The Ecological Restoration of Heavily Degraded Saline Wetland in the Yellow River Delta

As a result of discontinuous water flow, agriculture, and increasing urban use of fresh water affecting the natural wetlands of the Yellow River Delta, these areas have experienced significant degradation in the past two decades, ultimately diminishing the overall natural wetland land area in the region. This study aimed to address the issue of decreasing fresh water in the Yellow River Delta by studying the effects of three different approaches to restoration on long-term wetland recovery. The results of the study demonstrated that soil salt and available Na contents significantly decreased in response to all three restoration treatments. Impacts of the restoration treatments were more significant in 2009 than in 2010, as shown by the high rate of activity in the reed debris group. The highest phosphatase activity of the experimental period was also observed in the reed debris group. Meanwhile, a marked variation in soil nutrient elements (total carbon (TC), total nitrogen (TN), available phosphorus, and available potassium) was observed in the restoration treatment plots throughout the experimental period. TC and TN contents were generally higher in the restoration treatment groups than in the control group. Moreover, urease and phosphatase activity levels were highly correlated with one another, as well as with soil nutrient elements. In 2009, the yield of the Suaeda salsa plant was highest in the reed debris treatment group and lowest in the ploughing treatment group. The S. salsa plant did show a positive response to all of the different restoration treatments. Taken together, these results suggest that restoration approaches that implement ploughing techniques aided in the restoration of degraded saline wetlands.As a result of discontinuous water flow, agriculture, and increasing urban use of fresh water affecting the natural wetlands of the Yellow River Delta, these areas have experienced significant degradation in the past two decades, ultimately diminishing the overall natural wetland land area in the region. This study aimed to address the issue of decreasing fresh water in the Yellow River Delta by studying the effects of three different approaches to restoration on long-term wetland recovery. The results of the study demonstrated that soil salt and available Na contents significantly decreased in response to all three restoration treatments. Impacts of the restoration treatments were more significant in 2009 than in 2010, as shown by the high rate of activity in the reed debris group. The highest phosphatase activity of the experimental period was also observed in the reed debris group. Meanwhile, a marked variation in soil nutrient elements (total carbon (TC), total nitrogen (TN), available phosphorus, and available potassium) was observed in the restoration treatment plots throughout the experimental period. TC and TN contents were generally higher in the restoration treatment groups than in the control group. Moreover, urease and phosphatase activity levels were highly correlated with one another, as well as with soil nutrient elements. In 2009, the yield of the Suaeda salsa plant was highest in the reed debris treatment group and lowest in the ploughing treatment group. The S. salsa plant did show a positive response to all of the different restoration treatments. Taken together, these results suggest that restoration approaches that implement ploughing techniques aided in the restoration of degraded saline wetlands

Eco-physiological response mechanism of Tamarix chinensis to soil water changes in coastal wetlands of the Yellow River Delta

Elucidating the effect of soil moisture on the adaptation of dominant plants in coastal wetlands is important for predicting the evolution of vegetation in the region. In this paper, Tamarix chinensis, a dominant species in the Yellow River Delta, was used as the object to study the changes of its growth and physiological parameters with increasing soil salinity under different moisture conditions (normal watering, persistent drought and persistent waterlogging). Different salt stress (2‰, 5‰, 8‰, 12‰, 16‰, and 20‰) using pot experiments was also used to reveal the mechanism of soil moisture on its salt tolerance. The results showed that the relative growth rate between 5‰-8‰ soil salinity was the largest, and growth was significantly inhibited above 20‰. Among different moisture conditions, the difference in relative growth rate under normal watering and persistent drought were nonsignificant, while both were significantly lower than those under persistent waterlogging. With increasing soil salinity, relative water content and total chlorophyll content significantly decreased, and cell membrane permeability (malondialdehyde), sodium ion, osmoregulatory substances (proline, soluble protein), and protective enzyme activity (SOD) significantly increased, while changes in non-structural carbohydrates (NSC) were not significant. Compared with normal watering and persistent waterlogging, persistent drought had the lowest leaf relative water content, total chlorophyll content, and sodium ions, and the highest cell membrane permeability, osmoregulatory substances and protective enzyme activity. With increasing treatment time, the relative leaf water content and total chlorophyll content significantly decreased, and cell membrane permeability, osmoregulatory substances and protective enzyme activity increased more significantly than normal watering and persistent waterlogging. NSC increased under normal watering and persistent waterlogging, while significantly decreased under persistent drought. Correlation analysis showed that the relationships between sodium ions, total chlorophyll content and malondialdehyde were various under different moisture conditions. Under persistent drough, malondialdehyde was significantly positively correlated with relative conductivity, superoxide dismutase, proline, soluble protein and soluble sugar. Total chlorophyll content was the key indicator reflecting the salt and waterlogging tolerance of T. chinensis under normal watering and persistent waterlogging, while cell membrane damage was under persistent drought. In summary, T. chinensis has strong salt and waterlogging tolerance, but persistent drought with salt stress can have serious impacts on its growth and survival

Efficient gene editing in adult mouse livers via adenoviral delivery of CRISPR/Cas9

AbstractWe developed an adenovirus-based CRISPR/Cas9 system for gene editing in vivo. In the liver, we demonstrated that the system could reach the level of tissue-specific gene knockout, resulting in phenotypic changes. Given the wide spectrum of cell types susceptible to adenoviral infection, and the fact that adenoviral genome rarely integrates into its host cell genome, we believe the adenovirus-based CRISPR/Cas9 system will find applications in a variety of experimental settings

Bibliometric Analysis of Coastal and Marine Tourism Research from 1990 to 2020

Coastal and marine tourism (CMT) has become a growing and important subsector of the tourism industry in recent years. To identify the state of and trends in the field, a bibliometric analysis of CMT was conducted to evaluate global productivity over the past 31 years (1990-2020). All relevant publications in the analysis were extracted from the Web of Science Core Collection database. As a result, the review found that the identified 6190 documents showed an upward trend during this time period. The most productive and influential countries, institutions, and authors were also identified in this analysis, and the distribution of subject categories and journals was analyzed. VOSviewer was used to analyze the coauthorships among countries, institutions, and authors. Based on an analysis of the high-frequency keyword co-occurrence network, four major CMT research topics were identified: (1) the sustainable development of CMT, (2) the impact of CMT on destinations, (3) CMT management and conservation, and (4) the impact of climate change on CMT. This analysis can help reveal and determine the research focus and trends in the CMT field

Quantitative evaluation of contrast-enhanced ultrasonography in the diagnosis of chronic ischemic renal disease in a dog model.

OBJECTIVES: The aim of this feasibility study was to prospectively explore in a dog model of chronic ischemic renal disease (CIRD) the hypothesis that real-time contrast-enhanced ultrasonography (CEUS) can quantitatively evaluate the early perfusion changes of renal cortex. MATERIALS AND METHODS: In this animal care and use committee-approved study, the model of CIRD was carried out in healthy dogs (10.0~12.0 kg, n=5), by placing the Ameroid ring constrictors on the distal portion of right renal artery through operation. CEUS monitoring of right kidney perfusion was performed by intravenous bolus injection of 0.6 ml Sulfur hexafluoride filled microbubbles (SonoVue; Bracco S.P.A., Milan, Italy) every week after operation. The slope rate of ascending curve (A) and descending curve (α), area under curve (AUC), derived peak intensity (DPI), and time to peak (TTP) were measured in renal cortex using commercial quantification software (Q-LAB version 6; Philips Medical Systems, Bothell,WA,USA). The sensitivity of CEUS was compared with blood serum urea nitrogen (BUN) and serum creatinine (SCr) level. RESULTS: With the progression of CIRD, dogs showed delayed enhancement and perfusion in renal CEUS curve. Earliest significant changes happened 4 weeks after operation on DPI and TTP which changed from 13.04 ± 2.71 to 15.58 ± 4.75 dB and 9.03 ± 2.01 to 10.62 ± 6.04 sec, respectively (P<.05). CONCLUSIONS: CEUS can display the perfusion changes of CIRD in the early period

Effects of Seed Size and Sand Burial on Germination and Early Growth of Seedlings for Coastal <i>Pinus thunbergii</i> Parl. in the Northern Shandong Peninsula, China

This paper examines the effects of seed size and the depth of sand burial on seed germination and seedling development for Pinus thunbergii. Parl. Seeds from 20- to 30-year old trees grown in the coastal area of Yantai were divided into three size categories (large, medium, and small). The seeds were sown in pots with different depth of sand, and their germination and seedling growth during the first month were investigated. Results showed that large seeds possessed the highest 1000-seed weight and soluble sugar concentration. Large and medium seeds had a higher germination rate, germination index, vigor index, and seedling biomass than small seeds. With the increase in seed size, root mass ratio, root/shoot ratio, specific root length, and specific root area decreased, whereas leaf mass ratio increased. Sand burial depth significantly influenced seed germination and seedling growth, and the highest germination rate and seedling biomass were achieved with 2&#8211;3 cm sand burial. We also found that seedling biomass was positively related to germination rate, germination index, and vigor index, but was negatively related to mean germination time. Moreover, seedling biomass was negatively correlated with root mass ratio and root/shoot ratio, but positively correlated with leaf mass ratio, specific root length, and specific root area. The results suggest that seed size and sand burial depth are key factors in the regeneration of the coastal P. thunbergii forest

Characterization of Focal Liver Lesions Indistinctive on B Mode Ultrasound: Benefits of Contrast-Enhanced Ultrasound

Aim. The aim of this prospective study was to evaluate the additional value of contrast-enhanced ultrasound (CEUS) in identifying and characterizing of focal liver lesions (FLLs) that are indistinctive on B mode ultrasound (BMUS). Methods. The study focused on 70 consecutive patients (male 46, female 24; mean age, 53.1 years ± 10). All lesions were detected by MRI but could not be clearly visualized by BMUS. CEUS was performed by injected SonoVue® (Bracco Imaging Spa, Milan, Italy) as a quick bolus into the antecubital vein. All lesions were proved by pathologic and MRI findings as primary or metastatic hepatic malignancies. Results. On CEUS, 45 (64.2%) FLLs displayed arterial hyperenhancement and 55 (78.5%) lesions showed hypoenhancement in portal venous and late phase (PVLP). Homogeneous and complete hyperenhancement pattern during the arterial phase is highly suspicious for HCC in liver cirrhosis (96.8%). Arterial isoenhancement and early washout during PVLP are characteristic for metastasis (73.3%). For recurrence lesions, arterial hyperenhancement and isoenhancement during PVLP are more common (60%). Conclusion. CEUS may provide added diagnostic values in FLLs appearing indistinctive on BMUS. Presence of early arterial enhancement and washout during PVLP may be helpful for detection of those lesions

Effects of Groundwater Mineralization and Groundwater Depth on Eco-Physiological Characteristics of Robinia pseudoacacia L. in the Yellow River Delta, China

Groundwater plays a significant role in influencing the growth and distribution of Robinia pseudoacacia L. plantations, with the largest planting area in the Yellow River Delta, by affecting the soil water&ndash;salt environment. This study aimed to clarify the mechanism of groundwater&rsquo;s influence on the growth of R. pseudoacacia under different levels of groundwater mineralization (GWM) and groundwater depth (GWD). We simulated GWM of 0, 2 and 4 g L&minus;1, and GWD of 0.8, 1.3 and 1.8 m. As GWM increased, soil relative water content (SRWC) and soil salt (dissolved salt) content (SSC) increased; sapling biomass (SB), stem mass (SM), leaf mass (LM), photosynthesis characteristics (maximum net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (E) and water use efficiency (WUE)) decreased; root mass (RM), root mass ratio (RMR) and root&ndash;shoot ratio (RSR) first increased then decreased; stem mass ratio (SMR) first decreased then increased; and leaf mass ratio (LMR) increased. As GWD increased, SRWC decreased, but SSC first increased then decreased; SB, RM, RMR, RSR, and photosynthesis characteristics increased; SM and LM first increased then decreased; and SMR and LMR decreased. SRWC and SSC were negatively correlated with SB and photosynthesis characteristics. SRWC was negatively correlated with RMR and RSR, whereas it was positively correlated with LMR. SSC was negatively correlated with SMR, whereas it was positively correlated with LMR. The first principal component, including SB, RM, and photosynthesis characteristics, was related to sapling growth. The second principal component, including RMR, SMR, and RSR, was mainly related to biomass allocation. In conclusion, GWM and GWD affected the soil water and salt content, which were key factors influencing the photosynthesis and growth of R. pseudoacacia. Adjustments in biomass allocation and photosynthesis were the main adaptive strategies of R. pseudoacacia to salt, drought, and flooding stress

Tree Species Distribution Change Study in Mount Tai Based on Landsat Remote Sensing Image Data

Located in the Mount Tai state-owned forest farm, this study adopted Landsat multispectral remote sensing data in 2000 and 2016 on the GEE (Google Earth Engine) platform and selected four phases of images each year according to the phenological period. By dealing with the current situation map of forestry resources in 2000 and the field survey data in 2016, the samples of tree species distribution in 2000 and 2016 were obtained. On the basis of topographic correction with the empirical rotation model, this study used the random forest (RF) classifier to classify tree species from remote sensing images in 2000 and 2016, achieving high classification accuracy. The results showed that, after 16 years of evolution, the percentage of pine species in the forest decreased from 55.69% to 50.22%, with a percentage decrease as high as 5.47%. The percentage of black locust (Robinia pseudoacacia) increased from 10.15% in 2000 to 13.75% in 2016, with an increase of 3.60%. Quercus also had a positive growth in the area. This result reflected the expansion of black locust