RESUMO
Poyang lake (PYL), as China's largest freshwater lake, has been suffering from increasing total phosphorus (TP) pollution associated with rapid basinal socio-economic development. However, anthropogenic phosphorus stressors were rarely examined in PYL basin due to its large-scale and complex river-lake connection water system, hampering phosphorus pollution control efforts. In this study, water pollution stress from multiple anthropogenic activities is quantitatively examined in PYL basin based on a newly developed framework coupling grey water footprint (GWF) analysis with the SPARROW model. Results show that the phosphorus source-sink process in PYL basin has been well simulated by SPARROW model quantifying an overall TP delivery rate of 0.39, with catchments closer to PYL showing higher delivery rate of phosphorus (up to over 0.8). The GWF analysis demonstrates that anthropogenic phosphorus sources have imposed much higher pollution stress on PYL than its inflowing rivers, with twelve catchments nearby PYL identified as critical source areas of TP contamination. Agricultural farming, livestock & poultry production, and urban household are recognized as the dominant anthropogenic stressors burdening water environment of PYL. Based on these, policy recommendations are provided for advancing control of the phosphorus pollution stressors. The methodology is effective in refined examination of water pollution sources, which is expected to be applied in other watersheds providing informative diagnosis of water issues especially in lakes.
RESUMO
Human activities have placed significant pressure on the terrestrial biosphere, leading to ecosystem degradation and carbon losses. However, the full impact of these activities on terrestrial biomass carbon remains unexplored. In this study, we examined changes in global human footprint (HFP) and human-induced aboveground biomass carbon (AGBC) losses from 2000 to 2018. Our findings show an increasing trend in HFP globally, resulting in the conversion of wilderness areas to highly modified regions. These changes have altered global biomes' habitats, particularly in tropical and subtropical regions. We also found accelerated AGBC loss driven by HFP expansion, with a total loss of 19.99 ± 0.196 PgC from 2000 to 2018, especially in tropical regions. Additionally, AGBC is more vulnerable in the Global South than in the Global North. Human activities threaten natural habitats, resulting in increasing AGBC loss even in strictly protected areas. Therefore, scientifically guided planning of future human activities is crucial to protect half of Earth through mitigation and adaptation under future risks of climate change and global urbanization.
Assuntos
Carbono , Ecossistema , Humanos , Biomassa , Carbono/metabolismo , Mudança ClimáticaRESUMO
China produces a large amount of industrial effluent with multiple pollutants contained, along with a flourishing economy. This study aims to examine the dynamics between China's industrialization and accompanying environmental pressure based on the gray water footprint (GWF) concept. A newly proposed net GWF (NetGWF) and the decoupling index (DI) are applied to evaluate China's industrial activities during 2002-2015 in different modes considering typical, all, and individual pollutants. The NetGWF dynamics are further quantitatively decomposed into 17 effects of not only commonly assessed drivers but also industrial fixed capital formation, inventory variation, and import, using an advanced dynamic decomposition analysis approach. Results show NetGWF is an effective indicator measuring domestic water pollution stress from industrialization, with NetGWF-AllPlt (estimated using all pollutants) validated to be more reliable and sensitive than NetGWF-COD&NH3N (estimated using Chemical oxygen demand and Ammonia nitrogen). An overall decoupling between China's industrialization and wastewater pollution is identified with most of DIs less than 1.0 caused mainly by decreased (by around 40%) industrial NetGWFs for 2002-2015. Industrial fixed capital formation and export have caused main components of China's industrial GWF, with proportions of 37.3% and 30.8%, respectively, followed by urban household consumption (16.8%). Volatile phenol, Petroleum, and Ammonia nitrogen are recognized as three decisive contaminants to the industrial NetGWFs. Technological development is the dominant contributor (-50%) to decreasing China's industrial NetGWFs, while fixed capital formation (18%) and export (16%) are principal drivers increasing the NetGWFs. Based on these, we expect to provide informative findings for building a pollution-decoupled industrialization.
Assuntos
Poluentes Ambientais , Desenvolvimento Industrial , Análise da Demanda Biológica de Oxigênio , China , Água , Poluição da ÁguaRESUMO
A visible-light-induced palladium-catalyzed cascade reaction was developed by etherification/C-C coupling cyclization of α-bromoacetophenones with phenols. A series of dibenzo[b,d]oxepin-7(6H)-one derivatives were efficiently synthesized by using this method in good yields. Furthermore, this method was applied to the synthesis of protosappanin A. The protocol has advantages such as simple reaction conditions, wide range of substrates and high reaction efficiency.
RESUMO
OBJECTIVE: To observe the effects of probiotics supplementation on the natural killer T cell (NKT cell) and inflammatory factors in children with sepsis and its protective effect on long-term lung function. METHODS: A total of 100 children with sepsis admitted to the department of pediatric intensive care unit (PICU) of Henan Provincial People's Hospital from March 2021 to May 2022 were selected as the research objects. The children were randomly divided into placebo group and probiotic group, 50 cases in each group. In addition to the conventional treatment, the probiotic group was given oral or nasal administration of 0.5 g probiotics, three times a day for 30 days, and the placebo group received oral placebo. 40 healthy children were selected as the healthy control group. The levels of interleukins (IL-4, IL-10), interferon-γ (IFN-γ) and immunoglobulin E (IgE), percentages of NKT cell in blood and induced sputum, lung function of the two groups of children with sepsis were measured before treatment, 7 days after treatment, and during follow-up. All these data were compared with those of healthy children. Kaplan-Meier analysis was used to compare the incidence of cough varied cough (CVA) between the two septic groups. Multiple linear regression analysis was used to explore the influence of various factors on the proportion of NKT cells in induced sputum. RESULTS: In the placebo group, 2 cases died and 4 cases were lost to follow-up. In the probiotics group, 3 cases died and 5 cases were lost to follow-up. All the inflammatory factors of two groups decreased slowly after 7 day after treatment. There was no significance in the parameters of the two groups, but the levels of probiotic group declined more evidently. During the follow-up, a further decrease of inflammatory factors in probiotic group could be found, the levels of IL-4 and IL-10 were significantly different from those in the placebo group [IL-4 (ng/L): 20.3±9.3 vs. 27.6±11.9, IL-10 (ng/L): 23.1±6.8 vs. 14.4±4.4, both P < 0.05], with a significant decrease in IgE level (µg/L: 53.0±15.6 vs. 64.2±16.9, P < 0.05]. The results of flow cytometry showed that the percentage of NKT cell in peripheral blood in two septic groups decreased gradually, and the proportion of peripheral blood NKT cells in the probiotics group was significantly lower than that in the placebo group after 7 days of treatment [(4.2±0.9)% vs. (5.3±1.2)%, P < 0.05]. In the follow-up, the level of NKT cell in peripheral blood and induced sputum in probiotic group were lower than the placebo group [peripheral blood: (0.024±0.009)% vs. (0.029±0.008)%, induced sputum: (0.025±0.008)% vs. (0.035±0.01)%, both P < 0.05], which were similar to those in the healthy control group. Meanwhile, the percentage of predicted peak expiratory (PEF%) and ratio of forced expiratory volume in one second/forced vital capacity (FEV1/FVC) of probiotic group were higher than those in the placebo group [PEF%: (91.3±4.8)% vs. (85.8±8.6)%, FEV1/FVC ratio: (91.8±4.7)% vs. (87.2±7.4)%, both P < 0.05]. Although there was no significance in the incidence of CVA between two septic groups according to the Kaplan-Meier curve analysis, multiple linear regression analysis showed mechanical ventilation and allergic history were the risk factors for the increase of NKT cells [ß values were 0.584, 0.601, 95% confidence interval (95%CI) were 0.069 to 1.099, 0.011 to 1.192, P = 0.027, 0.046], and probiotics was an independent protective factor for the relieve of increase in NKT cells (ß value was -0.984,95%CI was -1.378 to -0.591, P = 0.001). CONCLUSIONS: Application of probiotics to septic children early could promote the recovery of NKT cell and inflammatory factors, and alleviate the lung function injury induced by them during follow-up, which is helpful to improve the long-term prognosis of the patients.
Assuntos
Probióticos , Sepse , Criança , Humanos , Interleucina-10 , Interleucina-4 , Probióticos/uso terapêutico , Pulmão , Tosse , Imunoglobulina ERESUMO
Single-atom catalysts have attracted tremendous interests in peroxymonosulfate (PMS)-based advanced oxidation processes due to their maximum atom utilization and high reactivity, however the role of nitrogen-coordinated metal (MNx) sites with different metal centers remain blurred. Herein, a series of single-atom metals anchored on nitrogen-doped carbons (denoted as M-N/C, M = Fe, Co, Cu, and Mn) using zeolitic imidazolate frameworks as precursors are constructed for PMS activation. Their catalytic activity order follows Fe > Co > undoped N/C > Cu > Mn, especially the degradation rates of the eight model pollutants for Fe-N/C and Co-N/C are 2.5-22.4 and 1.5-19.5 times higher than those for undoped N/C, respectively. Moreover, the nature of catalytic metal center can govern the degradation behaviors in the coexisting water constituents. Experimental and theoretical results reveal that singlet oxygen (1O2) is the main oxidant responsible for pollutant degradation and its evolution path over FeN4 or CoN4 sites (PMSâOH*â*Oâ1O2) is elucidated, between which FeN4 with lower energy barrier is more conducive to 1O2 generation. This study can not only provide guidance for the development of highly active atomic M-N/C catalysts, but also lead to a better molecular-level understanding of PMS activation mechanism over MN4 sites.
RESUMO
Mechanistic understanding and prediction of river algal blooms remain challenging. It is generally believed that these blooms are formed by the slowdown of water dynamics in tributaries due to the support of the main stream. However, few studies have investigated the impact of flow backward caused by the difference in water dynamics between the main stream and tributaries. Here, we focus on the eutrophication issue in the middle-lower reaches of the Han River, which is affected by the Middle Route of the South-to-North Water Diversion Project (SNWDP), the largest inter-basin water transfer project in Asia. We discover that the reversal of the Yangtze River water level could effectively alleviate the occurrence of Han River water blooms. The Yangtze River frequently back flows into the lower reaches of the Han River, with the probability of such events increasing as it nears the confluence (20 km from the Yangtze: 9.5 %, 10 km: 19.0 %, 8 km: 28.6 %). This flow backward carries nutrients that reduce the nitrogen to phosphorus ration (N:P), leading to a shift in the nutrient structure of the Han River. This change is concomitant with a significant decline in algae biomass (Chlorophyll-a = 11.19 µg·L-1 and algae density = 0.41×107 cells·L-1 under natural flow, Chlorophyll-a = 5.19 µg·L-1 and algae density = 0.18×107 cells·L-1 under flow backward), as well as a weakening of the correlation (R) between diatom density and chlorophyll-a concentration, i.e., R = 0.38 (p>0.05) under flow backward conditions versus R = 0.72 (p<0.01) under natural flow conditions. As phosphorus limitation typically suppresses algae growth, the correlation between diatom density and chlorophyll-a concentration can help to reveal the dominance of diatoms, with stronger correlations indicating greater diatom dominance. Consequently, our study provides evidence that the flow backward can alleviate river algal blooms by weakening the growth advantage of diatoms. This study could prove valuable in investigating the eutrophication mechanism within the complex hydrodynamic conditions of rivers. SYNOPSIS: Flow backward caused by the water level difference between the main streams and tributary alleviated the occurrence of river algal blooms in the confluence area.
RESUMO
Hypoxia, as a typical hallmark of the tumour microenvironment (TME), has been verified to exist in most malignancies and greatly hinders the outcome of tumour treatments, including chemotherapy, photodynamic therapy, radiotherapy, and immunotherapy. Various approaches to alleviate tumour hypoxia have been reported. Among them, biomimetic nanomaterial-facilitated tumour oxygenation strategies, based on the engagement of human endogenous proteins, red blood cells, the cell membrane, and catalase, are the most impressive due to their excellent tumour active-targeting ability and superior tumour-selective capability, which, however, have not yet been systematically reviewed. Herein, we are ready to describe the current progress in biomimetic nanomaterial-facilitated tumour oxygenation strategies and corresponding improvements in tumour treatment outputs. In this review, the underlying mechanism behind the superior effect of these biomimetic nanomaterials, compared with other materials, on alleviating the hypoxic TME is highlighted. Additionally, the ongoing problems and potential solutions are also discussed.
RESUMO
OBJECTIVE: To assess the effects of a single dose of vitamin D on 25-hydroxyvitamin D (25OHD) levels and clinical outcomes in children with vitamin D deficiency (VDD) and sepsis. METHODS: In this randomized, controlled trial, eligible children with VDD and sepsis were assigned to receive one dose of 150,000 IU of cholecalciferol or placebo. Serum concentrations of 25OHD, angiotensin-II (Ang-II), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were assessed at baseline and 8 days after treatment. The cardiovascular Sequential Organ Failure Assessment (cv-SOFA) score, septic shock incidence, duration of ventilation, and mortality were also examined. RESULTS: One hundred nine participants fulfilled the study requirements. The two groups had comparable baseline characteristics. Ang-II, IL-6, and TNF-α concentrations were all reduced after vitamin D supplementation. Furthermore, the cv-SOFA score (1.76 ± 0.8 vs. 2.3 ± 1.1) and incidence of septic shock (7% vs. 20%) were lower in the treatment group than in the control group. The duration of ventilation and mortality rates did not differ between two groups. CONCLUSIONS: A single dose of vitamin D improved 25OHD levels and the incidence of septic shock in children with VDD and sepsis.
Assuntos
Colecalciferol/administração & dosagem , Sepse/tratamento farmacológico , Choque Séptico/epidemiologia , Deficiência de Vitamina D/tratamento farmacológico , Vitamina D/análogos & derivados , Administração Oral , Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Humanos , Incidência , Lactente , Masculino , Escores de Disfunção Orgânica , Estudos Prospectivos , Sepse/sangue , Sepse/complicações , Índice de Gravidade de Doença , Choque Séptico/sangue , Choque Séptico/diagnóstico , Choque Séptico/prevenção & controle , Resultado do Tratamento , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/complicaçõesRESUMO
River algal blooms have become a challenging environmental problem worldwide due to strong interference of human activities and megaprojects (e.g., big dams and large-scale water transfer projects). Previous studies on algal blooms were mainly focused on relatively static water bodies (i.e., lakes and reservoirs), but less on the large rivers. As the largest tributary of the Yangtze River of China and the main freshwater source of the South-to-North Water Diversion Project (SNWDP), the Han River has experienced frequent algal blooms in recent decades. Here we investigated the algal blooms during a decade (2003-2014) in the Han River by two gradient boosting machine (GBM) models with k-fold cross validation, which used explanatory variables from current 10-day (GBMc model) or previous 10-day period (GBMp model). Our results advocate the use of GBMp due to its higher accuracy (median Kappa = 0.9) and practical predictability (using antecedent observations) compared to GBMc. We also revealed that the algal blooms in the Han River were significantly modulated by antecedent water levels in the Han River and the Yangtze River and water level variation in the Han River, whereas the nutrient concentrations in the Han River were usually above thresholds and not limiting algal blooms. This machine-learning-based study potentially provides scientific guidance for preemptive warning and risk management of river algal blooms through comprehensive regulation of water levels during the dry season by making use of water conservancy measures in large rivers.
Assuntos
Monitoramento Ambiental , Rios , China , Eutrofização , Humanos , LagosRESUMO
PURPOSE: Low vitamin D blood levels are related to many clinical outcomes in children with critically illness. However, the relationship of it and septic shock has not been systematically analyzed. The objective of this review was to evaluate the effect of vitamin D on septic shock and predict if vitamin D administration can improve prognosis of it. MATERIALS AND METHODS: Online databases were searched up to June 1st, 2017 for studies on the relation of vitamin D deficiency (VDD) and clinical outcomes on septic shock in children with critical illness. The primary end point was the effect of VDD on occurrence of septic shock. The secondary endpoints were the association of VDD and clinical outcomes related to septic shock. We summarized the strength of association between VDD and each factor on septic shock. Individual factors were defined as strong, moderate, weak, or inconclusive according to the numbers of the article supporting the relation between them. RESULTS: Eight studies published between 2012 and 2017, for a total of 1367 patients, were included in the final analysis. We extracted eight patient-level factors and among them one showed strong association of VDD and septic shock. Four factors demonstrated moderate or weak strength of evidence for it: nonresolution of shock, catecholamine refractory shock, fluid boluses, vasopressor use. But evidence for the association between VDD and severity of illness, stay of pediatric intensive care unit (PICU), are weak. Most of the articles showed no significant association between VDD and mortality. CONCLUSIONS: Among critically ill children, VDD might be associated with the occurrence and resolution of septic shock. A larger multicenter trial could conclusively confirm these findings. Further research is also needed to identify vitamin D administration for better outcomes in pediatric patients.
Assuntos
Choque Séptico/complicações , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/tratamento farmacológico , Vitamina D/uso terapêutico , Vitaminas/uso terapêutico , Pré-Escolar , Estado Terminal , Feminino , Humanos , Lactente , Masculino , Índice de Gravidade de Doença , Choque Séptico/sangue , Resultado do Tratamento , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Vitaminas/sangueRESUMO
River algal blooms have become a newly emerging global environmental issue in recent decades. Compared with water eutrophication in lakes and reservoirs, algal blooms in large river systems can cause more severe consequences to watershed ecosystems at the watershed scale. However, reveal the causes of river algal blooms remains challenging in the interdisciplinary of hydrological-ecological-environmental research, due to its complex interaction mechanisms impacted by multiple factors. In addition, there were still considerable uncertainties on the characteristics, impacts, driving factors, as well as the applicable water system models for river algal blooms. In this paper, we reviewed existing literature to elaborate the definition and negative effects of river algal blooms. We analyzed sensitive factors including nutrient, hydrological and climatic elements. We also discussed the application of ecohydrological models under complicated hydrological conditions. Finally, we explored the essence of the river algal bloom by the interaction effects of physical and biogeochemical process impacted by of climate change and human activities. The model-data integration accounting for multi-factor effects was expected to provide scientific guidance for the prevent and control of algal blooms in large river systems.
Assuntos
Monitoramento Ambiental , Eutrofização , Mudança Climática , Ecossistema , Humanos , Hidrologia , Lagos , RiosRESUMO
OBJECTIVES: Prostate adenocarcinoma (PRAD) is the most common cancer in men. The aim of this study was to reveal the critical long non-coding RNA (lncRNAs), microRNA (miRNAs) and mRNAs involved in the pathogenesis of PRAD. METHODS: The level 3 mRNA and miRNA sequencing data of PRAD were downloaded from The Cancer Genome Atlas database. Using the edgeR package of R, the differentially expressed mRNAs (DEGs), lncRNAs (DE-lncRNAs) and miRNAs (DE-miRNAs) between PRAD and normal tissues were screened. The Cox proportional hazards regression method in the survival package was used to select the lncRNAs significantly related to clinical characteristics. After the miRNA-lncRNA and miRNA-mRNA pairs were predicted, a regulatory network was constructed by the Cytoscape software. For the DEGs involved in the network, enrichment analysis was conducted by the Fisher algorithm. RESULTS: Compared to the normal samples, 25 DE-lncRNAs, 1421 DEGs and 68 DE-miRNAs were identified in the PRAD samples. The down-regulated MESTIT1 had a significantly negative correlation with overall survival. A total of 44 DE-miRNA-DE-lncRNA pairs were predicted, including the PCA3-miR-96 and UCA1-miR-96. Meanwhile, 33 DEGs targeted by miRNAs (for example, miR-96-CYP19A1) were found to correlate with cancers. CONCLUSION: Functional enrichment analysis showed that the reproductive development process (which involved TDRD1) was enriched for the DEGs implicated in the lncRNA-miRNA-mRNA regulatory network. The lncRNAs MESTIT1, PCA3, and UCA1; mRNAs CYP19A1 and TDRD1; as well as miR-96 might affect the pathogenesis of PRAD.
Assuntos
Adenocarcinoma/genética , Redes Reguladoras de Genes/genética , Neoplasias da Próstata/genética , RNA/genética , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Modelos de Riscos Proporcionais , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , RNA/análise , TranscriptomaRESUMO
Secondary salinisation has become a hot spot internationally due to its adverse effects on freshwater ecosystems. Although its effects on ecosystem patterns has been broadly studied, its potential effect on ecosystem functions, in particular on the functional traits of freshwater organisms, and functional trait recovery are largely unknown. In this study, we conducted a field investigation at 405 sample sites from May 2009 to July 2016 in surface mining-contaminated streams, in order to evaluate the influence of secondary salinisation on macroinvertebrate functional traits and the recovery potential of dominant functional traits. Results of univariate models showed that sensitive, very tolerant, gill-breathers, cutaneous-breathers, shredders, predators and gatherers were the most responsive indicators to enhanced specific conductivity and sulfate loadings with sensitive, gill-breathers, shredders and predators demonstrating a reduction in abundance, whereas cutaneous-breathers and gatherers exhibiting an increase. Complicated relationships among different species indicated that co-exclusions would not occur because all macroinvertebrate taxa exhibited positive correlations. Results of relative recovery potential showed that omnivores and gatherers recovered quickly following improvements in water quality, whereas gill-breathers, pneumostome-breathers, filterers and scrapers would be expected to recover slowly due to their sensitivity to both specific conductivity and sulfate and low drift propensity. Overall, secondary salinisation has posed severely ecological risks to macroinvertebrate functional attributes in surface mining-contaminated streams, and their effects should be considered in future conservation plans.
RESUMO
AIM: To assess the effects of probiotics on serum ghrelin levels and protection for lungs in children with acute lung injury (ALI). METHODS: This study was performed as a double-blind, randomized, and controlled trial in a pediatric intensive care unit (PICU). The eligible children with ALI were assigned to either probiotic treatment or an identical placebo for 10 days. Serum ghrelin, SP-A(surfactant protein-A), TNF-α, and IL-6 concentrations were assessed at baseline and at the end of trial. Meanwhile, pulmonary function test and echocardiography were examined, then VPEF (volume to peak tidal expiratory flow), TPEF/TE (the ratio of time taken to reach peak expiratory flow to total expiratory time), MAP (mean arterial pressure), and PAP (pulmonary artery pressure) were recorded. RESULTS: Eighty participants fulfilled the study requirements with 40 children for each group. The groups were comparable in baseline characteristics. Serum SP-A, TNF-α, and IL-6 levels in the probiotic group were 212.6 ± 52.9 ng/mL, 401.9 ± 56.4 pg/mL, and 245.1 ± 55.1 pg/mL on day 10, respectively, significantly lower levels compared to the control group where the same parameters were 248.2 ± 57 ng/mL, 449.4 ± 60.1 pg/mL, and 308.3 ± 92.2 pg/mL (P < 0.01). However, ghrelin concentrations were elevated in the intervention group (P < 0.05). On measurement of pulmonary function, the probiotic group demonstrated a VPEF of 26.1 ± 4.2 mL and TPEF/TE of 29.1 ± 4.7%, which were higher than the control group (24.7 ± 4.3 mL and 26.9 ± 4.7%, respectively) (P < 0.05). MAP and PAP also improved in the probiotic group (P < 0.05). Furthermore, ghrelin, SP-A, TNF-α, IL-6, and PAP were negatively correlated. Positive correlations were found between ghrelin, TPEF/TE, and MAP. There were no probiotic-associated adverse events during the observation. CONCLUSION: Probiotics administrated to children with ALI alleviates the inflammation of lungs, improves pulmonary function and circulation by ghrelin.
Assuntos
Lesão Pulmonar Aguda/sangue , Lesão Pulmonar Aguda/terapia , Grelina/sangue , Probióticos/uso terapêutico , Lesão Pulmonar Aguda/diagnóstico por imagem , Lesão Pulmonar Aguda/fisiopatologia , Pré-Escolar , Método Duplo-Cego , Ecocardiografia , Feminino , Humanos , Inflamação/sangue , Inflamação/tratamento farmacológico , Interleucina-6/sangue , Pulmão/fisiopatologia , Masculino , Probióticos/efeitos adversos , Estudos Prospectivos , Proteína A Associada a Surfactante Pulmonar/sangue , Testes de Função Respiratória , Fator de Necrose Tumoral alfa/sangueRESUMO
The sampling effort for detecting taxonomic distinctness of periphytic diatom communities was studied in coastal waters of the Yellow Sea, northern China, from May to June 2014. Samples with different sizes (microscopy glass slides) were collected at two depths of 1m and 3m. To obtain the communities with dissimilarities of <10%, 2 slide replicates were sufficient for sampling at a depth of 1m, while 4 were required for the those at a depth of 3m. The values of four taxonomic distinctness indices represented a low sensitivity to sample sizes over all exposure period ages: at a coefficient of variation of <10%, 2 and 9 slide replicates were required at a depth of 1m and 3m, respectively. We suggest that the sampling strategy of the diatoms for detecting taxonomic distinctness might be better at 1m than at a deeper layer in coastal waters.
Assuntos
Biodiversidade , Cilióforos/classificação , Diatomáceas/classificação , Monitoramento Ambiental/métodos , China , Ecossistema , Análise Multivariada , Microbiologia da Água , Poluentes da Água/análise , Purificação da ÁguaRESUMO
Biofilm-dwelling ciliates are primary components of the eukaryotic microperiphyton in both species composition and community structure. To evaluate the congruency of biofilm-dwelling ciliates as potential surrogates of the eukaryotic microperiphyton, a dataset was collected every month at four stations from the coastal waters of the Yellow Sea, northern China, and assessed. Sufficient species abundance data were obtained for ciliated protozoans at high taxonomic levels up to the family level, indicating a significant variation along the gradient of contamination. Correlation analyses revealed that the taxa richness of these matrices can explain > 85% of the variance in that of the full species dataset. The cost/benefit analysis showed that the protozoan subset at low resolutions up to the family level may be used as a potential surrogate of the original dataset. Thus, we suggest that the protozoan assemblages at genus- and/or family-level resolutions may be useful, cost-efficient surrogates of the original dataset for bioassessment in marine ecosystems.