1.2: Chapter 2: Beware: Be Aware - The Ethical Implications of Teachers Who Use Social Networking Sites (SNSs) to Communicate
Author Note
There are no conflicts of interest to disclose.
Correspondence concerning this chapter should be addressed to<EMAIL_ADDRESS>Introduction
As teachers strive to build productive and positive relationships with their students, parents, and colleagues, they may employ different techniques to do so. The main reason behind developing effective relationships with these stakeholders is to put students at the forefront of authentic learning. It is recognized that strengthening relationships with parents, students, and even colleagues can be one way to support student learning (Alberta Government, 2018). One of the most critical ways to foster strong relationships is through effective communication (White, 2016).
Teachers are tasked with sharing a multitude of information from events, field trips, and student learning progress to professional learning opportunities and resources. Known as command communication (White, 2016), teachers communicate “in clearly prescribed ways” (p. 70) using tools such as email, websites, and newsletters. As White (2016) points out, “[w]ritten communication is probably the most efficient and effective way teachers provide clear information” (p. 70). Teacher communication is not limited to the command function, but also to a relational function, which is the “basis of effective learning relationships and enables the development of communities of practice, dialogues, and fusions of horizons” (White, 2016, p. 71). Teachers can communicate with both functions to “maximize sharing of information and understanding” (White, 2016, p. 70). This can be challenging to accomplish, but with the integration of technology, teachers build relationships and communities, encourage dialogue, share information and overcome the barriers of time, distance, and even languages. Social Network Sites (SNSs), such as Facebook, Instagram, and Twitter, lend themselves as a platform to achieve strong teacher communication to build and strengthen relationships.
| Users connect and share various media, such as text and pictures, with followers, who are known as ‘friends’ online. Friends can comment on user posts. | |
| Users post 140-character messages (tweets) to followers. Tweets can be commented on and shared. Private messages are also available. | |
| Users share with followers photos and videos that can be commented on and shared. Altering or filtering is a common practice by users. |
Ethical Considerations of SNSs Use in K-12 Classrooms
This innovative use of SNSs creates ethical dilemmas for educators. From the lens of a consequentialist approach, “teachers are in a difficult position of trying to innovate in their classroom using SNSs while at the same time being conscious of the risks” (Henderson, et al., 2014, p. 2). This chapter will navigate the ethical implications teachers face when using SNSs to communicate the learning that happens in their classrooms.
The framework for teachers using SNSs for communication, adapted from Farrow’s (2016) OER Research Hub project, identifies the three normative ethical theories and highlights considerations for teachers who do engage with SNSs for communication purposes (Table 2.2). These ethical perspectives attempt to guide how teachers and students can and should behave, which rules and procedures they should adhere to, and which beliefs and values teachers should have (Farrow, 2016). SNSs used in the classroom context can be powerful, but what are the implications of balancing the pressure and desires to use social media for communication from our colleagues and parent community with the ethical expectations of the teaching profession?
| Principle | Duties & Responsibilities (deontological) |
Outcome
(consequentialist) |
Personal Development
(virtue) |
|---|---|---|---|
| Full disclosure |
|
|
|
| Privacy & data security |
|
|
|
| Informed consent |
|
|
|
| Integrity |
|
|
|
| Avoid harm/minimize risk |
|
|
|
| Respect for participant autonomy |
|
|
|
| Independence |
|
|
|
Full Disclosure
As teachers join the growing movement of using SNSs for their classroom communication (Auld & Henderson, 2014), there are expectations placed on them by their principal, districts, and professional bodies. Even though not explicitly defined, these expectations contain Nias’ (1999) six components of a culture of care, which include: being affective, responsibility for learners, responsibility for relationships in the school, self-sacrifice and obedience, over-conscientiousness, and identity (Figure 7.1). Teachers who use SNSs should employ a due culture of care to ensure that they meet the professional expectations placed upon them. This culture of care should include an evaluation of the consequences of using SNSs, followed by the disclosure of the consequences and pertinent information to the parties involved, including parents, students, and colleagues.
Luckin et al. (2009), as cited in Howard (2013), suggest that “[t]o facilitate effective use of Web 2.0 technology in the classrooms, teachers are encouraged to be willing to embrace risk and to consider small ways of navigating existing cultures and reframing old contexts to incorporate new ones” (p. 44). As teachers transform the purpose of SNSs to fit their classroom contexts, they should consider the notion of full disclosure, which is when the teacher makes all information and facts known (Oxford University Press, 2019). The following section will examine two components to this disclosure: teacher communication expectations and the use of personal learning networks to share and co-construct knowledge.
Teacher Policies and Procedures
Regardless of whether or not a teacher participates in SNSs, there are policies and procedures to which they must adhere to as a member of a professional association, not only for their own professional protection but also for the protection of colleagues, students, and parents. By following the specified policies and procedures for communication, teachers meet the aspects of a culture of care.
Teachers in Alberta, for example, are required to follow the ATA Code of Conduct, the Teaching Quality Standards, Freedom of Information and Protection of Privacy Act, and their own district’s Administrative Procedures. These guiding documents define what data and information teachers have access to, who can provide permission to use the platform, and how they can use it to support the learning that happens in their classrooms.
Due to the openness and highly connected nature of SNSs, teachers should communicate to parents, students, and colleagues (including administration) which SNSs they are using and their purpose for using those platforms. As well, teachers should notify stakeholders what they will be posting, before they post it. This will give parents and students opportunities to have input and the ability to give or refuse consent. As Henderson et al. (2014) point out, “teachers should be aware that this consent might need to be renegotiated at regular intervals” (p. 3). Auld and Henderson (2014) also argue that teachers have the responsibility to ensure that students (and parents) want their own virtual identities to be made public when using SNSs as a tool for communication. As students or parents comment on a post, they are at risk of exposing their online identity which they may not have considered.
Sharing and Co-Construction of Knowledge Through Personal Learning Networks (PLNs)
Many professionals have been adapting and adopting various emerging practices, such as using SNSs, to network, share, and co-create knowledge (Veletsianos, 2016). Teachers may find themselves using SNSs in the classroom for the same purposes, while guiding students in developing the skills to participate effectively in Personal Learning Networks (PLNs). “Research that suggests that such platforms can facilitate the shared construction of knowledge and peer interactions that support learning adds to the perception that SNSs, such as Facebook, could be a catalyst for classroom engagement and collaboration” (Howard, 2013, p. 43). Whether it is a teacher’s own PLN with other professionals or a student-based PLN, teachers should disclose what they, themselves, are gaining from integrating SNSs as a modality. As Auld and Henderson (2014) identify, “[t]eachers need to consider what the implications are for co-inhabiting spaces that are designed to connect people and share information” (p. 199); however, disclosure of benefits should not be limited to the teacher viewpoint. Emphasis should also be placed on the student viewpoint. What does the student have to gain or lose by participating in a PLN via SNSs? What opportunities and guidance will students (and parents for that matter) have to participate in PLNs? What opportunities exist to be part of a PLN if parents do not want to use SNSs? These are all aspects of full disclosure that teachers should consider and communicate.
As teachers disclose the purpose for using SNSs in their classroom practice, they should consider the six aspects of the culture of care. By keeping these practices student-centred, the argument could be made that the choices the teacher is making to build relationships and enhance communication are inherently good. By having an environment that is built on full disclosure, teachers will continue to build “a sense of community, people-making, and dialogue” which is foundational to school-family partnerships (White, 2016, p. 69).
It should be recognized that full disclosure should not be limited to the intent and should also include other considerations such as privacy and security. The next section will explore these elements and the ethical dilemmas they create.
Section 2: Privacy, Data Security, and Informed Consent
When it comes to the role of the teacher, and protection of privacy, evolving technology has created a need for privacy and security awareness. As mentioned in the previous section, teachers must follow various policies and procedures, such as the Freedom of Information and Protection of Privacy Act (FOIP) [New Tab] (Alberta Teachers Association, 1999), which is a legally binding document and mandatory. In this particular act, “the privacy of students and parents is protected by rules that school [administrative procedures] must follow in the collection, use, protection and disclosure of personal information” (para. 4). While engaging on SNS platforms, teachers may expose themselves, students, and parents to breaches of privacy and careless consent to the collection of data. In their paper, Regan and Jesse (2019) explored the ethical concerns of privacy in 21st-century learning and identified six distinct ethical concerns. The following section will explore three of the six privacy and data security concerns when teachers post and share content on SNSs.
Information Privacy
When posting any content online, there is exposure and formation to one’s identity. Regardless of whether a teacher creates a digital identity to connect with PLCs, share lessons, or celebrate the connections in the classroom, there is a tension between confidentiality and transparency. Teachers may carelessly expose themselves, parents, and students to the collection of data.
Teachers can enlist proper attitudes that help limit exposure. Summarized by Regan and Jesse (2019) as, “notice, consent, choice and transparency” (p. 170), when posting any information online, teachers are responsibility to those parties involved (students, parents, colleagues, etc.) to communicate the purpose and content of the post, to seek consent, and to allow those involved to choose what is posted or to be removed from the post, and to be able to see the post after submission.
Ownership of Information
Once content is posted, who owns the post and its contents? The answer depends on the SNS platform and its privacy policy. When looking at a privacy policy, or reading the terms of service before clicking accept, one may notice that these are long and complex documents. Readers can become lost in jargon, and, as a result, users accept the agreements without becoming aware of critical information, such as data collection and ownership of information. For example, Facebook’s Privacy Policy [New Tab] , which also includes Instagram, explains ownership of information.
According to Facebook (2019), “you own the intellectual property rights (things such as copyright or trademarks) in any such content that you create and share on Facebook” (“Your commitments” section); they go on to identify that if users share, post, or upload content, Facebook is granted the permissions to use, distribute, modify, copy, and create derivative products of the content. If a teacher posts a picture of students working in the classroom, the teacher has given Facebook and Instagram the ability to “store, copy, and share it with others” (Facebook, 2019, “Your commitments” section) based on the privacy settings. Even when parents grant permission to use photos of their child, they may not understand that the child’s photo may be used by third-party companies, based on the SNS platform. Students should be consulted when their work will be posted on SNSs, as they own the intellectual property rights to their content, and they may not want to give those platforms the ability to remix and reuse their work.
Understanding the agreements of SNS platforms is crucial to effective communication practices. Some may consider the practice of deleting the content after the school year is over, as those students move on to another classroom; however, teachers should be aware of the adage ‘once online, always online.’ Facebook identifies that if the content is deleted by the user, it will be removed from Facebook’s systems, though it may exist elsewhere (2019). As Molnar and Boninger (2015) point out, “[e]ducators are obliged not only to learn how student data may be gathered and exploited but also to develop privacy policies that protect their students from such exploitation” (p. 8).
Surveillance – AI
It would be naive to believe that one’s online presence is not tracked in some form or another. “Tracking software also records adult behaviour on the Internet, of course, although many adults may be unaware of it. Since educators are, however, responsible for the children entrusted to their care, they cannot afford to be uninformed about potential threats to student privacy” (Molnar and Boninger, 2015, p. 8). As soon as a teacher engages with SNSs, there is surveillance of their activity and that of the users to whom they are connected. For example, as soon as the student does connect to the content posted on the teacher’s SNS, marketers can track the student’s online activity and direct ads to that student (Molnar and Boninger, 2015, p. 7).
Even as teachers consider information privacy, ownership of information, and surveillance, they may still fail to protect all invested parties’ privacy. A common phenomenon exists known as the Privacy Paradox. First discussed by Barnes (2006), the Privacy Paradox identifies that there is a contradiction between online behaviour and privacy concerns (Table 2.3). The research conducted by Dienline and Trepte (2014) showed that people on SNSs “engage in self‐disclosing behaviours that do not adequately reflect their concerns” (p. 285). “Despite privacy concerns, users, most of the time, fail to protect their privacy within SNSs, thus putting themselves and other users at risk” (Sideri, et al., 2017, p. 79).
|
4 Privacy Paradox Phenomena of Social Network Sites
|
| 1. Large quantity of information disclosed online |
| 2. The illusion of privacy |
| 3. Discrepancy between context and behaviour (even when known to be public, act like SNSs are private) |
| 4. Users’ poor understanding of data processing actions by online businesses |
Knowing the phenomena, teachers can act in an ethical manner that ensures the protection of privacy to the best of their ability. Prior to the first post, teachers should read the privacy policy and terms of service of their chosen platform. They can then act according to what they are comfortable with and what is best for all users involved in the communication. Also, informing parents and students of the terms and allowing them to create their own limitations of content to be posted, would reduce the breach in privacy and data collection from the post.
In the end, even with instilled practices to limit the accessibility of data or enable privacy features, these features may dissolve at any point, leading to the risk that the content become public (Auld & Henderson, 2014). It is this point that leads to the exploration of what the teacher can do to maintain educational integrity by avoiding harm and minimizing risk.
Educational Integrity by Avoiding Harm and Minimizing Risk
When parents send their children to school, they entrust educators to provide quality education while ensuring that their child is cared for and protected. Known as in loco parentis , the teacher is in place of a parent and is given the same rights and responsibilities (Law Now, 2019). In Alberta, according to the competencies in the Teaching Quality Standard (2018), teachers are expected to “recognize that the professional practice of a teacher is bound by standards of conduct expected of a caring, knowledgeable and reasonable adult entrusted with the custody, care or education of students” (p. 3). When teachers engage in posting on SNSs, this care should still be practiced. As teachers aim to maximize the benefits of using SNSs as a form of communication, they should also take measures to minimize the potential risk of harm to themselves and those with whom they interact. This section will look at opportunities educators have to maintain educational integrity while avoiding harm and reducing risks when engaging in online communication.
Modelling Digital Communication
Teachers are held in high regard in society, and what they do in their personal lives will usually be viewed with a lens that relates to the profession. “The teacher acts in a manner which maintains the honour and dignity of the profession” (ATA, 2018, standard 18). This also applies to the teacher’s interaction with SNSs. Whether being used to connect with other teachers in PLCs, with parents and students, or with friends and family, “teachers need to maintain a respectful and professional identity” (Planbook.com, 2018, Section 1, para. 4).
In 2012, George Couros, an educator and recognized keynote speaker for professional audiences, posted a blog titled “Personal and Professional vs. Public and Private” [New Tab]. He discussed the debate of teachers having a personal SNS account separate from a professional account. His argument is that whether teachers have separate accounts or not, there is the potential for anyone to see the posted content. “What I am always aware of is that no matter who sees what I put out there, anyone can see it eventually, whether it is through me or someone else” (Couros, 2012, Section 1, para. 4). In fact, by combining the personal and professional accounts into one, teachers have a unique opportunity to model effective digital citizenship and digital literacy skills to their followers, which may include parents, students, and other teachers, rather than letting them figure it out on their own (Howard, 2013).
Setting Expectations
By communicating expectations for parents, students, colleagues, and themselves, teachers can reduce the risks that come with engaging in SNSs. “Even if we deem the benefits of SNSs worth the potential risks, a plan for managing those risks is warranted” (Howard, 2013, p. 44). It is interesting to note that due to the recent COVID-19 crisis (Spring 2020), educators have found themselves needing to turn to emerging technologies such as SNSs to communicate effectively with students and parents. If they do not set up expectations from the beginning of the school year, teachers may struggle with boundaries and guidelines for themselves, parents, and students. Teachers should look to their guiding policies and procedures to provide support for navigating this challenge. However, it is recognized that with the fast pace of technological change, these policies and procedures may need constant revision to remain current.
Many school districts have developed administrative procedures that identify the expectations of all parties involved with using SNSs. As Howard (2013) points out, “[p]olicies that prevent private one-to-one communication between teachers and students that do not generate a permanent record are extremely important to ensure the public’s trust that the users of these networks are operating above-board” (p. 50). For example, Elk Island Catholic Schools (2019) has Administrative Procedure 146, titled “Social Media”, which identifies expectations for division staff, students, and parents (Table 2.4).
| Procedures |
|---|
| 1. Principals shall: |
| 1.1 Ensure students, parents, and staff are aware of the Division’s expectations for responsible use of Social Media. |
| 1.2 Encourage parents to communicate to school personnel any concerns they may have about inappropriate use of Social Media. |
| 1.3 Ensure students, parents, and staff are educated in the appropriate use of Social Media and the associated benefits and dangers of a public online presence. |
When teachers do set guidelines for how SNSs will be used, they should include expectations for:
- Timeliness of posts
- Expectations and moderation of responses
- Procedures for one-to-one communication
- What will happen to content after the school year is over
- Limitations to having followers and following back
Teachers who model effective use and positive communication skills with SNSs remain consistent with the rights and responsibilities placed upon them as professionals. Each post should be considered an opportunity to develop digital literacy skills for teachers, students, and parents. By setting and following expectations, all stakeholders will reduce risk and the opportunity for harm. However, risk and harm are reduced not only by expectations, but also by understanding how using SNSs can impact autonomy and independence.
Respect for Participant Autonomy and Independence
Teachers may find themselves in situations where they are directed to engage with SNSs, such as when a school leader suggests that teachers can add a Twitter post about their weekly classroom events. When this occurs, teachers may feel obligated to use social media even if they do not feel comfortable with the digital tool. Alberta Education’s Learning and Technology Policy Framework (2013), Policy Direction 3 indicates that teachers are expected to “engage in professional growth opportunities that are broadened and diversified through technology, social media, and communities of practice” (Section 3, para. 1). Although some teachers may struggle to give up autonomy over their professional learning choices, they may still have control over what technologies they use or how they use them. The student-centred goal, is that “teachers . . . develop, maintain, and apply the knowledge, skills, and attributes that enable them to use technology effectively, efficiently, and innovatively in support of learning and teaching” (Alberta Education, 2013, Section 3, para 1). Teachers need to consider the magnitude of this responsibility when they do engage with SNSs, as they are in a position in which they can create and shape their own online persona, while also shaping and influencing the identity of their students. In this final section, we will expand on the ethical examination of the teacher’s role in shaping identity and equity of access.
(Re)Shaping Identity
When teachers use SNSs in their classroom, their motivation may be to build relationships, provide support, reduce the feeling of being isolated (for both student and teacher), build personal and professional learning environments, and to create and share knowledge (Forbes, 2018). SNSs are not limited to these opportunities and may provide other features and abilities, such as ‘going live’ to show parents the events in the classroom; however, the fact that teachers and students have the ability to use these features does not necessarily mean that they should.
As previously discussed, teachers and students who engage with SNSs may blur the lines between private and public identity. What teachers should consider is that as they post content such as pictures, student work, or discussions about what happened within the class, they create a digital footprint for themselves, as well as for their students, which may be accessed and retrieved by others (Auld & Henderson, 2014). As teachers move to a more digital learning environment, K-12 teachers are faced with the reality that their digital interactions influence identity, regardless of whether they take place on a private or public SNS account. Forbes (2018) eloquently points out that “what an individual does with social media does not occur in a vacuum and is likely to affect or influence others by virtue of the social character of the communications” (p.178). As teachers consider this influence, they are held ethically to the principle of responsible care, “where professionalism entails doing good and minimizing harm” ( Forbes , 2018, p.178).
To build on this idea of doing good and minimizing harm, teachers should consider the power of their influence. By modelling positive digital citizenship and literacy skills, they can inadvertently shape their own and students’ identities in a positive way. One example is practicing proper citations and copyright practices. As Auld and Henderson (2014) point out, the use of a picture of a celebrity or cartoon picture to create a social media avatar may seem harmless, but it is a breach of copyright and possible identity theft. This is an opportunity for a teachable moment that may have lasting effects on students’ identities and on the identity of the original subject whose image was used.
Teachers’ ability to model and shape identity is not just proximal. Auld and Henderson (2014) explain that “teachers can model how to respect the other even if they are not known to the students or the teacher” (p. 202). This removal of barriers is powerful, but the strength is limited by the opportunity for digital equity of access.
Equity of Access
Digital access and equity involve many components and ethical considerations that teachers should consider as they use SNSs. Rooted in social justice, there is a belief that emerging technologies, such as social media, will “level the playing field, effectively creating equal access to learning opportunities by democratizing information and instruction” (Bulger, 2016, p. 2). This is supported by the fact that creating an account on SNSs is most often free. As well, SNSs are ubiquitous communication platforms where, because they are digital, users can access assistive technologies such as speech to text, text to speech, and translation to participate in the discussion. By integrating SNSs in the classroom, teachers provide opportunities for all students to develop their online communication skills, not just the students who can afford to access the platforms from home (Howard, 2013).
The argument that SNSs are free is limited to the actual cost to participate on the site. In order to access SNSs, one needs technology and internet access in the first place. As well, parents may not want their children, or themselves, to communicate online. In order to respect the autonomy of parents and students, teachers may want to consider providing alternatives to online communication. By doing so, teachers follow the social justice principle of recognitive, which, as Lambert (2018) points out, involves recognition and respect for diverse views and experiences.
As teachers use SNSs for communication, their reach of influence is not limited to just their own identity, but beyond. In fact, the impact on identity is a community approach involving (but not limited to) teachers, parents, and students. To maintain the educational integrity that teachers are responsible for, teachers should also consider opportunities for autonomy when involving technology-based practices in their classrooms. By allowing for voice and choice by parents and students, teachers can continue, with effective communication, to build the sense of community that is needed (White, 2016), which was the goal in the first place.
Conclusion
As teachers decide to integrate SNSs into their classroom practices, they should consider the ethical implications that this type of technological opportunity creates. According to Auld and Henderson (2014), “a professional SNS profile is a potentially valuable strategy but it still requires considerable thought and considerable maintenance” (p. 199). By focusing on four main areas of ethical exploration, this chapter examined the topics of full disclosure, privacy and security, educational integrity, and autonomy and independence, in order to address how teachers can tackle the complexity and unique opportunities of using SNSs to communicate in their classroom.
No matter the tool, teachers should consider the magnitude of their responsibility when they do engage with SNS for communication. Part of the attraction of SNSs is the unique abilities to enhance communication, but one may want to have the mantra: just because you have the ability, doesn’t mean you should use it. By continually reflecting on the goal and ethical implications, teachers will have a strong foundation for the use of SNSs for communication.
Questions to Consider for Future Research
- Technology is always evolving, and with it, a teacher’s practice should evolve, too. COVID-19 has required teachers across the globe to move their classrooms to an online environment. Teachers who had never considered SNSs as a way to communicate are now adapting these platforms to fit their classroom needs. What impact will this mass uptake of using SNSs have on pedagogy?
- In what ways are teachers and students reshaping the role SNSs have in education?
- What ethical considerations should be considered when students who are under the age of consent use technology to support their learning?
- Lastly, as teachers model different competencies in their classroom, there are opportunities to embed digital literacies and citizenship while creating opportunities to develop PLNs online. What do students have to gain or lose by participating in a PLN via SNSs?
- What frameworks could teachers consider to scaffold students developing their own PLNs using SNS (refer to Appendix A)?
References
Alberta Education. (2013). Learning and technology policy framework. https://education.alberta.ca/media/1045/ltpf-quick-guide-web.pdf
Alberta Education. (2018). Teaching quality standard. https://education.alberta.ca/media/3739620/standardsdoc-tqs-_fa-web-2018-01-17.pdf
Alberta Teachers Association. (1999, March 30). What you should know about the FOIP Act. ATA News. https://www.teachers.ab.ca/News%20Room/ata%20news/Volume%2033/Number%2015/In%20the%20News/Pages/What%20you%20should%20know%20about%20the%20FOIP%20Act.aspx
Alberta Teachers Association. (2018). ATA code of professional conduct. https://www.teachers.ab.ca/SiteCollectionDocuments/ATA/Publications/Teachers-as-Professionals/IM-4E%20Code%20of%20Professional%20Conduct.pdf
Auld, G., & Henderson, M. (2014) The ethical dilemmas of social networking sites in classroom contexts. In G. Mallia (Ed.), The Social Classroom: Integrating Social Network Use in Education (pp. 192-207). Ringgold Inc. http://ezproxy.lib.ucalgary.ca/login?url=https://www-proquest-com.ezproxy.lib.ucalgary.ca/docview/1494511269?accountid=9838
Barnes, S. B. (2006). A privacy paradox: Social networking in the United States. First Monday , 11(9). https://doi.org/10.5210/fm.v11i9.1394
Bulger, M. (2016). Personalized learning: The conversations we’re not having . Data & Society. https://datasociety.net/pubs/ecl/PersonalizedLearning_primer_2016.pdf
Couros, G. (2012, November 18). Personal and professional vs. public and private. George Couros. https://georgecouros.ca/blog/archives/3432
Dienlin, T., & Trepte, S. (2015). Is the privacy paradox a relic of the past? An in‐depth analysis of privacy attitudes and privacy behaviors. European Journal of Social Psychology , 45 (3), 285– 297. https://doi.org/10.1002/ejsp.2049
Elk Island Catholic Schools. (2019, September). Social media. Administrative Procedure 146. https://www.eics.ab.ca/download/218652
Facebook. (2019, July 31). Terms of service . https://www.facebook.com/terms.php
Farrow, R. (2016). A framework for the ethics of open education. Open Praxis , 8 (2), 93-109. http://dx.doi.org/10.5944/openpraxis.8.2.291
Forbes, D. (2017). Professional online presence and learning networks: Educating for ethical use of social media. International Review of Research in Open and Distributed Learning, 18 (7), 175-190. https://doi.org/10.19173/irrodl.v18i7.2826
Henderson, M., Auld, G., & Johnson, N. F. (2014, September 30-October 3). Ethics of teaching with social media [Paper presentation]. Australian Computers in Education Conference 2014, Adelaide, SA. http://citeseerx.ist.psu.edu/viewdoc/download?doi=<IP_ADDRESS>9.2437&rep=rep1&type=pdf
Howard, K. E. (2013). Using Facebook and other SNSs in k-12 classrooms: Ethical considerations for safe social networking. Issues in Teacher Education, 22 (2), 39-54. https://digitalcommons.chapman.edu/education_articles/50/
International Council on Human Rights Policy. (2011). Navigating the dataverse: Privacy, technology, human rights. http://www.ichrp.org/files/reports/64/132_report_en.pdf
Law Now. (2019, September 3). In loco parentis . https://www.lawnow.org/in-loco-parentis/
Molnar, A., & Boninger, F. (2015). On the block: Student data and privacy in the digital age. National Education Policy Center. http://nepc.colorado.edu/publication/schoolhouse-commercialism-2014 .
Nias, J. (1999). Primary teaching as a culture of care. In J. Prosser (Ed.), School cultur e (pp. 66-81). SAGE Publications Ltd. http://dx.doi.org/10.4135/9781446219362.n5
Oxford University Press (OUP). (2019). Disclosure: definition of disclosure. https://www.lexico.com/en/definition/disclosure
Planbook. (n.d.). Digital ethics: Responsible social media practices for educators. https://blog.planbook.com/digital-ethics/
Regan, P., & Jesse, J. (2019). Ethical challenges of edtech, big data and personalized learning: Twenty-first century student sorting and tracking. Ethics and Information Technology , 21 (3), 167-179. https://doi.org/10.1007/s10676-018-9492-2
Roberts, V. (2019). Open educational practices (OEP): Design-based research on expanded high school learning environments, spaces, and experiences [Unpublished doctoral thesis]. University of Calgary.
Sideri, M., Kitsiou, A., Kalloniatis, C., Tzortzaki, E., & Gritzalis, S. (2017). “I have learned that I must think twice before…”. An educational intervention for enhancing students’ privacy awareness on Facebook. Communications in Computer and Information Science, 792, 79-94. https://doi.org/10.1007/978-3-319-71117-1_6
Velestianos, G. (Ed.). (2016). Emergence and innovation in digital learning: Foundations and applications. AU Press, Athabasca University. https://doi.org/10.15215/aupress/9781771991490.01
White, K. W. (2016). Teacher communication: A guide to relational, organizational, and classroom communication . ProQuest Ebook Central https://ebookcentral-proquest-com.ezproxy.lib.ucalgary.ca
Appendix A
| Teacher-Led Walled Garden of Open Learning | Transition Between Teacher-Led Walled Garden & Independent Open Learning | Developing Personal Learning Networks |
|---|---|---|
|
Up to age 11
AND/OR. Emerging open readiness learners |
Ages 11-14
AND/OR. Low & medium open readiness learners |
Ages 14+
AND/OR. High open readiness learners |
| Example: Teacher connects with their PLN to share classroom learning experience using classroom social media identity. | Example: Teacher co-designs for learning pathway that includes inside/outside experts & open/closed sharing of learning experiences. | Example: Teacher co-designs for learning pathway that encourages inside/outside classroom experts, nodes of learning, & perspectives in order to solve problem with choice open/closed sharing of learning. |
Media Attributions
- Figure 2.1 Six components of culture of care, adapted from Nias (1999) © Heather van Struen is licensed under a CC BY (Attribution) license
- Figure 2.2 Attitudes to limit exposure of privacy, adapted from Regan and Jesse (2019) © Heather van Struen is licensed under a CC BY (Attribution) license
- fig8_struen


1.5: Western Bias in Our Assumptions about Humanity
-
- Last updated
- Save as PDF
- Jennifer Hasty, David G. Lewis, & Marjorie M. Snipes
- OpenStax
Learning Objectives
By the end of this section, you will be able to:
- Define and recognize cultural bias.
- Analyze forms of cultural bias in our own interactions and institutions.
- Describe how the four fields of anthropology can work together to expose and overturn the misconceptions of cultural bias.
Euro-American ethnocentrism is everywhere in American culture—in our movies, advertising, museums, amusement parks, and news media. Though the styles have shifted somewhat in the past century, both primitivism and orientalism still persist as two discernible styles of bias.
Primitivism and Orientalism in Popular Culture
Think for a minute about the last time you saw an image of an African person. Was it, perhaps, an image of wide-eyed girl in tattered clothing in an advertisement from a development agency requesting a charitable donation? Or maybe it was a news media photograph of a child soldier wielding an AK-47 in a conflict zone in the Democratic Republic of the Congo or another African country. Africa is still popularly represented as a dark place full of deprivation and crisis. Africans are frequently infantilized as simple children who need the support and tutelage of White Western helpers. But isn’t it true, you may say, that poverty and violent conflicts are widespread in Africa? Isn’t the representation accurate to some degree?
The most troubled places on the African continent are the places where European colonialism was most brutal and violent. In what is now the Democratic Republic of the Congo, the Belgian king Leopold II oversaw a reign of terror against the local peoples, encouraging their enslavement for the lucrative rubber trade. Elsewhere in Africa, European colonial governments stole land from local peoples and confined them to reservations, forcing them to work on European plantations in order to pay taxes to the colonial government. Colonial officials fomented conflict by privileging some ethnic groups and repressing others. Where you see violence and conflict in Africa today, the roots can often be traced to the colonial period. Is this painful history included in American representations of Africa?
Moreover, there are many bright spots in Africa, places such as Ghana and Botswana, with growing economies and stable democracies. Would it surprise you to learn that Ghana has a space program? That there are more mobile phones than people in Kenya? That several electric cars are manufactured in Africa?
Similar distortions are applied to Native Americans, frequently represented as victims of history, poor and helpless, in need of outside help. The primitivist gaze shapes the representation of Native Americans in museums, which often feature dioramas of humble people with stone tools, buckskin clothes, and tepees, either living a simple life close to nature or engaged in tribal warfare, their bodies painted with vibrant colors. Of course, Native Americans do not live this way now, but these are the images that come to mind in the popular imagination. It is of course important for non-Native Americans to learn about the cultures of Native peoples before and during their contact with European settlers, but it is equally important to understand the legacies of history in the contemporary living conditions and activities of Native communities. Rather than seeing Native peoples as passive victims, popular culture should also depict the dynamic and creative responses of Native Americans to the forms of cultural violence enacted against them.
For instance, did you know that a Native food movement is surging across the United States, both on Native reservations and in American cities? Native food activists such as Karlos Baca and Sean Sherman are reviving and reinventing the balanced, healthy cuisines of their ancestors, featuring dishes such as braised elk leg and maple red corn pudding. Sherman and his partner, Dana Thompson, have founded the nonprofit group North American Traditional Indigenous Food Systems (NATIFS), devoted to preserving Native foodways. The group offers opportunities for tribes to set up Native cuisine restaurants, providing jobs and profits to communities with high unemployment. Watch this video to learn more about Sean Sherman and the Native Food movement.
Like primitivism, orientalism has endured in American and European cultures. In the two decades following the al-Qaeda attacks on American targets on September 11, 2001, the most prominent example of orientalism in American culture has been the stereotype that all Islamic peoples are fanatical and violent. The indiscriminate application of this stereotype to Islamic peoples across the Middle East was a major contributor to the 2003 American invasion of Iraq, a country that had nothing at all to do with the September 11 attacks. To promote the invasion, politicians used the orientalist notion that Iraq was a violent and irrational country stockpiling weapons of mass destruction (which turned out to be false). As the war raged on, the Iraqi people came to be categorized as either “unlawful combatants” or helpless victims of a cruel dictator. American officials argued that Iraqis needed the help of American troops to save them from their subjugation and teach them democracy.
For many Europeans and Americans, these forms of ethnocentric bias distort views of peoples living in large geographical regions of the globe. Misunderstanding other cultures this way can result in policies and military actions that do not achieve desired results. Moreover, ethnocentric bias promotes and reinforces inequality among social groups within multicultural societies. When people with certain ethnic or racial identities are seen as helpless or violent, they face discrimination in their pursuit of education, employment, and justice.
The Bias of Backwardness
Common to both primitivism and orientalism is the notion that European and Euro-American cultures are more advanced and civilized than other cultures. Since at least the 19th century, Euro-American thinking has been dominated by the idea that the various cultures of the world can be evaluated on a scale of sociocultural sophistication from least advanced to most advanced. Typically, Native American and African cultures were considered the most primitive, while those of Asia and the Middle East were thought of as slightly more developed but certainly not as civilized as the societies of Europe, which were ranked at the top as the epitome of human progress.
Early anthropology played a role in promoting this ethnocentric way of thinking. Nineteenth-century anthropologists detailed various hypothetical schemes charting the developmental stages that each culture would go through in its pursuit of the European ideal of civilization. One very prominent scheme was proposed by the British anthropologist Edward Tylor. Tylor suggested that each culture progressed from “savagery” to “barbarism” to “civilization.” Since the change from one stage to another could not be witnessed by the researcher, such “evolutionary” schemes were largely based on hypothetical conjecture, sometimes called “theorizing from the armchair.”
While some anthropologists played a role in popularizing this way of thinking, others worked to expose it as misguided and inaccurate. The writings of American anthropologist Franz Boas highlighted the fact that no culture is isolated in its process of developmental change. Instead, each culture develops through interactions with other cultures, as new ideas and inventions diffuse from one culture to the next. Moreover, cultural change is not structured by an overall trajectory of progress as defined by the European example; rather, cultures change in many ways, sometimes adopting new ways of doing things and other times reviving and reclaiming older ways. Through these varied patterns of change, each culture forges its own unique history.
While the evolutionary schemes of 19th-century anthropology have been disproven, the underlying notion of sociocultural progress toward a Euro-American ideal is still a widespread form of ethnocentric bias outside of anthropology. Many people still refer to some countries as “developed” and “modern” and others as “undeveloped” and “backward.” Think for a minute: Which countries are generally thought of as modern? Which ones are frequently referred to as undeveloped? What is really meant by these labels?
These labels are rooted in Euro-American values. Championing capitalism and technology, many Europeans and Americans view the generation of material wealth as the primary measure of the success of any society. The divide between the more and less “advanced” countries of the world is largely a distinction between the richer and poorer countries. European and American societies, which have become wealthy through the development of global trade and industrial capitalism, are considered the most successful. Societies that have not achieved the levels of wealth and technology associated with Euro-American industrial capitalism are sometimes labeled “undeveloped.” Societies that have not industrialized at all are sometimes called “premodern” or simply “traditional.”
As with older evolutionary schemes, this way of thinking relies on the notion that each society pursues economic development in isolation. The poorer countries of the world are told: if you work hard and apply the correct economic policies, then you too can become rich like the United States, the United Kingdom, and Germany. But how did those countries become rich in the first place? Certainly not in isolation. The Boasian emphasis on cultural interaction also applies to economic change. To a large degree, European and American societies became wealthy by dominating other societies and keeping them poor. European countries constructed a system of global capitalism designed to make them very rich by extracting raw materials and human labor from their colonies. In fact, that was the whole impetus for colonialism.
The cultural anthropologist Sidney Mintz is one of many who have studied how this happened. Mintz explored how European merchants designed a very lucrative system of production and consumption based on sugar (1985). As European consumers began developing a taste for sugar in the 17th century, European merchants developed sugar plantations in the New World using the labor of enslaved people transported from West Africa. Sugar produced on these plantations was exported to Europe and the rest of the world, earning a hefty profit for the European merchants who designed the system. Local people living in the places where sugar was produced did not benefit much from this trade, and enslaved people suffered and died for it. Similar systems were developed for the production of other global commodities such as cocoa, coffee, tea, and cotton. Some commodities required enslaved labor and others involved small farmers, but the basic structure of the trade was the same. The economies of many South Asian and African countries were designed entirely around the export of primary commodities, the production of which was controlled by European merchants who reaped the profits from this global trade. Many postcolonial countries still rely on the export of these primary commodities.
What do these historical processes mean for understanding the world today? European merchants and governments crafted strategic ways of thinking about the parts of the world they wanted to invade and colonize. To justify the development of the slave trade, the plantation system, and colonial rule, Europeans labeled many non-Europeans as backward peoples needing the civilizing influence of European domination. This form of bias persists in contemporary notions of backwardness applied to the poorer peoples and parts of the world.
In reality, the colonial system was a global mechanism for European merchants and governments to extract wealth from other parts of the world. European merchants took great care to maintain control over these forms of highly profitable trade, edging out local merchants and forbidding local competition. Even today, we see the remnants of this system in Euro-American domination of global trade. If the world seems divided between rich and poor, it is not because some countries work hard and others are “backward.” It is because the global system was founded on forms of inequality that endure into the present.
Profiles in Anthropology
Franz Boas (1858–1942)
Personal History: Franz Uri Boas was born in Germany to a middle-class Jewish family (Peregrine 2018). After completing a PhD in physics and mathematics, he worked as a geographer on an expedition to the Canadian Arctic, living and working with the Native Inuit peoples on Baffin Island. With his newfound passion for Native American culture, Boas returned to Germany to work at a museum and began conducting ethnographic and linguistic research among Native groups. In 1887, he came to the United States and established the first anthropology department at Clark University in Massachusetts. He spent most of his career as an anthropology professor at Columbia University and curator at the American Museum of Natural History in New York City.
Areas of Anthropology: Though he promoted a holistic approach integrating the four fields of anthropology, Boas was primarily a cultural anthropologist specializing in the Native peoples of the Northwest coast of North America. Between 1886 and 1900, he conducted 29 months of fieldwork in the region, focusing on the Kwakiutl peoples of Vancouver Island. He recorded myths, songs, and folklore in Native languages and described cultural activities such as food collection and artistic styles. Focusing on the linguistic and psychological aspects of this rich ethnographic data, Boas sought to understand Native perspectives and values. As the leading anthropologist of his time, he established an American tradition of recording ethnographic observations in meticulous detail and promoted the goal of reaching for an insider’s point of view.
Accomplishments in the Field: Boas profoundly disagreed with ethnocentric and racist theories circulating in the social sciences in the late 19th and early 20th centuries. Some anthropologists of the day identified some cultures as “primitive” or “savage,” arguing that each culture developed in isolation along a common trajectory toward “civilization.” Rejecting this model, Boas used his ethnographic data to show that cultures do not develop in isolation toward a common goal. Rather, each culture has its own unique historical trajectory, and cultures are constantly changing by sharing new ideas and practices.
Importance of His Work: Boas was horrified by the use of anthropological methods to support the theories and practices of White supremacy. In the 19th century, some American researchers measured the skulls of various ethnic groups, arguing that people who had immigrated to the United States from northern Europe had larger skulls and were therefore intellectually superior. In 1907, Boas conducted a survey for the U.S. Immigration Commission measuring the skulls of 17,821 American immigrants and their children. Comparing the head shapes of parents and children, Boas discovered that the children had larger skulls due to environmental factors in their new homeland, such as diet and medical care. His findings dealt a strong blow to race theory. Throughout his career, Boas spoke out against racism, arguing that biological differences have nothing to do with culture, language, or achievement.


Skip to main content
4.2: Course Objectives for Part III
-
-
Last updated
-
-
Save as PDF
-
Suggested Course Objectives for Part III—Sex, Gender, and Sexual Orientation
-
Read about, find, identify, interpret, understand, explain, critique, define, present factually and persuasively, and write about and/or discuss sex, gender, human sexuality, and sexual orientation from a sociologically scientific perspective.
-
Read about, find, identify, interpret, understand, explain, critique, define, present factually and persuasively, and write about and/or discuss sex, gender, human sexuality, and sexual orientation and be able to differentiate among them.
-
Read about, find, identify, interpret, understand, explain, critique, define, present factually and persuasively, and write about and/or discuss the various aspects of sex, gender, human sexuality, and sexual orientation.
-
Read about, find, identify, interpret, understand, explain, critique, define, present factually and persuasively, and write about and/or discuss prejudice and discrimination based on sex, gender, and sexual orientation and the various forms they take.
-
Read about, find, identify, interpret, understand, explain, critique, define, present factually and persuasively, and write about and/or discuss theories of sex, gender, and human sexuality, and the ongoing national debate concerning gay marriage.
-
Explain the impact of politics, the political process, as well as economic and social policies on the lives of people in the US based on their sex, gender, and sexual orientation.

-
Straight Males
-
Straight Females
-
Gay (Males)
-
Lesbian (Females)
-
Bisexual
-
Transgendered (Male to Female)
-
Transgendered (Female to Male)
-
Intersexed
-
Identify and differentiate among various theories of sex, gender, and sexual orientation.
-
Feminist Theory
-
Queer Theory
-
Know and analyze the various aspects of master status and the general impact of master status on the life chances of women and GLBTs in the US.
-
Find, interpret, understand, analyze, critique, and write about and/or discuss statistical information concerning stratification/inequality by sex, gender, and sexual orientation.
-
Find and interpret demographic data about women and GLBTs from the US Census and other valid and reliable sources.
-
Find, interpret, understand, analyze, critique, and write about and/or discuss statistical and historical information concerning sex, gender, and sexual orientation in the past and present in the US.
-
Understand, analyze, critique, and write about and/or discuss popular media’s interpretation of stratification/inequality by sex, gender, and sexual orientation.
-
Find, interpret, understand, analyze, critique, and write about and/or discuss legal policies concerning sex, gender, and sexual orientation in the US.
-
Find, read, interpret, understand, analyze, critique, and write about and/or discuss sex, gender, and sexual orientation studies found in peer reviewed scientific journal articles.


7.3: Marginal Revenue for Imperfectly Competitive Markets
selected template will load here
This action is not available.
The basics of profit maximization were described in Chapter 2 for a price-taking firm. A price-taking firm falls under the perfectly competitive market structure. Let us now extend the concept to other market structures, situations where firms are not price takers. Recall that marginal revenue (MR) was defined as the increase in revenue that results from producing an additional unit of output. Recall also that marginal cost (MC) was defined as the increase in total cost that results from producing an additional unit of output. Profit is maximized where MR = MC. One way to prove this is to use the logic of contradiction.
To prove that the only situation where profit could be maximized is if MR = MC, let us suppose otherwise. Suppose MR > MC, could profit be maximized? The answer is no. If the firm produced on more unit, its revenue would increase by MR but its cost would increase by MC. Since MR > MC, its profit would go up as it produced more. Thus, profit could not be at a maximum if MR > MC. Now suppose that MR < MC, could profit be maximized? Again the answer is no. If the firm produced one less unit, its revenue would go down by MR and its cost would go down by MC. Since MR < MC, its profit would go up as it produced less. Thus profits could not be maximized if MR < MC.
In Chapter 2, you learned that MR = P for a firm that is in a perfectly competitive market (a firm that is a price taker). In imperfectly competitive markets like monopoly, oligopoly, or monopolistic competition, this is not the case. In fact, MR < P in imperfectly competitive markets. This is because the price that the firm receives is impacted by quantity that the firm places on the market. A general formula for marginal revenue that applies to all market structures is
\[MR = P + \dfrac{\Delta P}{\Delta Q} Q.\]
The law of demand indicates that \(\dfrac{\Delta P}{\Delta Q} < 0\). If more is placed on the market, price will need to fall in order to induce additional consumers into the market and/or convince existing consumers to purchase larger amounts. Thus, marginal revenue depends on the quantity placed on the market so long as \(\dfrac{\Delta P}{\Delta Q}\) does not equal zero.
Look carefully at the MR formula above. The second term, \(\dfrac{\Delta P}{\Delta Q}Q\), is the slope of the inverse demand curve facing the firm multiplied by quantity. The first term, \(P\), is the inverse demand curve itself. Thus if you have a linear inverse demand curve of the form
\(P = a + bQ\), you can use the fact that \(b = \dfrac{\Delta P}{\Delta Q}\) and the general formula above to find a simple expression for marginal revenue:
\[MR = P + bQ = a + bQ + bQ \Rightarrow MR = a + 2bQ.\]
Thus, if the inverse demand curve is linear, then the marginal revenue curve will have the same intercept as the inverse demand curve and twice the slope. In the formula above, it is important to emphasize that the inverse demand curve in question is that which faces the firm. Unless the firm is a monopolist, the inverse demand curve facing the firm will be different than the inverse demand curve facing the market.
Using the definition of the point elasticity and a little bit of algebra, you can use the general formula for marginal revenue above to show that
\[MR = P(1 + \dfrac{1}{\varepsilon}),\]
where \(\varepsilon\) is the price elasticity of demand facing the firm. It is important to emphasize that in this case, \(\varepsilon\) is the elasticity facing the firm, which is not the same as the market elasticity. Only if the firm is a monopolist will the elasticity of market demand be the same as the elasticity of demand facing the firm.
There are two interesting implications of the elasticity version of the MR formula. First, if you know demand elasticity and assume profit maximizing behavior, you can arrive at an estimate of marginal cost because \(MR = MC\) when profits are maximized. Second, given a non-negative marginal cost, a firm that faces a downward sloping demand curve will always price in a region where demand is elastic. This argument has been made before in Chapter 3. Here you see it again in terms of the firm’s profit maximizing condition.
The difference between the elasticity of demand facing a firm and that facing the market is most pronounced in perfect competition. In perfect competition, there are many firms. Each firm is small relative to the size of the market. As a result, the firm can put more quantity on the market and not have a material effect on the market price. In this case, \(\dfrac{\Delta P}{\Delta Q} = 0\) and the elasticity of demand facing the firm is \(- \infty\). The market demand may be elastic or inelastic. However, the elasticity facing the firm is negative infinity (perfectly elastic). In other words, if the competitive firm attempts to raise its price, it loses all of its sales. Thus,
\[MR = P(1 + \dfrac{1}{- \infty}) = P.\]
This is the profit maximizing condition for price-taking firm that was presented earlier in Chapter 2.


9.5: Microfossils
Major Microfossil Groups
Microfossils are fossils that are less then 2 mm in size and require the aid of a microscope to study. Many taxonomic groups are represented in the microfossil record but here we will focus on some of the common mineralized microfossil groups. These include foraminifera , radiolarians , diatoms , ostracods , and conodonts . These microfossils are important tools for biostratigraphy and paleoclimatology. Other notable nonmineralized microfossils include spores and pollen .
Foraminifera
Foraminifera are an Order of single celled protista that have an extensive fossil record. These organism are aquatic and live inside a shell referred to as a test. Classification of the foraminifera genera is based on shell mineralogy, shell morphology, and internal shell structure. Foraminifera with shells composed of calcium carbonate are more readily preserved than organic (chitin) based groups and make up the bulk of the foraminifera fossil record. Some common fossil forming Genera are Textulariids, Fusulinids, Miliolids, Rotaliids, and Globigerinids. For more information please visit the Digital Atlas of Ancient Life's foraminifera webpage .
Most foraminifera are marine but there are a few freshwater varieties. The group ranges from the Cambrian to the present.


20.3: Gauss’s Law
-
- Last updated
- Save as PDF
Learning Objectives
By the end of this section, you will be able to:
- State Gauss’s law
- Explain the conditions under which Gauss’s law may be used
- Apply Gauss’s law in appropriate systems
We can now determine the electric flux through an arbitrary closed surface due to an arbitrary charge distribution. We found that if a closed surface does not have any charge inside where an electric field line can terminate, then any electric field line entering the surface at one point must necessarily exit at some other point of the surface. Therefore, if a closed surface does not have any charges inside the enclosed volume, then the electric flux through the surface is zero. Now, what happens to the electric flux if there are some charges inside the enclosed volume? Gauss’s law gives a quantitative answer to this question.
To get a feel for what to expect, let’s calculate the electric flux through a spherical surface around a positive point charge \(q\), since we already know the electric field in such a situation. Recall that when we place the point charge at the origin of a coordinate system, the electric field at a point \(P\) that is at a distance \(r\) from the charge at the origin is given by
\[\vec{E}_p = \dfrac{1}{4\pi \epsilon_0}\dfrac{q}{r^2}\hat{r}, \nonumber \]
where \(\hat{r}\) is the radial vector from the charge at the origin to the point \(P\). We can use this electric field to find the flux through the spherical surface of radius \(r\), as shown in Figure \(\PageIndex{1}\).
Then we apply \(\Phi = \int_S \vec{E} \cdot \hat{n} dA\) to this system and substitute known values. On the sphere, \(\hat{n}\) and \(r = R\) so for an infinitesimal area \(dA\),
\[\begin{align*} d\Phi &= \vec{E} \cdot \hat{n} dA \\[4pt] &= \dfrac{1}{4\pi \epsilon_0} \dfrac{q}{R^2} \hat{r} \cdot \hat{r} dA \\[4pt] &= \dfrac{1}{4\pi \epsilon_0} \dfrac{q}{R^2} dA. \end{align*} \]
We now find the net flux by integrating this flux over the surface of the sphere:
\[\Phi = \dfrac{1}{4\pi \epsilon_0} \dfrac{q}{R^2} \oint_S dA = \dfrac{1}{4\pi \epsilon_0} \dfrac{q}{R^2} (4\pi R^2) = \dfrac{q}{\epsilon_0}. \nonumber \]
where the total surface area of the spherical surface is \(4\pi R^2\). This gives the flux through the closed spherical surface at radius \(r\) as
\[\Phi = \dfrac{q}{\epsilon_0}. \nonumber \]
A remarkable fact about this equation is that the flux is independent of the size of the spherical surface. This can be directly attributed to the fact that the electric field of a point charge decreases as \(1/r^2\) with distance, which just cancels the \(r^2\) rate of increase of the surface area.
Electric Field Lines Picture
An alternative way to see why the flux through a closed spherical surface is independent of the radius of the surface is to look at the electric field lines. Note that every field line from \(q\) that pierces the surface at radius \(R_1\) also pierces the surface at \(R_2\) (Figure \(\PageIndex{2}\)).
Therefore, the net number of electric field lines passing through the two surfaces from the inside to outside direction is equal. This net number of electric field lines, which is obtained by subtracting the number of lines in the direction from outside to inside from the number of lines in the direction from inside to outside gives a visual measure of the electric flux through the surfaces.
You can see that if no charges are included within a closed surface, then the electric flux through it must be zero. A typical field line enters the surface at \(dA_1\) and leaves at \(dA_2\). Every line that enters the surface must also leave that surface. Hence the net “flow” of the field lines into or out of the surface is zero (Figure \(\PageIndex{3a}\)). The same thing happens if charges of equal and opposite sign are included inside the closed surface, so that the total charge included is zero (Figure \(\PageIndex{3b}\)). A surface that includes the same amount of charge has the same number of field lines crossing it, regardless of the shape or size of the surface, as long as the surface encloses the same amount of charge (Figure \(\PageIndex{3c}\)).
Statement of Gauss’s Law
Gauss’s law generalizes this result to the case of any number of charges and any location of the charges in the space inside the closed surface. According to Gauss’s law, the flux of the electric field \(\vec{E}\) through any closed surface, also called a Gaussian surface , is equal to the net charge enclosed \((q_{enc})\) divided by the permittivity of free space \((\epsilon_0)\):
\[\Phi_{\text{Closed Surface}} = \dfrac{q_{enc}}{\epsilon_0}. \nonumber \]
This equation holds for charges of either sign, because we define the area vector of a closed surface to point outward. If the enclosed charge is negative (Figure \(\PageIndex{4b}\)), then the flux through either \(S\) or \(S'\) is negative.
The Gaussian surface does not need to correspond to a real, physical object; indeed, it rarely will. It is a mathematical construct that may be of any shape, provided that it is closed. However, since our goal is to integrate the flux over it, we tend to choose shapes that are highly symmetrical.
If the charges are discrete point charges, then we just add them. If the charge is described by a continuous distribution, then we need to integrate appropriately to find the total charge that resides inside the enclosed volume. For example, the flux through the Gaussian surface \(S\) of Figure \(\PageIndex{5}\) is
\[\Phi = (q_1 + q_2 + q_5)/\epsilon_0. \nonumber \]
Note that \(q_{enc}\) is simply the sum of the point charges. If the charge distribution were continuous, we would need to integrate appropriately to compute the total charge within the Gaussian surface.
Recall that the principle of superposition holds for the electric field. Therefore, the total electric field at any point, including those on the chosen Gaussian surface, is the sum of all the electric fields present at this point. This allows us to write Gauss’s law in terms of the total electric field.
Gauss's Law
The flux \(\Phi\) of the electric field \(\vec{E}\) through any closed surface S (a Gaussian surface) is equal to the net charge enclosed \((q_{enc})\) divided by the permittivity of free space \((\epsilon_0)\):
\[\Phi = \oint_S \vec{E} \cdot \hat{n} dA = \dfrac{q_{enc}}{\epsilon_0}. \nonumber \]
To use Gauss’s law effectively, you must have a clear understanding of what each term in the equation represents. The field \(\vec{E}\) is the total electric field at every point on the Gaussian surface. This total field includes contributions from charges both inside and outside the Gaussian surface. However, \(q_{enc}\) is just the charge inside the Gaussian surface. Finally, the Gaussian surface is any closed surface in space. That surface can coincide with the actual surface of a conductor, or it can be an imaginary geometric surface. The only requirement imposed on a Gaussian surface is that it be closed (Figure \(\PageIndex{5}\)).
Example \(\PageIndex{1}\): Electric Flux through Gaussian Surfaces
Calculate the electric flux through each Gaussian surface shown in Figure \(\PageIndex{7}\).
Strategy
From Gauss’s law, the flux through each surface is given by \(q_{enc}/\epsilon_0\), where \(q_{enc}\) is the charge enclosed by that surface.
Solution
For the surfaces and charges shown, we find
a. \(\Phi = \frac{2.0 \, \mu\mathrm{C}}{\epsilon_0} = 2.3 \times 10^5\, \mathrm{N} \cdot \mathrm{m}^2/\mathrm{C}\).
b. \(\Phi = \frac{-2.0 \, \mu\mathrm{C}}{\epsilon_0} = -2.3 \times 10^5\, \mathrm{N} \cdot \mathrm{m}^2/\mathrm{C}\).
c. \(\Phi = \frac{2.0 \, \mu\mathrm{C}}{\epsilon_0} = 2.3 \times 10^5\, \mathrm{N} \cdot \mathrm{m}^2/\mathrm{C}\).
d. \(\Phi = \frac{-4.0 \, \mu\mathrm{C} + 6.0 \, \mu\mathrm{C} - 1.0 \, \mu\mathrm{C}}{\epsilon_0} = 1.1 \times 10^5\, \mathrm{N} \cdot \mathrm{m}^2/\mathrm{C}\).
e. \(\Phi = \frac{4.0 \, \mu\mathrm{C} + 6.0 \, \mu\mathrm{C} - 10.0 \, \mu\mathrm{C}}{\epsilon_0} = 0\).
Significance
In the special case of a closed surface, the flux calculations become a sum of charges. In the next section, this will allow us to work with more complex systems.
Exercise \(\PageIndex{1}\)
Calculate the electric flux through the closed cubical surface for each charge distribution shown in Figure \(\PageIndex{8}\).
- Answer a
-
\(3.4 \times 10^5 \,\mathrm{N} \cdot \mathrm{m}^2/\mathrm{C}\)
- Answer b
-
\(-3.4 \times 10^5 \,\mathrm{N} \cdot \mathrm{m}^2/\mathrm{C}\)
- Answer c
-
\(3.4 \times 10^5 \,\mathrm{N} \cdot \mathrm{m}^2/\mathrm{C}\)
- Answer d
-
0
Use this simulation to adjust the magnitude of the charge and the radius of the Gaussian surface around it. See how this affects the total flux and the magnitude of the electric field at the Gaussian surface.


15.5: Clinical Considerations
-
- Last updated
- Save as PDF
- Ying Liu
- City College of San Francisco
Learning Objectives
- Explain how disruption of ergosterol biosynthesis is an effective mode of action for antifungals
- Describe how certain nucleoside analogs act as effective antiviral drugs
- Explain antiretroviral therapy (ART) for treating HIV infections
Because fungi, protozoa, and helminths are eukaryotic, their cells are very similar to human cells, making it more difficult to develop drugs with selective toxicity. Additionally, viruses replicate within human host cells, making it difficult to develop drugs that are selectively toxic to viruses or virus-infected cells. Despite these challenges, there are antimicrobial drugs that target fungi, protozoa, helminths, and viruses, and some even target more than one type of microbe. Table \(\PageIndex{1}\), Table \(\PageIndex{2}\), Table \(\PageIndex{3}\), and Table \(\PageIndex{4}\) provide examples for antimicrobial drugs in these various classes.
Antifungal Drugs
The most common mode of action for antifungal drugs is the disruption of the cell membrane. Antifungals take advantage of small differences between fungi and humans in the biochemical pathways that synthesize sterols. The sterols are important in maintaining proper membrane fluidity and, hence, proper function of the cell membrane. For most fungi, the predominant membrane sterol is ergosterol . Because human cell membranes use cholesterol , instead of ergosterol, antifungal drugs that target ergosterol synthesis are selectively toxic (Figure \(\PageIndex{1}\)).
The imidazoles are synthetic fungicides that disrupt ergosterol biosynthesis; they are commonly used in medical applications and also in agriculture to keep seeds and harvested crops from molding. Examples include miconazole, ketoconazole, and clotrimazole, which are used to treat fungal skin infections such as ringworm, specifically tinea pedis (athlete’s foot), tinea cruris (jock itch), and tinea corporis. These infections are commonly caused by dermatophytes of the genera Trichophyton , Epidermophyton , and Microsporum . Miconazole is also used predominantly for the treatment of vaginal yeast infections caused by the fungus Candida , and ketoconazole is used for the treatment of tinea versicolor and dandruff, which both can be caused by the fungus Malassezia .
The triazole drugs, including fluconazole , also inhibit ergosterol biosynthesis. However, they can be administered orally or intravenously for the treatment of several types of systemic yeast infections, including oral thrush and cryptococcal meningitis, both of which are prevalent in patients with AIDS. The triazoles also exhibit more selective toxicity, compared with the imidazoles, and are associated with fewer side effects.
The allylamines , a structurally different class of synthetic antifungal drugs, inhibit an earlier step in ergosterol biosynthesis. The most commonly used allylamine is terbinafine (marketed under the brand name Lamisil), which is used topically for the treatment of dermatophytic skin infections like athlete’s foot, ringworm, and jock itch. Oral treatment with terbinafine is also used for the treatment of fingernail and toenail fungus, but it can be associated with the rare side effect of hepatotoxicity.
The polyenes are a class of antifungal agents naturally produced by certain actinomycete soil bacteria and are structurally related to macrolides. These large, lipophilic molecules bind to ergosterol in fungal cytoplasmic membranes, thus creating pores. Common examples include nystatin and amphotericin B . Nystatin is typically used as a topical treatment for yeast infections of the skin, mouth, and vagina, but may also be used for intestinal fungal infections. The drug amphotericin B is used for systemic fungal infections like aspergillosis, cryptococcal meningitis, histoplasmosis, blastomycosis, and candidiasis. Amphotericin B was the only antifungal drug available for several decades, but its use is associated with some serious side effects, including nephrotoxicity (kidney toxicity).
Amphotericin B is often used in combination with flucytosine, a fluorinated pyrimidine analog that is converted by a fungal-specific enzyme into a toxic product that interferes with both DNA replication and protein synthesis in fungi. Flucytosine is also associated with hepatotoxicity (liver toxicity) and bone marrow depression.
Beyond targeting ergosterol in fungal cell membranes, there are a few antifungal drugs that target other fungal structures (Figure \(\PageIndex{2}\)). The echinocandins, including caspofungin, are a group of naturally produced antifungal compounds that block the synthesis of β(1→3) glucan found in fungal cell walls but not found in human cells. This drug class has the nickname “penicillin for fungi.” Caspofungin is used for the treatment of aspergillosis as well as systemic yeast infections.
Although chitin is only a minor constituent of fungal cell walls, it is also absent in human cells, making it a selective target. The polyoxins and nikkomycins are naturally produced antifungals that target chitin synthesis. Polyoxins are used to control fungi for agricultural purposes, and nikkomycin Z is currently under development for use in humans to treat yeast infections and Valley fever (coccidioidomycosis), a fungal disease prevalent in the southwestern US. 1
The naturally produced antifungal griseofulvin is thought to specifically disrupt fungal cell division by interfering with microtubules involved in spindle formation during mitosis. It was one of the first antifungals, but its use is associated with hepatotoxicity. It is typically administered orally to treat various types of dermatophytic skin infections when other topical antifungal treatments are ineffective.
There are a few drugs that act as antimetabolites against fungal processes. For example, atovaquone, a representative of the naphthoquinone drug class, is a semisynthetic antimetabolite for fungal and protozoal versions of a mitochondrial cytochrome important in electron transport. Structurally, it is an analog of coenzyme Q, with which it competes for electron binding. It is particularly useful for the treatment of Pneumocystis pneumonia caused by Pneumocystis jirovecii . The antibacterial sulfamethoxazole-trimethoprim combination also acts as an antimetabolite against P. jirovecii .
Table \(\PageIndex{1}\) shows the various therapeutic classes of antifungal drugs, categorized by mode of action, with examples of each.
| Mechanism of Action | Drug Class | Specific Drugs | Clinical Uses |
|---|---|---|---|
| Inhibit ergosterol synthesis | Imidazoles | Miconazole, ketoconazole, clotrimazole | Fungal skin infections and vaginal yeast infections |
| Triazoles | Fluconazole | Systemic yeast infections, oral thrush, and cryptococcal meningitis | |
| Allylamines | Terbinafine | Dermatophytic skin infections (athlete’s foot, ring worm, jock itch), and infections of fingernails and toenails | |
| Bind ergosterol in the cell membrane and create pores that disrupt the membrane | Polyenes | Nystatin | Used topically for yeast infections of skin, mouth, and vagina; also used for fungal infections of the intestine |
| Amphotericin B | Variety systemic fungal infections | ||
| Inhibit cell wall synthesis | Echinocandins | Caspofungin | Aspergillosis and systemic yeast infections |
| Not applicable | Nikkomycin Z | Coccidioidomycosis (Valley fever) and yeast infections | |
| Inhibit microtubules and cell division | Not applicable | Griseofulvin | Dermatophytic skin infections |
Query \(\PageIndex{1}\)
Treating a Fungal Infection of the Lungs
Jack, a 48-year-old engineer, is HIV positive but generally healthy thanks to antiretroviral therapy (ART). However, after a particularly intense week at work, he developed a fever and a dry cough. He assumed that he just had a cold or mild flu due to overexertion and didn’t think much of it. However, after about a week, he began to experience fatigue, weight loss, and shortness of breath. He decided to visit his physician, who found that Jack had a low level of blood oxygenation. The physician ordered blood testing, a chest X-ray, and the collection of an induced sputum sample for analysis. His X-ray showed a fine cloudiness and several pneumatoceles (thin-walled pockets of air), which indicated Pneumocystis pneumonia (PCP), a type of pneumonia caused by the fungus Pneumocystis jirovecii . Jack’s physician admitted him to the hospital and prescribed Bactrim, a combination of sulfamethoxazole and trimethoprim, to be administered intravenously.
P. jirovecii is a yeast-like fungus with a life cycle similar to that of protozoans. As such, it was classified as a protozoan until the 1980s. It lives only in the lung tissue of infected persons and is transmitted from person to person, with many people exposed as children. Typically, P. jirovecii only causes pneumonia in immunocompromised individuals. Healthy people may carry the fungus in their lungs with no symptoms of disease. PCP is particularly problematic among HIV patients with compromised immune systems.
PCP is usually treated with oral or intravenous Bactrim, but atovaquone or pentamidine(another antiparasitic drug) are alternatives. If not treated, PCP can progress, leading to a collapsed lung and nearly 100% mortality. Even with antimicrobial drug therapy, PCP still is responsible for 10% of HIV-related deaths.
The cytological examination, using direct immunofluorescence assay (DFA), of a smear from Jack’s sputum sample confirmed the presence of P. jirovecii (Figure \(\PageIndex{3}\)). Additionally, the results of Jack’s blood tests revealed that his white blood cell count had dipped, making him more susceptible to the fungus. His physician reviewed his ART regimen and made adjustments. After a few days of hospitalization, Jack was released to continue his antimicrobial therapy at home. With the adjustments to his ART therapy, Jack’s CD4 counts began to increase and he was able to go back to work.
Antiviral Drugs
Unlike the complex structure of fungi, protozoa, and helminths, viral structure is simple, consisting of nucleic acid, a protein coat, viral enzymes, and, sometimes, a lipid envelope. Furthermore, viruses are obligate intracellular pathogens that use the host’s cellular machinery to replicate. These characteristics make it difficult to develop drugs with selective toxicity against viruses.
Many antiviral drugs are nucleoside analogs and function by inhibiting nucleic acid biosynthesis. For example, acyclovir (marketed as Zovirax) is a synthetic analog of the nucleoside guanosine (Figure \(\PageIndex{4}\)). It is activated by the herpes simplex viral enzyme thymidine kinase and, when added to a growing DNA strand during replication, causes chain termination. Its specificity for virus-infected cells comes from both the need for a viral enzyme to activate it and the increased affinity of the activated form for viral DNA polymerase compared to host cell DNA polymerase. Acyclovir and its derivatives are frequently used for the treatment of herpes virus infections, including genital herpes, chickenpox, shingles, Epstein-Barr virus infections, and cytomegalovirus infections. Acyclovir can be administered either topically or systemically, depending on the infection. One possible side effect of its use includes nephrotoxicity. The drug adenine-arabinoside, marketed as vidarabine, is a synthetic analog to deoxyadenosine that has a mechanism of action similar to that of acyclovir. It is also effective for the treatment of various human herpes viruses. However, because of possible side effects involving low white blood cell counts and neurotoxicity, treatment with acyclovir is now preferred.
Ribavirin, another synthetic guanosine analog, works by a mechanism of action that is not entirely clear. It appears to interfere with both DNA and RNA synthesis, perhaps by reducing intracellular pools of guanosine triphosphate (GTP). Ribavarin also appears to inhibit the RNA polymerase of hepatitis C virus. It is primarily used for the treatment of the RNA viruses like hepatitis C (in combination therapy with interferon) and respiratory syncytial virus. Possible side effects of ribavirin use include anemia and developmental effects on unborn children in pregnant patients. In recent years, another nucleotide analog, sofosbuvir (Solvaldi), has also been developed for the treatment of hepatitis C. Sofosbuvir is a uridine analog that interferes with viral polymerase activity. It is commonly coadministered with ribavirin, with and without interferon.
Query \(\PageIndex{1}\)
Query \(\PageIndex{1}\)
Inhibition of nucleic acid synthesis is not the only target of synthetic antivirals. Although the mode of action of amantadine and its relative rimantadine are not entirely clear, these drugs appear to bind to a transmembrane protein that is involved in the escape of the influenza virus from endosomes. Blocking escape of the virus also prevents viral RNA release into host cells and subsequent viral replication. Increasing resistance has limited the use of amantadine and rimantadine in the treatment of influenza A. Use of amantadine can result in neurological side effects, but the side effects of rimantadine seem less severe. Interestingly, because of their effects on brain chemicals such as dopamine and NMDA (N-methyl D-aspartate), amantadine and rimantadine are also used for the treatment of Parkinson’s disease.
Neuraminidase inhibitors , including olsetamivir (Tamiflu), zanamivir (Relenza), and peramivir (Rapivab), specifically target influenza viruses by blocking the activity of influenza virus neuraminidase, preventing the release of the virus from infected cells. These three antivirals can decrease flu symptoms and shorten the duration of illness, but they differ in their modes of administration: olsetamivir is administered orally, zanamivir is inhaled, and peramivir is administered intravenously. Resistance to these neuraminidase inhibitors still seems to be minimal.
Pleconaril is a synthetic antiviral under development that showed promise for the treatment of picornaviruses. Use of pleconaril for the treatment of the common cold caused by rhinoviruses was not approved by the FDA in 2002 because of lack of proven effectiveness, lack of stability, and association with irregular menstruation. Its further development for this purpose was halted in 2007. However, pleconaril is still being investigated for use in the treatment of life-threatening complications of enteroviruses, such as meningitis and sepsis. It is also being investigated for use in the global eradication of a specific enterovirus, polio. 6 Pleconaril seems to work by binding to the viral capsid and preventing the uncoating of viral particles inside host cells during viral infection.
Viruses with complex life cycles, such as HIV, can be more difficult to treat. First, HIV targets CD4-positive white blood cells, which are necessary for a normal immune response to infection. Second, HIV is a retrovirus, meaning that it converts its RNA genome into a DNA copy that integrates into the host cell’s genome, thus hiding within host cell DNA. Third, the HIV reverse transcriptase lacks proofreading activity and introduces mutations that allow for rapid development of antiviral drug resistance. To help prevent the emergence of resistance, a combination of specific synthetic antiviral drugs is typically used in ART for HIV (Figure \(\PageIndex{5}\)).
The reverse transcriptase inhibitors block the early step of converting viral RNA genome into DNA, and can include competitive nucleoside analog inhibitors (e.g., azidothymidine/zidovudine, or AZT) and non-nucleoside noncompetitive inhibitors (e.g., etravirine) that bind reverse transcriptase and cause an inactivating conformational change. Drugs called protease inhibitors (e.g., ritonavir) block the processing of viral proteins and prevent viral maturation. Protease inhibitors are also being developed for the treatment of other viral types. 7 For example, simeprevir (Olysio) has been approved for the treatment of hepatitis C and is administered with ribavirin and interferon in combination therapy. The integrase inhibitors (e.g., raltegravir), block the activity of the HIV integrase responsible for the recombination of a DNA copy of the viral genome into the host cell chromosome. Additional drug classes for HIV treatment include the CCR5 antagonists and the fusion inhibitors (e.g., enfuviritide), which prevent the binding of HIV to the host cell coreceptor (chemokine receptor type 5 [CCR5]) and the merging of the viral envelope with the host cell membrane, respectively. Table \(\PageIndex{4}\) shows the various therapeutic classes of antiviral drugs, categorized by mode of action, with examples of each.
Query \(\PageIndex{1}\)
| Mechanism of Action | Drug | Clinical Uses |
|---|---|---|
| Nucleoside analog inhibition of nucleic acid synthesis | Acyclovir | Herpes virus infections |
| Azidothymidine/zidovudine (AZT) | HIV infections | |
| Ribavirin | Hepatitis C virus and respiratory syncytial virus infections | |
| Vidarabine | Herpes virus infections | |
| Sofosbuvir | Hepatitis C virus infections | |
| Non-nucleoside noncompetitive inhibition | Etravirine | HIV infections |
| Inhibit escape of virus from endosomes | Amantadine, rimantadine | Infections with influenza virus |
| Inhibit neuraminadase | Olsetamivir, zanamivir, peramivir | Infections with influenza virus |
| Inhibit viral uncoating | Pleconaril | Serious enterovirus infections |
| Inhibition of protease | Ritonavir | HIV infections |
| Simeprevir | Hepatitis C virus infections | |
| Inhibition of integrase | Raltegravir | HIV infections |
| Inhibition of membrane fusion | Enfuviritide | HIV infections |
Link to Learning
To learn more about the various classes of antiretroviral drugs used in the ART of HIV infection, explore each of the drugs in the HIV drug classes provided by US Department of Health and Human Services at this website.
Key Concepts and Summary
- Because fungi, protozoans, and helminths are eukaryotic organisms like human cells, it is more challenging to develop antimicrobial drugs that specifically target them.
- Antifungal drugs interfere with ergosterol synthesis, bind to ergosterol to disrupt fungal cell membrane integrity, or target cell wall-specific components or other cellular proteins.
- Antiviral drugs inhibit viral entry, inhibit viral uncoating, inhibit nucleic acid biosynthesis, prevent viral escape from endosomes in host cells, and prevent viral release from infected cells.
- Because it can easily mutate to become drug resistant, HIV is typically treated with a combination of several antiretroviral drugs , which may include reverse transcriptase inhibitors, protease inhibitors, integrase inhibitors , and drugs that interfere with viral binding and fusion to initiate infection.
Footnotes
- 1 Centers for Disease Control and Prevention. “Valley Fever: Awareness Is Key.” www.cdc.gov/features/valleyfever/. Accessed June 1, 2016.
- 2 B. Chu et al. “A Benzimidazole Derivative Exhibiting Antitumor Activity Blocks EGFR and HER2 Activity and Upregulates DR5 in Breast Cancer Cells.” Cell Death and Disease 6 (2015):e1686
- 3 J.-X. Pan et al. “Niclosamide, An Old Antihelminthic Agent, Demonstrates Antitumor Activity by Blocking Multiple Signaling Pathways of Cancer Stem Cells.” Chinese Journal of Cancer 31 no. 4 (2012):178–184.
- 4 F. Imperi et al. “New Life for an Old Drug: The Anthelmintic Drug Niclosamide Inhibits Pseudomonas aeruginosa Quorum Sensing.” Antimicrobial Agents and Chemotherapy 57 no. 2 (2013):996-1005.
- 5 A. Jurgeit et al. “Niclosamide Is a Proton Carrier and Targets Acidic Endosomes with Broad Antiviral Effects.” PLoS Pathogens 8 no. 10 (2012):e1002976.
- 6 M.J. Abzug. “The Enteroviruses: Problems in Need of Treatments.” Journal of Infection 68 no. S1 (2014):108–14.
- 7 B.L. Pearlman. “Protease Inhibitors for the Treatment of Chronic Hepatitis C Genotype-1 Infection: The New Standard of Care.” Lancet Infectious Diseases 12 no. 9 (2012):717–728.