cognition in the 1st associative learning might be caused by noncognitive constraint, such as fearfulness when facing novel task setup and apparatus. We found that fast individuals interacted more with the problem box and solved it, whereas the slow birds were not. We suggest that personalities can influence cognitive performances and trigger a cognitive speed-improvement tradeoff under the novel context. However, there are no consistent cognitive styles that co-varied with different personalities.

Understanding PM2.5 concentration and removal efficiency variation in urban forest park-Observation at human breathing height.

To increase our knowledge of PM2.5 concentrations near the surface in a forest park in Beijing, an observational study measured the concentration and composition of PM2.5 in Beijing Olympic Forest Park from 2014 to 2015. This study analyzed the meteorological factors and removal efficiency at 1.5 m above the ground (human breathing height) over the day in the forest. The results showed that the average concentrations of PM2.5 near the surface peaked at 07:00-09:30 and reached their lowest at 12:00-15:00. Besides, the results showed that the annual concentration of PM2.5 in the forest was highest during winter, followed by spring and fall, and was lowest during summer. The main chemical components of PM2.5 near the surface in the forest were SO4 2- and NO3 -, which accounted for 68.72% of all water-soluble ions that we observed. The concentration of PM2.5 in the forest had a significant positive correlation with relative humidity and a significant negative correlation with temperature. The removal efficiency near the surface showed no significant variation through the day or year. In the forest, the highest removal efficiency occurred between 07:00 and 09:30 in summer, while the lowest occurred between 09:30 and 12:00 in winter.

Reactivation of Denervated Schwann Cells by Embryonic Spinal Cord Neurons to Promote Axon Regeneration and Remyelination.

In peripheral nerve injuries (PNIs) in which proximal axons do not regenerate quickly enough, significant chronic degeneration of Schwann cells (SCs) can occur at the distal stump of the injured nerve and obstruct regeneration. Cell transplantation can delay the degeneration of SCs, but transplanted cells fail to generate voluntary electrical impulses without downstream signal stimulation from the central nervous system. In this study, we combined cell transplantation and nerve transfer strategies to investigate whether the transplantation of embryonic spinal cord cells could benefit the microenvironment of the distal stump of the injured nerve. The experiment consisted of two stages. In the first-stage surgery, common peroneal nerves were transected, and embryonic day 14 (E14) cells or cell culture medium was transplanted into the distal stump of the CPs. Six months after the first-stage surgery, the transplanted cells were removed, and the nerve segment distal to the transplanted site was used to bridge freshly cut tibial nerves to detect whether the cell-treated graft promoted axon growth. The phenotypic changes and the neurotrophic factor expression pattern of SCs distal to the transplanted site were detected at several time points after cell transplantation and excision. The results showed that at different times after transplantation, the cells could survive and generate neurons. Thus, the neurons play the role of proximal axons to prevent chronic degeneration and fibrosis of SCs. After excision of the transplanted cells, the SCs returned to their dedifferentiated phenotype and upregulated growth-associated gene expression. The ability of SCs to be activated again allowed a favorable microenvironment to be created and enhanced the regeneration and remyelination of proximal axons. Muscle reinnervation was also elevated. This transplantation strategy could provide a treatment option for complex neurological injuries in the clinic.

GDNF pretreatment overcomes Schwann cell phenotype mismatch to promote motor axon regeneration via sensory graft.

In the clinic, severe motor nerve injury is commonly repaired by autologous sensory nerve bridging, but the ability of Schwann cells (SCs) in sensory nerves to support motor neuron axon growth is poor due to phenotype mismatch. In vitro experiments have demonstrated that sensory-derived SCs overcome phenotypic mismatch-induced growth inhibition after pretreatment with exogenous glial cell-derived neurotrophic factor (GDNF) and induce motor neuron axonal growth. Thus, we introduced a novel staging surgery: In the first stage of surgery, the denervated sensory nerve was pretreated with sustained-release GDNF, which was encapsulated into a self-assembling peptide nanofiber scaffold (SAPNS) RADA-16I in the donor area in vivo. In the second stage of surgery, the pretreated sensory grafts were transplanted to repair motor nerve injury. Motor axon regeneration and remyelination and muscle functional recovery after the second surgery was compared to those in the control groups. The expression of genes previously shown to be differently expressed in motor and sensory SCs was also analyzed in pretreated sensory grafts by qRT-PCR to explore possible changes after exogenous GDNF application. Exogenous GDNF acted directly on the denervated sensory nerve graft in vivo, increasing the expression of endogenous GDNF and sensory SC-derived marker brain-derived neurotrophic factor (BDNF). After transplantation to repair motor nerve injury, exogenous GDNF pretreatment promoted the regeneration and remyelination of proximal motor axons and the recovery of muscle function. Further research into how phenotype, gene expression and changes in neurotrophic factors in SCs are affected by GDNF will help us design more effective methods to treat peripheral nerve injury.

In-situ organic phosphorus mineralization in sediments in coastal wetlands with different flooding periods in the Yellow River Delta, China.

In-situ incubation experiments were performed in typical tidal flooding wetlands and seasonal flooding wetlands in the Yellow River Delta of China to investigate sediment organic phosphorus (OP) mineralization and its influencing factors. The results showed that the sediment net P mineralization rate (RNPM) exhibited consistent seasonal variations in both wetlands, and it was more stable in the tidal flooding wetlands than in the seasonal flooding wetlands. Sediment P mineralization was greatly influenced by plant uptake and flooding erosion, and the freshwater input by flow-sediment regulation replenished the inorganic phosphorus (IP) pool in the wetland sediments. The OP, IP and total P in the sediments of the tidal flooding wetlands were in a state of dynamic equilibrium throughout the plant growing season, and plant uptake peaked during the period from August to September. In the seasonal flooding wetlands, rainfall and flow-sediment regulation were the key factors influencing the conversion between OP and IP. Besides sediment salinity and pH, microbial biomass and enzyme activities were also the key factors influencing the sediment RNPM in both wetlands. The findings of this study indicated that flooding frequencies and salinity could highly impact sediment P mineralization, and that the IP levels in sediments might be influenced by wetland hydrology and salinity.

Comparison of efficacy and complications between two types of staging arthroplasty in treating chronic septic hip arthritis: A retrospective clinical study.

Septic hip arthritis is a rare but serious disease, which is often persistent, able to transform into a chronic infection, and difficult to cure. The present study aimed to compare the midterm outcomes between the staging of a total hip arthroplasty via the Girdlestone surgery (a resection of the head and neck) and the Girdlestone combined with a cement spacer in treating chronic septic hip arthritis, as well as to compare the postsurgery efficacy and complications between the two groups. A total of 13 patients (14 total hip joints) were enrolled and retrospectively analyzed. For the stage I surgery, four patients (five hips) underwent the resection of the head and neck, and nine patients (nine hips) underwent the resection of the head and neck combined with the implantation of a bone cement spacer. After the infection was fully controlled, the patients in both groups underwent cementless total hip arthroplasties as stage II surgeries. The mean follow-up period was 24.2 months. The curative effects and complications of the patients were recorded and compared. It was found that the application of the staging arthroplasty for treating a chronic septic hip was conducive to the complete clearance of lesions. Notably, the implantation of a bone cement spacer containing antibiotics in the stage I surgery prevented joint contracture caused by a head and neck resection, reducing the risk of infection recurrence between the two stages of the operation. This effectively maintained the length of the lower limbs, simplified the stage II complete hip arthroplasty and reduced operative hemorrhage, thus achieving improved recovery of joint function after the stage II arthroplasty. The results suggested that the implantation of a cement spacer at the stage I surgery was more effective in treating chronic septic hip arthritis.