Methods for nematode extraction.

Author(s):  
Nicole Viaene ◽  
Johannes Hallmann ◽  
Leendert P. G. Molendijk

Abstract Nematodes can be present in different matrices. This chapter describes several methods to extract nematodes from soil and plant parts. It is crucial that an appropriate method is chosen for the purpose of the research as different types of nematodes, and even different nematode stages, are extracted depending on the method. Factors to consider for choosing the optimal extraction method are the extraction efficiency of the method, the maximum sample size that can be analysed and costs of the extraction equipment. In addition, water consumption, labour and the time needed before nematodes can be examined can be important factors.

Author(s):  
Nicole Viaene ◽  
Johannes Hallmann ◽  
Leendert P. G. Molendijk

Abstract Nematodes can be present in different matrices. This chapter describes several methods to extract nematodes from soil and plant parts. It is crucial that an appropriate method is chosen for the purpose of the research as different types of nematodes, and even different nematode stages, are extracted depending on the method. Factors to consider for choosing the optimal extraction method are the extraction efficiency of the method, the maximum sample size that can be analysed and costs of the extraction equipment. In addition, water consumption, labour and the time needed before nematodes can be examined can be important factors.


2019 ◽  
Vol 9 (17) ◽  
pp. 3514 ◽  
Author(s):  
Jenna Walsh ◽  
Joseph Sanford ◽  
Rebecca Larson

Biochar amendment to soil is a method used to mitigate losses of nitrogen leaching through agricultural soils. Multiple methods for extraction of nitrogen have been used, and recent studies have indicated that traditional soil extraction methods underestimate biochar nitrate. This study evaluated the nitrate extraction efficiency of a KCl extraction method under different temperature (20 and 50 °C) and duration (24 and 96 h) conditions. Increasing the duration of extraction from 24 to 96 h did not have a significant impact on extraction efficiency. However, increasing temperature resulted in nitrate extraction efficiencies above 90%. Rinsing the biochar once with deionized (DI) water following filtration after extraction increased the extraction efficiency significantly, but any subsequent rinses were not significant. This study recommends extracting nitrate from biochar using 2 M KCl at 50 °C for a period of 24 h with one additional rinse to increase nitrate recovery above 90%. However, future studies should evaluate this procedure for different types of biochar produced from alternative biomasses and at varying temperatures.


2021 ◽  
Vol 21 (12) ◽  
pp. 5812-5834
Author(s):  
Rachana Yadwade ◽  
Saili Kirtiwar ◽  
Balaprasad Ankamwar

Bio-fabrication of iron oxide nanoparticles by using different sources of plants, plant parts and microbial cells have become a great topic of interest nowadays due to its eco-friendly nature. The stabilizing and capping agents in biological sources are biocompatible, stable and non-toxic which make its use beneficial for various biomedical applications. The bacteria are able to utilize metal ions and convert them into their respective nanoparticles by secreting different biomolecules. The plants and plant parts contain different types of phytochemicals which play a key role in synthesis and bio-fabrication of nanoparticles. Iron oxide nanoparticles are known to have various applications in the fields of medicine, environment etc. This review summarizes the applications of iron oxide nanoparticles as antimicrobial agent, drug delivery agent, material for removal of heavy metals and dyes from aqueous system etc. Due to these wide applications of iron oxide nanoparticles its demand in various fields is increasing considerably. This review describes different approaches which are used for biosynthesis of iron oxide nanoparticles and their applications. The review also summarizes about the surface modification strategies of iron oxide nanoparticles by using different polymers, polyelectrolytes which can be used for in-vivo applications.


2011 ◽  
Vol 340 ◽  
pp. 318-323
Author(s):  
Wen Yi Zhang ◽  
Ning Han ◽  
Li Rong Yao ◽  
Xiao Lan Qiu ◽  
Xiao Liang Chen

The MC-LR from the the blue-green algae of Taihu Lake was extracted, at the same time, a set of microcystins extraction method with methanol as extraction solvent and purification method with C18-SPE as purification workstations were established. The extraction solvent concentration, extraction time, extraction solvent amount, leacheate concentration and eluent concentration were used to research the extraction efficiency of MC-LR. Finally, 80% methanol was used to wash microcytins to make MC-LR high purity and the purity was over 85%. This research presented a method of low cost and high efficiency. It provided the foundation for the further research of microcytins.


2020 ◽  
pp. 096228022098078
Author(s):  
Bosheng Li ◽  
Liwen Su ◽  
Jun Gao ◽  
Liyun Jiang ◽  
Fangrong Yan

A delayed treatment effect is often observed in the confirmatory trials for immunotherapies and is reflected by a delayed separation of the survival curves of the immunotherapy groups versus the control groups. This phenomenon makes the design based on the log-rank test not applicable because this design would violate the proportional hazard assumption and cause loss of power. Thus, we propose a group sequential design allowing early termination on the basis of efficacy based on a more powerful piecewise weighted log-rank test for an immunotherapy trial with a delayed treatment effect. We present an approach on the group sequential monitoring, in which the information time is defined based on the number of events occurring after the delay time. Furthermore, we developed a one-dimensional search algorithm to determine the required maximum sample size for the proposed design, which uses an analytical estimation obtained by the inflation factor as an initial value and an empirical power function calculated by a simulation-based procedure as an objective function. In the simulation, we tested the unstable accuracy of the analytical estimation, the consistent accuracy of the maximum sample size determined by the search algorithm and the advantages of the proposed design on saving sample size.


Water ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 46
Author(s):  
Yonghua Wang ◽  
Na Li ◽  
Shengnan Jiang ◽  
Xi Chen

Water sources are an indispensable resource for human survival. Monitoring the pollution status of the surrounding environment is necessary to protect water sources. Research on the environmental matrix of deep eutectic solvents (DESs) has expanded rapidly because of their high extraction efficiency for various target analytes, controllable synthesis, and versatile structure. Following the synthesis of hydrophobic deep eutectic solvents (HDESs), their application in aqueous matrices broadened greatly. The present review conducted a survey on the pollutant extraction methods based DESs in environmental matrices from two aspects, application methods and matrix types; discussed the potential risk of DESs to the environment and future development trends; and provided some references for researchers to choose DES-based extraction methods for environmental research.


2019 ◽  
Author(s):  
Rob Cribbie ◽  
Nataly Beribisky ◽  
Udi Alter

Many bodies recommend that a sample planning procedure, such as traditional NHST a priori power analysis, is conducted during the planning stages of a study. Power analysis allows the researcher to estimate how many participants are required in order to detect a minimally meaningful effect size at a specific level of power and Type I error rate. However, there are several drawbacks to the procedure that render it “a mess.” Specifically, the identification of the minimally meaningful effect size is often difficult but unavoidable for conducting the procedure properly, the procedure is not precision oriented, and does not guide the researcher to collect as many participants as feasibly possible. In this study, we explore how these three theoretical issues are reflected in applied psychological research in order to better understand whether these issues are concerns in practice. To investigate how power analysis is currently used, this study reviewed the reporting of 443 power analyses in high impact psychology journals in 2016 and 2017. It was found that researchers rarely use the minimally meaningful effect size as a rationale for the chosen effect in a power analysis. Further, precision-based approaches and collecting the maximum sample size feasible are almost never used in tandem with power analyses. In light of these findings, we offer that researchers should focus on tools beyond traditional power analysis when sample planning, such as collecting the maximum sample size feasible.


Author(s):  
Never Mujere

Research is aimed at the discovery and interpretation of facts, revision of accepted theories or laws in the light of new facts or practical application of such new or revised theories or laws. A sample provides needed information about the population quickly. However, there is no guarantee that any sample will be precisely representative of the population from which it comes. It is cheaper to observe a part rather than the whole. This chapter is a discussion on sampling in research and it is mainly designed to equip researchers with knowledge of the general issues to consider when sampling. The purpose of sampling in research, dangers of sampling and how to minimize them, types of sampling and guides for deciding the sample size are discussed. For a clear flow of ideas, a few definitions of the terms used are given. They highlight the types and methods of sampling, sampling errors and discusses techniques of sample size determination. Different types of sampling technique, how to carry them out, and their advantages and disadvantages are also introduced.


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