scholarly journals Pyrite oxidization accelerates bacterial carbon sequestration in copper mine tailings

2019 ◽  
Vol 16 (2) ◽  
pp. 573-583
Author(s):  
Yang Li ◽  
Zhaojun Wu ◽  
Xingchen Dong ◽  
Zifu Xu ◽  
Qixin Zhang ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Mine Tailings ◽  
Sulfide Mineral ◽  
Stable Isotope Probing ◽  
Gene Copy ◽  
Autotrophic Bacteria ◽  
Two Samples ◽  
Cbbl Gene ◽  
Heavy Fractions

Abstract. Polymetallic mine tailings have great potential as carbon sequestration tools to stabilize atmospheric CO2 concentrations. However, previous studies focused on carbonate mineral precipitation, whereas the role of autotrophic bacteria in mine tailing carbon sequestration has been neglected. In this study, carbon sequestration in two samples of mine tailings treated with FeS2 was evaluated using 13C isotope, pyrosequencing and DNA-based stable isotope probing (SIP) analyses to identify carbon fixers. Mine tailings treated with FeS2 exhibited a higher percentage of 13C atoms (1.76±0.06 % for Yangshanchong and 1.36±0.01 % for Shuimuchong) than did controls over a 14-day incubation, which emphasized the role of autotrophs in carbon sequestration with pyrite addition. Pyrite treatment also led to changes in the composition of bacterial communities, and several autotrophic bacteria increased, including Acidithiobacillus and Sulfobacillus. Furthermore, pyrite addition increased the relative abundance of the dominant genus Sulfobacillus by 8.86 % and 5.99 % in Yangshanchong and Shuimuchong samples, respectively. Furthermore, DNA SIP results indicated a 8.20–16.50 times greater gene copy number for cbbL than cbbM in 13C-labeled heavy fractions, and a Sulfobacillus-like cbbL gene sequence (cbbL-OTU1) accounted for 30.11 %–34.74 % of all cbbL gene sequences in 13C-labeled heavy fractions of mine tailings treated with FeS2. These findings highlight the importance of the cbbL gene in bacterial carbon sequestration and demonstrate the ability of chemoautotrophs to sequester carbon during sulfide mineral oxidation in mine tailings. This study is the first to investigate carbon sequestration by autotrophic bacteria in mine tailings through the use of isotope tracers and DNA SIP.

scholarly journals Pyrite oxidization accelerates bacterial carbon sequestration in copper mine tailings Type of contribution

2018 ◽  
Author(s):  
Yang Li ◽  
Zhaojun Wu ◽  
Xingchen Dong ◽  
Zifu Xu ◽  
Zhongjun Jia ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Mine Tailings ◽  
Copy Number ◽  
Isotope Labeling ◽  
Gene Copy Number ◽  
Stable Isotope Probing ◽  
Gene Copy ◽  
Cbbl Gene ◽  
Heavy Fractions

Abstract. Polymetallic mine tailings have great potential as carbon sequestration tools to stabilize atmospheric CO2 concentrations. However, previous studies focused on carbonate mineral precipitation, while the role of autotrophs in carbon sequestration by mine tailings has been neglected. In this study, carbon sequestration in two mine tailings treated with FeS2 and 13C-labeled CO2 was analyzed using 13C isotope labeling, pyrosequencing and DNA-based stable isotope probing (SIP) to identify carbon fixers. Mine tailings treated with FeS2 exhibited a higher percentage of 13C atoms (1.76 ± 0.06 in Yangshanchong and 1.36 ± 0.01 in Shuimuchong) than the control groups over a 14-day incubation, as well an increase in the total organic carbon (TOC) content (0.20 ± 0.11 mg/g in Yangshanchong and 0.28 ± 0.14 mg/g in Shuimuchong). These data demonstrated the role of autotrophs in carbon sequestration with pyrite addition. Pyrite treatment led to changes in the composition of bacterial communities, and the genera Sulfobacillus (8.04 %) and Novosphingobium (8.60 %) were found to be dominant in these communities. In addition, the DNA-SIP results indicated that the cbbL gene copy number was 8.20–16.50 times greater than the cbbL gene copy number in 13C-labeled heavy fractions. Furthermore, a Sulfobacillus-like cbbL gene sequence (cbbL-OTU1) accounted for 30.11–34.74 % of all cbbL gene sequences in the 13C-labeled heavy fractions of mine tailings treated with FeS2. These findings highlight the importance of the RubisCO form I-encoding gene, cbbL, in bacterial carbon sequestration and demonstrate the ability of chemoautotrophs to sequester carbon during sulfide mineral oxidation in mine tailings. This study is the first to investigate carbon sequestration by autotrophic groups in mine tailings through the use of isotope tracers and DNA-SIP.

scholarly journals The Role of Collaborative Projects in Rural Women's Empowerment and Conservation of Environment: Case Study of Hossein Abad Plain in Sarbishe

2020 ◽  
Vol 4 (2) ◽  
pp. 177-184
Author(s):  
Khadijeh Bouzarjomehri ◽  
◽  
Sayyedeh Somayeh Katami ◽  
Keyword(s):  
Carbon Sequestration ◽  
Rural Women ◽  
T Test ◽  
Wilcoxon Test ◽  
Total Carbon ◽  
Social Aspect ◽  
Unequal Variance ◽  
Collaborative Project ◽  
Two Samples

Today, the emission of greenhouse and global warming are two major global environmental threats. This research attempts to investigate the mediating role of carbon sequestration collaborative project in empowering women and thereby protecting the environment. This is a descriptive-analytic study using questionnaire as an instrument for data collection. A comparison was made between empowerment of women in the target villages where carbon sequestration collaborative project was implemented and control villages with no development plan. The population consisted of women living in villages with more than 20 families in Sarbishe city. A sample of 319 people from the target villages and 354 people from control villages were selected using Cochrane formula. The data analysis in the two samples was done by using t test, Mann-Whitney Wilcoxon test and unequal variance. Based on results, Carbon Sequestration Project in women's economic empowerment is effective in protecting the environment and in all indicators except for the index. From the social aspect, according to the output of t test, the differences in social indicators were significant between two groups of women. In total, carbon sequestration project in the under study area had led to empowerment of rural women, prevention of land degradation and environmental protection

Lattice Thermal Conductivity Modelling of a Diatomic Nanoscale Material

2020 ◽  
Vol 10 (5) ◽  
pp. 602-609
Author(s):  
Adil H. Awad
Keyword(s):  
Thermal Conductivity ◽  
Lattice Thermal Conductivity ◽  
Phonon Scattering ◽  
Correction Term ◽  
Nanoscale Material ◽  
New Approach ◽  
Two Samples ◽  
Conductivity Modelling ◽  
Callaway Model

Introduction: A new approach for expressing the lattice thermal conductivity of diatomic nanoscale materials is developed. Methods: The lattice thermal conductivity of two samples of GaAs nanobeam at 4-100K is calculated on the basis of monatomic dispersion relation. Phonons are scattered by nanobeam boundaries, point defects and other phonons via normal and Umklapp processes. Methods: A comparative study of the results of the present analysis and those obtained using Callaway formula is performed. We clearly demonstrate the importance of the utilised scattering mechanisms in lattice thermal conductivity by addressing the separate role of the phonon scattering relaxation rate. The formulas derived from the correction term are also presented, and their difference from Callaway model is evident. Furthermore their percentage contribution is sufficiently small to be neglected in calculating lattice thermal conductivity. Conclusion: Our model is successfully used to correlate the predicted lattice thermal conductivity with that of the experimental observation.

Evaluating the Role of Community-Managed Forest in Carbon Sequestration and Climate Change Mitigation of Tripura, India

2021 ◽  
Vol 232 (5) ◽  
Author(s):  
Dipankar Deb ◽  
Mary Jamatia ◽  
Jaba Debbarma ◽  
Jitendra Ahirwal ◽  
Sourabh Deb ◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Sequestration ◽  
Climate Change Mitigation ◽  
Managed Forest ◽  
Change Mitigation

The Role of Individual and Dyadic Planning in Couples’ Daily Goal Pursuits

2021 ◽  
pp. 014616722199763
Author(s):  
Ophir Katzenelenbogen ◽  
Nina Knoll ◽  
Gertraud Stadler ◽  
Eran Bar-Kalifa
Keyword(s):  
Daily Basis ◽  
Goal Achievement ◽  
Daily Diaries ◽  
Goal Progress ◽  
Wide Range ◽  
Two Samples ◽  
Individual Planning ◽  
Goal Pursuits ◽  
Complementary Strategy

Planning promotes progress toward goal achievement in a wide range of domains. To date, planning has mostly been studied as an individual process. In couples, however, the partner is likely to play an important role in planning. This study tested the effects of individual and dyadic planning on goal progress and goal-related actions. Two samples of couples ( N = 76 and N = 87) completed daily diaries over a period of 28 and 21 days. The results indicate that individual and dyadic planning fluctuate on a daily basis and support the idea that dyadic planning is predominantly used as a complementary strategy to individual planning. As expected, individual and dyadic planning were positively associated with higher levels of action control and goal progress. In Sample 2, dyadic planning was only associated with goal progress on days in which individuals felt that they were dependent upon their partners’ behaviors to achieve their goals.

Van rechtvaardigheid naar uitputting en bevlogenheid

2012 ◽  
Vol 25 (2) ◽  
Author(s):  
Peter Verboon ◽  
Klaas Schakel ◽  
Karen van Dam
Keyword(s):  
Organizational Justice ◽  
Affective Commitment ◽  
Positive Behavior ◽  
Mediating Role ◽  
Two Samples ◽  
Group Engagement ◽  
Relationship Of ◽  
The Relationship ◽  
Moderating Role

From justice to exhaustion and engagement. The role of affective commitment to the organization From justice to exhaustion and engagement. The role of affective commitment to the organization In two studies the relationship between perceived organizational justice and emotional exhaustion and engagement was studied. Especially, the role of affective commitment to the organization in this relationship was examined. According to the group engagement model of Tyler and Blader (2003), procedural justice will result in positive behavior and attitudes because it increases commitment to the organization, thus implying that affective commitment mediates the relationship of justice with exhaustion and engagement. Conversely, Glazer and Kruse (2008) argue that a strong commitment to the organization can mitigate the effect of stressors, like injustice perceptions, on exhaustion and engagement, implying a moderating effect of commitment. These models were tested in two samples with employees working in a police organization. Both studies supported the mediating role of commitment; no evidence was found for a moderating role of commitment. The implication of these outcomes and the limitations of the study are discussed.

Psychological Safety, Need for Cognition, and Proactivity among Public Sector Employees

2019 ◽  
Vol 34 (2) ◽  
pp. 99-126
Author(s):  
Kim Byeongjo
Keyword(s):  
Public Sector ◽  
Self Efficacy ◽  
Psychological Safety ◽  
Need For Cognition ◽  
Work Behavior ◽  
Equation Modeling ◽  
Proactive Behavior ◽  
Two Samples ◽  
Public Sector Employees

While employee proactivity has been hailed in management literature as a critical characteristic enabling an organization to accomplish its goals, little is known about how public sector employees exert proactivity at work. This study examines the effect of individual and contextual factors that enhance proactive work behavior among public sector employees. Using two samples of nonprofit hospital employees and part-time graduate students working in the public sector, we investigate the role of the need for cognition and psychological safety in promoting proactive behavior at work. We also examine the mediating role of self-efficacy in the relationship between the two antecedents and proactive behavior. We first confirm the measurement invariance across two samples and then examine hypothesized relationships using structural equation modeling. Our results show that both the need for cognition and perceived psychological safety promote proactive behavior through the mediation of employee’s role breadth self-efficacy.

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