A diatom-based index for the biological assessment of eastern Canadian rivers: an application of correspondence analysis (CA)

2006 ◽  
Vol 63 (8) ◽  
pp. 1793-1811 ◽  
Author(s):  
Isabelle Lavoie ◽  
Stéphane Campeau ◽  
Martine Grenier ◽  
Peter J Dillon
Keyword(s):  
Correspondence Analysis ◽  
Biological Assessment ◽  
Specific Reference ◽  
Diatom Community ◽  
Ph Values ◽  
Maximum Variance ◽  
Complete Restoration ◽  
Index Value ◽  
Impacted Site ◽  
Reference Community

We developed a diatom-based index that integrates the effects of multiple stresses on streams and provides information related to the "distance" from the nonimpacted state. The Eastern Canadian Diatom Index (IDEC) was based on a correspondence analysis (CA) to develop a chemistry-free index where the position of the sites along the gradient of maximum variance (first axis) is strictly determined by diatom community structure and is therefore independent of measured environmental variables. The index value indicates the distance of each diatom community from its specific reference community. A high index value represents a non- or less-impacted site, while a low index value represents a more heavily impacted site. Two sub-indices were developed based on two sets of reference communities. The IDEC-circumneutral includes the sites that have reference communities characteristic of slightly acidic or neutral environments. The IDEC-alkaline includes the sites that have reference communities characteristic of environments where pH values are naturally higher than 7.5. The distinction between the two sub-indices is fundamental to make sure that each stream has the potential to reach a high IDEC value following complete restoration of its ecosystem.

scholarly journals RATTAN DIVERSITY AND BROAD EDAPHIC NICHES IN A TROPICAL RAINFOREST OF BUTON, SULAWESI, INDONESIA

REINWARDTIA ◽  
2016 ◽  
Vol 15 (2) ◽  
pp. 99
Author(s):  
ROSIE PRITCHETT ◽  
AURORA PHILLIPS ◽  
ANI MARDIASTUTI ◽  
ANDREW POWLING
Keyword(s):  
Correspondence Analysis ◽  
Soil Ph ◽  
Tropical Rainforest ◽  
Mean Difference ◽  
Weak Version ◽  
Ph Values ◽  
Wide Range ◽  
Show Evidence ◽  
Made In

PRITCHETT, R., PHILLIPS, A., MARDIASTUTI, A. & POWLING, A. 2016. Rattan diversity and broad edaphic niches in a tropical rainforest of Buton, Sulawesi, Indonesia. Reinwardtia 15(2): 99 – 110. — This paper attempts to answer the question: how can at least 20 species of rattan palms in the genus Calamus (family Palmae (Arecaceae)) co -exist in a rainforest? A survey of rattans was made in Lambusango Forest on Buton, an island close to south east Sulawesi, in Indonesia. Rattan species and numbers were recorded in 87 quadrats of 30 × 10 m, laid out along linear transects in habitats with a variety of soils. Evidence for edaphic (soil) niches was sought. Different rattan species were found to be adapted to soils with different conductivity and pH values. Standardised mean difference (d) scores were calculated for pairs of species based on their response to soil pH. Of the 66 pairs tested, 61 were found to be significantly different statistically. Such differences suggest, but do not prove, that many species occupy different edaphic niches. It was found that species which show a preference for soils with intermediate pH values (5.0 to 6.5) can grow in soils with a wide range of pH values, implying broad edaphic niches and that competition between these species is weak. Correspondence analysis shows that many species do not distinguish greatly between many soils with intermediate pH values. It is concluded that rattan species show evidence for having different edaphic niches, although the niches for many species are broad. It is speculated that many rattan species may be ecologically equivalent and that a weak version of ecological neutrality theory may apply.

scholarly journals Hoşrük Çayı (Elazığ-Türkiye) Zooplanktonu

2018 ◽  
Vol 6 (5) ◽  
pp. 607
Author(s):  
Serap Saler ◽  
Songül Yüce ◽  
Burcu Çelik ◽  
Hilal Bulut
Keyword(s):  
Common Species ◽  
Zooplankton Species ◽  
Monthly Basis ◽  
H Index ◽  
Ph Values ◽  
Measuring Devices ◽  
Index Value ◽  
Richness Index ◽  
Number Of Individuals

Samples of zooplankton were taken from Hoşrük Stream between March 2104 and February 2015 at 3 stations on a monthly basis. Water temperature, dissolved oxygen and pH values are determined from the stream by portable measuring devices. Shannon Wiever (H'), Simpson (D) and Margalef (M) index values are calculated monthly using the relevant formulas. A total of 28 zooplankton species were identified during the survey. There are 18 species of Rotifera, 8 species of Cladocera and 2 species of Copepoda. Rotifers took the first place in terms of both number of taxa, number of individuals and frequency of occurrence. Polyarthra dolichoptera from rotifers has been detected in 10 samples and is the most common species among all zooplankton species. Cyclops vicinus from Copepoda was the second dominant species observed for 9 months. May was the month in which the maximum number of taxa (20 species) was recorded, least taxa (2 species) was recorded in January. Shannon Wiever species richness index value (H') reached the highest value of H' = 1.51 in July. The Margalef index value was also calculated as M = 2.22 at the highest at May, Simpson index value D = 0.89 calculated in its highest level at March. Determination of low H' index values were indicating that stream is poor in terms of species diversity.

Temporal variation of mayfly community (Ephemeroptera) in response to ecological attributes in Gadana river, Tamilnadu, India

ENTOMON ◽  
2020 ◽  
Vol 45 (2) ◽  
pp. 115-122
Author(s):  
Sivaruban Thambiratnam ◽  
Barathy Sivaruban ◽  
Srinivasan Pandiarajan ◽  
Isack Rajasekaran
Keyword(s):  
Community Structure ◽  
Temporal Variation ◽  
Water Temperature ◽  
Correspondence Analysis ◽  
Rainy Season ◽  
Ecological Factors ◽  
Shannon Index ◽  
Rainy Period ◽  
Ecological Attributes ◽  
Ph Values

In the study of diversity and distribution of Ephemeroptera in Gadana River and relationship between Ephemeropteran community and ecological factors, revealed a total of 2056 specimens belonging to 25 genera and 7 families. The diversity and distribution of Ephemeroptera were higher during the rainy season, contrasted with non-rainy period. The high scores of Shannon index and Simpson’s index indicate that Gadana River is hale and healthy and it bolsters more diverse taxa. The pH values accomplish greatest range in the months of January and August; it legitimately impacts on diversity of mayflies. Leptophlebiidae and Baetidae were the most ubiquitous families present in the Gadana River. Canonical  Correspondence Analysis (CCA) shows that rainfall, pH, DO and water temperature were to be the significant stressor in altering the community structure of mayflies.

Evaluation of dissolution properties of silymarin capsules at different pH values

Planta Medica ◽  
2013 ◽  
Vol 79 (13) ◽  
Author(s):  
A Uzunovic ◽  
S Pilipovic ◽  
A Elezovic ◽  
A Sapcanin ◽  
O Rahic
Keyword(s):  
Ph Values ◽  
Dissolution Properties

The Disappearance of Heparin Activity with Liver Globulins and Determinations of Heparinase

1963 ◽  
Vol 10 (01) ◽  
pp. 071-080 ◽  
Author(s):  
L. B Jaques ◽  
C Mary Jaques
Keyword(s):  
Anticoagulant Activity ◽  
Rabbit Liver ◽  
Dissociation Curve ◽  
Ph Values ◽  
Phenol Extraction ◽  
Progressive Loss ◽  
Heparin Activity

SummaryPreparations were made of rabbit liver globulin by the method of Jaques for heparinase and their effect on heparin studied. The results confirmed the observations of a progressive loss of anticoagulant activity with globulin in 0.9% saline, of a loss of metachromatic activity after phenol extraction and the reversal of the latter by alkali. The latter observations were due to the solubility in phenol of heparin on combination with protein. With suitable preparations, a decrease in anticoagulant activity without decrease in metachromatic activity was observed, i.e. conversion of heparin to uroheparin. Loss of heparin due to combination with protein and resulting precipitation, solubility in phenol, etc. followed a protein pH-dissociation curve. Loss of heparin anticoagulant activity due to heparinase was maximal at pH 5.4. No loss of heparin occurred at pH values more acid than 5 or more alkaline than 7.

The Effect of Current Ratio and Debt to Asset Ratio on Net Profit Margin and Stock Prices: A Study of Basic Industry and Chemicals Companies

2020 ◽  
pp. 282-294
Author(s):  
Sudirman S ◽  
Muhammad Wahyuddin Abdullah ◽  
Muhammad Obie
Keyword(s):  
Stock Prices ◽  
Stock Exchange ◽  
Secondary Data ◽  
Profit Margin ◽  
Current Ratio ◽  
Industry Sector ◽  
Basic Industry ◽  
Net Profit ◽  
Equity Ratio ◽  
Index Value

This study examined the effect of current ratio and debt to asset ratio on net profit margin and stock prices of the sector basic industry and chemicals companies listed on the Indonesia Stock Exchange in the period 2015-2019. The object of research was the stock prices of companies in the Basic Industry and Chemicals sector, which have been published through the official website of the Indonesian capital market. It was used secondary data derived from the monthly statistics, including Current Ratio data, Net Profit Margin, Debt to Asset Ratio, and data on closing prices for the period 2015-2019. In analyzing data, it was used path analysis of secondary data obtained from the basic industry sector financial statements of 60 companies. The company's performance in this sector is considered quite good when seen from the movement of the index value in the last five years. The results show that direct current ratio had a positive and significant effect on the net profit margin, and the debt to equity ratio did not significantly influence the net profit margin. The current ratio has a positive and significant effect on stock prices, and the debt to equity ratio has a negative and not significant effect on stock prices. In contrast, the net profit margin has a significant effect on stock prices in the basic industry sector companies on the Indonesia Stock Exchange. Indirectly the current ratio has a positive and significant effect on stock prices. In contrast, the debt to asset ratio has a negative and not significant effect on the company's stock prices in the basic industry sector on the Indonesia Stock Exchange.

Analysis on Research Paper Publication Recommendation System with Composition of Papers and Conferences Matrices

2020 ◽  
pp. 120-127
Author(s):  
Htay Htay Win ◽  
Aye Thida Myint ◽  
Mi Cho Cho
Keyword(s):  
Social Network ◽  
Dimensionality Reduction ◽  
Correspondence Analysis ◽  
Recommendation System ◽  
Research Paper ◽  
Topic Modelling ◽  
Research Papers ◽  
The Right ◽  
Publication Recommendation

For years, achievements and discoveries made by researcher are made aware through research papers published in appropriate journals or conferences. Many a time, established s researcher and mainly new user are caught up in the predicament of choosing an appropriate conference to get their work all the time. Every scienti?c conference and journal is inclined towards a particular ?eld of research and there is a extensive group of them for any particular ?eld. Choosing an appropriate venue is needed as it helps in reaching out to the right listener and also to further one’s chance of getting their paper published. In this work, we address the problem of recommending appropriate conferences to the authors to increase their chances of receipt. We present three di?erent approaches for the same involving the use of social network of the authors and the content of the paper in the settings of dimensionality reduction and topic modelling. In all these approaches, we apply Correspondence Analysis (CA) to obtain appropriate relationships between the entities in question, such as conferences and papers. Our models show hopeful results when compared with existing methods such as content-based ?ltering, collaborative ?ltering and hybrid ?ltering.

Investigation of Some Water Quality Parameters of Pond Water under Mymensingh Municipality

2015 ◽  
Vol 8 (1) ◽  
pp. 85-89
Author(s):  
F Zannat ◽  
MA Ali ◽  
MA Sattar
Keyword(s):  
Water Quality ◽  
Water Samples ◽  
Chemical Properties ◽  
Pond Water ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Urban Region ◽  
Mn Toxicity ◽  
Ph Values ◽  
Drinking Water Standard

A study was conducted to evaluate the water quality parameters of pond water at Mymensingh Urban region. The water samples were collected from 30 ponds located at Mymensingh Urban Region during August to October 2010. The chemical analyses of water samples included pH, EC, Na, K, Ca, S, Mn and As were done by standard methods. The chemical properties in pond water were found pH 6.68 to 7.14, EC 227 to 700 ?Scm-1, Na 15.57 to 36.00 ppm, K 3.83 to 16.16 ppm, Ca 2.01 to 7.29 ppm, S 1.61 to 4.67 ppm, Mn 0.33 to 0.684 ppm and As 0.0011 to 0.0059 ppm. The pH values of water samples revealed that water samples were acidic to slightly alkaline in nature. The EC value revealed that water samples were medium salinity except one sample and also good for irrigation. According to drinking water standard Mn toxicity was detected in pond water. Considering Na, Ca and S ions pond water was safe for irrigation and aquaculture. In case of K ion, all the samples were suitable for irrigation but unsuitable for aquaculture.J. Environ. Sci. & Natural Resources, 8(1): 85-89 2015

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