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1.
Sci Total Environ ; 773: 145421, 2021 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-33582356

RESUMO

Harmful cyanobacterial blooms are a widespread destruction to the processes and function of aquatic ecosystems. To study effects of cyanobacterial blooms on plankton diversity and composition, we analyzed data of cyanobacterial, eukaryotic phytoplankton, metazoan zooplankton, and physicochemical samples collected from 24 sites for four seasons in 2017 and 2018 from the large, shallow Lake Taihu. We found that cyanobacterial abundance significantly correlated with phytoplankton biomass, species richness, functional richness and evenness, and zooplankton biomass, Shannon's diversity, Simpson's evenness, and functional evenness and richness. High cyanobacterial abundance during summer did not result in low species and functional diversities for both phytoplankton and zooplankton compared with other seasons. Species and functional diversities of sites with high cyanobacteria abundance were not significantly lower than other sites with relatively low cyanobacteria abundance. Structure equation modeling indicated that cyanobacteria had direct influence on phytoplankton and zooplankton compositions. Physicochemical and temporal-spatial factors had direct influence on phytoplankton and zooplankton, and had indirect influence on phytoplankton and zooplankton through direct influence on cyanobacteria. Variance partitioning analysis quantified that cyanobacteria alone and interactions with physicochemical and spatial-temporal factors explained about 10% of phytoplankton variation and 26% of zooplankton variation. Our results indicate that cyanobacteria have substantial effects on phytoplankton and zooplankton biodiversity and community composition. Physicochemical and spatial-temporal factors could potentially obscure the detection of cyanobacterial effects on plankton in Lake Taihu that has cyanobacterial blooms in all seasons. Our findings may improve the understanding of dynamics and responses of plankton communities to environmental changes and cyanobacterial bloom disturbance and enhance the capability of assessing the effectiveness of eutrophication management and restoration of aquatic ecosystems.

2.
Sci Total Environ ; 755(Pt 2): 142503, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-33045606

RESUMO

Changes in climate are known to alter air temperature and precipitation and their associated thermal and hydrological regimes of freshwater systems, and such alterations in habitat are anticipated to modify fish composition in fluvial systems. Despite these expected changes, assessing climate change effects on habitat and fish over large regions has proven challenging. The goal of this study is to describe an approach to assess and identify stream reaches within a large region that are susceptible to climate changes based on responses of multiple fish species to changes in thermal and hydrological habitats occurring with changes in climate. We present a six-step approach to connect climate, habitat, and fish responses, demonstrated through an example to assess effects of climate change on fishes for all stream reaches in a large U.S. ecoregion (955,029 km2). Step 1 identified measures of air temperature and precipitation expected to change substantially in the future. Step 2 identified the climatic measures strongly associated with stream thermal and hydrologic metrics calculated from measured data from a subset of streams. Step 3 linked thermal and hydrologic metrics identified in Step 2 with abundances of fish species from the same stream reaches, and these fishes were combined into groups based on similar associations with specific thermal or hydrologic metrics. Step 4 used the linkages between fish groups and climatic measures and their associated thermal and hydrologic metrics to classify stream reaches. Step 5 assigned all stream reaches into classes based on the established classification under current climate measures and then re-assigned all stream reaches using projected climatic measures for three future time windows. Step 6 assessed changes in classes of stream reaches between current and future climate conditions. Stream reaches projected to change in stream classes were considered "vulnerable" to future climate change, as they would no longer support the same fish composition. The projected vulnerable streams for the years 2040, 2060, and 2090 were mapped and summarized to identify temporal patterns and identify their spatial distribution, along with underlying mechanisms leading to changes. Our results showed that 45.7% of the 320,000 reaches and 49.3% of the overall 650,000 km stream length in the study region were expected to change stream class by the year 2090, with spatially-explicit changes including streams' responding to changing air temperature or precipitation. This study provides critical guidance for integrating climate projections, landscape factors, stream habitat data, and fish data into a meaningful approach for understanding linkage. Outcomes greatly improve our ability to describe habitat changes at a stream reach scale throughout large regions, and they can aid in prioritizing management strategies to adapt to climate change at local and regional scales.

3.
Carbohydr Polym ; 246: 116589, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32747248

RESUMO

Inulin (IN), a fructan-type plant polysaccharide, is widely found in nature. The major plant sources of IN include chicory, Jerusalem artichoke, dahlia etc. Studies have found that IN possessed a wide array of biological activities, e.g. as a prebiotic to improve the intestinal microbe environment, regulating blood sugar, regulating blood lipids, antioxidant, anticancer, immune regulation and so on. Currently, IN is widely used in the food and pharmaceutical industries. IN can be used as thickener, fat replacer, sweetener and water retaining agent in the food industry. IN also can be applied in the pharmaceutics as stabilizer, drug carrier, and auxiliary therapeutic agent for certain diseases such as constipation and diabetes. This paper reviews the physiological functions of IN and its applications in the field of pharmaceutics, analyzes its present research status and future research direction. This review will serve as a one-in-all resource for the researchers who are interested to work on IN.

4.
Biomed Pharmacother ; 125: 109869, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32007916

RESUMO

Ixeris sonchifolia (IS), principally its dried form, is widely used as traditional and folk medicines in some Asian countries, especially China. In this review, we summarized its traditional uses, chemical constituents, quality control measures, pharmacological activities, therapeutic evaluation, toxicity evaluation and clinical applications. 130 chemical constituents isolated from IS have been reported, including flavones, sesquiterpenes, triterpenes, phenylpropanoids, organic acids and others. They showed various pharmacological activities, such as protecting cardiocerebral vascular system, anticancer effect and antiviral etc. The quality control evaluation studies, clinical applications, other possible applications and suggestions for future research also were discussed. The aim of this review is to critically appraise the available literature and suggest directions for further development of IS to improve its medical value and use.

5.
Sci Total Environ ; 713: 136515, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-31951840

RESUMO

Understanding the ecological impacts of large-scale hydraulic projects is critical for maintaining ecosystem health while meeting human water needs. It is, however, currently hindered by a lack of direct evidence on ecological impacts associated with this type of project particularly on water quality and fish communities. Here, we characterized patterns and variations of fish communities and water quality in five impounded lakes of the Chinese South-to-North Water Diversion Project (SNWDP), with the aim of better understanding potential ecological impacts of inter-basin water transfers. We found that 1) the impacts of water transfer on water quality in the impounded lakes was generally characterized by hydrological parameters (e.g. total suspended solids, turbidity, transparency, chlorophyll a, dissolved oxygen, conductivity and total hardness) in an upstream-downstream direction; 2) increased hydrological connectivity may have favored biological invasion (e.g. Tridentiger bifasciatus) and promoted a potential biotic homogenization among the impounded lakes; and 3) there was a pattern of decreased fish abundance and biomass from the upstream to downstream lakes with fish communities strongly driven by changing water quality patterns across the impounded lakes. These findings improve our understanding of ecological impacts of large-scale hydraulic projects and provide a significant basis for water agencies with similar water transfer systems to optimize their water transfer management in order to minimize ecological impacts.


Assuntos
Lagos , Qualidade da Água , Animais , China , Clorofila A , Ecossistema , Água
6.
Ambio ; 49(4): 926-938, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31506845

RESUMO

China has over 1320 freshwater fish species, 877 of which are endemic. In recent decades, over-exploitation and landscape pressures have threatened them and led to a severe aquatic biodiversity crisis. In response, large-scale fishing bans have been promulgated to protect freshwater biodiversity in major Chinese rivers since the early 1980s. Here, we present the historical background and current challenges to the fishing bans. Implementing large-scale fishing bans may help improve China's current freshwater biological resources and biodiversity to some extent. But implementing fishing bans alone is not sufficient to solve the crisis because of shortcomings of the current bans and expanding human pressures in most river basins. Thus, we recommend regulating other anthropogenic pressures, expanding duration and extent of current fishing regulations, establishing a comprehensive monitoring program, and initiating basin-scale ecological rehabilitation. These programs are also needed in other developing countries facing similar biodiversity crises and human pressures.


Assuntos
Conservação dos Recursos Naturais , Pesqueiros , Animais , Biodiversidade , China , Água Doce , Humanos , Rios
7.
Environ Monit Assess ; 190(3): 152, 2018 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-29460185

RESUMO

Key environmental factors and the mechanisms of their influence on the physicochemical habitats and macroinvertebrate communities of streams may vary among ecoregions. We studied the differences in environmental (land use and physicochemical) factors and the mechanisms of their influence on macroinvertebrate assemblages between mountain and lowland ecoregions in central China. We applied generalized linear models to identify key environmental factors that influence macroinvertebrate metrics consisting of taxa richness, Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa, percentages of EPT and intolerant individuals, and the Shannon-Wiener diversity index. Environmental factors and macroinvertebrate metrics significantly differed between the ecoregions. Mountain streams had significantly lower nutrients and %silt, but had twice higher total taxa richness than lowland streams. Watershed land uses were key drivers that influenced the physical habitat in the mountain ecoregion and were the main drivers that influenced both physical and chemical conditions in the lowland ecoregion. Correspondingly, watershed scale land uses, as well as physical and chemical variables, explained more variance in macroinvertebrate metrics than local-scale land uses in both mountain and lowland ecoregions. The overall biological variation was explained better by watershed-scale than by reach-scale land uses, whereas the spatial scale over which land use and physicochemical variables influence streams varied across ecoregions. Our results suggest that better landscape planning should be adopted for watershed management to improve water quality and physical habitat, and thus the conservation and restoration of macroinvertebrate biodiversity.


Assuntos
Altitude , Ecossistema , Monitoramento Ambiental/métodos , Invertebrados/classificação , Rios/química , Qualidade da Água , Animais , Biodiversidade , China , Modelos Teóricos
8.
Cell Biosci ; 7: 56, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29118968

RESUMO

Background: Diffuse intrinsic pontine glioma is an infiltrative, often high-grade glioma of the brainstem that is not amenable to surgical resection. The current treatment of DIPG by radiation therapy showed dramatically improvement of patient's condition, however, the tumor recurs rapidly. More and more studies are focused on the genetic and epigenetic drivers of DIPGs, which may provide more and more novel therapy target for DIPG. EZH2 has been proved to be a potential therapeutic target for H3K27M-mutant pediatric gliomas recently. Meanwhile, BET family protein is a hot target in many different types of cancers, including DIPG. In this study, we performed the treatment of both EZH2 and BET inhibitor for DIPG cells. Results: The combination of these two inhibitors exhibited better inhibition of the tumor growth both in vitro and in vivo compared to use the inhibitor individually. This inhibition was performed by blocking the proliferation and promoting the cell apoptosis. Meanwhile, combination treatment of these two inhibitors would also affect the epigenetic markers which were abnormal in the tumors of the certain set of genes. Conclusion: Thus we provided a novel therapy strategy for clinical treatment of DIPG.

9.
Sci Total Environ ; 586: 879-889, 2017 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-28233615

RESUMO

Despite the prevalence of damming as a global disturbance to river habitats, detailed reach-based assessments of the ecological effects of dams are lacking, particularly across large spatial extents. Using data from nearly 50,000 large dams, we assessed stream network fragmentation and flow alteration by large dams for streams of the conterminous USA. We developed 21 dam metrics characterizing a diversity of dam influences operating at both localized (e.g., distances-to-dams) and landscape scales (e.g., cumulative reservoir storage throughout stream networks) for every stream reach in the study region. We further evaluated how dams have affected stream fish assemblages within large ecoregions using more than 37,000 stream fish samples. Streams have been severely fragmented by large dams, with the number of stream segments increasing by 801% compared to free-flowing streams in the absence of dams and a staggering 79% of stream length is disconnected from their outlet (i.e., oceans and Great Lakes). Flow alteration metrics demonstrate a landscape-scale disturbance of dams, resulting in total upstream reservoir storage volumes exceeding estimated annual discharge volumes of many of the nation's largest rivers. Further, we show large-scale changes in fish assemblages with dams. Species adapted to lentic habitats increase with dams across the conterminous USA, while rheophils, lithophils, and intolerant fishes decrease with dams. Overall, fragmentation and flow alteration by dams have affected fish assemblages as much or more than other anthropogenic stressors, with dam effects generally increasing with stream size. Dam-induced stream fragmentation and flow alteration are critical natural resource issues. This study emphasizes the importance of considering dams as a landscape-scale disturbance to river habitats along with the need to assess differential effects that dams may have on river habitats and the fishes they support. Together, these insights are essential for more effective conservation of stream resources and biotic communities globally.


Assuntos
Ecossistema , Peixes , Rios , Movimentos da Água , Animais , Conservação dos Recursos Naturais , Ecologia , Estados Unidos
10.
Pharmaceutics ; 8(3)2016 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-27598191

RESUMO

Biodegradable polymer-based injectable in situ forming depot (ISD) systems that solidify in the body to form a solid or semisolid reservoir are becoming increasingly attractive as an injectable dosage form for sustained (months to years) parenteral drug delivery. Evaluation of long-term drug release from the ISD systems during the formulation development is laborious and costly. An accelerated release method that can effectively correlate the months to years of long-term release in a short time such as days or weeks is economically needed. However, no such accelerated ISD system release method has been reported in the literature to date. The objective of the current study was to develop a short-term accelerated in vitro release method for contraceptive levonorgestrel (LNG)-containing ISD systems to screen formulations for more than 3-month contraception after a single subcutaneous injection. The LNG-containing ISD formulations were prepared by using biodegradable poly(lactide-co-glycolide) and polylactic acid polymer and solvent mixtures containing N-methyl-2-pyrrolidone and benzyl benzoate or triethyl citrate. Drug release studies were performed under real-time (long-term) conditions (PBS, pH 7.4, 37 °C) and four accelerated (short-term) conditions: (A) PBS, pH 7.4, 50 °C; (B) 25% ethanol in PBS, pH 7.4, 50 °C; (C) 25% ethanol in PBS, 2% Tween 20, pH 7.4, 50 °C; and (D) 25% ethanol in PBS, 2% Tween 20, pH 9, 50 °C. The LNG release profile, including the release mechanism under the accelerated condition D within two weeks, correlated (r² ≥ 0.98) well with that under real-time conditions at four months.

11.
Soft Matter ; 12(24): 5359-71, 2016 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-27216558

RESUMO

Block copolymers based on poly(styrene) having pendent trimethyl styrenylbutyl ammonium (with four carbon ring-ionic group alkyl linkers) or benzyltrimethyl ammonium groups with a methylene bridge between the ring and ionic group were synthesized by reversible addition-fragmentation radical (RAFT) polymerization as anion exchange membranes (AEMs). The C4 side chain polymer showed a 17% increase in Cl(-) conductivity of 33.7 mS cm(-1) compared to the benzyltrimethyl ammonium sample (28.9 mS cm(-1)) under the same conditions (IEC = 3.20 meq. g(-1), hydration number, λ = ∼7.0, cast from DMF/1-propanol (v/v = 3 : 1), relative humidity = 95%). As confirmed by small angle X-ray scattering (SAXS), the side chain block copolymers with tethered ammonium cations showed well-defined lamellar morphologies and a significant reduction in interdomain spacing compared to benzyltrimethyl ammonium containing block copolymers. The chemical stabilities of the block copolymers were evaluated under severe, accelerated conditions, and degradation was observed by (1)H NMR. The block copolymer with C4 side chain trimethyl styrenylbutyl ammonium motifs displayed slightly improved stability compared to that of a benzyltrimethyl ammonium-based AEM at 80 °C in 1 M NaOD aqueous solution for 30 days.

12.
Dongwuxue Yanjiu ; 37(2): 67-74, 2016 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-27029863

RESUMO

Low-head dam impoundments modify local habitat and alter fish assemblages; however, to our knowledge, the pattern of how fish assemblages in the impoundments relate to local habitat, tributary position, and dam characteristics is still unclear. We used data collected in 62 impoundments created by low-head dams in headwater streams of the Qingyi River, China, to examine relationships between fish assemblages and local habitat, tributary position, and dam characteristics. We also assessed the relative importance of the three groups of factors in determining fish species richness and composition. Linear regression models showed that fish species richness was related to substrate heterogeneity, confluence link, and dam number upstream. Redundancy analysis showed that fish species compositions were influenced by substrate heterogeneity, confluence link, dam height, dam numbers upstream and downstream. Overall, dam characteristics were more important in affecting fish species richness but less important in determining fish species composition than local habitat (i.e., substrate heterogeneity) and tributary position. Our results suggest that low-head dam may affect fish species richness in impoundments by modifying local habitat and constraining fish movement, and the relative abundances of those fish species may depend more on species habitat presences and stream size than on impoundment size and number.


Assuntos
Ecossistema , Peixes , Rios , Distribuição Animal , Animais , Biodiversidade , China , Peixes/fisiologia
13.
Sci Total Environ ; 511: 341-53, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25553548

RESUMO

Variable selection is a critical step in development of empirical stream health prediction models. This study develops a framework for selecting important in-stream variables to predict four measures of biological integrity: total number of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa, family index of biotic integrity (FIBI), Hilsenhoff biotic integrity (HBI), and fish index of biotic integrity (IBI). Over 200 flow regime and water quality variables were calculated using the Hydrologic Index Tool (HIT) and Soil and Water Assessment Tool (SWAT). Streams of the River Raisin watershed in Michigan were grouped using the Strahler stream classification system (orders 1-3 and orders 4-6), k-means clustering technique (two clusters: C1 and C2), and all streams (one grouping). For each grouping, variable selection was performed using Bayesian variable selection, principal component analysis, and Spearman's rank correlation. Following selection of best variable sets, models were developed to predict the measures of biological integrity using adaptive-neuro fuzzy inference systems (ANFIS), a technique well-suited to complex, nonlinear ecological problems. Multiple unique variable sets were identified, all which differed by selection method and stream grouping. Final best models were mostly built using the Bayesian variable selection method. The most effective stream grouping method varied by health measure, although k-means clustering and grouping by stream order were always superior to models built without grouping. Commonly selected variables were related to streamflow magnitude, rate of change, and seasonal nitrate concentration. Each best model was effective in simulating stream health observations, with EPT taxa validation R2 ranging from 0.67 to 0.92, FIBI ranging from 0.49 to 0.85, HBI from 0.56 to 0.75, and fish IBI at 0.99 for all best models. The comprehensive variable selection and modeling process proposed here is a robust method that extends our understanding of watershed scale stream health beyond sparse monitoring points.


Assuntos
Monitoramento Ambiental/métodos , Rios , Poluição da Água/estatística & dados numéricos , Animais , Teorema de Bayes , Biodiversidade , Ecossistema , Peixes , Hidrologia , Insetos , Michigan , Modelos Teóricos , Poluição da Água/análise
14.
Chem Commun (Camb) ; 50(31): 4092-5, 2014 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-24618920

RESUMO

A unique one-step cross-linking strategy that connects quaternary ammonium centers using Grubbs II-catalyzed olefin metathesis was developed. The cross-linked anion exchange membranes showed swelling ratios of less than 10% and hydroxide conductivities of 18 to 40 mS cm(-1). Cross-linking improved the membranes' stability to hydroxide degradation compared to their non-cross-linked analogues.

15.
Environ Manage ; 51(6): 1147-63, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23609304

RESUMO

Land use change and other human disturbances have significant impacts on physicochemical and biological conditions of stream systems. Meanwhile, linking these disturbances with hydrology and water quality conditions is challenged due to the lack of high-resolution datasets and the selection of modeling techniques that can adequately deal with the complex and nonlinear relationships of natural systems. This study addresses the above concerns by employing a watershed model to obtain stream flow and water quality data and fill a critical gap in data collection. The data were then used to estimate fish index of biological integrity (IBI) within the Saginaw Bay basin in Michigan. Three methods were used in connecting hydrology and water quality variables to fish measures including stepwise linear regression, partial least squares regression, and fuzzy logic. The IBI predictive model developed using fuzzy logic showed the best performance with the R (2) = 0.48. The variables that identified as most correlated to IBI were average annual flow, average annual organic phosphorus, average seasonal nitrite, average seasonal nitrate, and stream gradient. Next, the predictions were extended to pre-settlement (mid-1800s) land use and climate conditions. Results showed overall significantly higher IBI scores under the pre-settlement land use scenario for the entire watershed. However, at the fish sampling locations, there was no significant difference in IBI. Results also showed that including historical climate data have strong influences on stream flow and water quality measures that interactively affect stream health; therefore, should be considered in developing baseline ecological conditions.


Assuntos
Mudança Climática , Meio Ambiente , Modelos Teóricos , Abastecimento de Água , Animais , Peixes , Lógica Fuzzy , Michigan , Análise de Regressão , Rios , Movimentos da Água , Poluentes Químicos da Água/análise , Qualidade da Água
16.
Environ Manage ; 50(5): 875-87, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22961585

RESUMO

Identifying appropriate spatial scales is critically important for assessing health, attributing data, and guiding management actions for rivers. We describe a process for identifying a three-level hierarchy of spatial scales for Michigan rivers. Additionally, we conduct a variance decomposition of fish occurrence, abundance, and assemblage metric data to evaluate how much observed variability can be explained by the three spatial scales as a gage of their utility for water resources and fisheries management. The process involved the development of geographic information system programs, statistical models, modification by experienced biologists, and simplification to meet the needs of policy makers. Altogether, 28,889 reaches, 6,198 multiple-reach segments, and 11 segment classes were identified from Michigan river networks. The segment scale explained the greatest amount of variation in fish abundance and occurrence, followed by segment class, and reach. Segment scale also explained the greatest amount of variation in 13 of the 19 analyzed fish assemblage metrics, with segment class explaining the greatest amount of variation in the other six fish metrics. Segments appear to be a useful spatial scale/unit for measuring and synthesizing information for managing rivers and streams. Additionally, segment classes provide a useful typology for summarizing the numerous segments into a few categories. Reaches are the foundation for the identification of segments and segment classes and thus are integral elements of the overall spatial scale hierarchy despite reaches not explaining significant variation in fish assemblage data.


Assuntos
Pesqueiros , Recursos Hídricos , Ecossistema , Monitoramento Ambiental , Sistemas de Informação Geográfica , Rios
17.
Sci Total Environ ; 435-436: 380-91, 2012 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22871465

RESUMO

Anthropogenic activities such as agricultural practices can have large effects on the ecological components and overall health of stream ecosystems. Therefore, having a better understanding of those effects and relationships allows for better design of mitigating strategies. The objectives of this study were to identify influential stream variables that correlate with macroinvertebrate indices using biophysical and statistical models. The models developed were later used to evaluate the impact of three agricultural management practices on stream integrity. Our study began with the development of a high-resolution watershed model for the Saginaw River watershed in Michigan for generating in-stream water quality and quantity data at stream reaches with biological sampling data. These in-stream data were then used to explain macroinvertebrate measures of stream health including family index of biological integrity (FamilyIBI), Hilsenhoff biotic index (HBI), and the number of Ephemeroptera, Plecoptera , and Trichoptera taxa (EPTtaxa). Two methods (stepwise linear regression and adaptive neuro-fuzzy inference systems (ANFIS)) were evaluated for developing predictive models for macroinvertebrate measures. The ANFIS method performed the best on average and the final models displayed the highest R(2) and lowest mean squared error (MSE) for FamilyIBI (R(2)=0.50, MSE=29.80), HBI (R(2)=0.57, MSE=0.20), and EPTtaxa (R(2)=0.54, MSE=6.60). Results suggest that nutrient concentrations have the strongest influence on all three macroinvertebrate measures. Consistently, average annual organic nitrogen showed the most significant association with EPTtaxa and HBI. Meanwhile, the best model for FamilyIBI included average annual ammonium and average seasonal organic phosphorus. The ANFIS models were then used in conjunction with the Soil and Water Assessment Tool to forecast and assess the potential effects of different best management practices (no-till, residual management, and native grass) on stream integrity. Based on the model predictions, native grass resulted in the largest improvement for all macroinvertebrate measures.


Assuntos
Conservação dos Recursos Naturais/métodos , Modelos Biológicos , Rios , Agricultura , Animais , Ecossistema , Monitoramento Ambiental/métodos , Invertebrados , Michigan , Modelos Estatísticos , Fósforo/análise , Poaceae , Compostos de Amônio Quaternário/análise , Qualidade da Água
18.
J Neurol Sci ; 315(1-2): 67-71, 2012 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-22166855

RESUMO

BACKGROUND: Toll-like receptors 2 (TLR2) and TLR4 are involved in the microglia-mediated inflammatory response, Aß plaque formation and Aß clearance in Alzheimer's disease (AD). Our previous studies have shown that variants in the TLR2 and TLR4 genes are associated with the risk of AD. Therefore, we hypothesize that there may be significant changes in TLR2 and TLR4 expressions on peripheral blood mononuclear cells (PBMCs) from patients with AD when compared to healthy control subjects. METHODS: Sixty patients with late-onset AD (LOAD) and 60 healthy controls matched for sex and age were recruited. Flow cytometry (FCM) was used to detect expressions of TLR2 and TLR4 proteins and real-time quantitative RT-PCR was performed to determine TLR2 and TLR4 mRNAs. RESULTS: Compared with controls, expressions of TLR2 and TLR4 mRNAs were up-regulated in LOAD patients (TLR2/beta-actin mRNA: 0.390±0.204 versus 0.281±0.167, P<0.01; TLR4/beta-actin mRNA: 0.503±0.195 versus 0.322±0.183, P<0.01). The proteins levels were higher in LOAD patients than in controls (TLR2: 97.12±1.67% versus 41.07±18.44%, P<0.01, TLR4: 66.56±23.74% versus 14.83±4.31, P<0.01). In both cases, either AD or control group, TLR2 and TLR4 mRNAs expressions were positively correlated with the levels of proteins (TLR2: r=0.980 and 0.976,P<0.01; TLR4: r=0.938 and 0.970, P<0.01), respectively. There were significant negative correlations between TLR levels and MMSE score (TLR2: r=-0.32; P=0.01; TLR4: r=-0.29; P=0.02). In addition, CC genotype can increase the expression of TLR4 in AD patients. CONCLUSION: This study gives the first evidence that expressions of TLR2 and TLR4 in PBMCs were markedly elevated in LOAD patients.


Assuntos
Doença de Alzheimer/metabolismo , Leucócitos Mononucleares/metabolismo , Receptor 2 Toll-Like/biossíntese , Receptor 4 Toll-Like/biossíntese , Regulação para Cima/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/patologia , Biomarcadores/sangue , Feminino , Humanos , Leucócitos Mononucleares/patologia , Masculino , RNA Mensageiro/biossíntese , Receptor 2 Toll-Like/sangue , Receptor 2 Toll-Like/genética , Receptor 4 Toll-Like/sangue , Receptor 4 Toll-Like/genética
19.
J Neuroinflammation ; 8: 136, 2011 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-21989233

RESUMO

BACKGROUND: Toll-like receptor 2 (TLR2) represents a reasonable functional and positional candidate gene for Alzheimer's disease (AD) as it is located under the linkage region of AD on chromosome 4q, and functionally is involved in the microglia-mediated inflammatory response and amyloid-ß clearance. The -196 to -174 del polymorphism affects the TLR2 gene and alters its promoter activity. METHODS: We recruited 800 unrelated Northern Han Chinese individuals comprising 400 late-onset AD (LOAD) patients and 400 healthy controls matched for gender and age. The -196 to -174 del polymorphism in the TLR2 gene was genotyped using the polymerase chain reaction (PCR) method. RESULTS: There were significant differences in genotype (P = 0.026) and allele (P = 0.009) frequencies of the -196 to -174 del polymorphism between LOAD patients and controls. The del allele was associated with an increased risk of LOAD (OR = 1.31, 95% CI = 1.07-1.60, Power = 84.9%). When these data were stratified by apolipoprotein E (ApoE) ε4 status, the observed association was confined to ApoE ε4 non-carriers. Logistic regression analysis suggested an association of LOAD with the polymorphism in a recessive model (OR = 1.64, 95% CI = 1.13-2.39, Bonferroni corrected P = 0.03). CONCLUSIONS: Our data suggest that the -196 to -174 del/del genotype of TLR2 may increase risk of LOAD in a Northern Han Chinese population.


Assuntos
Doença de Alzheimer/genética , Grupo com Ancestrais do Continente Asiático/genética , Grupos Étnicos/genética , Predisposição Genética para Doença , Polimorfismo Genético , Receptor 2 Toll-Like/genética , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino
20.
Brain Res ; 1381: 202-7, 2011 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-21236243

RESUMO

The amyloid beta-protein (A-ß) deposits in the brains of patients with Alzheimer's disease (AD) are closely associated with innate immune responses that were assumed to play a pivotal role in the pathogenesis of AD. Toll-like receptor 4 (TLR4) is thought to contribute to Aß clearance. Studies have reported the presence and functional significance of the TLR4/11367 polymorphism in a Han Chinese population. To evaluate the involvement of the TLR4/11367 polymorphism in the risk of late-onset Alzheimer's disease (LOAD), we performed a case-control study to analyze the genotype and allele distributions of the TLR4/11367 polymorphism in a Han Chinese population (137 LOAD cases and 137 healthy controls). There were significant differences in genotype and allele frequencies between LOAD cases and controls (genotype P<0.001, allele P<0.001). After stratification by APOE ε4-carrying status, the C allele of the TLR4/11367 polymorphism was still significantly associated with LOAD in APOE ε4 non-carriers (OR=5.77, 95% CI=3.03-11.00, P<0.001) and carriers (OR=2.03, 95% CI=1.03-3.98, P=0.04). In addition, a logistic regression analysis also conferred positive association between TLR4/11367C and LOAD (dominant model: ORa=3.08, 95% CI=1.60-5.93, P=0.001; recessive model: ORa=8.79, 95% CI=3.31-23.36, P<0.001; additive model: ORa=2.75, 95% CI=1.73-4.37, P<0.001) after adjustment for age, gender, and the APOE ε4 carrier status. This study gives the first evidence that the TLR4/11367 polymorphism was associated with LOAD in a Han Chinese population.


Assuntos
Doença de Alzheimer/genética , Polimorfismo Genético , Receptor 4 Toll-Like/genética , Idoso , Idoso de 80 Anos ou mais , Alelos , Apolipoproteína E4/genética , Grupo com Ancestrais do Continente Asiático/genética , Estudos de Casos e Controles , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Razão de Chances
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