**Iloprost**

Iloprost is a more stable carbacyclin derivative of prostacyclin and can be administered intermittently, as the hemodynamic effects of a single dose are sustained for approximately 60-120 min, although the plasma half-life time of intravenously administered iloprost is known to be between 20-30 min (Theodoraki et al., 2002). This form of treatment appears to be promising combining the advantages of NO and the lack of problems of intravenous administration. Iloprost causes a significant reduction in MPAP and PVR and a significant increase in cardiac output after its administration since there is a substantial reduction in right ventricular afterload. It cannot be ruled out that a decrease in systemic vascular resistance (SVR) may occur during its administration but not to a degree that can affect arterial blood pressure dramatically.

Aerosolized iloprost has been described as a more potent pulmonary vasodilator than NO in patients with PH (Winterhalter et al., 2008). Its longer half-life firstly confers effective protection against the rebound phenomenon and, secondly, may facilitate the pharmacological effective transfer of the inhaler material from the pulmonary into the systemic arterial circulation.

Iloprost remains stable at room temperature and does not undergo any molecular changes on exposure to light, in comparison to PGI2 (Fattouch et al., 2003). Also, inhaler iloprost can be rapidly and simply administered intraoperatively, irrespective of ventilator type. Unlike the situation with NO, inhaled iloprost treatment can also be continued with an ultrasonic nebulizer during weaning from the ventilator and after extubation.

Episodes of PH during heart transplantation procedures can be successfully treated with the administration of iloprost without unwanted side effects or significant systemic impact (Theodoraki et al., 2006).

Right heart failure after left ventricular assist device (LVAD) implantation is an acute lifethreatening event. In patients with intraoperative severe acute right heart failure after implantation of a LVAD, successful weaning from CPB was possible after inhaled iloprost was added (Winterhalter et al., 2006).

In addition to its beneficial hemodynamic profile, aerosolized iloprost also exerted beneficial effects on arterial oxygenation, which probably reflected the more potent effects of iloprost on the pulmonary vascular bed and the more pronounced increase of mixed-venous oxygen saturation (Hoeper et al., 2000).

#### **NO donors**

Inhaled NTG decreases PH without producing systemic vasodilatation (Yurtseven et al., 2003). Further studies are warranted to define their potential utility because nebulization of these drugs does not require an expensive apparatus like the one required for NO nebulization.

#### **Phosphodiesterase – 3 inhibitors**

Milrinone inhibits the breakdown of cAMP, thereby promoting pulmonary vasodilatation. There are few recent studies which demonstrated the beneficial effects of inhaled milrinone on PH during weaning of patients from CPB.

Inhaled milrinone prevents pulmonary endothelial dysfunction after CPB, and its hemodynamic and oxygenation profiles are safer than those of intravenous milrinone (Lamarche et al., 2005).


**3. Mechanism of action of probiotics against** *Salmonella*

Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Amongst the many benefits associated with the consumption of probiotics, modulation of the immune system has received considerable attention (Borchers, Keen, & Gershwin, 2002; Borchers, Selmi, Meyers, Keen, & Gershwin, 2009).

Previously, it was thought that administration of bacteria such as probiotics to neonates directly reduced infection by pathogens due to competition amongst the bacteria for attachment sites and nutrients and, that beneficial bacteria would out-compete pathogens within the GIT. This competition, coined as "competitive exclusion" was first described in 1973 by Nurmi and Rantala (Nurmi& Rantala, 1973). Their data indicated that early administration of beneficial bacteria to chicks prevented infection by pathogens. Since Nurmi and Rantala proposed competitive exclusion could be used as a method to prevent *Salmonella* infection, numerous researchers have reported the ability of live bacterial cultures to also reduce colonization of opportunistic microorganisms in the gastrointestinal tract (Callaway et al., 2008; Wagner et al., 2003; Hollister et al., 1999; Corrier et al., 1998; Hume et al., 1998; Nisbet et al., 1998) and probiotic organisms (J. P. Higgins et al., 2010; S. E. Higgins et al., 2008; Vicente et al., 2008; J. P. Higgins et al., 2007; Bielke et al., 2003; Patterson & Burkholder, 2003). Yet, understanding of how probiotics mediate these health benefits, specifically reduction of *Salmonella* infection, is very limited.

Balanced gastrointestinal microflora and immune-stimulation are major functional effects attributed to the consumption of probiotics (Amit-Romach, Uni, & Reifen, 2010; Boirivant & Strober, 2007; Boirivant, Amendola, & Butera, 2008; Flint, O'Toole, & Walker, 2010; Flore, Francois, & Felicite, 2010; Ibrahim et al., 2010; Klein, Sanders, Duong, & Young, 2010; Nayak, 2010). Many probiotic effects are mediated through immune regulation, particularly through balance control of pro-inflammatory and anti-inflammatory cytokines (Di Giacinto, Marinaro, Sanchez, Strober, & Boirivant, 2005; Foligne et al., 2010; Hacini-Rachinel et al., 2009; Jobin, 2010; Li, Xia, & Li, 2009). However, several animal and human studies have provided unequivocal evidence that specific strains of probiotics are able to stimulate multiple aspects of innate immunity (Amit-Romach et al., 2010; Boirivant & Strober, 2007; Boirivant et al., 2008; Farnell et al., 2006; Romanin et al., 2010; Weiss et al., 2010) as well as to increase humoral immunity (Fang, Elina, Heikki, & Seppo, 2000; Galdeano, de Leblanc Ade, Carmuega, Weill, & Perdigon, 2009; Leblanc, Fliss, & Matar, 2004; Nermes, Kantele, Atosuo, Salminen, & Isolauri, 2011).

Using a *Salmonella* challenge model, an effective LAB probiotic, administered 2 hours after *Salmonella* challenge, had no effect during the first 12 hours on increasing cecal colonization by this pathogen, although marked and rapid decreases were observed between 12 and 24 hours post-challenge (J. P. Higgins et al., 2007; J. P. Higgins et al., 2010). Later, using the same model and microarray analysis of gut mRNA expression, gene expression differences in birds treated with a *Lactobacillus-*based probiotic were compared to saline treated birds. At 12h postprobiotic treatment, 170 genes were significantly different (P<0.05), but by 24h post treatment, the number of differentially regulated genes were 201. Pathway analysis revealed that at both time points, genes associated with the NFκB complex were significantly regulated, as well as genes involved in apoptosis. Probiotic-induced differential regulation of the genes *GAS2* and *CYR61* may result in increased apoptosis in the ceca of chicks. Because *Salmonella* is an intracellular pathogen, it was suggested that increased apoptosis may be a mechanism by which B11 reduces *Salmonella* infection (S. E. Higgins et al*.,* 2011).

Alternative Strategies for *Salmonella* Control in Poultry 263

**24***Weissella confusa Lactobacillus casei Lactobacillus casei Clostridium*

**27** *Weissella confusa Lactobacillus casei Lactobacillus casei Weissella confusa*

**Midi system ID Microbial ID Inc.**

*Lactobacillus*

*Lactobacillus delbreuckiibulgaricus*

*cellobiosus Lactobacillus casei Weissella confusa*

*Pediococcus*

*cellobiosus*

*Lactobacillus*

*Lactobacillus sanfranciscensis*

*Lactobacillus gasseri*

**Biolog ID Dept. of Poultry Sc. U. of Arkansas**

*clostridiiforme*

*Lactobacillus hamsteri*

*Weissella paramesenteroides*

> *Lactobacillus salivaruis*

> *Lactobacillus salivarius*

*gasseri Unable to identify*

*ruminis Unable to identify*

*fermentum Unable to identify*

*cellobiosus Unable to identify*

**Midi system ID Micro Test Lab Inc.**

> *Enterococcus cecorum*

> *Lactobacillus delbreuckiibulgaricus*

> *Lactobacillus*

*acidilactici*

*Lactobacillus fermentum*

*Lactobacillus helveticus*

*Lactobacillus helveticus*

*parvulus Unable to identify Lactobacillus*

Table 1. Comparisons between MicroSeq , MIDI, and Biolog identifications of FloraMaxTM

**5.** *Bacillus* **spore***-***based probiotic for** *Salmonella* **control and performance**

In spite of the success showed by the development of the LAB probiotic for use in commercial poultry as described above, there is still an urgent need for commercial probiotics that are shelf-stable, cost-effective and feed-stable (tolerance to heat pelletization process) to increase compliance and widespread utilization. Among the large number of probiotic products in use today some are bacterial spore formers, mostly of the genus

**40***Weissella confusa Lactobacillus casei Lactobacillus*

**LAB ID**

**16S RNA Sequencing (FIRST 500 bp) Microbial ID Inc.**

*parvulus*

*parvulus*

*salivaruis*

*paramesenteroides*

*salivaruis*

*salivarius*

**37B** *Weissella confusa Pediococcus*

**18***Pediococcus*

**29***Pediococcus*

**36***Lactobacillus*

**44***Weissella*

**46***Lactobacillus*

**48***Lactobacillus*

**52***Pediococcus*

**enhancement in poultry**

1Adapted from Tellez et al., 2006

lactic acid bacteria1


*Edited by Hesam Kamyab*

Palm oil biomass is constantly produced in large quantities throughout the world as a waste product of the vast palm oil plantations. Biomass from the palm oil industry has been converted into value-added products to a limited extent via thermochemical, chemical, physical, and biochemical conversion routes. However, a significant amount of biomass, such as OPF and OPT, is still left in plantations. A pragmatic approach to converting them to value-added products will not only result in a cleaner environment but also generate significant revenue for the government. It is also suggested that more attention be paid to bioproducts in order to present them in an appealing form to endusers, thereby encouraging good patronage.

ISBN 978-1-83962-755-2

*Elaeis guineensis*

Published in London, UK © 2022 IntechOpen © Nelson J Botilu / iStock


*Article* **Does Scientific Evaluation Matter? Improving Digital Simulation Games by Design-Based Research**

### **Sven Ivens \* and Monika Oberle**

Department of Political Science, University of Goettingen, 37073 Goettingen, Germany<EMAIL_ADDRESS>
**\*** Correspondence<EMAIL_ADDRESS>
Received: 26 July 2020; Accepted: 2 September 2020; Published: 9 September 2020

**Abstract:** Grounded in a design-based research approach, the aim of this article is to determine whether scientific evaluations help to (a) identify and fix problems in educational interventions and (b) eventually foster a more effective and positive evaluated intervention. Therefore, data from a longer-term evaluation of short digital simulation games about the European Parliament for civic education in schools were used. The data included three cycles of interventions with preand post-evaluations starting with the first prototype in 2015/2016 (*n* = 209), the second cycle in 2017/18 (*n* = 97), and the last one in 2019/20 (*n* = 222). After each evaluation, major problems and critiques regarding the simulation game were discussed with the developers, and changes were implemented in the game design. The four most important problems, the processes by which they were improved and the reactions of the participants in the following evaluations are pointed out in the article. A comparison of the last and first evaluation cycle showed an overall improvement of the simulation game regarding its effectiveness in transferring EU knowledge and the participants' general satisfaction with the simulation game. This study underlines the value of the design-based research approach for developing educational interventions and can be useful for further work on civic education measures and the implementation of digital simulation games.

**Keywords:** digital simulation game; design-based research; empirical research; civic education; European Union

### **1. Introduction**

The effectiveness of active citizenship education programs, tools, and interventions are often measured and evaluated by scientists in many different ways, reaching from qualitative interviews or self-reflections to (quasi-) experimental studies and large n survey studies. But what happens after the evaluation is done and the article is published? Is measuring and evaluating civic education programs and teaching tools an end in itself, or does doing so help to actually increase the effectiveness of these programs? This article investigates the usefulness of scientific evaluation in civic education according to the design-based research approach. This quite new research approach goes a step further, as it focuses not only on evaluating educational interventions but also on enhancing them according to the collected evaluation data and then evaluating them again to see if the changes were effective until the educational intervention leads to a satisfactory result (Anderson and Shattuck 2012). It has recently been used for research on subject didactics in school (Peters and Roviró 2017), on higher education (Ford et al. 2017), blended learning (Ustun and Tracey 2020), and simulation games (Koivisto et al. 2018) but has not yet been used for improving digital simulation games in civic education.

To break new ground, the design-based research approach presented here uses data from an ongoing evaluation study about short digital simulation games in civic education (Oberle et al. 2017). Analog simulation games are a widely used method in civic education (Massing 1997), and simulation

game producers are trying to digitalize them in order to use the positive effects of digitalization for their products (Kaiser et al. 2017). Since 2015, a research team at the chair of Political Science/Didactics of Politics of Göttingen University has been evaluating the usage of a newly developed short digital simulation game about the European Parliament in school classes, developed and implemented by the Berlin-based German company planpolitik (www.planpolitik.de). Three evaluation cycles were conducted in 2015/2016, 2017/2018, and 2019/2020 (for results of the first cycle of evaluated game implementation, see Oberle et al. 2017). Between the iterations, the results were presented to the game developers, and possible dysfunctional elements were pointed out. Based on these data and on the overarching question "Does Scientific Evaluation Matter?" this article will investigate the following research questions:

The questions will be answered using data from all three evaluation cycles, mainly focussing on the first and last evaluation as they are similar in their sample composition and are showing a direct contrast between the first prototype and the final product. Additionally, an interview with planpolitik's head developer was made to identify and explain the improvements.

The article is structured as follows: after this introduction the use and literature of digital simulation games in civic education as well as the design-based research approach will be elucidated, followed by a detailed description of the research design. In the results section, the shortcomings of the simulation game, the improvements needed to address them and the effectiveness of the improvements will be explained one after another, ending with a direct comparison of the first and last evaluations of the game. A conclusion will sum up the most important findings and place them in context with the overarching question of the article.

### **2. Digital Simulation Games in Civic Education**

Face-to-face simulation games are a widely used method in civic education (Massing 2010), and their value for civic education in schools (Oberle et al. 2018; Oberle et al. 2020) as well as in political science education in universities (Fink 2015; Duchatelet 2019; Lohmann 2019) has been extensively discussed. On the contrary, there is hardly any research, let alone empirical research, about digital simulation games in civic education (Bachen et al. 2015; Oberle et al. 2017). Empirical studies about simulation-based learning in education, in general, show that simulations have a more positive effect when used in combination with modern technology, like VR or digitalization (Chernikova et al. 2020).

There are many expectations and theoretical considerations regarding the benefits of digital simulation games: e.g., they are supposed to improve intrinsic motivation (Le et al. 2013) and strengthen negotiation skills, teamwork, and empathy (Gabriel 2012). The digitalization of simulation games also has the potential to multiply the reach of the didactical method of simulation games, as they can be played online in a fully prepared gaming environment. Thus, the presence of a professional instructor to administer them in the classroom is no longer needed (Kaiser et al. 2017). Furthermore, they can be played independently from location and time. This can make them accessible for a broader range of pupils and, given the technical equipment, relatively easy to implement into regular teaching.

Alongside theoretical articles, most studies regarding the use of digital simulation games are case studies reported by teachers in practitioner journals (DiCamillo and Gradwell 2012), qualitative studies taking a student's perspective (Schnurr et al. 2013), or are based on computer/video games (López and Cáceres 2010; Motyka 2018). Overall, the results of these qualitative studies show that participants are rather satisfied with the digital simulation games but also voice criticism, especially regarding a lack of face-to-face communication and a high workload. However, there is a scarcity of quantitative, quasi-experimental studies regarding the effects of digital simulation games in civic education as well as their development over time. An example of a good quasi-experimental study has been conducted

by Bachen and colleagues (Bachen et al. 2015) who used a pretest-posttest design to analyze the effect of a digital simulation game on 301 American high school students. Their results showed an increase in political interest, especially by uninformed and "low-performing" students. They also criticized the lack of studies of digital simulations in civic and social science education.

Lastly, there was a pilot study by Oberle and colleagues (Oberle et al. 2017), which analyzed the effects of a short digital simulation game from the German company planpolitik about decision-making in the European Parliament. This research will be elaborated upon further in the research design portion as the study presented here is based on the continuing evaluation of this digital simulation game. The pilot study suggested that there is not enough research on the topic and that the theoretical expectations in digital simulation games might be exaggerated as the study shows that an analog simulation game worked better in comparison. Furthermore, the digital simulation game had hardly any effect on any of the student dispositions measured; it even had a negative effect on objective EU knowledge. Additionally, the students assessed the analog simulation game more positively than the digital one. However, the authors also note that the digital simulation game was in an early stage, and digital simulation games in civic education, in general, are a very new development, which has not yet been studied sufficiently (Kaiser et al. 2017). To tackle this research deficit, the Göttingen research team continued to evaluate the digital simulation, shared the research with the developers, and used a design-based research approach to further improve the digital simulation game as a useful educational measure for teaching about the European Union (EU).

### **3. Design-Based Research in Educational Science**

Design-based research is an increasingly popular practical research method that helps to bring research and practice together in order to generate effective educational interventions and methods (Van den Akker et al. 2006). Educational researchers started using it at the beginning of the 21st century to "increase the impact, transfer and translation of education research into improved practice" (Anderson and Shattuck 2012, p. 2) and simultaneously develop their theories further. It is mainly used to study innovative learning environments, especially those using new technologies and/or complex interventions in a classroom setting (Sandoval and Bell 2004) and should be used in new fields where pedagogical content knowledge, e.g., regarding instructional strategies, is poor (Ford et al. 2017). Thus, it is a promising method to study digital simulation games about (European) politics.

Design-based research can complement experimental and quasi-experimental research but differs from it in some important aspects (Hoadley 2004; Jen et al. 2015). However, it goes further than just evaluating the intervention and its effects: the method at hand also focuses on optimizing the interventions. Therefore, the improvement of the intervention itself is an outcome (Hoadley 2004; Design-Based Research Collective 2003). To accomplish this, the research methodology is quite open, and researchers can "select and use differing methods, selecting them as they see need" (Maxcy 2003, p. 59), which includes but is not limited to (quasi-) experimental pre-/post designs, developmental evaluations (Patton 2011), interviews, observations, and questionnaires.

Design-based research also needs more than one evaluation cycle and often multiple iterations of testing, evaluating, and improving the interventions until the educational intervention is suitable for its purpose (Lewis et al. 2020), which makes it "difficult to know when (or if ever) the research program is completed" (Anderson and Shattuck 2012, p. 2). On that score, design-based researchers argue that the implementation and evaluation of the intervention have to be taken out of the laboratory and have to be studied in a real-world setting (Barab and Squire 2004).

Lastly, design-based research builds on close cooperation between practitioners/developers and the researchers themselves (Kuhn and Quigley 1997; Štemberger and Cencic 2016), as the practitioners usually lack the necessary skills for scientific research, and researchers lack the technical knowledge and practical skills to develop and implement the intervention.

This close relationship between practitioners and researchers as well as the in-depth involvement of researchers in the development process of the intervention are two main points of criticism against design-based research (Barab and Squire 2004). Similar to many qualitative methods, there is a "narrow line between objectivity and bias" (Anderson and Shattuck 2012, p. 5) for researchers using the method, and similar to qualitative methods, there are different ways to minimize this bias (Onwuegbuzie and Leech 2007). One would be to triangulate the data drawn from the evaluations with a researcher who is not involved in the project.

Another problem of design-based research is the long duration of design-based research projects, as they usually require at least two iterations, often more, to be complete (Anderson and Shattuck 2012). To tackle this, Herrington and colleagues (Herrington et al. 2007) recommend using design-based research in doctoral dissertations over a four-year period or in multi-year research agendas.

Many examples of the use of design-based research have been published in edited volumes in recent years (see, for example, Kay and Luckin 2018). One Ph.D. thesis, in particular, was focused on the study and development of analog simulation games for civic education, the cumulative dissertation of Knogler (2014). In his dissertation, he developed a school course over three weeks, including an analog simulation game about the future of a community's energy supply (Knogler and Lewalter 2014). Following the design-based research approach, he tested the prototype with 112 pupils in German high schools, evaluated the test with a pretest-posttest design, and used the results to further develop the intervention. The re-developed intervention was used on another sample of 156 German pupils and tested again with the same pretest-posttest design. With that design, he could show that only the re-designed intervention had a positive effect on the pupils' appreciation of the value of science. All in all, the prototype had hardly any effect, whereas the re-design intervention affected all measured dimensions (Knogler and Lewalter 2014). The research design in the article is similar to the design by Knogler but with multiple cycles of testing, evaluation, developing, and testing again, and will be described in detail in the next chapter.

### **4. Research Design**

Following the design-based research approach, the design of this research was focused on an intervention, a 90-min-long synchronous digital simulation game. The simulation game was designed for secondary level high school students in Germany and is about the European Parliament and its political decision-making process regarding the topics of asylum and data protection policy. The game was developed by the Berlin-based company planpolitik and implemented with an accompanying scientific evaluation by the chair of political science/civic education at the University of Göttingen in 2015/2016. The results of the scientific evaluation were then discussed with the developers from planpolitik, and changes were made accordingly. A second iteration with a smaller sample (see Table 1) followed in 2017/2018, and a third iteration with a larger sample in 2019/2020. For this article, we mainly focus on the differences between the first and the last evaluation cycles as both samples are quite similar, and the sample of the second iteration is quite small (see Table 1).

**Table 1.** Pretest-Posttest Sample Description for All Three Evaluation Cycles.

\* = measured by place of birth and parents' place of birth; \*\* = measured by amount of books in parents' household (Sieben and Lechner 2019).

The main defaults of the simulation game, which the first evaluation pointed out, will be presented. The changes planpolitik made according to this evaluation will be disclosed using an interview with Konstantin Kaiser from planpolitik, who is in charge of digital simulation games and their development. The results of the last evaluation will clarify whether the changes had a positive effect on the result and evaluation of the simulation game in 2019/2020. The results and evaluation of the 2015/2016 and 2019/2020 iterations will be compared in the crucial points to determine whether the designed-based research approach has led to more effective evaluation.

### *4.1. Sample Description*

All classes that played the simulation game were from schools in the German state of Lower Saxony since the European Information Center of Lower Saxony is funding the implementation of the games at school. The European Information Center is also in charge of promoting the simulation game and recruiting classes to play it. Therefore, the sample selection was not random; teachers signed in with their classes voluntarily. That also led to the different sizes of the respective samples (see Table 1), as there were fewer classes signing in for the game in 2017/2018, as well as fewer teachers willing to facilitate the scientific evaluation. The samples not only differ in size, but also in school type, as in 2015/2016 pupils from grammar schools and comprehensive schools participated, in 2017/2018 only pupils from grammar schools, and lastly, in 2019/2020 classes from grammar schools and vocational schools signed up to take part in the simulation game. This resulted in an age difference between the last and the first sample, which is a critical point of this study and will be further addressed in the discussion of the limitations of this article.

Nevertheless, the focus of this article is on the first and third evaluation cycles, as these samples are quite similar in size, cultural capital, and the percentage of pupils attending grammar schools. A possible migration background was not assessed in the first study. All three samples consist of pupils who participated both in the pretest and in the posttest.

### *4.2. Research Instruments*

The accompanying scientific evaluations were made in a pre-, post-, and follow-up design including mainly closed yet some open questions as well as an EU knowledge test in the first and third samples, modeled based on the EU knowledge test by Monika Oberle (Oberle 2012). The survey measures different concepts including subjective EU knowledge, internal efficacy, attitudes towards the EU, and political interest (derived from Deutsche 2010; Gille et al. 2006; Kerr et al. 2010; Oberle and Forstmann 2015; Vetter 2013; Westle 2006). The evaluation of the simulation game is carried out in the posttest with 19 four-scaled Likert items with 1 for "not at all" to 4 for "fully agree" which measure the simulation game in the dimensions of general satisfaction, subjective learning effect, and motivational effect (see Table 2). All statistical analyses conducted for this paper were completed with SPSS 25. The posttest survey also includes open questions regarding what participants liked, disliked, and would improve in the simulation game, which were analyzed and categorized with the qualitative content analysis after (Mayring 2010) using MAXQDA 2018 (VERBI GmbH, Berlin Germany).

Lastly, a guided expert interview was conducted with Konstantin Kaiser from planpolitik to document the improvements made in the simulation game and to find out whether the implemented improvements followed the suggestions from the scientific evaluation.

### **5. Results**

To answer the research questions properly, the result section is structured as follows. First, the main dysfunctions of the simulation game, which were revealed in the first evaluation, will be displayed one after another. The improvements planpolitik made will be displayed, and the third evaluation will be checked for changes in the evaluation regarding the dysfunctional area. After all dysfunctions have been explained, discussed, and the effects of the improvements have been verified, the effectiveness and assessment of the 2019/2020 implementations will be compared to the first one to answer the second research question.

### *5.1. The Chat Function*

One of the most criticized functions in the first application of the simulation game was the chat function. The chat function was on an extra page in the simulation and participants had to actively click on the page to see if they had new messages as opposed to modern social media pages, where you get a notification that you have new messages. Therefore 29.4% of the participants in 2015/2016 rated the technical features of the chat system as rather bad and 11.8% as very bad, similar to the rates of the communication via chat in general with 25.6% as rather bad and 15.9% as very bad. In the open questions, 26.5% of all comments complained about technical problems with the chat system, and only 8.2% of comments mentioned the chat system in a positive way (see Appendix A).

Since this was a major dysfunction of the simulation game made clear by the evaluation, changes in this area were recommended, which planpolitik also took seriously, as can be seen from this interview quote:

*Interviewer*: "It can be seen from the results of 2015/2016 both in the open questions and in the evaluation of the simulation game that the chat and the chat function were seen very critically by the participants. Did you (planpolitik) react to this result of the evaluation?"

*Planpolitik*: "Yes, for sure! That was a little bit like a slap in the face for us. In technical developments, especially in this phase, there are always problems. The implementations that we made there at the beginning with the schools that you also evaluated 2015, 2016 were simply super important for us to find all these problems and to see them as well, and of course we responded to that and then made improvements in many ways."

The mentioned improvements include a notification for new messages so that participants can react swiftly to messages, and the flow of the game could be enhanced. Furthermore, a like and dislike function for contributions in debates and in the group forum was added. The positive effect of the changes can already be seen in the 2017/2018 evaluation and are still present in the 2019/2020 evaluation (see Table 3). The average ratings for the technical features of the chat and the general communication by chat are initially increasing between the first and second cycles towards a more positive view and remain that way in the later evaluation (see Table 3). Therefore, participants are more satisfied with the improved chat in the later versions.

A similar development can be seen in the open questions: in 2019/2020, 13.3% of all comments actually mention the chat system as something they explicitly liked about the game. The negative comments about the chat systems decrease to 8.4% in the 2017/2018 evaluation and to 12.4% in the 2019/2020 evaluation, which is a decrease by more than half compared to 26.5% in 2015/2016.

**Table 3.** Mean Value Comparison of Chat Function Assessment Using Cohen's d (Cohen 1988).

 The Final Vote*/*The End of the Game*

The simulation game ends with a final vote on the legislation draft the students were required to produce during the simulation of the European Parliament. In 2015/2016, the draft was a text written by the participants themselves. It took some time to agree on single formulations, leading to many votes on the draft in the parliament to end the game, and the draft was not satisfying for many participants. This already was a problem in the 2015/2016 evaluation, as the result of the simulation was that the category rated the worst in the evaluation with 49% of the participants having assessed it as rather bad or very bad. In the small 2017/2018 evaluation, after fixing the chat problem, the discontent was even bigger, with nearly 58% of the participants ticking rather bad or very bad in the evaluation. Furthermore, 16.9% of the complaints in the open questions focused on the issue of the result of the game and the final voting process (see Appendix A). The two evaluations led to a change in planpolitik's voting system, as you can see in this part of the interview:

*Interviewer*: "In 2017/2018, the end of the simulation game specifically the final vote was especially criticized. Did you change or customize the voting regarding the final vote of the game after the critical results of the evaluation?"

*Planpolitik*: "No, we did not. That is also confusing for me. No idea. We did not change anything." Interviewer: "So absolutely nothing? Since 2015 is was always the same?"

*Planpolitik*: "Although no, yes. Right. In 2015 it was still free text. And so everyone could formulate each word individually [ . . . ] we changed it so that we use prewritten sentence building blocks as drop-downs, that's what you call them, so you can select them by clicking on such a field."

The 2017/2018 implementation was still with the old version of the game, and the evaluation of this cycle made the dysfunction of the final voting system even more evident. The improvement towards a drag and drop version was made by planpolitik, and the participants can now build their legislation draft by choosing out of different text blocks going in one political direction or another, which can be changed in order to achieve a majority approval for the draft. The positive effect of this change is clearly visible in the newest evaluation. Compared to the average assessment of the end result of the simulation game in 2017/2018 (M = 2.33; SD = 0.98), the 2019/2020 evaluation had a medium positive increase of the assessment with a Cohen's d value of 0.67 (M = 2.93; SD = 0.81), thus moving the end result and the final vote from the worst-assessed category to a rather highly assessed category in the newest evaluation. Furthermore, there was only one complaint in the open questions about the final voting system (see Appendix A).

### *5.3. Role Description*/*Role Identification*

A smaller but noteworthy change in the simulation game is the role description. In the first evaluation, the participants were quite satisfied with their role description, but the evaluation indicated a lack of role identification, and as for the open questions, only 8.2% of the comments were mentioning positive role identification. Planpolitik reacted and changed the role description after 2015/2016:

*Interviewer*: "Since 2015/2016 role identification is increasing; in 2015/2016 it was relatively low with 9% and nearly doubled after that. Did you do something with the role description over time?"

*Planpolitik*: "Yes, we have revised the role description. The page used to be just statistical information, like a book, just plain text. We have divided these (pages) into three modules, let's say. And then small questions in between. So we have included several interactive elements."

The role description changed from a predetermined role description to an interactive role design process that should increase the role identification as the participants have a greater influence on their own role. The later evaluations can support this claim: in 2017/2018, 17.1% of all comments on the game mention a positive role identification, similar to 2019/2020 with 19%, doubling the percentage of positive comments compared to 2015/2016 (see Appendix A).

### *5.4. The Learning E*ff*ect*

The last, yet very important factor that the design-based research impacted is the effect of the simulation game on objective EU knowledge measured by the knowledge test. In the first evaluation of the simulation game, the results of the knowledge test showed a small decrease of EU knowledge; thus, the participation in the simulation game had a negative effect on the objective EU Knowledge of the participants (Cohen's d −0.21). This was, of course, not intended and the opposite effect of what the game should actually do. The evaluation pointed this out, and planpolitik reacted and changed the setting of the digital simulation game:

*Planpolitik*: "We changed nothing in the game itself but we added a presentation for the teachers, so in the introduction before the game starts, there is now a presentation for the teacher which the teacher will show the pupils. Now we are doing an online simulation game. This and that will happen and that helps to structure the expectations of the pupils and then they know better what is coming for them and what they will be learning about and that there is a committee and they are simulating a law-making process and just the classification where they are and what they are doing right now. Before that we just threw them into cold water. Thereby, I think, it is clearer to the people what they are doing and then they can better learn and save the information."

In educational science, there are clear indicators that combining and structure in educational interventions help the learner to better understand and receive knowledge (Jang et al. 2010; Sierens et al. 2009). The positive impact of the restructuring can also be seen in the 2019/2020 evaluation as the game now has a positive effect on objective knowledge (see Table 4).

**Table 4.** Mean Value Comparison of Objective Knowledge Using Cohen's d and *t*-test.

So the effect on objective knowledge turned from a small significant decrease to a small significant increase, which can be expected for a 90-minute intervention.

### *5.5. General Comparison*

For the second research question about the passage to a more effective and appreciated digital simulation game through the use of design-based research and scientific evaluation, in this section, a comparison between the first and the most recent evaluation will be done. Therefore, the participants' evaluations of the games and the effect on the participants will be highlighted and compared, the

first one being the general assessment of the three dimensions of the simulation game assessment (see Table 5).

**Table 5.** Mean Value Comparison of All Three Dimensions of Simulation Game Assessment in the First and Last Evaluation Cycles.

The last evaluation was the most positive one in all dimensions, especially in the dimension of general satisfaction Not only does the general assessment of the simulation games show positive development, but the direct comparison of the adjectives the participants associate with the games also makes the advancements of the latest version clearer (see Figure 1).

**Figure 1.** Comparison Simulation Game Adjectives Assessed by Participants in 2015/2016 and 2019/2020; 1 Indicates Strong Rejection and 4 Strong Agreement.

Overall, the participants rate the 2019/2020 simulation game, on the one hand, in all positive aspects higher, like the diversification of the game, find it is more interesting and exciting, and especially perceive it as more realistic, and on the other hand, in all negative aspects rate lower, particularly the nerve-racking and exhausting part, than the first version.

− Looking at the effects of the simulation games, the 2015/2016 version had nearly no effect on all measured constructs (attitudes towards the EU, willingness of political participation, political interests, internal efficacy) except a negative effect on EU knowledge and a small positive effect on the willingness to engage in illegal political participation (Cohen's d 0.24), like political vandalism and civil disobedience. The newest version of the simulation game had a positive effect on objective EU knowledge and still had a small positive effect on the willingness to participate in politics illegally (Cohen's d 0.20). Additionally, there is a significant positive effect on internal efficacy (*t*-test 3.69 \*\*\*) that has only a very small effect size according to the Cohen's d value (0.17). Lastly, in the third evaluation cycle, pupils' general attitudes towards the European Union became slightly less positive (−0.21) after having played the game, but the general attitudes towards the EU were very positive in this sample from the beginning. Comparing the mean values of general EU attitudes in the posttests, the values of the third cycle are still higher than those of the first cycle.

In conclusion, the new version is now expanding the knowledge of its participants and slightly enhancing their internal political efficacy, which is what the educational intervention was meant to do. It still inspires them a bit towards illegal political participation and decreases the initially very high level of positive attitudes towards the EU. On the other EU-related political dispositions captured in the evaluation, the simulation game has no effect; given that it only takes 90 min, strong effects on attitudes were not expected.

### **6. Discussion**

The results support certain aspects of the design-based approach, for instance, the importance of multiple iterations and evaluation cycles (Lewis et al. 2020; Anderson and Shattuck 2012; Herrington et al. 2007). The participants in the first iteration were very focused on the problems with the chat, drawing attention to this point of criticism. Therefore, problems regarding the "final vote/the end of the game", which were already present but not the main point of criticism in the first iteration, were neglected but became more visible during the second iteration. The results also underline the usefulness of mixed-method approaches in design-based research (Maxcy 2003). For example, while statistical analysis uncovered the problem with the chat system, it was the qualitative content analysis (Mayring 2010) of the open questions that showed what the problem actually was, thus making it easier for the developers to fix it.

So did scientific evaluation matter in the presented case? In the example of these short digital simulation games, a design-based research approach designed after Anderson's and Shattuck's (Anderson and Shattuck 2012) was implemented. The implementation followed the recommendations of design-based research literature and was leaning on the work of (Knogler and Lewalter 2014), including a close cooperation between researchers and developers (Kuhn and Quigley 1997), as well as multiple iterations over time. This led to a more effective and positively rated version of the educational intervention that is now expanding the knowledge of its participants and slightly enhancing their internal political efficacy, which is what the digital simulation game was meant to do (Kaiser et al. 2017; Oberle et al. 2017). Even though the effects of the short simulation games are still small, they now do help students to learn about the European Parliament; indeed, the size of the effects is considerable in view of the limited length of the intervention (90 min). Therefore, the scientific evaluation did matter in developing a better-functioning education measure, which is, according to the design-based research approach, a goal in itself (Hoadley 2004; Design-Based Research Collective 2003). The positive results are also in line with similar studies from the fields of blended-learning (Ustun and Tracey 2020) and face-to-face simulation games (Knogler and Lewalter 2014; Koivisto et al. 2018), showing the design-based-research approach as a suitable way to enhance digital simulation games in civic education, too.

Of course, limitations of the study need to be taken into account for an appropriate interpretation of its results. The main limitation of the study is its quasi-experimental setting; as opposed to purely experimental studies, it is not guaranteed that the shifts in the effects and assessments between the three evaluations are coming from the improvements planpolitik made or from other influences. In experimental settings, other potential factors of influence can be controlled, whereas in quasi-experimental settings this can only be done to a limited extent as there is no control of the Wi-Fi connection and technical equipment of the school, the behavior of the pupils, or other possible influences. Another important limitation is the sample composition and size: the 2017/2018 sample is very small and all samples having different compositions of school types leading to differences in age and other potentially influencing factors. As already underlined in the description of the sample, another point of limitation is that the sample selection was not random as the classes were signed up for participation by their teachers on a voluntary basis. Therefore, the results should be interpreted with care. Overall, the sample size is still too small and arbitrary for general assumptions but the results can point in a direction for further large n studies in this field.

### **7. Conclusions**

Four major flaws of the first version of the digital simulation game—respectively, the dysfunctional chat, the end result/final vote of the game, the role description, and the negative learning effect—were pointed out in an attempt to answer the first research question. Following the design-based research approach (Anderson and Shattuck 2012), dysfunctions were processed and could be improved, leading to a more positive assessment by the participants in the later evaluations. Thus, the final evaluation of the simulation game was more positive than the evaluation before, and the game's effects regarding participants' objective EU knowledge and internal political efficacy were enhanced as compared to the earlier evaluations (Oberle et al. 2017).

Similar to the research of (Knogler and Lewalter 2014), the simulation game was enhanced through design-based research and is now more useful for practical applications. The study has limitations and its results cannot be generalized, but they do support the request that educational interventions like simulation games, digital and analog ones, should be accompanied by empirical evaluations to enhance their potential and to point out possible design/application failures. Close cooperation between evaluators and developers can lead to a more effective intervention (Štemberger and Cencic 2016); new ideas and prototypes should be tested and investigated closely, and this effort should not stop after one cycle of evaluation.

Scientific evaluation matters and can improve programs, tools, and methods in the important field of civic education. Further long term studies, including large n studies as well as qualitative studies, should accompany new civic education programs inspired by the design-based research approach to critically analyze the effectiveness of such measures and to make sure learners can benefit from the best civic education possible.

**Author Contributions:** Conceptualization, S.I.; methodology, S.I.; investigation, S.I.; formal analysis, S.I.; writing—original draft preparation, S.I. and M.O.; writing—review and editing, S.I. and M.O. All authors have read and agreed to the published version of the manuscript.

**Funding:** We acknowledge support by the Open Access Publication Funds of the University of Goettingen. **Conflicts of Interest:** The authors declare no conflict of interest.

### **Appendix A**

**Table A1.** Extract of the Results of the Qualitative Content Analysis Focusing on the Problems Discussed in the Article.

### **References**

Motyka, Marc. 2018. *Digitales, Spielbasiertes Lernen im Politikunterricht*. Wiesbaden: Springer VS. [CrossRef]

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**2. Sampling and samples**

*Trace Metals in the Environment - New Approaches and Recent Advances*

into the ecosystem.

The resource being mined, geology of an area and technology adopted are some of the factors that influence the nature, characteristic properties and level of mine waste generated at specific mines. Mining companies in South Africa, due to legislations and regulations pertaining to general waste management at mining sites, endeavour to manage waste generated during their operations in a bid to avoid the release of contaminants into the environment [1]. Unfortunately, some level of contaminants, which constitute crushed, sand-like materials, still finds their way

By definition, mine dumps, also known as residue stockpiles, refer to any debris, discard, tailing, slimes, screening, slurry, waste rock, foundry sand, beneficiation plant waste, ash or any other product derived from or incidental to a mining operation and which is stockpiled, stored or accumulated for potential reuse, or which is disposed of, by the holder of a mining right, mining permit, production right or an old order right [2, 3]. Generally, mine wastes are unwanted, currently uneconomic, solid and liquid materials found at or near mine sites that largely constitute one of the world's major waste streams due to their composition of high concentrations of elements and compounds that impact negatively on humans and animals, the surrounding environment and plants alike [4]. An alarming number of mine dumps often characterised by a complex mixture of metals and dust particles are located at several jurisdictions of the country. This implies that during windy conditions, exposure to dust could be high for close-by inhabitants. Other challenging issues associated with mine wastes include environmental impacts such as the loss of agricultural lands because of their conversion to waste storage facilities and the successive introduction of sediments and other impurities into adjoining surface and groundwater from water running over exposed chemically reactive wastes [5–8]. Most mine wastes have heavy metals (HMs) as a major component, and their continued circulation in soil and water puts the world in a nerve-wracking situation due to their toxic and deleterious effects [9]. HMs such as cadmium (Cd), thallium (Ti), zinc (Zn), lead (Pb), arsenic (As), mercury (Hg), chromium (Cr), copper (Cu), lead (Pb), iron (Fe) and nickel (Ni) are naturally occurring components of the earth's crust and are often referred to as metallic chemical elements with a relatively high density—at least five times the specific gravity of water [10]. At trace concentrations, HMs such as Cu, Cr + 3, Zn, Mn, Co and molybdenum (Mo) are of biological significance; however long-term exposures and high concentrations impact negatively on several biomolecules. It is noteworthy to mention that at very

low concentrations, Hg, Cd, Cr + 6, As and Pb stand to be very toxic [11].

diverse environmental problems to humans, animals and plants [14].

Sediments are vital components of aquatic habitat as they can retain contaminants that are not bioavailable to humans [12]. Pollutants are released into water bodies via processes such as sediment resuspension, desorption and redox reactions of sorptive substances. This further explains why sediments despite being reservoirs could at the same time act as likely source of pollutants in the aquatic system [12, 13]. Mine tailings (MT) having the possibilities of containing some HMs are seen in different areas of Blesbokspruit in Ekurhuleni Municipality, South Africa. Over the years, these mine tailings solidify, leaving mountainous structures made of very fine sand particles. Several agents of erosion such as wind and surface run-off after heavy rainfall transport sediments to surrounding water bodies (rivers). These rivers are major sources of water supply to agricultural lands and may constitute

A comprehensive understanding of the physicochemical features of soil and water pollutants provides a platform for careful soil management aimed at reducing the adverse effect of the pollutants on the ecosystem. Heavy metals from mine tailings in ionic solutions sometimes contaminate groundwater via leaching and are absorbed by plants; thus it is introduced to the food chain [15]. In another instance,

**36**

### **2.1 Description of the sampling site**

Due to outraging scarcity of water resources, South Africa is referred as a semi-arid nation. Study materials were obtained from a mine tailing dump facility located within the Blesbokspruit catchment (26°10′12″S 28°27′52″E), Heidelberg (34°01′59″S 18°52′28″E) and Suikerbosrand (26°29′46″S 28°21′00″E) rivers, respectively, all of which constitute part of the Vaal River Barrage secondary catchment, located in the eastern region of the Gauteng Province. The Blesbokspruit catchment has in it an important and international wetland covering an area of about 1858 km2 with a Ramsar recognition dated as far back as 1986. This wetland has a gold mine tailing dump located very close to it and provides support and habitat to several species of birds and plants [16]. Extended part of the study area is used for agricultural activities such as cultivation of crops and rearing of animals. The sampling sites (**Figure 1a**) were selected due to what seems to be the ironic presence of an abandoned gold mine tailing dump that has located next to it an artificial wetland. The wetland was supposed to aid in remediation of the discharge from the mines. In addition, an informal settlement characterised with mostly rural–urban dwellers that engage in farming activities was also in proximity. The rivers being considered in this study are to the best of our knowledge the major water sources for farming activities such as irrigation and feeding of local cows. The subsistence farmers within this area created artificial channels in a bid to redirect water from the streams to special reservoirs that service mostly the animals (**Figure 1b**). During rainfall and often windstorms, sediments from the tailing dumps get eroded into the wetland and subsequently into the surrounding rivers as a result of overflow and surface run-offs (**Figure 1c**).

#### **2.2 Collection of samples and pretreatment**

Using sterile bottles, water samples were randomly obtained from four sampling sites located at various directions and distances within the Blesbokspruit catchment. The water samples were assigned names: wetland (WL), Blesbokspruit (BS), Heidelberg (HB) and Suikerbosrand (SB). Soil samples (mine tailing sediments) were collected using a Teflon-coated soil auger and put in labelled polyethylene bags with clear designation MT1–MT4, respectively. The collected water samples from identified streams were stored in an insulated icebox and transported to the laboratory for storage at 4o C prior to further analysis. Collected soil samples were oven

#### **Figure 1.**

*(a) Map of South Africa showing the Blesbokspruit water catchment [17]; (b) study area showing tailing dump site, wetland and river; (c) transfer mechanism of trace metals/elements.*

**39**

*Mobility of Trace Element Contaminants from Abandoned Gold Mine Dump to Stream Waters…*

mechanically pass through a sieve for particle distribution [18]. Approximately 2 g aliquots of the various soil samples were weighed into a Teflon crucible and then moistened with 100 mL of 1 M HCl acid in a microwave digestion system for the determination of the HCl-soluble fraction of heavy metals. The mixtures were covered and placed on a shaker for 12 hours at 130 rpm. The solutions were filtered using a Whatman filter paper and the filtrates stored in sterile bottles prior to being analysed for heavy metals using inductively coupled plasma-optical emission

At very high pressure using a mould, 10 g of each of the representative soil samples were pelletised and then inserted in the sample compartment of an X-ray fluorescence (XRF; Rigaku ZSX PrismusII), to help in analysing the elemental

Morphological and mineralogical phase analyses of the tailing material were carried out using a scanning electron microscope (SEM, Tescan Vega 3 XMU) operated with an Oxford software and X-ray diffractometer (XRD; Rigaku Ultima IV),

In a soil-to-water suspension (1:2.5, w/w), the pH of representative soil samples was determined, while electrical conductivity (EC) was measured in a 1:5 soil-towater suspension using a Crison multimeter model MM 41. Also carried out was an assessment of the total dissolved solids (TDS) in guidelines as stipulated by stan-

For precision analysis, all reagents used were of analytical standards, while apparatus and glassware inclusive were acid-washed with a 5% nitric acid. Multiple levels of calibration standard solutions are prepared from a Certipur ICP multielement standard (Merck KGaA) by diluting the stock multi-elemental standard

were the same as described in a similar study as reported by Okereafor et al. [20].

**Table 1** highlights the textural characteristics of the tailing sediments as gotten from mechanical sieve analysis. The main fractions of all tailing sediments were fine sand (0.150–0.075 mm) and clay (0.075–0.053 mm) with average composition of 66.03% for fine sand, 23.08% clay and 10.89% silt, respectively. With fine sand constituting a major part of the soil within the tailing dump site which are loose with little or no vegetation cover, wind and soil erosion particularly during continued rainfall are likely to occur with no restriction. The steep and inclined nature of

) in 0.5% (v/v) nitric acid. The calibration curves for all the

. The conditions of the ICP

compositions of the various minerals that make up the soil samples.

Soil samples (tailing sediments) were oven dried at 100o

spectrometry (ICP-OES, GBC Quantima Sequential).

C and then stored in polyethylene bags for mineralogical and heavy

C for 24 hours and

*DOI: http://dx.doi.org/10.5772/intechopen.90818*

dried at 100o

**3. Analysis**

respectively.

dard protocols of APHA [19].

solution (1000 mg L−1

**4. Results and discussion**

**3.2 Quality assurance and quality control**

studied elements were in the range of 0.01–1.0 mg L−1

**4.1 Particle size distribution of tailing sediments**

**3.1 Experimental analysis**

metal analyses.

*Mobility of Trace Element Contaminants from Abandoned Gold Mine Dump to Stream Waters… DOI: http://dx.doi.org/10.5772/intechopen.90818*

dried at 100o C and then stored in polyethylene bags for mineralogical and heavy metal analyses.


**3.1 Levels of units**

The sequence builds up from a foundation towards higher levels of organisation:

This hierarchy has been carefully developed and it is argued (although not definitively) that each of these levels have particular properties which separate it from those lying at other levels in the hierarchy.

At each of these levels, the social unit focused on has 'internal' and 'external' features: the elements that make it up and its relationships to other units within which it is contextualized. In a network approach, which is a major way of investigating the latter issue, relations between nodes are studied, not characteristics of nodes themselves. Network linkages within any type of social entity (e.g. between individuals but also between organisations) are possible. This interest in linkages can be taken to **follow** approaches looking at characteristics of social entities (on the grounds that you need to know something about x and about y before you examine their relationship). However, often network analysis is seen as the study of relationships amongst people rather than relations amongst any type of social unit as it is depicted in this chapter.

It is important to note that the various levels do NOT neatly (at least not necessarily) nest within each other in a linked-up hierarchy. Social structures at various levels cross-cut and interweave and may (or may not) have any connection with others operating at different scales or with different trajectories.


**3.3 Mutations**

The failure of repair mechanisms and constant exposure to PAHs induce mutagenesis in cells. These mutations are present in multiple genes including those that participate in cell survival. In particular, p53 mutations are associated with risk of carcinogenesis in PAHexposed individuals. Since the p53 protein is a transcription factor that regulates cell proliferation, differentiation, apoptosis, and DNA repair, mutations induced in this important protein could lead to severe damage in cells and genes. Some studies have associated p53 mutations to PAH exposure (Mordukhovich, et al., 2010, Yoon, et al., 2003). Another common target of mutagenesis is the ras gene (Ross & Nesnow, 1999). A study by Gray et al. (2001) revealed that exposure to BaP in mice increases mutation of the K-ras gene.

#### **3.4 Carcinogenesis**

Forming adducts in DNA repair-related genes is not the only mechanism by which PAHs induce carcinogenesis. An additional danger amounts from their resemblance to steroid hormones allowing PAHs the ability to activate estrogen receptors and metabolism. The ability of several PAHs to displace natural estrogens and occupy ER binding sites, at least to some extent, implies a potential mechanism of action in endocrine tissues that is ER-

DNA Damage Caused by Polycyclic Aromatic Hydrocarbons: Mechanisms and Markers 133

the initial detection of damaged DNA. On the other hand, TC-NER does not require XPC, however the stalled RNA Polymerase complex is displaced in order to allow the NER proteins to access the damaged DNA. After this process, TC-NER and GG- NER proceed in identical ways. XPA and RPA (Replication Protein-A) then bind at the location of injury and further aid in damage detection. Subsequently, the XPB and XPD helicases unwind the DNA duplex in the surrounding area of the lesion. The endonucleases XPG and ERCC1 (Excision Repair Cross-Complementing group-1)/XPF then cleave one strand of the DNA at positions 3' and 5' to the damage, respectively, generating a 30 base oligonucleotide containing the lesion. This oligonucleotide is displaced, permitting gap repair synthesis (performed by DNA Pol Delta/Epsilon, and other accessory proteins). Finally, DNA ligase seals the nick in the repaired strand (Fig. 6). Several studies demonstrate that certain polymorphisms in NER genes alter the efficiency of DNA repair (Shen, et al., 2006, Vodicka, et al., 2004). Four polymorphisms, XPA - 4G/A (rs1800975), ERCC1 C8092A (rs3212986), XPD Lys751Gln (rs1052559), and XPF Ser835Ser (rs1799801), are associated with a reduced capacity for DNA repair and an increased susceptibility to various cancers (Hu, et al., 2004, Monzo, et al., 2007). However, a recent study reports that significant opportunities exist for an interaction between the XPA-4 G/A polymorphism and PAH exposure on sperm DNA damage (Gu, et al., 2010). Although some PAHs lack "bay" and/or "fjord" regions, such as anthracene for example, this molecule also induces DNA damage, activating repair mechanisms, and has in fact has been shown to induce NER and MMR pathways (Desler, et al., 2009).These findings provide support for the

BER involves the combined activity of some specific proteins that recognize and excise DNA damage, replacing the damaged moiety with normal nucleotides. PAH adducts are repaired by this mechanism. BER consists of three important steps: first, removal of the incorrect base by an appropriate DNA N-glycosylase to create an AP site (apurinic/apyrimidinic site); second, cutting off the damaged DNA strand by AP endonuclease upstream of the AP site, therefore creating a 3'-OH terminus adjacent to the AP site and finally, extension of the 3'- OH terminus by DNA polymerase, accompanied by excision of the AP site. Several enzymes are required to complete these three steps. In humans, there are at least six different glycosylases that bind specifically to a target base and hydrolyze the N-glycosylic bond generating the AP or abasic site. Next, the AP site is processed by the APE1 system (AP Endonuclease-1, or HAP1/REF1/APEX), which cuts the phosphodiester backbone adjacent to the 5' end of the AP site, resulting in a 3' hydroxyl group and a transient 5' dRP (abasic deoxyribose phosphate). The removal of the dRP is accomplished by DNA Pol Beta (polymerase beta) activity, which adds one nucleotide to the 3' end of the nick and removes the dRP moiety through the action of an AP lyase (Bennett, et al., 1997). DNA Pol Beta also interacts with XRCC1. DNA Pol Beta is therefore crucial for the inclusion of different components of BER at sites of DNA damage and promoting repair efficiency (Fig. 6). The BER pathway deals with smaller damage to individual bases, such as oxidation, methylation, depurination, and deamination. If the adducts are left unrepaired, they may cause permanent mutations (Boysen & Hecht, 2003). If these mutations are situated at critical sites, including tumor suppressor genes, DNA repair-related genes or oncogenes, they may lead to cellular transformation and the development of tumors. A recent study demonstrates that BER plays an important role in DNA repair in cells exposed to PAHs. Chinese hamster ovary cells (CHO) deficient in the BER pathway were found to be more

importance of NER pathway in DNA damage induced by PAHs.

**4.2 Base excision repair (BER)**

mediated (Santodonato, 1997). Nevertheless, the most important mechanism of carcinogenesis is a deficient DNA repair system in key genes involved in cell cycle control. Since chronic exposure to PAHs is related to a high rate of mutagenesis it is probable that damage to DNA is cumulative. Several studies have associated chronic occupational PAH exposure to multiple types of cancer including cancer of the bladder, lung, kidney, liver, and breast (Boffetta, et al., 1997, Dickey, et al., 1997, Karami, et al., 2011, Shen, et al., 2003).

Fig. 5. Structures and interaction of two common adducts: (A) BPDE-dG adduct and (B) BPDE-dA adduct.


*2.2. MAP1B Immunoexpression and Clinicopathological and Genomic Correlations in UTUC and UBUC*

The association of clinicopathological characteristics with *MAP1B* immunoreactivity is shown in Table 2. We found, in UTUC cases, that high *MAP1B* expression was markedly associated with synchronous multiple tumors (*p* = 0.024), advanced pT status (*p* = 0.005) (Figure 2A–C), positive lymph node metastasis (*p* = 0.002), the presence of vascular invasion (*p* < 0.001), and an increased mitotic rate (*p* < 0.001) (Table 2 and Figure 2D). Similarly, in cases with UBUC, we found evidence of associations between increased *MAP1B* expression and advanced pathological tumor stage (*p* < 0.001), positive lymph node metastasis (*p* = 0.012), a high histological tumor grade (*p* = 0.016), the presence of vascular invasion (*p* = 0.045), and an increased mitotic rate (*p* = 0.006) (Table 2 and Figure 2E). Of note, none of the 30 cases displaying high *MAP1B* expression enrolled for mutational analysis were positive for *MAP1B* mutation, suggesting a mutation-independent expression of *MAP1B*.

**Figure 2.** Representative sections of *MAP1B* immunostaining. Note the stepwise increments in *MAP1B* immunoreactivity from the nontumoral urothelial epithelium (inlet) and (**A**) noninvasive papillary UCs to (**B**) non–muscle-invasive (pT1), and (**C**) muscle-invasive (pT2–pT4) UCs. A comparison of mitotic activity showed significantly higher mitotic rates in (**D**) UTUC and (**E**) UBUC cells with increased *MAP1B* expression than in cells with low expression.

*Cancers* **2020** , *12*, 630


**Conflict of interest**

The authors declare no conflict of interest. All illustrations were designed and drawn by author Dr. Eman Elagamey. *Perspective Chapter: Cyanobacteria – A Futuristic Effective Tool in Sustainable Agriculture DOI: http://dx.doi.org/10.5772/intechopen.109829*


**Author details**

Muhtarima Jannat1 , Md. Mostafa Masud1 , Mushfika Nusrat1 , Samrin Bashar1 , Mamuna Mahjabin Mita1 , Muhammad Iqbal Hossain1 , Md. Zahangir Alam1 , Sabina Yeasmin2 and Md. Rashidul Islam1 \*

1 Laboratory of Plant Bacteriology and Biotechnology, Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh, Bangladesh

2 Agro Innovation Laboratory, Department of Agronomy, Bangladesh Agricultural University, Mymensingh, Bangladesh

\*Address all correspondence to<EMAIL_ADDRESS>
© 2022 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Aflatoxins and Fumonisins Contamination of Maize in Bangladesh: An Emerging Threat… DOI: http://dx.doi.org/10.5772/intechopen.101647*


**1. Introduction**

Diabetes Mellitus (DM) is a chronic metabolic medical condition that is diagnosed in 422 million people globally and every year 1.6 million deaths are attributed to this condition [1]. It is a disease that can lead to many other severe medical problems and affects almost all the different systems in the body. Diabetes as a result of autoimmune condition, where the pancreatic β-cells are destroyed compromising insulin production, is referred to as Type 1 Diabetes Mellitus (T1DM), while diabetes caused by several other factors including increasing insulin resistance is referred to as Type 2 Diabetes Mellitus (T2DM). As the classic symptom of diabetes is increase in circulating blood glucose, one of the important treatment criteria is focused on food consumption and the type of nutrients consumed. Several diets have been advocated to patients, in addition to life style changes such as increased physical activity and an organized exercise regimen. As carbohydrates are the main source of glucose, diets closely look at reducing carbohydrate intake followed by fat consumption. A major risk factor for developing diabetes is being obese. So many diet plans for diabetic patients focus on weight loss. We will discuss the different diets, nutritional supplements and any alternative and complementary medical choices the patients can opt for.


**1.1.3 Uncertainty set constraint approaches for general mismatch**

Very recently, many approaches have been proposed for improving the robustness of the standard minimum variance distortionless response (MVDR) beamformer. Their main ideas are based on the definition of the uncertainty set and the worst-case performance optimization, but these algorithms are all classified to the diagonal loading technique.

Jian Li et al propose the robust Capon beamformer under the constraint of steering vector uncertainty set [20], then the constraint of steering vector norm is imposed and the doubly constraint robust Capon beamformer is proposed [22]. For the two beamformers, although they give the exact weight vectors, and the methods of finding the optimal loading level, but their performance improvements are not obvious. Actually, the constraint of uncertainty set is the essence of the two robust beamformers, and the two beamfomer have the same robustness characteristic. F.Vincent and O.Besson also analyze the performance of the beamformer under the uncertainty set constraint approximatively, but they can't give the exact loading level [36].

S. A. Vorobyov et al propose a robust beamformer in the presence of an arbitrary unknown signal steering vector mismatch [19], although they prove the proposed approach equivalent to the loading sample matrix inversion (LSMI) algorithm, but they can't give the direct 88 Fourier Transform Applications

all these methods provide excellent robustness against the signal direction mismatch, they are not robust against other types of mismatches caused by poor array calibration, unknown sensor mutual coupling, near-far wavefront mismodeling, signal wavefront distortions, source spreading, and coherent/incoherent local scattering, as well as other effects [17].

Chun-Yang Chen and P.P.Vaidyanathan consider a simplified uncertainty set which contains only the steering vectors with a desired uncertainty range of direction of arrival (DOA) [25], although the closed-form solution is given, and the diagonal loading level can be computed by the iteration method systematically, but how to determine the DOA

Several other approaches are known to provide the improved robustness against more general types of mismatches, for example, the algorithms that use the diagonal loading of the sample covariance matrix [14][16], the eigenspace-based beamformer [11][30][31], and the covariance matrix taper (CMT) approach [32]-[34]. For the diagonal loading method, a serious drawback is that there is no reliable way to choose the diagonal loading level, F.Vincent and O.Besson propose the method to select the optimal loading level with a view to maximizing the signal-to-noise ratio (SNR) in the presence of steering vector errors and it is shown that the loading is negative, but they can't give the exact solution, instead of the approximate solution, moreover, they can't give the expression of steering vector errors [35]. The eigenspace-based approach is essentially restricted in its performance at low SNR and when the dimension of the signal-plus-interference subspace is high, and the dimension must be known in the latter technique [31]. The CMT approach is known to provide an excellent robustness in scenarios with nonstationary interferers, however, its robustness against mismatches of the desired signal array response may be unsatisfactory, furthermore,

Very recently, many approaches have been proposed for improving the robustness of the standard minimum variance distortionless response (MVDR) beamformer. Their main ideas are based on the definition of the uncertainty set and the worst-case performance optimization, but these algorithms are all classified to the diagonal loading technique.

Jian Li et al propose the robust Capon beamformer under the constraint of steering vector uncertainty set [20], then the constraint of steering vector norm is imposed and the doubly constraint robust Capon beamformer is proposed [22]. For the two beamformers, although they give the exact weight vectors, and the methods of finding the optimal loading level, but their performance improvements are not obvious. Actually, the constraint of uncertainty set is the essence of the two robust beamformers, and the two beamfomer have the same robustness characteristic. F.Vincent and O.Besson also analyze the performance of the beamformer under the uncertainty set constraint approximatively, but they can't give the

S. A. Vorobyov et al propose a robust beamformer in the presence of an arbitrary unknown signal steering vector mismatch [19], although they prove the proposed approach equivalent to the loading sample matrix inversion (LSMI) algorithm, but they can't give the direct

uncertainty range is the critical problem.

**1.1.2 Robust approaches for general mismatch**

it can also be explained as the diagonal loading [33].

exact loading level [36].

**1.1.3 Uncertainty set constraint approaches for general mismatch**

method to compute the optimal weight vector, and the second-order cone (SOC) programming-based approach is used to solve the original problem. Ayman Elnashar et al make use of the diagonal loading technique to implement the robust beamformer [24], but the optimal value of diagonal loading level is not solved exactly, alternatively, the diagonal loading technique is integrated into the adaptive update schemes by means of optimum variable loading technique. R. G. Lorenz and S. P. Boyd also solve the similar beamformer by the Lagrange multiplier techniques [23], but they express the weight vector and the array manifold as the direct sum of the corresponding real and imaginary components. Almir Mutapcic et al show that worst-case robust beamforming with multiplicative uncertainty in the weights can be cast as a tractable convex optimization problem [37], but they can't give the solving method, In fact, the proposed robust beamformer with uncertain weights can be converted to that in [19] equivalently.

S. Shahbazpanahi et al consider the general-rank signal model, and the robust beamformer is proposed for the distributed sources [21], therein, an elegant closed-form solution is given, but its performance improvement depends on the constraint parameter severely, and is not up to optimal.


Contents

#### **Preface XI**

Preface

ars and specialists in the field.

Book "Advances in Nanofibers" is a research publication that covers original research on developments within the Nanofibers field of study. The book is a collection of reviewed scholarly contributions written by different authors. Each scholarly contribution represents a chapter and each chapter is complete in itself but related to the major topics and objectives. The chapters included in the book are: Electrospun Nanofiber Based Solid Phase Extraction, Electrospun Nanofibers: From Rational Design, Fabrication to Electrochemical Sensing Ap‐ plications, Chitin Nanofibers, Preparations and Applications, Fabrication of Nanofibrous Scaffolds by Electrospinning, Carbon Nanofiber Concrete for Damage Detection of Infra‐ structure, Materials and Processes for Ion Permeable Separating Membranes by Electro-Spinning, Nanofibers Reinforced Polymer Composite Microstructures, Use of Self-Assembly Nanofibre Biomaterials for Neural Repair After Injury. The target audience comprises schol‐

> **Dr. Russell Maguire** Boeing Technical Fellow,

> > Bellevue WA, USA

President, Global Nanocomposites LLC