Individual tree segmentation of airborne and UAV LiDAR point clouds based on the watershed and optimized connection center evolution clustering.

Light detection and ranging (LiDAR) data can provide 3D structural information of objects and are ideal for extracting individual tree parameters, and individual tree segmentation (ITS) is a vital step for this purpose. Various ITS methods have been emerging from airborne LiDAR scanning (ALS) or unmanned aerial vehicle LiDAR scanning (ULS) data. Here, we propose a new individual tree segmentation method, which couples the classical and efficient watershed algorithm (WS) and the newly developed connection center evolution (CCE) clustering algorithm in pattern recognition. The CCE is first used in ITS and comprehensively optimized by considering tree structure and point cloud characteristics. Firstly, the amount of data is greatly reduced by mean shift voxelization. Then, the optimal clustering scale is automatically determined by the shapes in the projection of three different directions. We select five forest plots in Saihanba, China and 14 public plots in Alpine region, Europe with ULS or ALS point cloud densities from 11 to 3295 pts/m2. Eleven ITS methods were used for comparison. The accuracy of tree top detection and tree height extraction is estimated by five and two metrics, respectively. The results show that the matching rate (R match) of tree tops is up to 0.92, the coefficient of determination (R 2) of tree height estimation is up to .94, and the minimum root mean square error (RMSE) is 0.6 m. Our method outperforms the other methods especially in the broadleaf forests plot on slopes, where the five evaluation metrics for tree top detection outperformed the other algorithms by at least 11% on average. Our ITS method is both robust and efficient and has the potential to be used especially in coniferous forests to extract the structural parameters of individual trees for forest management, carbon stock estimation, and habitat mapping.

Human Activity Changes During COVID-19 Lockdown in China-A View From Nighttime Light.

Strict lockdowns were implemented in China to fight Coronavirus Disease 2019 (COVID-19). We explored the nighttime light (NTL) of China's four cities in five stages of COVID-19 including case free period, newly appeared period, rising period, outbreak period, and stationary period. Using six categories of points of interest data ("company," "recreation," "healthcare," "residence," "shopping," and "traffic facility") and random forest models, we found that dimming light of four cities is associated with the epidemic development and human activity changes. When confirmed cases appeared, healthcare associated NTL radiance increased rapidly in Wuhan and Guangzhou, but decreased in the fourth and fifth stages. Companies in all cities were resuscitated in the fifth stage, while companies in Guangzhou was resuscitated in the fourth stage. Shopping related NTL radiance in Wuhan increased quickly in the fifth stage which indicated some resuscitation. In addition, compared to gross domestic product, the trend in electric power consumption was consistent with the trend in NTL radiance. The above findings contribute to the making of control policies for COVID-19 as well as other infectious diseases.

Performance of PBL-Based Image Teaching in Clinical Emergency Teaching.

At present, with the rapid increase of emergency knowledge and the improvement of people's requirements for medical quality, the traditional teaching mode cannot fully meet the needs of emergency teaching in the new era. This paper is aimed at improving the clinical emergency teaching mode by problem based learning (PBL) teaching method and improving the comprehensive ability of clinical emergency of medical students. This article proposes a problem-based PBL imaging teaching method, combining the characteristics and content of clinical emergency courses, focusing on students, highlighting the problem-solving process, and improving students' creative thinking ability. To cultivate students' interest in clinical learning, develop their self-learning ability, train their teamwork and communication skills, and cultivate their ability to set, question, and solve questions, so as to promote medical students' overall comprehensive ability to integrate specialized knowledge and clinical practice. In this paper, the PBL teaching method and the traditional teaching method of comparative experiments show that the PBL teaching method can more effectively highlight the characteristics of clinical emergency medicine teaching mode and make full use of the limited emergency teaching resources, so as to improve the quality of clinical emergency teaching. Compared with the traditional teaching mode, the theoretical knowledge and clinical operation skills of medical students under the PBL teaching mode are improved by 13%. Autonomous learning ability, communication ability, and creative thinking ability have also been relatively improved.

[Less-than-subtotal parathyroidectomy in MEN1-ralated primary hyperparathyroidism: a case report].

This case reported a case of multiple endocrine neoplasia type 1（MEN1）. The patient was admitted to hospital on January 17 2020 due to persistent ostealgia and the elevated calcium level in the last 2 years. Laboratory tests showed elevated parathyroid hormone（PTH） and serum calcium level, which were 2295 ng/L（normal, 10-69 ng/L） and 3.15 mmol/L（normal, 2.03-2.54 mmol/L）. Ultrasound of the neck found a solid nodule under the left inferior pole of thyroid, while 99mTc-MIBI SPECT/CT showed enhancement at the same place. Subsequently, cranial MRI found a tumor in sellar area, and abdominal MRI showed a tumor in left adrenal gland. Finally, the patient was diagnosed as MEN1.

Glycinergic Signaling in Macrophages and Its Application in Macrophage-Associated Diseases.

Accumulating evidences support that amino acids direct the fate decision of immune cells. Glycine is a simple structural amino acid acting as an inhibitory neurotransmitter. Besides, glycine receptors as well as glycine transporters are found in macrophages, indicating that glycine alters the functions of macrophages besides as an inhibitory neurotransmitter. Mechanistically, glycine shapes macrophage polarization via cellular signaling pathways (e.g., NF-κB, NRF2, and Akt) and microRNAs. Moreover, glycine has beneficial effects in preventing and/or treating macrophage-associated diseases such as colitis, NAFLD and ischemia-reperfusion injury. Collectively, this review highlights the conceivable role of glycinergic signaling for macrophage polarization and indicates the potential application of glycine supplementation as an adjuvant therapy in macrophage-associated diseases.

Germ-line mutations in WDR77 predispose to familial papillary thyroid cancer.

The inheritance of predisposition to nonsyndromic familial nonmedullary thyroid cancer (FNMTC) remains unclear. Here, we report six individuals with papillary thyroid cancer (PTC) in two unrelated nonsyndromic FNMTC families. Whole-exome sequencing revealed two germ-line loss-of-function variants occurring within a 28-bp fragment of WDR77, which encodes a core member of a transmethylase complex formed with the protein arginine methyltransferase PRMT5 that is responsible for histone H4 arginine 3 dimethylation (H4R3me2) in frogs and mammals. To date, the association of WDR77 with susceptibility to cancer in humans is unknown. A very rare heterozygous missense mutation (R198H) in WDR77 exon 6 was identified in one family of three affected siblings. A heterozygous splice-site mutation (c.619+1G > C) at the 5' end of intron 6 is present in three affected members from another family. The R198H variant impairs the interaction of WDR77 with PRMT5, and the splice-site mutation causes exon 6 skipping and results in a marked decrease in mutant messenger RNA, accompanied by obviously reduced H4R3me2 levels in mutation carriers. Knockdown of WDR77 results in increased growth of thyroid cancer cells. Whole-transcriptome analysis of WDR77 mutant patient-derived thyroid tissue showed changes in pathways enriched in the processes of cell cycle promotion and apoptosis inhibition. In summary, we report WDR77 mutations predisposing patients to nonsyndromic familial PTC and link germ-line WDR77 variants to human malignant disease.

A Germline CHEK2 Mutation in a Family with Papillary Thyroid Cancer.

Approximately 5% of all cases of papillary thyroid cancer (PTC) are inherited. However, the susceptibility gene(s) for nonsyndromic familial PTC (FPTC) remain unclear. We performed whole genome sequencing of peripheral blood DNA samples from two affected family members with PTC. CHEK2 transcript expression and the protein levels of CHK2 and p53 were evaluated in the thyroid tissues from two affected members of the kindred and sporadic PTC cases. The entire CHEK2 coding sequence was examined by Sanger sequencing in blood DNA samples from 242 sporadic PTC patients. We identified a novel heterozygous germline mutation in CHEK2 (c.417C→A) that was detected in all available affected members of a kindred with FPTC. This variant was found in only 1 out of 264,200 persons in the Genome Aggregation Database and the NHLBI Trans-Omics for Precision Medicine program. The CHEK2 c.417C→A variant introduces a premature termination codon (Y139X). We found reduced CHK2 protein expression in tumor samples from the two patients who carried the variant as compared with sporadic cases without the variant. The Y139X loss-of-function variant led to reduced p53 phosphorylation and decreased p53 protein level. In addition, two rare missense variants (R180C and H371Y) in CHEK2 were identified in 5 (2%) of 242 patients with sporadic PTC. Our findings suggest that the CHEK2 Y139X variant may be associated with FPTC.

Overexpression of HIPK2 attenuates spinal cord injury in rats by modulating apoptosis, oxidative stress, and inflammation.

HIPK2 is considered to be a tumor suppressor. It also has been implicated in several functions such as apoptosis and inflammation that are linked to spinal cord injury (SCI). However, whether HIPK2 ameliorates the neurological pain of SCI remains unclear. Here, we investigated the effects of HIPK2 on neurological function, oxidative stress, levels of inflammatory cytokines and expression of Bcl-2/Bax in an SCI model. Firstly, we evaluated the therapeutic effects of HIPK2 on neurological pain in the SCI rat using the Basso, Beattie and Bresnahan scores and H & E staining. Overexpression of HIPK2 significantly elevated the levels of brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF), and reduced the mRNA expression of Nogo-A and RhoA in SCI rats. Furthermore, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays showed that overexpression of HIPK2 significantly reduced the number of apoptotic cells. Overexpression of HIPK2 also decreased expression of Bax and Caspase-3 and elevated expression of Bcl-2 in the SCI model, indicating that HIPK2 exhibited its protective activity by inhibiting SCI-induced apoptosis. Then, we measured the serum concentrations of malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX). We also determined the mRNA and protein levels of nuclear factor-κB p65 unit, tumor necrosis factor-α (TNF-α), and interleukin (IL)-1ß. HIPK2 overexpression reduced oxidative stress and the levels of inflammatory cytokines compared with SCI control animals. Additionally, acetylation of HIPK2 was reduced in SCI rats. Overexpression of HIPK2 could enhance autophagy by elevating the expression of Beclin-1 and LC3-II while autophagy is regarded as a beneficial regulator to improve spinal cord injury. Together, overexpression of HIPK2 improved contusive SCI induced pain by modulating oxidative stress, Bcl­2 and Bax signaling, and inflammation, and also regulating autophagy.

[Study on multi-angular polarized spectrum characteristics of leaf based on some indoor experimental data].

In the present study, we acquired multi-angular polarized spectrum of three kinds of leaves with different surface structures, and calculated the multi-angular spectral degree of polarization DOP based on Stokes parameters to explore its variation tendency with wavelength and the relationship between the leaf polarized reflectance and its physiological parameters and the relative observational geometric condition. The results show that although the spectral degree of polarization of the 3 kinds of leaves has obvious differences in value because of the leaf surface structures, the general trend of the DOP curve keeps consistent, and this trend could be explained by analyzing the properties of both specular and diffuse components of the leaf reflectance. The peak value of the DOP appears in the specular direction of the principal plane, and grows with the increase in the incident zenith angle. The analysis of the data demonstrates that compared to the other two experimental bands, the near infrared band shows a better discrimination in showing the relationship between DOP and the observational geometric configuration for all the three kinds of leaves, but the value of the DOP is smaller. Considering the effect of variation in chlorophyll content, DOP of the red band has more stable value than the near infrared band, whereas the water content has barely influence in both of the bands.

[Morphological study on early development of brain derived neurophic factor-positive neurons in the frontal lobe of human fetus].

OBJECTIVE: To investigate the growth and development of brain derived neurophic factor(BDNF)-positive neurons in the frontal lobe of human fetus. METHODS: The expression of the BDNF-positive neurons in the frontal lobe of human fetus in the 2(nd),3(rd),and 4(th) month of gestation were observed with the streptavidin-biotin-complex/immunoperoxidase(SABC)method. RESULTS: By the second month of gestation,BDNF-positive neurons were seen in the subventricular layer of the frontal lobe of cerebellum.By the third month of gestation,BDNF-positive neurons in the central layer were in various shapes,with big nucleus,less cytoplasm,and small processes.By the fourth month of gestation,BDNF-positive neurons in the central layer grew larger in size,cytoplasm increased,the BDNF-positive expression was enhanced with deeper dyeing,and the nerve fibers and particles were distributed between neurons;also,the BDNF-positive neurons were seen in the marginal layer of the frontal lobe of cerebrum. CONCLUSION: BDNF-positive neurons may participate in the early development of the frontal lobe of cerebrum of human fetus.

[Inversion of winter wheat water content with the relationship between canopy parameters and spectra based on different irrigations].

In order to monitor the canopy water content of winter wheat, canopy spectrums of winter wheat with narrow-band were resampled to broad-band according to relative spectral response (RSR) function of TM5. And then, normalized different water index (NDWI) and simple water index (WI) were calculated with broad-band reflectance. Fuel moisture content (FMC) and equivalent water thickness for canopy (EWTc) were got using dry weight, fresh weight and leaf area (index). The results show that b7 of TM5 is better than b5 in inversing canopy water content of winter wheat. Meanwhile, NDWI is more suitable than WI. Suitable fitting equations are built with NDWI (b4, b7) for FMC and EWTc, whose R2 reaches to 0.576 9 and 0.695 6, respectively. Finally, the spatial mapping of canopy water content is done with fitting equations. The results demonstrate that canopy water content of winter wheat is high in west and low in east in the studied area, and it's high in booting stage and low in milk stage.

[Modeling polarimetric BRDF of leaves surfaces].

The purpose of the present paper is to model a physical polarimetric bidirectional reflectance distribution function (pBRDF), which can character not only the non-Lambertian but also the polarized features in order that the pBRDF can be applied to analyze the relationship between the degree of polarization and the physiological and biochemical parameters of leaves quantitatively later. Firstly, the bidirectional polarized reflectance distributions from several leaves surfaces were measured by the polarized goniometer developed by Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences. The samples of leaves include two pieces of zea mays L. leaves (young leaf and mature leaf) and a piece of E. palcherrima wild leaf. Non-Lambertian characteristics of directional reflectance from the surfaces of these three leaves are obvious. A Cook-Torrance model was modified by coupling the polarized Fresnel equations to simulate the bidirectional polarized reflectance properties of leaves surfaces. The three parameters in the modified pBRDF model, such as diffuse reflectivity, refractive index and roughness of leaf surface were inversed with genetic algorithm (GA). It was found that the pBRDF model can fit with the measured data well. In addition, these parameters in the model are related with both the physiological and biochemical properties and the polarized characteristics of leaves, therefore it is possible to build the relationships between them later.