scholarly journals Disentangling the Effect of Seasonal Dynamics on Meiobenthic Community Structure From River Matla of Sundarbans Estuarine System, India

2021 ◽  
Vol 8 ◽  
Author(s):  
Moumita Ghosh ◽  
Sumit Mandal
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Sedimentary Environment ◽  
Ecological Status ◽  
Principal Component ◽  
Future Research ◽  
Taxonomic Structure ◽  
Estuarine System ◽  
Entire Study ◽  
Functional Attributes

In estuarine sediment, meiobenthos serve as an excellent candidate to perform a range of ecosystem services. However, even though the taxonomic sufficiency of meiobenthos in detecting spatiotemporal gradients is well recognized, very little is known about their functional attributes in response to environmental descriptors. To bridge this knowledge gap, the taxonomic structure and trait-based functional diversity patterns of meiobenthic assemblage, focusing on nematode species composition, were assessed for the first time from the unexplored central sector of Sundarbans Estuarine System (SES). Sediment samples were collected seasonally (monsoon, winter, spring, and summer) selecting a total of eight stations across River Matla (the widest and longest river of SES). Distinct seasonal successional patterns had been observed in meiobenthic abundance modulated by seasonal alteration in the sedimentary environment (PERMANOVA, p < 0.05). Our study revealed a strong preponderance of meiobenthic density in spring (2978 ± 689.98 ind. 10 cm–2) and lowest during monsoon (405 ± 51.22 ind. 10 cm–2). A total of 11 meiobenthic taxa were identified with the dominance of nematodes. Altogether, 79 species of nematode belonging to 22 families had been identified across the entire study area and nematode assemblage was dominated by Sabatieria praedatrix, Sphaerolaimus balticus, Desmodora communis, Dorylaimopsis punctata, and Daptonema hirsutum. Principal component analysis depicted a distinct separation of seasons with reference to environmental variables. Distance-based redundancy analysis delineated that meiobenthic communities were mainly structured by organic matter, salinity, and dissolved oxygen concentration. Biological trait analyses of nematode assemblages were applied to gather the ecological information based on morphological and ecological characteristics. The most common morphotypes were slender body shape, clavate tail shape, striated cuticle pattern, and non-selective deposit feeders with colonizing abilities of 2–3 (c–p score in a scale from 1 to 5). Results from BIO-ENV showed that sediment organic matter and dissolved oxygen played overriding roles in shaping the functional compositions of nematodes. Thus, the characterization of meiobenthos and nematode assemblages in the context of taxonomic as well as functional attributes represents a first step toward building of baseline data which could help to evaluate the ecological status of SES and direct future research priorities concurrently.

scholarly journals CHANGES IN CONCENTRATIONS OF ORGANIC MATTER IN THE MOUTHS OF THE DOTNUVELE AND SMILGA RIVERS

2018 ◽  
Author(s):  
Stefanija MISEVIČIENĖ
Keyword(s):  
Organic Matter ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Anthropogenic Activities ◽  
Precipitation Amount ◽  
Ecological Status ◽  
Sources Of Pollution ◽  
Temperature And Precipitation ◽  
Quality Of Water ◽  
The Difference

The quality of water in rivers of central Lithuania is often bad due to intensive anthropogenic activities. When rivers flow through the town’s territory, concentrated pollution, such as rainwater, industrial and productional waste water discharges, contributes to diffuse sources of pollution. If biogenic substances are the main indicators for diffuse pollution, organic matter, expressed as BOD, is the indicator for concentrated pollution. The article provides the 2013 – 2017 monitoring data on the changes of organic matter in the water of the Dotnuvele and Smilga Rivers and discusses the reasons for fluctuations in concentrations of BOD7. The aim of the research is to investigate the changes in the organic matter of the Dotnuvele and Smilga Rivers, depending on meteorological factors. For chemical analysis, water samples were taken quarterly. Water analysis was carried out by the ASU Chemical Analytical Laboratory of Water Resources Engineering Institute. The amount of organic matter (BOD7) is calculated as the difference in oxygen content after 7 days of incubation, while the amount of dissolved oxygen (O2) in the water is determined by the electrochemical probe method. The concentrations of BOD7 and O2 in the water of both rivers is compared with the criteria for assessing the ecological status of surface water bodies. The research has shown that the dissolved oxygen concentrations in rivers’ water are strongly influenced by water temperature and precipitation. The lower the temperature, the more of the dissolved oxygen is found in rivers’ water (r = -0.64). A lower precipitation amount, which reaches the rivers, increases the amount of dissolved oxygen in them (r = -0.45). The increase of BOD7 concentrations in rivers’ water was caused by higher precipitation amount (r = 0.46), higher air (r = 0.41) and lower water temperature (r = -0.41). The ecological status of the Dotnuvele River was usually good, while Smilga was average.

scholarly journals The dynamics of fluorescent dissolved organic matter in the Paranaguá estuarine system, Southern Brazil

2011 ◽  
Vol 59 (4) ◽  
pp. 311-326 ◽  
Author(s):  
Paloma Kachel Gusso-Choueri ◽  
Rodrigo Brasil Choueri ◽  
Ana Teresa Lombardi ◽  
Eunice C Machado
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Fluorescence Emission ◽  
Principal Component ◽  
Estuarine System ◽  
Southern Brazil ◽  
Fluorescent Dissolved Organic Matter ◽  
Tidal Condition ◽  
Dom Characterization ◽  
Different Sources

The aim of this study was to investigate the dynamics of the fluorescent dissolved organic matter (FDOM) in Paranaguá Estuarine System (PES) as to infer about the contribution of allochthonous FDOM to the estuarine waters in relation to tidal condition and seasons. Fluorescence spectroscopy was used for such purpose and DOM characterization through fluorescence emission was performed using excitation wavelengths of λex 350 nm and λex 450 nm, the two main fluorescence groups known to be present in natural DOM. Relations between emission wavelength (λem) and environmental variables, and the relevance of these variables to the different tides and seasons were identified by principal component analysis. The results showed that the first class of fluorophores (λex 350 nm) changed from the river (freshwater) towards the estuary, whilst the second class (λex 450 nm) has a more conservative nature and does not change as significantly as the first. Allochthonous DOM contribution to the estuarine system is intensified during the rainy season, especially in spring tides, whereas in the dry season the ratio of autochthonous DOM to total DOM in PES waters increased. We concluded that the variation of maximum λem of the first class of fluorophores (λex 350 nm) is mainly related to allochthonous contribution, whilst the maximum of emission for the second class of fluorophores (λex 450 nm) is dependent on the contribution of the different sources of organic matter (freshwater and marine water DOM contribution).

scholarly journals Impact of aquaculture on distribution of dissolved organic matter in coastal Jeju Island, Korea, based on absorption and fluorescence spectroscopy

2021 ◽  
Author(s):  
Jeonghyun Kim ◽  
Yeseul Kim ◽  
Sung Eun Park ◽  
Tae-Hoon Kim ◽  
Bong-Guk Kim ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Fluorescence Spectroscopy ◽  
Dissolved Organic Matter ◽  
Coastal Water ◽  
Coastal Region ◽  
Principal Component ◽  
Distribution Patterns ◽  
Organic Pollution ◽  
Jeju Island

AbstractIn Jeju Island, multiple land-based aquafarms were fully operational along most coastal region. However, the effect of effluent on distribution and behaviours of dissolved organic matter (DOM) in the coastal water are still unknown. To decipher characteristics of organic pollution, we compared physicochemical parameters with spectral optical properties near the coastal aquafarms in Jeju Island. Absorption spectra were measured to calculate the absorption coefficient, spectral slope coefficient, and specific UV absorbance. Fluorescent DOM was analysed using fluorescence spectroscopy coupled with parallel factor analysis. Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) were measured using high-temperature catalytic oxidation. The DOC concentration near the discharge outlet was twice higher than that in natural groundwater, and the TDN concentration exponentially increased close to the outlet. These distribution patterns indicate that aquafarms are a significant source of DOM. Herein, principal component analysis was applied to categorise the DOM origins. There were two distinct groups, namely, aquaculture activity for TDN with humic-like and high molecular weights DOM (PC1: 48.1%) and natural biological activity in the coastal water for DOC enrichment and protein-like DOM (PC2: 18.8%). We conclude that the aquafarms significantly discharge organic nitrogen pollutants and provoke in situ production of organic carbon. Furthermore, these findings indicate the potential of optical techniques for the efficient monitoring of anthropogenic organic pollutants from aquafarms worldwide.

scholarly journals Age, Sex and Cerebral Microbleed Effects On White Matter Degradation After Traumatic Brain Injury

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 886-887
Author(s):  
Andrei Irimia ◽  
Ammar Dharani ◽  
Van Ngo ◽  
David Robles ◽  
Kenneth Rostowsky
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Diffusion Tensor ◽  
Diffuse Axonal Injury ◽  
Principal Component ◽  
Older Age ◽  
Analysis Of Covariance ◽  
Future Research ◽  
Cerebral Microbleed

Abstract Mild traumatic brain injury (mTBI) affects white matter (WM) integrity and accelerates neurodegeneration. This study assesses the effects of age, sex, and cerebral microbleed (CMB) load as predictors of WM integrity in 70 subjects aged 18-77 imaged acutely and ~6 months after mTBI using diffusion tensor imaging (DTI). Two-tensor unscented Kalman tractography was used to segment and cluster 73 WM structures and to map changes in their mean fractional anisotropy (FA), a surrogate measure of WM integrity. Dimensionality reduction of mean FA feature vectors was implemented using principal component (PC) analysis, and two prominent PCs were used as responses in a multivariate analysis of covariance. Acutely and chronically, older age was significantly associated with lower FA (F2,65 = 8.7, p < .001, η2 = 0.2; F2,65 = 12.3, p < .001, η2 = 0.3, respectively), notably in the corpus callosum and in dorsolateral temporal structures, confirming older adults’ WM vulnerability to mTBI. Chronically, sex was associated with mean FA (F2,65 = 5.0, p = 0.01, η2 = 0.1), indicating males’ greater susceptibility to WM degradation. Acutely, a significant association was observed between CMB load and mean FA (F2,65 = 5.1, p = 0.009, η2 = 0.1), suggesting that CMBs reflect the acute severity of diffuse axonal injury. Together, these findings indicate that older age, male sex, and CMB load are risk factors for WM degeneration. Future research should examine how sex- and age-mediated WM degradation lead to cognitive decline and connectome degeneration after mTBI.

scholarly journals Nutrient behavior in a highly-eutrophicated tropical estuarine system

2016 ◽  
Vol 28 (0) ◽  
Author(s):  
Nilva Brandini ◽  
◽  
Ana Paula de Castro Rodrigues ◽  
Ilene Matanó Abreu ◽  
Luiz Carlos Cotovicz Junior ◽  
...  
Keyword(s):  
Organic Matter ◽  
Chlorophyll A ◽  
River Mouth ◽  
Nutrient Concentrations ◽  
Phytoplankton Production ◽  
Small Scale ◽  
Estuarine System ◽  
Temperature Conductivity ◽  
Se Brazil ◽  
Iguaçu River

Abstract Aim: There are few studies dealing with the biogeochemical processes occurring in small estuaries receiving high sewage loading in tropical regions. The aim of this investigation was to characterize the biogeochemical behavior of nutrients in superficial waters collected at the Iguaçu estuarine system, during specific conditions (neap tide), located at the inner sector of a heavily eutrophicated embayment (Guanabara Bay, SE Brazil). Methods Physical and chemical variables were measured in situ (pH, temperature, conductivity, salinity, total dissolved solids, transparency, dissolved oxygen), whereas suspended particulate matter, chlorophyll a, phaepigments and nutrients (carbon, nitrogen and phosphorus forms) were measured in laboratory across the mesohaline estuarine gradient. Results The Iguaçu River mouth is in a high stage of eutrophication, considering nutrient concentrations, chlorophyll a and transparency of water column. Results indicate a transition from heterotrophic conditions to autotrophic conditions, since the nutrients concentrations showed a decreasing pattern along the saline gradient, while the chlorophyll an increased over the transects. The pH values and chlorophyll : phaeopigments ratios are significantly related to the amount and quality of organic matter contents, especially at transects under strong marine influence. More than 95% of the dissolved and total nitrogen concentrations are represented by NH4+ contributions, which are related to the ammonification of organic matter contents in this region, indicating the existence of untreated sewage loads in this area. Conclusion In this study, the Iguaçu River seemed to contribute with high inputs of nutrients that support important phytoplankton production at the inner regions of the bay related to the CO2 sink and autotrophic metabolism, showing the importance of verifying the biogeochemical behaviors of nutrients in estuarine areas, even in small scale.

scholarly journals Linking patterns of freshwater discharge and sources of organic matter within the Río de la Plata estuary and adjacent marshes

2017 ◽  
Vol 68 (9) ◽  
pp. 1704 ◽  
Author(s):  
Leandro Bergamino ◽  
Mark Schuerch ◽  
Adriana Tudurí ◽  
Silvina Carretero ◽  
Felipe García-Rodríguez
Keyword(s):  
Organic Matter ◽  
Surface Sediments ◽  
Sediment Cores ◽  
Freshwater Discharge ◽  
C3 Plants ◽  
Estuarine System ◽  
Rio De La Plata ◽  
Río De La Plata ◽  
La Plata ◽  
Matter Transport

We investigated carbon isotopic ratios (δ13C) v. carbon to nitrogen (C : N) ratios for surface sediments throughout a large estuarine system (Río de la Plata, RdlP), combined with sediment cores from adjacent marshes to infer main carbon sources. We also evaluated the influence of the El Niño–Southern Oscillation (ENSO) and associated high freshwater-discharge events on the organic-matter transport within the estuary. The isotopic pattern in surface sediments of the RdlP showed the upper reaches to be influenced by riverine particulate matter (δ13C range: –24 to –26‰). Similarly, in the sediment cores from marshes of the upper reaches, δ13C values decreased from –24‰ in ancient sediments to –28‰ in recent sediments, reflecting an increased contribution of organic matter from land, including C3 plants and freshwater phytoplankton, during the past 50 years. However, the lower reaches represent a depositional environment of marine algae (δ13C range: –21 to –23‰), with no influence of detritus from adjacent marshes, indicating minor erosion of the marshes in the lower reaches operating as carbon-sink habitats. Our isotopic analysis showed that the transport and deposition of terrigenous organic matter within the RdlP and adjacent marsh habitat appear to be both temporally and spatially linked to hydrology patterns.

scholarly journals The Genus Plagiothecium Schimp. (Plagiotheciaceae, Bryophyta) in Eurasia: An Annotated Checklist with Distribution and Ecological Data

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 868
Author(s):  
Grzegorz J. Wolski ◽  
Samar Nour-El-Deen ◽  
Alicja Cienkowska ◽  
Daniel Bożyk ◽  
Wagieh El-Saadawi
Keyword(s):  
Relevant Literature ◽  
Single Species ◽  
Future Research ◽  
Ecological Data ◽  
Widespread Species ◽  
Entire Study ◽  
Distribution Maps ◽  
Sectional Classification ◽  
Pleurocarpous Moss ◽  
Annotated Checklist

An annotated checklist of the pleurocarpous moss genus Plagiothecium in Eurasia is presented for the first time based on a thorough review of the literature. Data have been compiled from previous relevant works conducted on the genus over more than 70 years and published up to the end of June 2020 for 107 Eurasian countries (and islands). Sectional classification is based on molecular phylogeny of the genus published recently. A total of 41 taxa are reported, including 29 species and 12 infraspecific taxa (nine varieties and three forms) belonging to eight sections. The highest numbers of taxa were found in China (20 taxa), the Russian Federation (20 taxa) and Japan (18 taxa), while the smallest numbers of taxa were recorded in the Middle East, Central Asia and the islands area. Not a single species of Plagiothecium was recorded in 26 regions, whereas P. denticulatum, P. nemorale and P. cavifolium turned out to be the most widespread species in the entire study area. They were recorded in most of the surveyed countries and islands. For each accepted taxon, information on relevant literature, synonyms, distribution within Eurasia and globally are provided. Comments on each taxon, ecological preferences, and notes on doubtful records are also included. Additionally, distribution maps for each recognised taxon are supplied. This checklist can enlighten and foster a better understanding of the distribution, diversity, and ecology of Plagiothecium in Eurasia and provides an incentive for future research on the genus.

The psychology quadrant: an outcome measure based on the START risk assessment

2017 ◽  
Vol 19 (1) ◽  
pp. 14-22
Author(s):  
Matthew John Gill ◽  
Samantha Brookes
Keyword(s):  
Risk Assessment ◽  
Factor Structure ◽  
Psychiatric Rehabilitation ◽  
Principal Component ◽  
Future Research ◽  
Psychological Outcome ◽  
Content Type ◽  
Health Rehabilitation ◽  
Mental Health Rehabilitation ◽  
Outcome Tool

Purpose The purpose of this paper is to develop a psychological outcome tool which reflects the relationship between clusters of items on the Short Term Assessment of Risk and Treatability (START) risk assessment and different categories of psychological progress in male inpatient psychiatric services. Design/methodology/approach A principal component analysis (PCA) was conducted on data from 135 male psychiatric rehabilitation patients’ START risk assessments. Findings PCA identified four strength psychology quadrants which were explained by a five-factor structure and four vulnerability quadrants which were explained by a four-factor structure. The development of the psychology quadrant, its usefulness in establishing a treatment pathway and areas of future research are also discussed. Originality/value Developing accessible, transparent outcome measures using evidence-based practice is highly relevant within the field of mental health rehabilitation.

Estimating Store Brand Shelf Space: A New Framework Using Neural Networks and Partial Least Squares

2009 ◽  
Vol 51 (2) ◽  
pp. 1-19 ◽  
Author(s):  
Monica Gomez ◽  
Shintaro Okazaki
Keyword(s):  
Least Squares ◽  
Partial Least Squares ◽  
Structural Equation ◽  
Statistical Treatment ◽  
Principal Component ◽  
Future Research ◽  
Store Brand ◽  
Shelf Space ◽  
Managerial Implications ◽  
Space Data

Despite abundant research that examines the effects of store brands on retail decision making, little attention has been paid to the predictive model of store brand shelf space. This paper intends to fill this research gap by proposing and testing a theoretical model of store brand shelf space. From the literature review, 11 independent variables were identified (i.e. store format, reputation, brand assortment, depth of assortment, in-store promotions, leading national brands’ rivalry, retailers’ rivalry, manufacturers’ concentration, store brand market share, advertising, and innovation) and analysed as potential predictors of the dependent variable (i.e. store brand shelf space). Data were collected for 29 product categories in 55 retail stores. In designing the statistical treatment, a three-phase procedure was adopted: (1) interdependence analysis via principal component analysis; (2) dependence analysis via neural network simulation; and (3) structural equation modelling via partial least squares. The findings corroborate our proposed model, in that all hypothesised relationships and directions are supported. On this basis, we draw theoretical as well as managerial implications. In closing, we acknowledge the limitations of this study and suggest future research directions.

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