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1.
Proc Biol Sci ; 290(1999): 20230333, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-37253426

RESUMEN

Exceptionally preserved fossils of soft-bodied organisms provide unique evidence of evolutionary history, but they are often contentious; different approaches frequently produce radically different reconstructions of taxa and their affinities. Conflict arises due to difficulties in disentangling the three non-independent factors that underlie all morphological variation within and between fossils: ontogeny, taphonomy and phylogeny. Comparative data from extant organisms can be extremely powerful in this context, but is often difficult to apply given the multi-dimensionality of anatomical variation. Here, we present a multivariate ordination method using discrete morphological character data from modern taxa at different ontogenetic and taphonomic stages (semaphoront and 'semataphonts'). Analysing multiple axes of morphological variation simultaneously allows us to visualize character combinations that are likely to exist in fossil specimens at intersecting stages of growth and decay, and thus constrain interpretation of fossils. Application to early vertebrates finds variation in fossil specimens to be accounted for by all three axes: primarily decay in Mayomyzon, ontogeny in Priscomyzon and phylogeny in 'euphaneropoids' and Palaeospondylus. Our demonstration of empirical multi-factorial variation underscores the power of multivariate approaches to fossil interpretation, especially non-biomineralized taxa. As such, this conceptual approach provides a new method for resolving enigmatic taxa throughout the fossil record.


Asunto(s)
Fósiles , Paleontología , Animales , Filogenia , Evolución Biológica , Morfogénesis
2.
Int J Legal Med ; 135(3): 967-977, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33230566

RESUMEN

Age determination of insects collected from vertebrate remains is an essential step in estimating time since colonization as related to the post-mortem interval. Long-established methods for making such estimates rely on determining age related to stage of development at the time of collection in relation to conditions experienced. However, such estimates are based on the completion of a stage of development. Methods allowing for more precise estimates of age (i.e., within a stage of development) are sorely needed. This study examined the potential of volatile organic compounds emitted by blow fly, Ch. rufifacies (Macquart), immatures to determine stage of development, which could potentially be used to estimate the age. Volatile organic compounds (VOCs) from the larval and pupal stages of Ch. rufifacies were collected by headspace solid-phase micro-extraction followed by gas chromatography-mass spectrometry (GC-MS). Analyses indicated 37 compounds shift quantitatively, as well as qualitatively, as the larvae and pupae age. Furthermore, compounds, such as 2-ethyl-1-hexanol, phenol, butanoic acid, hexadecanoic acid, octadecanoic acid, 2-methyl propanamide, and 2-methyl butanoic acid, serve as indicator compounds of specific stages within Ch. rufifacies development. This information could be important to determine if these compounds can be used in the field to predict the presence of certain developmental stages, in order to determine the potential of using volatile markers to estimate time of colonization.


Asunto(s)
Calliphoridae/química , Calliphoridae/crecimiento & desarrollo , Entomología Forense , Compuestos Orgánicos Volátiles/análisis , Animales , Cromatografía de Gases y Espectrometría de Masas , Larva/química , Larva/crecimiento & desarrollo , Pupa/química , Pupa/crecimiento & desarrollo , Microextracción en Fase Sólida
3.
Parasitol Res ; 119(6): 1713-1728, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32405803

RESUMEN

In this study, we followed an integrative taxonomy approach to describe two new species of Gyrodactylus von Nordmann, 1832, and to identify specimens of G. breviradix Vega, Razzolini, Arbetman, and Viozzi, 2019, all three collected from ten spotted live-bearer Cnesterodon decemmaculatus (Jenyns, 1842), an endemic and widespread poeciliid from the Pampean region, which is the southernmost occurring species of the Poeciliidae in the Americas. Gyrodactylids were first characterized morphologically and mophometrically, and when possible, sequences of the Internal Transcribed Spacers (ITS1-5.8S-ITS2) and the cytochrome oxidase II (COII) were used to delimit species. Gyrodactylus breviradix, Gyrodactylus marplatensis n. sp., and Gyrodactylus pampeanus n. sp. were found on the fins and body surface of C. decemmaculatus in La Tapera Creek, Mar del Plata, Buenos Aires province, Argentina. A phylogenetic analysis combining newly generated sequences of one of the new species, G. marplatensis n. sp., and of G. breviradix, along with those available in GenBank for a further 36 species of Gyrodactylus, revealed that G. marplatensis n. sp. is a sister taxon of Gyrodactylus decemmaculati Vega, Razzolini, Arbetman, and Viozzi, 2019. Genetic distances for the ITS and COII gene were estimated among Gyrodactylus spp. and further supported the validity of the new species. Overall, morphometric and molecular data coincided in delimiting the new taxa, thus demonstrating the value of integrative taxonomy for the erection of new species of Gyrodactylus and species identification.


Asunto(s)
Ciprinodontiformes/parasitología , Enfermedades de los Peces/parasitología , Trematodos/clasificación , Animales , Argentina , ADN de Helmintos/genética , ADN Espaciador Ribosómico/genética , Complejo IV de Transporte de Electrones/genética , Filogenia , Análisis de Secuencia de ADN , Especificidad de la Especie , Trematodos/anatomía & histología , Trematodos/genética
4.
J Environ Manage ; 231: 1004-1011, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30602224

RESUMEN

Calluna vulgaris-dominated habitats are valued for ecosystem services such as carbon storage and for their conservation importance. Climate and environmental change are altering their fire regimes. In particular, more frequent summer droughts will result in higher severity wildfires. This could alter the plant community composition of Calluna habitats and thereby influence ecosystem function. To study the effect of fire severity on community composition we used rain-out shelters to simulate drought prior to experimental burns at two Calluna-dominated sites, a raised bog and a heathland. We analysed species abundance in plots surveyed ca. 16 months after fire in relation to burn severity (indicated by fire-induced soil heating). We found that fire severity was an important control on community composition at both sites. Higher fire severity increased the abundance of ericoids, graminoids and acrocarpous mosses, and decreased the abundance of pleurocarpous mosses compared to lower severity fires. At the raised bog, the keystone species Sphagnum capillifolium and Eriophorum vaginatum showed no difference in regeneration with fire severity. Species and plant functional type beta-diversity increased following fire, and was similar in higher compared to lower severity burns. Our results further our understanding of the response of Calluna-dominated habitats to projected changes in fire regimes, and can assist land managers using prescribed fires in selecting burning conditions to achieve management objectives.


Asunto(s)
Briófitas , Calluna , Incendios , Ecosistema , Suelo
5.
Environ Monit Assess ; 190(12): 695, 2018 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-30386937

RESUMEN

The importance of monitoring anthropogenic changes in a lotic system is not limited to chemical water quality monitoring. The addition of biological monitoring allows fish to be used as bioindicators because of their varying tolerance to pollution. For this study, we utilized long-term water quality and fish data to evaluate temporal changes brought on by passage of the Clean Water Act (1972). Non-metric multidimensional scaling (NMS) was used to describe changes in the fish community and also heavy metal concentrations of the West Fork White River in Muncie, Indiana, USA, over the past 33 years. A linear mixed effects model was used to evaluate the relationship between heavy metal concentrations and the fish community. The NMS results for both heavy metals and fish were separated into distinct decadal clusters. The shift in fish community data represented by NMS axis 1 was characterized by a drop in pollution-tolerant species and an increase in intolerant species. Decreases in heavy metal concentrations of chromium, zinc, and lead were also significant predictors of changes in the fish community. All NMS fish axis had a positive slope indicating an increase in intolerant species as heavy metal concentrations decreased. Our findings indicate that the water quality improvements documented in the West Fork White River have directly impacted its local fish community.


Asunto(s)
Monitoreo del Ambiente/métodos , Peces , Metales Pesados/análisis , Ríos/química , Contaminantes Químicos del Agua/análisis , Animales , Indiana , Alimentos Marinos , Calidad del Agua
6.
Environ Sci Pollut Res Int ; 30(32): 79001-79014, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37278896

RESUMEN

The growth and development of phytoplankton are influenced by physico-chemical parameters, which can also affect the spatial distribution of phytoplankton community structure. However, it is unclear whether environmental heterogeneity caused by multiple physico-chemical factors can affect the spatial distribution of phytoplankton and its functional groups. In this study, we investigated the seasonal variation and spatial distribution of phytoplankton community structure and its relationships with environmental factors in Lake Chaohu from August 2020 to July 2021. We recorded a total of 190 species from 8 phyla, which were divided into 30 functional groups, including 13 dominating functional groups. The average annual phytoplankton density and biomass were (5.46 ± 7.17) × 107 cells/L and 4.80 ± 4.61 mg/L, respectively. The density and biomass of phytoplankton were higher in summer ((14.64 ± 20.34) × 107 cells/L, 10.61 ± 13.16 mg/L) and autumn ((6.79 ± 3.97) × 107 cells/L, 5.57 ± 2.40 mg/L), with the M and H2 of dominant functional groups. The dominant functional groups were N, C, D, J, MP, H2, and M in spring, whereas functional groups C, N, T, and Y dominated in winter. The distribution of phytoplankton community structure and dominant functional groups exhibited significant spatial heterogeneity in the lake, which was consistent with the environmental heterogeneity of the lake and could be classified into four locations. Location I had higher phytoplankton density and biomass than the other three locations. Additionally, dominant functional groups M, C, and H2 were present throughout the lake, and all 13 dominant functional groups were observed in Location II. Our findings suggest that environmental heterogeneity is a key factor influencing the spatial distribution of phytoplankton functional groups in Lake Chaohu.


Asunto(s)
Lagos , Fitoplancton , Biomasa , Estaciones del Año , China , Monitoreo del Ambiente
7.
Genes (Basel) ; 14(3)2023 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-36981002

RESUMEN

Species overlapping in habitat use can cohabit depending on how they exploit resources. To understand segregation in resource use, an exhaustive knowledge of the diet is required. We aimed to disentangle the diet composition of the Falkland Flightless Steamer Duck Tachyeres brachypterus and the Patagonian Crested Duck Lophonetta specularioides sharing a coastal environment. Using DNA extracted from scats and Illumina sequencing, we generated a list of molecular operational taxonomic units. Both ducks consumed a variety of invertebrates, frequently overlapping in the taxa consumed. However, only the Falkland Flightless Steamer Ducks consumed fish, which might be indicative of dietary specialization and inter-specific segregation in the restricted space that these birds share. Moreover, the female and male Falkland Flightless Steamer Ducks consumed different fish prey, with almost one-third of the fish taxa being consumed by females only and another similar number consumed by males only. This result might suggest a case of intra-specific competition, triggering sexual segregation. Additionally, we detected parasitic Platyelminthes (Cestoda and Trematoda), with different frequencies of occurrence, probably related to the different diet compositions of the ducks. This study provides the necessary baseline for future investigations of the ecological segregation of these ducks.


Asunto(s)
Patos , Parásitos , Animales , Masculino , Femenino , Patos/genética , Incidencia , Dieta , Secuenciación de Nucleótidos de Alto Rendimiento , Islas del Atlántico
8.
Toxics ; 11(12)2023 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-38133358

RESUMEN

The possibility of plants growing on serpentine soils and the ability of serpentine minerals to accumulate significant amounts of metals was the basis for developing a method for using serpentine-containing materials to restore vegetation in areas with a high level of metal pollution. Serpentine-containing products obtained from phlogopite mining overburden (Kovdor, Murmansk region, Russia) with and without thermal activation were used in a field experiment on the remediation of industrially polluted peat soil. According to the geochemical mobility of the components, one of four fractions was allocated depending on the acidic (HCl) concentration of the solution used for the material treatment: readily mobile (0.001 mol/L), mobile (0.01 mol/L), potentially mobile (0.1 mol/L), and acid-soluble (1.0 mol/L). This study showed that the addition of serpentinites to peat soil changed the fraction composition. The most significant changes were noted for serpentinite components such as Ca and Mg: their concentrations increased 2-3 times even in the smallest portion of serpentine material. On the contrary, the contents of metals in the readily mobile fraction decreased 3-18, 3-23, 5-26, and 2-42 times for Cu, Ni, Fe, and Al, respectively. The main factor causing the decrease in metal mobility was the pH rise due to the release of Ca and Mg compounds into the soil solution. This study showed that the addition of serpentine-containing material at 25 vol.% to peat soil was sufficient to create a geochemical barrier with a stable-functioning vegetation cover. All serpentine-containing materials are recommended for the remediation of large industrially polluted areas.

9.
Microorganisms ; 10(11)2022 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-36363742

RESUMEN

Harmful cyanobacterial blooms in freshwater ecosystems are closely associated with changes in the composition of symbiotic microbiomes, water quality, and environmental factors. In this work, the relationship between two representative harmful cyanobacterial species (Anabaena sp. and Microcystis sp.) and their associated bacterial assemblages were investigated using a 16S rRNA-based meta-amplicon sequencing analysis during a large-scale cultivation of cyanobacteria under different light conditions with limited wavelength ranges (natural light, blue-filtered light, green-filtered light, and dark conditions). During the cultivation periods, the growth pattern of cyanobacteria and bacterial composition of the phycosphere considerably varied in relation to light restrictions. Unlike other conditions, the cyanobacterial species exhibited significant growth during the cultivation period under both the natural and the blue light conditions. Analyses of the nitrogenous substances revealed that nitrogen assimilation by nitrate reductase for the growth of cyanobacteria occurred primarily under natural light conditions, whereas nitrogenase in symbiotic bacteria could also be activated under blue light conditions. Sphingobium sp., associated with nitrogen assimilation via nitrogenase, was particularly dominant when the cell density of Microcystis sp. increased under the blue light conditions. Thus, cyanobacteria could have symbiotic relationships with ammonium-assimilating bacteria under light-limited conditions, which aids the growth of cyanobacteria.

10.
Huan Jing Ke Xue ; 43(6): 3097-3105, 2022 Jun 08.
Artículo en Zh | MEDLINE | ID: mdl-35686779

RESUMEN

Lake Hongze is an essential storage lake for the "Eastern Route of the South-North Water Diversion Project" and plays an important role in climate adjustment and flood prevention and control. To study the structural evolution of phytoplankton communities in Lake Hongze and their relationship with environmental factors and to understand the status of the ecosystem of Lake Hongze before the "ten-year fishing ban," monthly monitoring was carried out from 2015 to 2020. During the study period, total nitrogen showed a significant downward trend starting in 2017, the total phosphorus and chemical oxygen demand declined slightly, the water temperature had no obvious change trend, and the water depth and transparency increased from 2015 to 2018 and then declined significantly. A total of 102 genera of phytoplankton in eight phyla were identified, with a total of 310 species. The dominant phytoplankton phyla mainly included Chlorophyta and Bacillariophyta, followed by Cyanophyta and Pyrrophyta. The dominant genera were Scenedesmus, Aulacoseira, Cryptomonas, Cyclotella, Tetraedron, Microcystis, and Dolichospermum. The results of non-metric multidimensional scaling (NMDS) showed that the structural composition of the phytoplankton community differed significantly among years, seasons, and sampling areas, mainly due to the redistribution among dominant genera. NMDS analysis also indicated that variation in the phytoplankton community in Lake Hongze was mainly related to water temperature, total nitrogen, total phosphorus, water depth, and transparency. Total nitrogen, water depth, and phytoplankton community structure were significantly correlated with interannual succession, whereas water temperature, total nitrogen, and phytoplankton seasonal succession were also significantly correlated. Combined with the measures taken by the management department in recent years, the changes in the structure of the phytoplankton community may be related to the removal of the fence and other management and restoration measures in Lake Hongze.


Asunto(s)
Chlorophyta , Cianobacterias , Diatomeas , China , Ecosistema , Monitoreo del Ambiente , Lagos/química , Nitrógeno/análisis , Fósforo/análisis , Fitoplancton , Estaciones del Año , Agua/análisis
11.
Food Chem ; 371: 131113, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34571407

RESUMEN

Determining the geographical origin of wines is a major challenge in wine authentication, but little information is available regarding non-parametric statistical approaches for wines. In this study, we collected 33 domestic Chardonnay wines vinified on a small scale from grapes cultivated in Japan, and 42 Chardonnay wines imported from 8 countries, for oxygen stable isotope and multi-element analyses. Non-metric multidimensional scaling (NMDS), kernel principal component analysis (KPCA) and principal component analysis (PCA) were applied to the oxygen stable isotopic compositions (δ18O) and the concentrations of 18 elements in the wines to compare the extractions by parametric and non-parametric methods. The non-parametric methods, NMDS and KPCA, separated domestic from imported Chardonnay wines better than the parametric method, PCA. Of 19 variables, 18 were important for geographical discrimination, with the δ18O value being the most significant in all statistic methods. Non-parametric multivariate analyses will help discriminate domestic from imported Chardonnay wines.


Asunto(s)
Vitis , Vino , Japón , Oxígeno , Isótopos de Oxígeno/análisis , Vino/análisis
12.
Data Brief ; 42: 108170, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35510258

RESUMEN

The data presented in this article are related to the research article titled "Arthropod and fungal herbivory at the dawn of angiosperm diversification: The Rose Creek plant assemblage of Nebraska, U.S.A." (Xiao et al., 2021). These data correspond to an examination of arthropod and fungal herbivory on 2084 plant specimens from the Early Cretaceous (late Albian) Rose Creek locality of southeastern Nebraska, USA. Ten datasets have been assembled to describe and contextualize the diversity and intensity of herbivory at Rose Creek, as documented in Appendices of the online supplementary material. Appendices S4 and S5 provide a list and the frequency distributions by major clade and species/morphotype of all plant taxa examined. Appendix S6 outlines general procedures for documenting herbivory on plants and how the data was acquired. Appendix S9a and S9b provide rarefaction analyses for plant taxa to demonstrate sampling sufficiency, which is paralleled by rarefaction analyses of Appendix S9c and S9d that indicate sampling of damage types are robust. The comprehensive dataset of Appendix S12 lists plant taxa horizontally by major clade/group and species/morphotype versus vertically listed feeding classes, functional feeding groups (FFGs) and damage types (DTs). The basic metrics of DTs, feeding event occurrences, DT host-plant specialization, and number of matrix cells are displayed, with data subtotals and totals. This data matrix serves as the central source of data for the study, and records the six metrics of DT richness, DT frequency, DT host-plant specialization, percent of area herbivorized, and feeding event occurrences. Three of these metrics are used for establishing component community structure of the three most herbivorized taxa (Figs 8-10), and the relationships among plant hosts and FFGs in the non-metric multidimensional scaling analysis (Fig. 11) (Xiao et al., 2021). Appendix S15 is a list DTs, with their assigned host-plant specialization of 1 for generalized, 2 for intermediate specificity, and 3 for specialized. Appendix S16 is a table that provides plant surface areas (cm2) and their percentages that have been removed due to herbivory. Appendix S18 provides descriptions and ancillary data for 14 new DTs described from Rose Creek. A listing of the herbivory index (herbivorized surface area divided by total surface area) of plant assemblages and individual plant species in Appendix S19 provides comparisons among Rose Creek, other fossil, and modern plant assemblages. Lastly, Appendix S23 lists from the literature of arthropod species forming the well-documented herbivore component communities of five modern plant species to the three most herbivorized taxa at Rose Creek shown in Fig. 12. Some of the metrics used to quantitatively measure the diversity and intensity of herbivory are recent, such as feeding event occurrences, whereas others such as herbivorized surface area and host-plant specialization values have had a longer use in plant-arthropod studies.

13.
J Adv Res ; 38: 41-54, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35572399

RESUMEN

Introduction: Soil biota plays a crucial role in the terrestrial ecosystem. There is growing momentum to understand the community structure and diversity of total belowground soil biota across large ecological scales. Soil biota follow divergent trends with respect to soil physiochemical properties in different ecosystems; however, little is known about their response to stand development across multiple soil depths in Chinese fir plantations, which is the most important tree species across all over China, popular for its timber production. Objectives: Here, we investigated the community assembly of soil bacteria, fungi, archaea, protists and animals across three different vertical soil profiles (0-10, 10-20, 20-40 cm) using a chronosequence of Chinese fir representing five different stand ages (5, 8, 21, 27, 40 years) in South China. Methods: High throughput illumine Hiseq2500 sequencing. Results: Our results showed that soil biotic communities exhibited a decreasing trend in alpha diversity of bacteria, fungi, protists and animals with increasing soil depth; however, archaea showed an opposite trend. Most abundant soil bacterial, fungal, archaeal, protist and animal classes were Acidobacteriia, Agaricomycetes, Bathyarchaeia, Chlorophyceae and Clitellata, respectively. Correlation of vertical distribution of biotic communities and variations in soil physiochemical properties explained that total nitrogen (TN), available phosphorus (AP) and pH were the most influencing factors for changes in soil biotic communities. Although the stand age was a contributing factor for fungal and animal beta diversity, however, as compared to soil depth, it was not dominatingly influencing the structure of other biotic communities. Conclusions: Collectively, these results reveal a new perspective on the vertical variation and distinct response patterns of soil biotic communities at a fine scale across different stand ages of Chinese fir plantations.


Asunto(s)
Cunninghamia , Animales , Archaea , Bacterias , Ecosistema , Bosques , Suelo/química , Microbiología del Suelo
14.
Animals (Basel) ; 11(4)2021 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-33810250

RESUMEN

Fences have been widely implemented to reduce the risk of wildlife-vehicle collisions, wildlife disease spread, and crop damage. To manufacture fences, it is imperative to assess the behavioural responses of the target species. Here, we investigated the success rate of fences and classified eight behavioural responses of Korean water deer (Hydropotes inermis argyropus) to different fence heights. We explored the association of 801 behavioural responses and defined a threshold based on 40 events by applying non-metric multidimensional scaling and a binary logistic generalised linear mixed model. With fences lower and higher than 1.2 m, recession and rest were the dominant behaviours, respectively, before the deer crossed the fences by performing vertical and running jumps. Considering all independent events, 0.9 m was the marginal threshold, with highly variable outliers over this value. Placing exit pathways for deer and eliminating possible resting areas outside fences are essential for reducing the number of successful jump attempts. The optimal fence height could differ based on conditional factors; however, we recommend a height of 1.5 m considering the cost and roadkill risk. In conclusion, exploring and classifying the behavioural responses of the target species may be critical for establishing appropriate fence protocols.

15.
J Ginseng Res ; 45(2): 334-343, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33841014

RESUMEN

BACKGROUND: Gut microbiota mainly function in the biotransformation of primary ginsenosides into bioactive metabolites. Herein, we investigated the effects of three prebiotic fibers by targeting gut microbiota on the metabolism of ginsenoside Rb1 in vivo. METHODS: Sprague Dawley rats were administered with ginsenoside Rb1 after a two-week prebiotic intervention of fructooligosaccharide, galactooligosaccharide, and fibersol-2, respectively. Pharmacokinetic analysis of ginsenoside Rb1 and its metabolites was performed, whilst the microbial composition and metabolic function of gut microbiota were examined by 16S rRNA gene amplicon and metagenomic shotgun sequencing. RESULTS: The results showed that peak plasma concentration and area under concentration time curve of ginsenoside Rb1 and its intermediate metabolites, ginsenoside Rd, F2, and compound K (CK), in the prebiotic intervention groups were increased at various degrees compared with those in the control group. Gut microbiota dramatically responded to the prebiotic treatment at both taxonomical and functional levels. The abundance of Prevotella, which possesses potential function to hydrolyze ginsenoside Rb1 into CK, was significantly elevated in the three prebiotic groups (P < 0.05). The gut metagenomic analysis also revealed the functional gene enrichment for terpenoid/polyketide metabolism, glycolysis, gluconeogenesis, propanoate metabolism, etc. CONCLUSION: These findings imply that prebiotics may selectively promote the proliferation of certain bacterial stains with glycoside hydrolysis capacity, thereby, subsequently improving the biotransformation and bioavailability of primary ginsenosides in vivo.

16.
Huan Jing Ke Xue ; 41(4): 1648-1656, 2020 Apr 08.
Artículo en Zh | MEDLINE | ID: mdl-32608670

RESUMEN

As a water storage lake for the South-to-North Water Diversion Project, it is crucial to examine changes in aquatic ecosystem structures in Lake Luoma, Jiangsu province. Field sampling was carried out in Lake Luoma monthly from 2014 to 2018 to study the relationship between the phytoplankton community structure and environmental factors. During the studied period, total nitrogen, permanganate index, and electrical conductivity in water column gradually increased, whereas fluoride content declined. The pattern of total phosphorus and dissolved oxygen was not distinct. A total of 71 genera of phytoplankton were identified from 2014 to 2018, and the average monthly biomass variation ranged from 0.16 to 5.51 mg·L-1. Bacillariophyta and Chlorophyta were the dominant phyla in the four years, followed by Pyrrophyta and Cryptophyta. The dominant genera were Synedra sp., Chroomonas spp., Aulacoseira spp., Dinobryon sp., Scenedesmus spp. , Fragilaria spp., Mougeotia sp. , Ankistrodesmus sp. , and Euglena spp. The results showed that the phytoplankton community structure significantly changed in the four years, which was mainly ascribed to the redistribution of biomass. Specifically, in addition to the dominance of Bacillariophyta and Chlorophyta, the dominance of Pyrrophyta and Cyanophyta increased during the last two years. Non-metric multidimensional scaling analysis showed that variation of the phytoplankton community in Lake Luoma was mainly related to total nitrogen, fluoride, water temperature, total phosphorus, dissolved oxygen, pH, conductivity, and permanganate index, among which the total nitrogen, water temperature, and fluoride concentration dominated the phytoplankton community change after the generalized additive model test. Water temperature is the driving factor affecting seasonal changes of the phytoplankton community. Total nitrogen and fluoride concentrations are the driving factors affecting the interannual variation in the phytoplankton community. Our study indicated that in recent years, the implementation of the ban on sand mining and demolition of the enclosed aquaculture in Lake Luoma has affected the water environment, resulting in a significant succession of the phytoplankton community.


Asunto(s)
Lagos , Fitoplancton , China , Ecosistema , Monitoreo del Ambiente , Nitrógeno/análisis , Fósforo/análisis , Estaciones del Año
17.
Sci Total Environ ; 748: 141398, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-32805569

RESUMEN

Alterations in natural flow regimes caused by dams can significantly alter the aquatic habitats of stream organisms. However, few studies have characterized flow regulation to assess its impacts on stream fauna in the context of interannually variable extreme floods. This study aims to understand the variation in stream animals along flow regulation gradients due to hydropower dams in a catchment experiencing typhoons. We observed freshwater fishes and stream insects at fully regulated sites (receiving residual flow), moderately regulated sites (receiving hydropower outflow), and nonregulated site (tributary) in the Mimi River catchment in southern Japan, in summer and winter from 2010 to 2018. We computed indicators of hydrologic alteration (IHA) in each calendar/water (July to June) year from 2007 to 2017 and selected subsets of IHA based on principal component analysis (PCA) and variance inflation factor. The largest variance was mainly explained by minimum discharge levels (e.g., 30-day annual minimum) and flow variability among IHAs, distinguishing the moderately regulated and nonregulated sites from fully regulated sites because of residual flow and suppressed high pulses in the fully regulated sites. Generalized additive models revealed that annual maxima of specific discharge were most significant predictors of fish and insect metrics while its effects were generally inconsistent between summer and winter. Non-metric multidimensional scaling revealed that insect communities were clustered into the regulation extents in both seasons. The differences in winter fauna between the regulated and nonregulated sites, characterized by Ephemeroptera-Plecoptera-Trichoptera abundance, were associated with maximum discharge and high pulse numbers. Fish community variation did not correspond to flow regime gradients. Our findings on mechanistic ecohydrological consequences of various flow regulations, supported by long-term observations, will be useful for river managers attempting to compensate for alterations in flow regime and ecological integrity.


Asunto(s)
Tormentas Ciclónicas , Ríos , Animales , Ecosistema , Peces , Insectos , Japón , Movimientos del Agua
18.
Acta Pharm Sin B ; 10(3): 475-487, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32140393

RESUMEN

ProBiotic-4 is a probiotic preparation composed of Bifidobacterium lactis, Lactobacillus casei, Bifidobacterium bifidum, and Lactobacillus acidophilus. This study aims to investigate the effects of ProBiotic-4 on the microbiota-gut-brain axis and cognitive deficits, and to explore the underlying molecular mechanism using senescence-accelerated mouse prone 8 (SAMP8) mice. ProBiotic-4 was orally administered to 9-month-old SAMP8 mice for 12 weeks. We observed that ProBiotic-4 significantly improved the memory deficits, cerebral neuronal and synaptic injuries, glial activation, and microbiota composition in the feces and brains of aged SAMP8 mice. ProBiotic-4 substantially attenuated aging-related disruption of the intestinal barrier and blood-brain barrier, decreased interleukin-6 and tumor necrosis factor-α at both mRNA and protein levels, reduced plasma and cerebral lipopolysaccharide (LPS) concentration, toll-like receptor 4 (TLR4) expression, and nuclear factor-κB (NF-κB) nuclear translocation in the brain. In addition, not only did ProBiotic-4 significantly decreased the levels of γ-H2AX, 8-hydroxydesoxyguanosine, and retinoic-acid-inducible gene-I (RIG-I), it also abrogated RIG-I multimerization in the brain. These findings suggest that targeting gut microbiota with probiotics may have a therapeutic potential for the deficits of the microbiota-gut-brain axis and cognitive function in aging, and that its mechanism is associated with inhibition of both TLR4-and RIG-I-mediated NF-κB signaling pathway and inflammatory responses.

19.
Methods Mol Biol ; 1875: 333-343, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30362015

RESUMEN

In this chapter, we give an introduction to innovative attempts for the collection, identification, and statistical analysis of volatile organic compound (VOC) patterns emitted by phytoplasma-infected plants compared to healthy plants by the use of state-of-the-art techniques. This encompasses headspace-sampling techniques, gas chromatography coupled with mass spectrometry, and identification of VOC patterns by the "Automated Mass Spectral Deconvolution and Identification System" (AMDIS) followed by appropriate statistical analysis.


Asunto(s)
Phytoplasma/patogenicidad , Plantas/química , Compuestos Orgánicos Volátiles/análisis , Cromatografía de Gases y Espectrometría de Masas , Plantas/microbiología , Análisis de Componente Principal , Programas Informáticos
20.
Chemosphere ; 193: 591-601, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29169135

RESUMEN

Three Canon bench-scale bioreactors with a volume of 2 L operating in parallel were configured as submerged biofilters. In the present study we investigated the effects of a high ammonium concentration (320 mgNH4+· L-1) and different concentrations of organic matter (0, 100 and 400 mgCOD·L-1) on the nitrogen removal capacity and the bacterial community structure. After 60 days, the Canon biofilters operated properly under concentrations of 0 and 100 mgCOD·L-1 of organic matter, with nitrogen removal efficiencies up to 85%. However, a higher concentration of organic matter (400 mgCOD·L-1) produced a partial inhibition of nitrogen removal (68.1% efficiency). The addition of higher concentrations of organic matter a modified the bacterial community structure in the Canon biofilter, increasing the proliferation of heterotrophic bacteria related to the genera of Thauera, Longilinea, Ornatilinea, Thermomarinilinea, unclassified Chlorobiales and Denitratisoma. However, heterotrophic bacteria co-exist with Nitrosomonas and Candidatus Scalindua. Thus, our study confirms the co-existence of different microbial activities (AOB, Anammox and denitrification) and the adaptation of a fixed-biofilm system to different concentrations of organic matter.


Asunto(s)
Reactores Biológicos/microbiología , Nitrógeno/análisis , Eliminación de Residuos Líquidos/métodos , Compuestos de Amonio , Bacterias/clasificación , Biopelículas , Desnitrificación , Filtración , Nitrógeno/química , Nitrógeno/metabolismo , Nitrosomonas , Aguas Residuales/química , Aguas Residuales/microbiología , Microbiología del Agua , Contaminantes del Agua/análisis , Contaminantes del Agua/metabolismo
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