Seasonal dynamics of Zooplankton functional groups in relation to environmental variables in Xiquanyan Reservoir, Northeast China

In this study, the concept of functional feeding groups was used to classify and model the seasonal variation of zooplankton functional groups in relation to environmental variables. A total of 48 zooplankton species were observed in the reservoir and grouped into 8 functional groups. Both environmental variable and the biomass of zooplankton functional groups vary spatially and seasonally. Water temperature, water transparency, total nitrogen and nitrates were significantly higher in summer, while chlorophyll-a and ammonium were higher in autumn and spring, respectively. Biomass of zooplankton was significantly higher in summer (245.81 μg/L), followed by autumn (196.54 μg/L) and spring (54.25 μg/L). Group RF (rotifer filter feeders) dominated in spring, accounting for 80% of the total biomass. In summer and autumn, group RC (rotifer carnivore) and SCF (small copepods and cladocerans filter feeders) were the dominant, respectively. Total nitrogen, total phosphorus, ammonium, chlorophyll-a and water transparency were the major factor influencing zooplankton community. Group RF was positively influenced by ammonium and total phosphorus, while RC, SCF and MCF (middle copepods and cladocerans filter feeders) were positively correlated with chlorophyll-a. Top-down control of phytoplankton by groups RC, SCF and MCF in Xiquanyan reservoir is not strong enough to produce negative effect. Increase in predator size biomass did not strengthen top-down control on prey. It is quite clear that the zooplankton function groups of Xiquanyan reservoir followed a predictable seasonal pattern. This therefore highlights the significance of environmental variables in structuring plankton composition in the reservoir.The concept of functional feeding groups was used to classify and model the seasonal variation of zooplankton functional groups in relation to environmental variables. Zooplankton species were grouped into 8 functional groups that vary spatially and followed a predictable seasonal pattern. Total nitrogen, total phosphorus, ammonium, chlorophyll-a and water transparency were the major factor influencing zooplankton community. Top-down control of phytoplankton by zooplankton in Xiquanyan reservoir is not strong enough to produce negative effect

Spatial and temporal variation of phytoplankton functional groups in extremely alkaline Dali Nur Lake, North China

In this study, the concept of phytoplankton functional groups was used to assess phytoplankton community structure in an attempt to better understand their spatial and seasonal variation in extremely alkaline Dali Nur Lake. Samples were collected for analysis during spring, summer and autumn for a period of two years. We identified 13 phytoplankton functional groups (Lo, S1, H1, P, C, MP, X3, Y, X2, W1, J, F, and T) among 37 species out of which 7 groups Lo, H1, P, C, MP, X2, and F were dominant. The biomass of phytoplankton functional groups in the Lake exhibited a strong seasonal variation with the highest biomass value observed in autumn and lowest in spring. Functional groups MP, P, and C were dominant in spring when the temperatures were very low. Groups H1 and X2 were the dominant in summer corresponding to higher temperatures. In autumn groups Lo and X2 were the dominant corresponding to high levels of total phosphorus (TP). Our study revealed that alkalinity, pH, arsenic, chemical oxygen demand, and TP are the most important physical–chemical variables structuring the phytoplankton functional groups in Dali Nur Lake. Functional groups Lo and X2 were mainly influenced by TP while groups MP and P flourished better under high conditions of arsenic. This study reveals the importance of physical–chemical variables in the spatial and seasonal gradient, in structuring phytoplankton functional groups, and consequently in the assessment of environmental status of the lake

Seasonal dynamics of zooplankton functional group and its relationship with physico-chemical variables in high turbid nutrient-rich Small Xingkai Wetland Lake, Northeast China

In this study, the concept of functional traits was used to classify zooplankton into functional groups and their seasonal dynamics were determined in relation to physico-chemical factors in a highly turbid and nutrient-rich wetland. This study revealed a seasonal variation of both physico-chemical factors and biomass of zooplankton functional groups. Water temperature (TEP), total phosphorus (TP), ferrous ion (Fe2+) and total carbon (TC) were significantly higher in summer while water transparency (SD) was notably higher in spring. Zooplankton functional group biomass was higher in summer (5.11 mg/L) followed by winter, autumn and spring (0.91, 0.72 and 0.28 mg/L, respectively). Large copepods and cladoceran carnivore (LCC) was the dominant functional group in spring accounting for about 86.7% of the total biomass. In summer, MCF (Middle copepods and cladocerans filter feeders) was the dominant group probably because of the optimal temperature and availability of nutrients. Pearson correlation and RDA analysis results suggested that Fe2+, TP and TEP were the major factors influencing zooplankton functional groups. Notably, turbidity was not the main factor despite the fact that Small Xingkai Wetland Lake is a very turbid lake. The variation of zooplankton functional groups among seasons highlights the role of physico-chemical factors in structuring zooplankton composition

Bottom-up and top-down effects on phytoplankton functional groups in Hulun Lake, China

The debates about the extent to which phytoplankton in freshwater ecosystems are regulated by top-down or bottom-up forces have been ongoing for decades. This study examines the effects of bottom-up and top-down factors on the phytoplankton functional groups in a eutrophic lake. Phytoplankton and zooplankton were sampled and physical-chemical variables measured from May 2019 to October 2019 in Lake Hulun, China. Approximately 43 phytoplankton species were observed and grouped into 23 functional groups. For the zooplankton, about 27 species were observed and classified into 8 functional groups. The study revealed that the bottom-up effects of physical-chemical variables on some phytoplankton functional groups was stronger than the top-down effects of zooplankton. Water temperature (WT), total phosphorus (TP), total nitrogen (TN), conductivity (Cond), water transparency (SD), and dissolved oxygen (DO) significant influence the biomass of the phytoplankton functional groups. The biomass of phytoplankton functional groups was influenced positively by nutrient availability likely because nutrients influence the growth and reproduction of phytoplankton in freshwater. WT and DO had a positive influence on biomass of phytoplankton functional groups. Conversely, phytoplankton biomass revealed a decreasing trend when SD and Cond significantly increased. This study showed that zooplankton functional groups were positively correlated with phytoplankton biomass implying that the top-down control of phytoplankton by the zooplankton in the lake is not strong enough to produce a negative effect. It is evident that the zooplankton functional groups in Lake Hulun are controlled more by bottom-up force than top-down.This study examines the effects of bottom-up (physical-chemical) and top-down (predation) factors on the phytoplankton functional groups in a eutrophic lake. The study revealed that the bottom-up effects of physical-chemical variables on some phytoplankton functional groups was stronger than the top-down effects of zooplankton. The study further showed that zooplankton functional groups were positively correlated with phytoplankton biomass implying that the top-down control of phytoplankton by the zooplankton in Lake Hulun is not strong enough to produce a negative effect. These finding serve as a basis for identifying how phytoplankton dynamics are influenced, which have implications for developing sustainable management strategies and conserving services of Lake Hulun and other eutrophic fresh water lakes

Applications of cold atmospheric plasma in immune-mediated inflammatory diseases via redox homeostasis: evidence and prospects

As a representative technology in plasma medicine, cold atmospheric plasma (CAP) has beneficial outcomes in surface disinfection, wound repair, tissue regeneration, solid tumor therapy. Impact on immune response and inflammatory conditions was also observed in the process of CAP treatment. Relevant literatures were collected to assess efficacy and summarize possible mechanisms of the innovation. CAP mediates alteration in local immune microenvironment mainly through two ways. One is to down-regulate the expression level of several cytokines, impeding further conduction of immune or inflammatory signals. Intervening the functional phenotype of cells through different degree of oxidative stress is the other approach to manage the immune-mediated inflammatory disorders. A series of preclinical and clinical studies confirmed the therapeutic effect and side effects free of CAP. Moreover, several suggestions proposed in this manuscript might help to find directions for future investigation

Vitrification of Pronuclear Zygotes Perturbs Porcine Zygotic Genome Activation

Zygotic genome activation (ZGA) plays an essential role in early embryonic development. Vitrification is a common assisted reproductive technology that frequently reduces the developmental competence of embryos. However, the effect of vitrification on porcine ZGA and gene expression during ZGA remains largely unclear. Here, we found that vitrification of pronuclear zygotes derived from parthenogenetic activation (PA) and in vitro fertilization (IVF) resulted in a significant reduction in the rates of 2-cell, 4-cell, and blastocysts, but did not affect the quality of blastocysts. Functional research revealed that RNA polymerase II Inhibitor (α-amanitin) treatment significantly reduced global transcriptional activity and developmental efficiency of both 4-cell and 8-cell embryos, implying an essential role of ZGA in porcine early embryonic development. Furthermore, vitrification did not affect the synthesis of nascent mRNA of 2-cell embryos, but significantly inhibited global transcriptional activity of both 4-cell and 8-cell embryos, suggesting an impaired effect of vitrification on porcine ZGA. Correspondingly, the single-cell analysis showed that vitrification caused the downregulation or upregulation expression of maternal genes in 4-cell embryos, also significantly decreased the expression of zygotic genes. Taken together, these results indicated that vitrification of pronuclear zygotes impairs porcine zygotic genome activation

A Study of Phytoplankton Community Structure in Duobukuer Nature Reserve

In spring, summer, autumn 2015, we studied the seasonal variation of phytoplankton community structure in six rivers within Duobukuer Nature Reserve, and made preliminary evaluation of the water quality in Duobukuer Nature Reserve based on phytoplankton diversity. The results showed that a total of 7 phyla, 41 genera, 66 species and varieties of phytoplankton were identified in Duobukuer Nature Reserve; the annual species composition was dominated by diatom (59%) which also preponderated in dominant species (84.3%), biomass (68%) and abundance (75%), with no significant seasonal variation. Shannon-Wiener diversity index (H') and Pielou evenness index (J) were used to evaluate the water quality in 13 sampling points, and the results showed that the water quality was good in Duobukuer Nature Reserve, the sampling points 5, 6 and 12 presented β-pollution, and other sampling points were in an oligosaprobic-clean state

Phytoplankton functional groups response to environmental parameters in Muling River basin of northeast China

The present study was carried out in the biggest tributary of Ussuri River of boundary between China and Russia. The Muling River basin has undergone a long-term dredging works, and waterbody became seriously turbid. The succession of phytoplankton functional groups succession and environmental factors in the river were sampled in 2015. We totally identified 83 species, belonging to 17 functional groups which 5 were predominant, including group F, M, MP, P and Y. The seasonal succession of phytoplankton functional groups was M/P-F/MP/P-MP/P. Results of Spearman correlation analysis and canonical correspondence analysis (CCA) revealed that phytoplankton functional groups were mainly influenced by nutrient concentrations and light availability including total nitrogen (TN), ammonium nitrogen (NH4+–N), nitrate nitrogen (NO3−–N), N:P ratio (N:P), water depth (D) and transparency (SD) in the basin.The concept of functional feeding groups was used to classify and reveal the seasonal variation of phytoplankton functional groups in relation to environmental parameters. Phytoplankton species were grouped into 17 functional groups that vary significant spatially and seasonally. The pattern of phytoplankton functional groups seasonal successions decided by the five predominant functional groups. Total nitrogen, ammonium nitrogen, nitrate nitrogen, N:P ratio, water depth and transparency were the major factor influencing phytoplankton community in this basin

Spatiotemporal gait parameter fluctuations in older adults affected by mild cognitive impairment: comparisons among three cognitive dual-task tests

Abstract Backgrounds Gait disorder is associated with cognitive functional impairment, and this disturbance is more pronouncedly when performing additional cognitive tasks. Our study aimed to characterize gait disorders in mild cognitive impairment (MCI) under three dual tasks and determine the association between gait performance and cognitive function. Methods A total of 260 participants were enrolled in this cross-sectional study and divided into MCI and cognitively normal control. Spatiotemporal and kinematic gait parameters (31 items) in single task and three dual tasks (serial 100-7, naming animals and words recall) were measured using a wearable sensor. Baseline characteristics of the two groups were balanced using propensity score matching. Important gait features were filtered using random forest method and LASSO regression and further described using logistic analysis. Results After matching, 106 participants with MCI and 106 normal controls were recruited. Top 5 gait features in random forest and 4 ~ 6 important features in LASSO regression were selected. Robust variables associating with cognitive function were temporal gait parameters. Participants with MCI exhibited decreased swing time and terminal swing, increased mid stance and variability of stride length compared with normal control. Subjects walked slower when performing an extra dual cognitive task. In the three dual tasks, words recall test exhibited more pronounced impact on gait regularity, velocity, and dual task cost than the other two cognitive tests. Conclusion Gait assessment under dual task conditions, particularly in words recall test, using portable sensors could be useful as a complementary strategy for early detection of MCI