scholarly journals Effect of Current Velocity on Cd Accumulation in the Aquatic Moss Fontinalis antipyretica

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 157
Author(s):  
Antón Vázquez-Arias ◽  
Sofía Debén ◽  
Adrián Casanova ◽  
Carme Pacín ◽  
Jesús R. Aboal ◽  
...  
Keyword(s):  
Regression Model ◽  
Water Flow ◽  
Current Velocity ◽  
Aquatic Environment ◽  
Water Velocity ◽  
Fontinalis Antipyretica ◽  
Aquatic Moss ◽  
Cd Accumulation ◽  
Aquatic Mosses ◽  
The Relationship

With the aim of further standardizing biomonitoring techniques with aquatic mosses, the relationship between the velocity of water flow and cadmium (Cd) accumulation in transplants of the moss Fontinalis antipyretica was investigated. For this purpose, moss transplants were exposed in a controlled aquatic environment to different concentrations of Cd (0, 4, 16 and 36 ng g−1) and different water velocities (10, 30, 50, 70 and 90 cm s−1). The Cd concentrations in the moss transplants mainly depended on the Cd concentration in the water, but a small fraction of the variance was explained by water velocity. The Cd concentrations in moss were standardized to remove the effect of the concentration in the water so all the data could be analyzed together. The regression model for the standardized concentrations explained 23% of the variance in Cd accumulation in F. antipyretica and water velocity proved to be a significant predictor of Cd accumulation.

scholarly journals Developing a Biotechnological Tool for Monitoring Water Quality: In vitro Clone Culture of the Aquatic Moss Fontinalis Antipyretica

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 145 ◽  
Author(s):  
S. Debén ◽  
J.R. Aboal ◽  
P. Giráldez ◽  
Z. Varela ◽  
J.A. Fernández
Keyword(s):  
Water Quality ◽  
Growth Rate ◽  
Large Scale ◽  
N:P Ratio ◽  
Medium Composition ◽  
Fontinalis Antipyretica ◽  
Active Biomonitoring ◽  
Aquatic Moss ◽  
Aquatic Mosses

One of the main factors limiting active biomonitoring with aquatic mosses is the lack of sufficient material. A laboratory culture of the moss would solve this problem and thus convert the technique into a valuable biotechnological tool for monitoring water quality. With this aim, we first established small and large scale axenic in vitro culture systems for the aquatic moss Fontinalis Antipyretica. We then attempted to enhance the growth rate of the cultures by modifying temperature, photoperiod and medium composition (N:P ratio, P concentration, CO2 supply, NH4NO3 supply and sucrose supply). None of these modifications greatly increased the in vitro growth rate. However, the growth rates were sufficiently high (relative to the initial weight of the cultures) in both systems (45 and 6 mg·day−1·g−1· for flasks and bioreactors respectively) to enable the production of large amounts of material. The ability to culture the material will substantially improve the applicability of the moss bag technique.

Using The Fully Modified M Method In Estimating The Effect Of Cultivated Area On Barley Production In Iraq For The Period 1970-2018

2020 ◽  
Vol 2020 (66) ◽  
pp. 101-110
Author(s):  
. Azhar Kadhim Jbarah ◽  
Prof Dr. Ahmed Shaker Mohammed
Keyword(s):  
Regression Model ◽  
Moving Average ◽  
Estimation Method ◽  
Estimation Methods ◽  
Autoregressive Moving Average ◽  
Moving Average Models ◽  
Error Terms ◽  
Relationship Of ◽  
The Relationship ◽  
Barley Crop

The research is concerned with estimating the effect of the cultivated area of barley crop on the production of that crop by estimating the regression model representing the relationship of these two variables. The results of the tests indicated that the time series of the response variable values is stationary and the series of values of the explanatory variable were nonstationary and that they were integrated of order one ( I(1) ), these tests also indicate that the random error terms are auto correlated and can be modeled according to the mixed autoregressive-moving average models ARMA(p,q), for these results we cannot use the classical estimation method to estimate our regression model, therefore, a fully modified M method was adopted, which is a robust estimation methods, The estimated results indicate a positive significant relation between the production of barley crop and cultivated area.

scholarly journals An Illustrated Guide to Estimation of Water Velocity in Unregulated River for Hydrokinetic Performance Analysis Studies in East Malaysia

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1330
Author(s):  
Almalik Mohd Saupi ◽  
Nashiren Mailah ◽  
Mohd Mohd Radzi ◽  
Kamarul Mohamad ◽  
Saiful Ahmad ◽  
...  
Keyword(s):  
Regression Model ◽  
Water Level ◽  
Rural Areas ◽  
Electrical Energy ◽  
Peninsular Malaysia ◽  
Water Velocity ◽  
Velocity Estimation ◽  
Coefficient Of Determination ◽  
Velocity Data ◽  
Model Equations

Electrification coverage in Sarawak is the lowest at 78.74%, compared to Peninsular Malaysia at 99.62% and Sabah at 82.51%. Kapit, Sarawak, with 88.4% of its population located in rural areas and mostly situated along the main riverbanks, has great potential to generate electrical energy with a hydrokinetic system. Yearly water velocity data is the most significant parameter with which to perform a hydrokinetic analysis study. Nevertheless, the data retrieved from local river databases are inadequate for river energy analysis, thus hindering its progression. Instead, flow rates and rainfall data had been utilized to estimate the water velocity data. Till present, there is still no publication has been found on estimating of water velocity data in unregulated river using water level. Therefore, a novel technique of estimating the daily average water velocity data in unregulated rivers is proposed. The modelling of regression equation for water velocity estimation was performed and two regression model equations were generated to estimate both water level and water velocity on-site and proven to be valid as the coefficient of determination values had been R2 = 87.4% and R2 = 87.9%, respectively. The combination of both regression model equations can be used to estimate long-term time series water velocity data for type-C unregulated river in remote areas.

The relationship between disability and suicide: prospective evidence from the Ten to Men cohort

2018 ◽  
Vol 41 (4) ◽  
pp. 707-713 ◽  
Author(s):  
Allison Milner ◽  
Anne-Marie Bollier ◽  
Eric Emerson ◽  
Anne Kavanagh
Keyword(s):  
Mental Health ◽  
Logistic Regression ◽  
Regression Model ◽  
Logistic Regression Model ◽  
People With Disabilities ◽  
Cross Sectional ◽  
Longitudinal Cohort ◽  
The Past ◽  
The Relationship

Abstract Background People with disabilities often face a range of social and economic adversities. Evidence suggests that these disadvantages result in poorer mental health. Some research also indicates that people with disabilities are more likely experience thoughts about suicide than people without disability, although most of this research is based on small cross-sectional samples. Methods We explored the relationship between self-reported disability (measured at baseline) and likelihood of reporting thoughts of suicide (measured at follow up) using a large longitudinal cohort of Australian males. A logistic regression model was conducted with thoughts of suicide within the past 12 months (yes or no) as the outcome and disability as the exposure. The models adjusted for relevant confounders, including mental health using the SF-12 MCS, and excluded males who reported thoughts of suicide at baseline. Results After adjustment, there was a 1.48 (95% CI: 0.98–2.23, P = 0.063) increase in the odds of thoughts of suicide among men who also reported a disability. The size of association was similar to that of being unemployed. Conclusions Males reporting disability may also suffer from thoughts of suicide. We speculate that discrimination may be one explanation for the observed association. More research on this topic is needed.

scholarly journals Relative Influences of Review and Engagement Auditor Rotation on Audit Quality: Evidence from China

2021 ◽  
Vol 14 (1) ◽  
pp. 171-206
Author(s):  
Sang Ho Kim ◽  
Jianqun Xi
Keyword(s):  
Regression Model ◽  
Logit Model ◽  
Audit Quality ◽  
Discretionary Accruals ◽  
Shared Responsibility ◽  
First Year ◽  
Audit Firm ◽  
Auditor Rotation ◽  
Audit Partner Rotation ◽  
The Relationship

Manuscript type: Research paper Research aims: This study focuses on the effects of audit partner rotation on audit quality (AQ) in China. In particular, we examine the effects of review auditors (RAs) and engagement auditors (EAs) on AQ when they voluntarily and mandatorily rotate. Design/Methodology/Approach: The data in this study are retrieved from the Chinese Stock Market and Accounting Research (CSMAR) database. We develop an OLS regression model and logit model respectively to test the hypotheses developed. Finally, we have 13,856 firm-year observations collected for the first regression model, and 16,893 firm-year observations gathered for the second logit model from 2003 to 2015. Research findings: Findings show that RAs are more likely to behave opportunistically to retain clients by weighing up the benefits and costs of compromising audit quality in the first year after a rotation. The results imply that RAs may have an incentive to acquiesce the clients’ accounting irregularities in their first year of audit engagement when they are mandatorily rotated. However, we do not find this trend in terms of EAs’ rotation, suggesting that EAs are less affected by the auditor-client relationship compared to RAs. In addition, we find that RAs are less likely to issue modified audit opinions (MOPI) as the magnitude of negative discretionary accruals (DA) increases when they are voluntarily rotated. Theoretical contribution/Originality: Previous studies have investigated the relationship between mandatory audit partner rotation and audit quality. The results are mixed and inconclusive. Our study contributes to the extant literature by considering RAs’ opportunistic behaviour after mandatory rotation, which has not been explored in previous studies. In China, only a few studies have examined the relationship between mandatory audit partner rotation and audit quality. Our study is one of the first study focusing on the RA’s influence on AQ. Practitioner/Policy implication: The findings of our study can help Chinese authorities, listed firms and academics gain more understanding on whether mandatory audit partner rotation improves audit quality in practice. Since RAs have greater incentive to retain the existing client, we propose that RAs should bear more responsibility for the audit work, instead of the equally shared responsibility with EAs. Research limitation/Implications: Our study is subject to some limitations. First, our study adopts the performance-adjusted discretionary accruals as a proxy for audit quality. However, there can be a measurement error in estimating discretionary accruals. Second, we focus on the auditor rotation and exclude the case of audit firm rotation. Since the AQ can be affected by various factors, audit firm rotation can also affect AQ. Third, although we test the relative effects of RAs and EAs in audit work, we do not examine the effect of RAs’ characteristics such as their professional experience, educational background, and years of service. AQ can be affected by RAs’ characteristics.

scholarly journals Decrease in Serum Urate Level Is Associated With Loss of Visceral Fat in Male Gout Patients

2021 ◽  
Vol 12 ◽  
Author(s):  
Zijing Ran ◽  
Xiaomei Xue ◽  
Lin Han ◽  
Robert Terkeltaub ◽  
Tony R. Merriman ◽  
...  
Keyword(s):  
Regression Model ◽  
Visceral Fat ◽  
Multiple Linear Regression Model ◽  
Serum Urate ◽  
Multiple Regression Model ◽  
Final Visit ◽  
Visceral Fat Area ◽  
Serum Urate Level ◽  
Lowering Therapy ◽  
The Relationship

ObjectiveTo clarify the relationship between serum urate (SU) decrease and visceral fat area (VFA) reduction in patients with gout.MethodsWe retrospectively analyzed 237 male gout patients who had two sets of body composition and metabolic measurements within 6 months. Subjects included had all been treated with urate-lowering therapy (ULT) (febuxostat 20–80 mg/day or benzbromarone 25–50 mg/day, validated by the medical record). All patients were from the specialty gout clinic of The Affiliated Hospital of Qingdao University. The multiple linear regression model evaluated the relationship between change in SU [ΔSU, (baseline SU) – (final visit SU)] and change in VFA [ΔVFA, (baseline VFA) – (final visit VFA)].ResultsULT resulted in a mean (standard deviation) decrease in SU level (464.22 ± 110.21 μmol/L at baseline, 360.93 ± 91.66 μmol/L at the final visit, p <0.001) accompanied by a decrease in median (interquartile range) VFA [97.30 (81.15–118.55) at baseline, 90.90 (75.85–110.05) at the final visit, p < 0.001]. By multiple regression model, ΔSU was identified to be a significant determinant variable of decrease in VFA (beta, 0.302; p = 0.001).ConclusionsThe decrease in SU level is positively associated with reduced VFA. This finding provides a rationale for clinical trials to affirm whether ULT promotes loss of visceral fat in patients with gout.

scholarly journals Human Trafficking and Displacement in South Asia: An Econometric Analysis

2017 ◽  
Vol 65 (1) ◽  
pp. 73-76
Author(s):  
Tanjina Rahman ◽  
Md Israt Rayhan ◽  
Nayeem Sultana
Keyword(s):  
Regression Model ◽  
South Asia ◽  
Human Trafficking ◽  
Internal Displacement ◽  
Probit Regression ◽  
Safety Nets ◽  
Internally Displaced ◽  
Internally Displaced Person ◽  
Social Safety Nets ◽  
The Relationship

Human trafficking has received increased media and national attention. Despite concerted efforts to combat human trafficking, the trade in persons persists and in fact continues to grow. This paper describes the relationship and distinction between trafficking and ethnic fragmentation, conflict, internally displaced person by different measures of control. To explain the relationship between these factors, this study uses a Probit regression model. It appears that ethnic conflict leads the internal displacement of individuals from networks of family and community, and their access to economic and social safety nets. Dhaka Univ. J. Sci. 65(1): 73-76, 2017 (January)

scholarly journals Caracterización ficológica en manantiales de la cuenca baja del sistema hidrológico del Pánuco, México

2017 ◽  
pp. 21 ◽  
Author(s):  
Javier Carmona-Jiménez ◽  
Gustavo Montejano-Zurita
Keyword(s):  
Environmental Factors ◽  
Light Intensity ◽  
Current Velocity ◽  
Growth Forms ◽  
Factors Affecting ◽  
Similarities And Differences ◽  
The Relationship

The results of a phycofloristic study on three springs in the Huasteca Potosina region are presented; 67 species are reported. Floristic similarities and differences among the springsare analized, as well as the relationship between species and environmental factors. Microhabitas were defined in the springs as well as the principal algal asociations that characterize them. Light intensity and current velocity are the most important factors affecting the predominant growth forms present in this type of habitat.

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