Positive effects of brisk walking and Tai Chi on cognitive function in older adults: An fNIRS study.

Exercise has shown to have beneficial effects on cognition in older adults. The purpose of this study was to investigate the cortical hemodynamic responses during the word-color Stroop test (WCST) prior and after acute walking and Tai Chi exercise by functional near-infrared spectroscopy (fNIRS). Twenty participants (9 males, mean age 62.8 ± 5.2), first underwent a baseline WCST test, after which they took three WCST tests in a randomized order, (a) after sitting rest (control), (b) after 6 minutes performing Tai Chi Quan, and (c) after a bout of 6 minutes brisk walking. During these four WCST tests cortical hemodynamic changes in the prefrontal area were monitored with fNIRS. Both brisk walking and Tai Chi enhanced hemodynamic activity during the Stroop incongruent tasks, leading to improved cognitive performance (quicker reaction time). Brisk walking induced a greater hemodynamic activity in the right dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex (VLPFC) area, whereas Tai Chi induced a greater bilateral hemodynamic activity in the DLPFC and VLPFC areas. The present study provided empirical evidence of enhanced hemodynamic response in task- specific regions of the brain that can be achieved by a mere six minutes of brisk walking or Tai Chi in older adults.

Prefrontal cortical hemodynamics and functional network organization during Tai Chi standing meditation: an fNIRS study.

Introduction: Tai Chi standing meditation (Zhan Zhuang, also called pile standing) is characterized by meditation, deep breathing, and mental focus based on theories of traditional Chinese medicine. The purpose of the present study was to explore prefrontal cortical hemodynamics and the functional network organization associated with Tai Chi standing meditation by using functional near-infrared spectroscopy (fNIRS). Methods: Twenty-four channel fNIRS signals were recorded from 24 male Tai Chi Quan practitioners (54.71 ± 8.04 years) while standing at rest and standing during Tai Chi meditation. The general linear model and the SPM method were used to analyze the fNIRS signals. Pearson correlation was calculated to determine the functional connectivity between the prefrontal cortical sub-regions. The small world properties of the FC networks were then further analyzed based on graph theory. Results: During Tai Chi standing meditation, significantly higher concentrations of oxygenated hemoglobin were observed in bilateral dorsolateral prefrontal cortex (DLPFC), ventrolateral prefrontal cortex (VLPFC), frontal eye field (FEF), and pre-motor cortex (PMC) compared with the values measured during standing rest (p < 0.05). Simultaneously, significant decreases in deoxygenated hemoglobin concentration were observed in left VLPFC, right PMC and DLPFC during Tai Chi standing meditation than during standing rest (p < 0.05). Functional connectivity between the left and right PFC was also significantly stronger during the Tai Chi standing meditation (p < 0.05). The functional brain networks exhibited small-world architecture, and more network hubs located in DLPFC and VLPFC were identified during Tai Chi standing meditation than during standing rest. Discussion: These findings suggest that Tai Chi standing meditation introduces significant changes in the cortical blood flow and the brain functional network organization.

[Effects of Long-term Fertilization on Soil Nutrient Characteristics and Microbial Resource Restrictions in a Terrace on the Loess Plateau].

Long-term fertilization has an important effect on soil fertility and soil microbial activity. In order to explore the effects of long-term fertilization on soil extracellular enzyme activities and nutrient characteristics in a terrace on the Loess Plateau, we based our investigation on the long-term nutrient localization plot of Ansai Soil and Water Conservation Experimental Station, Chinese Academy of Sciences. We measured the soil physicochemical properties, microbial biomass, and extracellular enzyme activities of six fertilization treatments, which included no fertilization (CK); manure and nitrogen fertilization (MN); manure and phosphate fertilization (MP); manure, nitrogen, and phosphate fertilization (MNP); manure (M); and nitrogen and phosphate fertilization (NP). The results showed that all fertilization treatments significantly increased soil nutrient content and soil extracellular enzyme activities compared with that in CK. Correlation analysis showed that extracellular enzyme activity and soil physicochemical properties had an extremely significant correlation. The redundancy analysis indicated that soil nutrient and soil microbial biomass could explain 79.66% and 74.87% of the variation in soil extracellular enzyme activity and its stoichiometric ratio, respectively. Thus, the effects of fertilization on soil fertility were primarily through influencing soil extracellular enzyme activities indirectly. M, MN, MP, and MNP significantly improved soil organic carbon (SOC); soil total nitrogen (STN); and carbon (C), nitrogen (N), and phosphorus (P) source enzyme content; however, MNP changed the soil pH, which had an inhibitory effect on microbial activities. Vector analysis showed that the microbial communities of all treatments were in the condition of P limitation. Although MNP could alleviate the extent of P limitation, there was no significant difference between M and MP. Our study indicated that long-term application of manure[7500 kg·(hm2·a)-1]could meet the nutrient requirements of dryland crop growth, and long-term application of manure combined with phosphorus fertilization could alleviate the resource constraints faced by microorganisms. Consequently, our results provide a new insight into improving regional nitrogen excess.

Effect of Walnut Meal Peptides on Hyperlipidemia and Hepatic Lipid Metabolism in Rats Fed a High-Fat Diet.

As a natural active substance that can effectively improve blood lipid balance in the body, hypolipidemic active peptides have attracted the attention of scholars. In this study, the effect of walnut meal peptides (WMP) on lipid metabolism was investigated in rats fed a high-fat diet (HFD). The experimental results show that feeding walnut meal peptides counteracted the high-fat diet-induced increase in body, liver and epididymal fat weight, and reduce the serum concentrations of total cholesterol, triglycerides, and LDL-cholesterol and hepatic cholesterol and triglyceride content. Walnut meal peptides also resulted in increased HDL-cholesterol while reducing the atherosclerosis index (AI). Additionally, the stained pathological sections of the liver showed that the walnut meal peptides reduced hepatic steatosis and damage caused by HFD. Furthermore, walnut meal peptide supplementation was associated with normalization of elevated apolipoprotein (Apo)-B and reduced Apo-A1 induced by the high-fat diet and with favorable changes in the expression of genes related to lipid metabolism (LCAT, CYP7A1, HMGR, FAS). The results indicate that walnut meal peptides can effectively prevent the harmful effects of a high-fat diet on body weight, lipid metabolism and liver fat content in rats, and provide, and provide a reference for the further development of walnut meal functional foods.

Comparative genome analyses of four rice-infecting Rhizoctonia solani isolates reveal extensive enrichment of homogalacturonan modification genes.

BACKGROUND: Plant pathogenic isolates of Rhizoctonia solani anastomosis group 1-intraspecific group IA (AG1-IA) infect a wide range of crops causing diseases such as rice sheath blight (ShB). ShB has become a serious disease in rice production worldwide. Additional genome sequences of the rice-infecting R. solani isolates from different geographical regions will facilitate the identification of important pathogenicity-related genes in the fungus. RESULTS: Rice-infecting R. solani isolates B2 (USA), ADB (India), WGL (India), and YN-7 (China) were selected for whole-genome sequencing. Single-Molecule Real-Time (SMRT) and Illumina sequencing were used for de novo sequencing of the B2 genome. The genomes of the other three isolates were then sequenced with Illumina technology and assembled using the B2 genome as a reference. The four genomes ranged from 38.9 to 45.0 Mbp in size, contained 9715 to 11,505 protein-coding genes, and shared 5812 conserved orthogroups. The proportion of transposable elements (TEs) and average length of TE sequences in the B2 genome was nearly 3 times and 2 times greater, respectively, than those of ADB, WGL and YN-7. Although 818 to 888 putative secreted proteins were identified in the four isolates, only 30% of them were predicted to be small secreted proteins, which is a smaller proportion than what is usually found in the genomes of cereal necrotrophic fungi. Despite a lack of putative secondary metabolite biosynthesis gene clusters, the rice-infecting R. solani genomes were predicted to contain the most carbohydrate-active enzyme (CAZyme) genes among all 27 fungal genomes used in the comparative analysis. Specifically, extensive enrichment of pectin/homogalacturonan modification genes were found in all four rice-infecting R. solani genomes. CONCLUSION: Four R. solani genomes were sequenced, annotated, and compared to other fungal genomes to identify distinctive genomic features that may contribute to the pathogenicity of rice-infecting R. solani. Our analyses provided evidence that genomic conservation of R. solani genomes among neighboring AGs was more diversified than among AG1-IA isolates and the presence of numerous predicted pectin modification genes in the rice-infecting R. solani genomes that may contribute to the wide host range and virulence of this necrotrophic fungal pathogen.

[Effects of drought stress on the stoichiometric characteristics in different organs of three shrub species]. / 干旱胁迫对3种灌木不同器官化学计量特征的影响.

In order to explore how water stress affects the stoichiometric characteristics in leaves, stems, very fine roots (0-1 mm), fine roots (1-2 mm) and thick roots (>2 mm) of three shrub species, we studied the effects of three water treatments [(75±5)%, (55±5)% and (35±5)% of field water capacity (FC)] on the stoichiometric characteristics of different organs of Syringa oblata, Rosa xanthina and Forsythia suspensa in a pot experiment. The results showed that there were significant differences in nitrogen (N) and phosphorus (P) contents, C:N, C:P and N:P of the same organ among the three species. With the intensification of drought stress, there was no significant change of C content in all organs of the three species. The N content increased in leaves, but decreased gradually in stems. The N content in very fine roots and fine roots increased first and then decreased. The P content decreased in leaves and stems, while increased first and then decreased in very fine roots and fine roots. Under drought stress, leaf C:N decreased, C:P and N:P of leaf and stem increased. There was the strongest effect of drought stress on the C:N of very fine roots and C:P and N:P of leaves. There was the least effect of drought stress on C:N, N:P of thick roots and C:P of very fine roots. There was no significant correlation between the contents of C, N in soil and the contents of C, N and P in shrub organs, but soil P content was significantly correlated with the contents of C, N and P in leaves and roots. It was concluded that the relative P limitation in soil was the most important factor affecting the stoichiometric characteristics of shrub organs. Drought had different effects on the stoichiometry of different organs in different shrub species. The stoichio-metry of leaves and very fine roots was more sensitive to drought stress than that of other organs. Drought might affect the stoichiometric characteristics especially related to P in different organs of shrubs, mainly by affecting plant absorption of soil P and its distribution in different organs.

First Report of Colletotrichum siamense Causing Anthracnose on Zinnia elegans Jacq. in China.

Zinnia elegans (syn. Zinnia violacea), known as common zinnia, is one of the most spectacular ornamental plants in the family Asteraceae. Zinnia plants are widely cultivated in China for their impressive range in flower colours and profuse bloom over a long period. In April 2019, Zinnia plants grown in Ningbo Botanical Garden (29°56'57″N, 121°36'20″E) were found to have many circular necrotic lesions. In the early infection stage, the lesions appeared as small circular specks which developed later into large spots (15 to 32 mm diameter). Typical symptoms appeared to be grayish white centers with a chlorotic edges and disease incidence reached approximately 80% of plants in the affected field. Moreover, the growth of Zinnia plants was seriously affected by the disease. To identify the causative pathogen associated with the disease, 10 symptomatic leaves were collected from ten different Zinnia plants. Leaf tissues were cut from the lesion margins, surface sterilized with 75% ethanol for 30 seconds and rinsed three times in sterile distilled water. The leaf tissues were then dipped into 10% sodium hypochlorite for 2-3 minutes, washed three times in distilled water and dried on a sterile filter paper. After drying, the surface-sterilized leaf discs were transferred to potato dextrose agar (PDA) plates and incubated at 28°C for 2 to 3 days under the 12 h photoperiod. A total of ten pure fungal isolates were obtained and all the isolates displayed the same colony structure. Afterwards, three pure strains were randomly selected (F1, F3 and F5) for further study. The fungal colonies showed gray to brownish aerial mycelia with pink-colored masses of conidia. Conidia were one-celled, hyaline, cylindrical to subcylindrical, spindle-shaped with obtuse ends, measuring from 15.6 to 17.3 × 4.6 to 5.1 µm with both ends rounded. These morphological characteristics were consistent with the description of Colletotrichum gloeosporioides complex (Weir et al. 2012). The identity of a representative isolate, F3, was confirmed by a multilocus approach. Genomic DAN of isolate F3 was extracted and partial sequences of actin (ACT), chitin synthase (CHS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ribosomal internal transcribed spacer (ITS), manganese-superoxide dismutase (SOD2) , glutamine synthatase (GS), beta-tubulin (TUB2) and calmodulin (CAL) were amplified and sequenced as previously described (Weir et al. 2012). These nucleotide sequences were deposited in GenBank (accession MN972436 to MN972440, and MT266559 to MT266561; all sequences in FASTA format are shown (Supplementary S1). BLAST analysis of ITS, ACT, CHS, GAPDH and GS sequences from the F3 isolate revealed similarity to C. gloeosporioides voucher strain ZH01 with 100%, 100%，99%, 99% and 99% identity, respectively. SOD, TUB2 and CAL sequences showed similarity to C. siamense with 100%, 100% and 100% identity, respectively. The phylogenetic trees were constructed by Maximum Likelihood method (ML) using JTT model implemented in the MEGA 7. Results inferred from the concatenated sequences (ACT, CHS, GAPDH, ITS, SOD, GS, TUB2 and CAL) placed the isolate F3 within the C. siamense cluster (Supplementary S2). To confirm pathogenicity of the fungus, Koch's postulates were conducted by spraying 20 Zinnia plants (60-day-old) with a 1 × 106 conidia/ml suspension. Plants were maintained in the growth chamber at 25°C and 85% relative humidity. After 10 to 15 days, symptoms were observed on all inoculated leaves and resembled those observed in the field, whereas the control plants remained asymptomatic. Here, C. siamense was isolated only from the infected Zinnia leaves and identified by morphological and gene sequencing analyses. C. siamense has been reported in many crops in China (Yang et al. 2019; Chen et al. 2019; Wang et al. 2019). However, to our knowledge, this is the first report of anthracnose caused by C. siamense on Zinnia elegans in China. References Chen, X., Wang, T., Guo, H., Zhu, P. K., and Xu, L. 2019. First report of anthracnose of Camellia sasanqua caused by Colletotrichum siamense in China. Plant Dis. 103:1423-1423. Wang, Y., Qin, H. Y., Liu, Y. X., Fan, S. T., Sun, D., Yang, Y. M., Li, C. Y., and Ai, J. 2019. First report of anthracnose caused by Colletotrichum siamense on Actinidia arguta in China. Plant Dis. 103:372-373. Weir, B. S., Johnston, P. R., and Damm, U. 2012. The Colletotrichum gloeosporioides species complex. Stud. Mycol. 73: 115-180. Yang, S., Wang, H. X., Yi, Y. J., and Tan, L. L. 2019. First report that Colletotrichum siamense causes leaf spots on Camellia japonica in China. Plant Dis. 103:2127-2127.

[Kinetic parameters and temperature sensitivity of soil nitrogen and phosphorus transforming enzymes in Robinia pseudoacacia plantations under different vegetation zones on the Loess Plateau, China]. / é»„åœŸé«˜åŽŸä¸åŒæ¤è¢«å¸¦äººå·¥åˆºæ§æž—åœŸå£¤æ°®ç£·è½¬åŒ–é ¶åŠ¨åŠ›å­¦å‚æ•°åŠå ¶æ¸©åº¦æ•æ„Ÿæ€§.

Soil enzymes are catalysts for organic matter decomposition, the kinetic characteristics of which are important indicators of the catalytic performance of enzymes, with important role in evalua-ting soil health quality. We examined the responses of soil enzyme kinetic parameters to temperature change and the variation characteristics of their temperature sensitivity (Q10) in Robinia pseu-doacacia plantation soil under three different vegetation zones on the Loess Plateau. The results showed that the potential maximum reaction rate (Vmax) and the half-saturation constant (Km) of alanine transaminase (ALT), leucine aminopeptidase (LAP) and alkaline phosphatase (ALP) all increased linearly with the increasing incubation temperature. The zonal regularity of forest zone > forest-steppe zone > steppe zone was presented in Vmax. The temperature sensitivity of Vmax(Q10(Vmax)) ranged from 1.14 to 1.62, and the temperature sensitivity of Km(Q10(Km)) ranged from 1.05 to 1.47, with both values being lower in forest-steppe zone than other vegetation zones. In low and high temperature regions, the variations of Q10 in different soil enzymes differed among vegetation zones. Results from redundancy analysis showed that Q10 had a significant correlation with environmental variables, especially soil nutrients, indicating that Q10 would be affected by other environmental factors besides temperature.

[Soil Aggregate Stability and Its Stoichiometric Characteristics in Robinia pseudoacacia Forest within Different Vegetation Zones on the Loess Plateau, China].

With the aim of studying the effects of different vegetation zones on soil aggregate stability and its stoichiometric characteristics, the soils under Robinia pseudoacacia plantations located within different vegetation zones on the Loess Plateau were selected as the research object. Indicators including the content, stoichiometry, and stability of different aggregate fractions were analyzed. The results showed that the content of >2 mm and 0.25-2 mm, the mean diameter (EMWD), and the geometric mean diameter (EGMD) of aggregate fractions were in the order of forest zone > forest-steppe zone > grassland zone. However, the stability proxies of aggregate fractions across the three vegetation zones indicated that the content and erodibility (K factor) of 0.053-0.25 mm exhibited an opposite trend. The overall trend of the soil organic carbon and total nitrogen of aggregate fractions among the three vegetation zones was that the forest zone significantly overtopped the forest-steppe zone and grassland zone, while the content of total phosphorus showed no significant differences among the three vegetation zones. Additionally, the content of soil organic carbon and total nitrogen of < 0.053 mm and 0.25-2 mm was the highest among the different fractions in the grassland zone, while that of 0.053-0.25 mm and 0.25-2 mm was the highest in the forest-steppe zone. In contrast, there were no significant differences in the content of organic carbon and total nitrogen in the forest zone among the different aggregate fractions. The total phosphorus content topped in < 0.053 mm fractions in the grassland zone and the forest-steppe zone, while that in the forest zone had no significant differences among the different aggregate fractions. Besides, the C:N ratios of < 0.053 mm and 0.053-0.25 mm in the steppe zone and the forest-steppe zone were higher than that in the forest zone, while that of 0.25-2 mm and >2 mm had insignificant differences among the three vegetation zones. The C:P and N:P ratios of fractions in the forest zone were significantly higher than that in the forest-steppe zone and steppe zone. Overall, the stability and stoichiometry of soil aggregate fractions exhibited relatively significant differences among the three vegetation zones. Additionally, the stability, soil organic carbon, and total nitrogen content of aggregate fractions in the forest zone were generally higher than those in the forest-steppe zone and grassland zone.

Quantification of hydrogen peroxide in plant tissues using Amplex Red.

Reactive oxygen species (ROS) are by-products of photosynthesis and respiration in plant tissues. Abiotic and biotic stressors also induce the production and temporary accumulation of ROS in plants, including hydrogen peroxide (H2O2), whereby they can act as secondary messengers/chemical mediators in plant defense signaling and lead to programmed cell death. H2O2 acts as a hub for critical information flow in plants. Despite such key roles in fundamental cellular processes, reliable determination of H2O2 levels in plant tissues is hard to achieve. We optimized an Amplex Red-based quantitation method for H2O2 estimation from plant tissue lysate. The standard limit of detection and quantitation was determined as 6 and 18picomol respectively. In this study we also quantified constitutive and/or induced levels of H2O2 in three model plants, Pinus nigra (Austrian pine), Oryza sativa (rice), and Arabidopsis thaliana. Overall, assay sensitivity was in the nmolg-1 FW range. Commonly used additives for H2O2 extraction such as activated charcoal, ammonium sulfate, perchloric acid, polyvinylpolypyrrolidone, and trichloroacetic acid either degraded H2O2 directly or interfered with the Amplex Red assay. Finally, We measured stability of Amplex Red working solution over one month of storage at -80°C and found it to be significantly stable over time. With appropriate modifications, this optimized method should be applicable to any plant tissue.

First description and expression analysis of tumor necrosis factor receptor-associated factor 6 (TRAF6) from the swimming crab, Portunus trituberculatus.

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is a cytoplasmic adapter protein that mediates signals induced by the tumor necrosis factor receptor (TNFR) superfamily and the interleukin-1 receptor (IL-1R). In the present study, the full-length cDNA of TRAF6 (Pt-TRAF6) was identified in a marine crab, Portunus trituberculatus. Pt-TRAF6 ORF is predicted to encode a 599-amino acid protein, including a RING type zinc finger, two TRAF-type zinc fingers, and a meprin and TRAF homology (MATH) domain. The overall amino acid sequence identity between Pt-TRAF6 and other TRAF6s ranged from 50.9 to 51.3% for shrimp and from 16.1 to 19.4% for insects. The Pt-TRAF6 gene contains six exons and five introns, which is different from the organization of the insect TRAF6 gene. Pt-TRAF6 transcripts were broadly expressed in all tissues tested, and their expression was higher in hemocytes, gills, the intestine, and heart than in muscle. Interestingly, the level of Pt-TRAF6 transcript differed between male and female crabs. After Vibrio alginolyticus or lipopolysaccharide (LPS) challenge, the Pt-TRAF6 transcript was down-regulated in hemocytes and up-regulated in gills. Moreover, Pt-TRAF6 expression was altered sooner in the LPS challenge group than in the V. alginolyticus challenge group. These results indicate that Pt-TRAF6 may respond to Gram-negative bacterial infections.

1H-MRS assessment of the therapeutic effect of bilateral intraventricular BDNF infusion into APP/PS1 double transgenic mice.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by extracellular accumulation of amyloid deposits. Brain-derived neurotrophic factor (BDNF) is a neurotrophic factor whose levels have been shown to be decreased in AD brains. BDNF supplementation can offer improvement in the course of AD. However, the means of assessment are still relatively limited. In the present study, 1H-MRS was used to evaluate the therapeutic effects of bilateral intraventricular BDNF infusion into Alzheimer's disease APP/PS1 double transgenic mice. For comparison to the 1H-MRS observations, Fluoro-Jade B staining and immunofluorescence for beta amyloid peptides (Aß), glial fibrillary acidic protein, and tropomyosin-related kinase B (TrkB) were also performed. Our results showed that N-acetylaspartate (NAA) levels increased and myoinositol levels decreased in the BDNF group compared with the PBS group. However, the BDNF group NAA level was still lower than the control group at 6 weeks after infusion. These changes correlated with increased immunoreactivity for TrkB, decreased compact Aß peptide containing plaques, and decreased Fluoro-Jade B-positive cells in the BDNF-infused mice compared to vehicle controls. These findings demonstrate that 1H-MRS may be a promising means of evaluating the therapeutic effects of BDNF on AD.

Comparative study of genes expressed from rice fungus-resistant and susceptible lines during interactions with Magnaporthe oryzae.

Rice blast disease caused by Magnaporthe oryzae is the most important fungal disease of rice. To understand the molecular basis of interaction between the fungus and rice, we constructed a cDNA library from a rice-resistant line inoculated with M. oryzae. One hundred and fifty-three cDNA clones were sequence analyzed, of which 129 exhibited significant nucleotide sequence homology to known genes, 21 were homologous to unknown genes, while three clones did not match to any database. However, these three unmatched clones showed sequence homology at protein level in the protein databases and one of them encoded a disease resistance-related protein kinase and was abundant in the EST collection. Northern analysis showed that this disease resistance-related protein kinase gene was induced by inoculation and only expressed in the rice-resistant, but not susceptible, lines. Southern analysis showed that this gene was present in a single copy in the rice genome and co-segregated with the M. oryzae resistance in the cross of the resistant and susceptible lines. This study illustrates that sequencing of ESTs from inoculated resistant plants can reveal genes responsive to pathogen infection, which could help understand plant defense mechanisms.