About Us texts posted by 35 top-tier Chinese universities on their official websites at two time-points: the turn of the century and the year of 2021. The 35 universities were drawn from China’s “Double First Class” Initiative that prioritises the development of a select group of elite universities in China. Close textual analyses focussing on the attitudinal markers with reference to their contexts were conducted to identify the themes evaluated in the About Us texts; Wilcoxon signed-rank tests were run to quantitatively compare the relative frequencies of the attitudinal markers between the two phases, which was then supplemented by diachronic qualitative comparisons on the fine-grained linguistic features surrounding the markers. The study identified seven major themes positively appraised by the universities at both time-points. It also revealed diachronic differences in the use of attitudinal markers, reflecting a mediated change of promotional strategies over the past 20 years or so in the Chinese higher education context. These findings point to the influence of market, government, and tradition on Chinese top-tier universities’ promoting strategies and the role of social cognition in shaping student choice. They also suggest the emergence of a higher education system with Chinese characteristics that features a reconciliation of market and government forces.This study explored the marketisation process of top-tier Chinese universities by scrutinising their self-promotional strategies over the past two decades. Drawing on  The powerful encroachment of globalisation and neoliberalism has accelerated the marketisation of higher educational institutions worldwide. As a result, universities are increasingly seen as competing entities that endeavour to commercialise their educational products in the global higher education marketplace. To commodify education, marketised universities adopt managerial protocols originally prevalent in the business world, such as quality control, auditing and ranking performance, quantifying students’ experience, and vying for a favourable position in league tables .This marketisation logic is also manifest in Chinese universities, as they are observed to lure quality faculty with attractive monetary incentives , build uTop-tier universities in China have been generously funded by the central government since the 1990s. Different supporting strategies and initiatives such as the Project 211, Project 985 and Double First Class Initiative have provided continuous financial and policy support to foster the development of top-tier Chinese universities in different historical periods. The Double First Class Initiative, the latest national strategy, aims to help dozens of Chinese universities become influential competitors in the global higher education marketplace.About Us webpages of top-tier Chinese universities, and investigates how the promotional strategies, and more broadly the marketisation process, are verbally reflected in the virtual genre over the past two decades.Owing to its convenient and economic accessibility, the Internet has served as an increasingly popular tool for universities’ self-promotional activities over the past 20 years or so. Chinese universities, like their Western counterparts, have capitalised on their official websites to publicise their strengths and features so as to promote their brands and attract prospective students. This study focuses on the texts on the Self-promotion has become all the more popular among universities around the world as it has grown increasingly competitive for institutions of higher learning to attract quality faculty and students, obtain public and private funds, and secure collaboration with industries. Universities have deployed a variety of institutional activities to carry out self-promotion. Open Days, for example, provide an opportunity for the universities to invite perspective students and their parents to visit their campuses to get to know more about various aspects of the universities through live experience and engagement . StudentIn all these promotional activities semiotic symbols play a vital role, as the success and efficiency of these self-propagandas depend heavily on the way in which the universities are visually or verbally presented to their stakeholders. Visual semiotics, due to the special affordances they possess, can be communicated to the audience in a more straightforward manner . As a reStudies have also probed the use of symbolic meaning and visual metaphor in pictures presented by the universities . Ng and Aside from visual pictures, some research has focussed on the emblem and logo of universities and investigated the promotional functions performed by these visual elements. Symbolic meanings represented in universities’ icons have been found to contribute to visualising institutional identities–corporates competing in the higher education market or organisations enacting local and academic tradition, contextualised in specific cultures . Such idCompared with the visual semiotics, the promotional mission executed by verbal texts has drawn much more research attention. Texts in students’ brochures and prospectuses, faculty recruitment advertisements, missions and visions, university self-introductions, presidents’ welcoming messages and graduation speeches have been extensively analysed with varying theoretical underpinnings and analytic lenses. Some researchers took a genre perspective and decoded the rhetorical moves of the verbal texts, based on which the promotional agenda behind the moves was revealed . Others enterprise  in the texts on universities’ websites, clearly suggesting the commercialisation of higher education. The study also found that the universities tended to promote their academic entrepreneurship through ample use of positively loaded lexis on both sides of the searched keywords. Another corpus study on university websites revealed that the keyword research was often collocated with quality and world, indicating that quality and globalisation of research were foregrounded in the self-promotion . For example, adopting the corpus-based approach, romotion . Moreoveromotion  has scrustructed . In thisstructed .According to themselves in a positive manner, whereas the latter group evaluated entities external to them, such as local industry and technology. About Us texts of top-tier and second-tier universities in China and America. The examination of the Attitude markers revealed that while Chinese universities seemed to construct a more university-centric, authoritative, and distant image, their American counterparts tended to build a more people-oriented, friendly, and approachable image. The top-tier universities in both countries underscored their prestige and history, while the second-tier ones appeared to foreground the positive college experience their students could enjoy.Previous studies have employed the Attitude framework to investigate the evaluative meanings communicated in universities’ promotional texts . It is nApart from the cross-country and cross-tier comparisons, there were also diachronic studies that compared the promotional texts produced at different historical periods, though this research did not focus specifically on Attitude markers e.g., . These sThere is no doubt that the studies reviewed above have shed much light on the marketisation of higher education. However, what seem to be under-researched are how this historical transition is discursively manifested, and how Attitude markers contribute to the realisation of such discursive manifestation. In view of these gaps, the following research questions are posed to guide this study.1.About Us texts?What are the major themes positively evaluated in the top-tier Chinese universities’ 2.About Us texts over the past two decades?Are there changes in the use of attitudinal markers in the 3.About Us texts over the past two decades?What meaning construction has been realised in the About Us texts was carried out with reference to the contexts to locate Attitude markers and to identify themes related to the markers. Statistical measures and close textual examination were employed to address the second research question: the diachronic comparisons on the use of the markers. To these ends, an About Us corpus was constructed to cater to the fine-grained lexico-grammatical, thematic, and statistical analyses. Finally, the themes identified in the first research question and the diachronic changes noted in the second one were brought together and scrutinised to answer the third research question.This study employed a mixed method research design to answer the three research questions. Detailed lexico-grammatical analysis of the About Us texts of the selected Chinese universities as our raw materials. The collection of data involved the following steps: sampling top-tier Chinese universities, retrieving the online About Us texts of the sampled universities at the two time points, and importing the raw texts into a corpus tool for the ensuing coding and analysis of attitude markers.To answer the three research questions, we collected online About Us texts of top-tier Chinese universities, we selected the very best universities listed in the ‘‘Double First Class’’ universities (Category A) by the Chinese MOE, which included 36 prestigious universities in Mainland China. While it posed little challenge to retrieve the latest About Us texts posted on their official webpages by the 36 universities, we initially had some difficulties in getting the earlier versions of About Us texts posted by these universities around 2,000, because the websites had been regularly or irregularly updated, and the texts had kept changing. The issue was finally addressed by the Wayback Machine1, an Internet archival library, which could help get the earlier versions of the online texts of 35 universities, with the earliest being East China Normal University  and the latest Fudan University . As a result, these 35 universities were sampled for this study and correspondingly their About Us texts posted around 2000 (Phase I) and 2021 (Phase II) were retrieved. As our study was interested in the attitudinal markers in the The 70 texts were then imported into a corpus tool, UAM CorpusTool, for coding and further analysis. The Attitude Framework, as the coding scheme, was inputted into the CorpusTool to facilitate the coding process. Both automated and manual coding approaches were used to assign coding labels of the coding scheme to the text segments with any attitudinal meanings. A second coder who was familiar with the Appraisal framework and the operation of the UAM CorpusTool was invited to code 10% of the data. Her coding results were compared against with the results coded by the first author, and a satisfactory inter-coding agreement (94.3%) was observed. Fuzzy and ambiguous cases were settled through discussion and consulting with an expert in discourse semantics and a senior administrator of a university. Subsequent to these steps, the first author coded all the remaining data. Coding validity was also checked through two rounds of reviewing and within-group comparison among instances assigned with the same labels.About Us texts. Particular attention was paid to the contents and the contexts of the Attitude instances, such as the appraiser/appraised, the polarity of the Attitude construed, and the characteristics displayed in the evaluations.Data analysis in this study involved both textual examination which was qualitative in nature and statistical comparisons which were quantitative in nature. For the first research question, instances of the different types of Attitude markers identified through the CorpusTool were closely examined to explore the themes positively evaluated in the As for the second research question, statistical analysis was first conducted to compare the frequencies of different types of Attitude at the two time points. To offset the text length effects, we standardised the raw frequencies of attitude markers in the corpora to relative frequencies  for the diachronic comparisons. Both Kolmogorov–Smirnov and Shapiro–Wilk tests showed that the standardised data from the Phase I corpus were not normally distributed. As such, we ran four Wilcoxon signed-rank tests to compare the relative frequencies of the four types of markers  between the two phases. Wilcoxon signed-rank tests are non-parametric tests where two sets of data from the same participants are compared when normality in the data is not assumed. The α value was set at 0.05 for all the Wilcoxon signed-rank tests. The statistical tests were then followed by nuanced qualitative analysis, where instances of the different types of Attitude markers were scrutinised to identify diachronic differences in construing the attitudinal meanings. The UAM CorpusTool automatically categorised the coded textual extracts into different groups according to their attitudinal meanings, so that grouped examples were offered for detailed textual analysis. In-depth textual analysis facilitated a contextualised understanding of the attitudinal markers. As with the theme analysis noted above, we also considered the contents and the contexts of the Attitude instances in the in-depth textual analysis.The analysis of data for the last research question was primarily based on the answers to the first two research questions. The major themes unveiled and the diachronic differences identified in the earlier analyses were compared and synthesised to explore the underlying meanings constructed in the texts.About Us texts. Altogether, 2,598 Attitude markers were identified in the two corpora, 925 in the Phase I corpus and 1,673 in the Phase II corpus. n = 6) negative instances.Our analysis of the corpus data revealed a high density of attitude markers in the About Us texts of the selected top-tier Chinese universities during the past two decades, including geographic location/city, scenery and landscape, history and culture, academic and research strength, faculty capacity, alumni and students, and international collaboration and cooperation.Our detailed textual analysis revealed seven major themes positively evaluated in the Given the fact that all the top-tier universities are located in metropolitans with glamorous social resources, rich cultural heritage and abundant employment opportunities, the universities made full use of such advantages to attract prospective students. Extracts 1 and 2 are examples where the host cities are positively evaluated for the institutions’ promotional purposes.(1)famous city in the middle reaches of the Changjiang (Yangtze River) .HUST is located in Wuhan, a (2)thriving metropolis in South China, the university today covers a total area of 391 hectares .Located in the city of Guangzhou, a per se. Extracts 3 and 4 are overt examples where campus scenery and landscape are positively appraised.The universities often prided themselves on their scenery and environment, which were always portrayed as attractive and pleasant. Such portrayals and evaluations were generally arranged in the texts prior to the promulgation of academic matters, the signature feature of higher education. This indicates universities’ strategy of prioritising a cosy and enjoyable learning environment over learning (3)picturesque scenery, with its campus running along the seashore at the foot of mountains .The university is set amidst (4)favourable environment and beautiful landscape, make a wonderful place for learning and research .The university campuses, with their Aside from the concrete and tangible physical entities, soft powers of universities, such as institutional history, tradition, culture and spirit, were also accoladed, as seen in Extracts 5 and 6.(5)long history, a glorious revolutionary tradition and a fine academic tradition .Wuhan University is a famous university with a (6)time-honoured institutions of higher learning in China with profound cultural heritage, its origin can be traced back to 1902 .SEU, as one of the Although the aforementioned themes are instrumental in attracting prospective students, what students care most about in the universities are learning opportunities, acquisition of academic knowledge, and development of abilities. In this regard, these top-tier universities have a competitive edge over less prestigious universities, and thus made frequent positive evaluations in relation to their strengths in academic disciplines and research outputs, as exemplified in Extracts 7 and 8.(7)strong disciplines, the University has built a science and technology industry system which consists mainly of biology and biochemistry, special materials, fine chemicals, electronic information, and mechanical and electrical equipment .Supported by its (8)high scientific research level and technological innovation level .SJTU enjoys an increasingly The academic and research advantages of universities, however, were not always positively evaluated as non-human entities, because all the academic and research outputs were achieved by humans. Advantages in this regard were also appraised from the perspective of human agents or producers. As shown in Extracts 9 and 10, faculties members were frequently praised in terms of their teaching and research abilities.(9)the most distinguished in the nation .SJTU’s faculty is, by any measures one might use, one of (10)esteemed scholars as teachers .In the 1920s and 1930s, Nankai had already gathered About Us texts, students and alumni were positively appraised as beneficiaries of educational services provided by the universities, as shown in Extract 11. They were often praised as capable actors making contributions to the industry or the entire nation. Extract 12 is a case in point.In the (11)colourful and lively life in the campus .Students of CUN enjoy a (12)outstanding RUC alumni have made important contributions in various sectors including government, academia, finance, communication, and education .Since Renmin University of China was established, more than 250,000 Internationalisation is another selling point for the top-tier universities. The prestigious universities have more access to international cooperation, such as academic exchange programms and research collaboration, than other universities do. These activities were often underscored by the elite universities to attract students who are interested in such international opportunities to broaden their horizons. Extracts 13 and 14 are examples where international collaboration and cooperation are positively evaluated.(13)extensive international academic exchanges, and has the capability of academic exchanges in all subjects and with all countries and regions .Xiamen University has promoted (14)leading position in this field .As one of the first Chinese universities to carry out international Chinese education, it enjoys a About Us texts produced at both time points used positive Attitude markers to highlight the seven major themes summarised above for the promotional purpose, quantitative and qualitative analyses did reveal some differences in the use of Attitude markers between the two time points. The following section reports the identified diachronic differences.Although the About Us texts at the two time points. The Wilcoxon signed-rank test on Attitude as an aggregate category showed that there was a significant difference between the two corpora. The texts in Phase II  used significantly more Attitude markers than those in Phase I , Z = −2.817, p = 0.005. Under this aggregate Attitude category are subcategories of Affect, Judgement, and Appreciation.As mentioned earlier, four Wilcoxon signed-rank tests were run to compare the relative frequencies of attitude markers in the Z = −0.051, p = 0.959. Affect markers appeared with very low frequencies in both Phase I corpus  and Phase II corpus . The universities revealed positive feelings and emotions expressed by both faculty and students. Notably, their happiness was most frequently associated with the universities’ services and facilities, as demonstrated in Extracts 15 and 16.The Wilcoxon signed-rank test on Affect indicated that the two corpora used this sub-type of Attitude markers with similar frequencies, (15)celebrate their holidays .All nationalities keep their good traditional customs and (16)enjoy global high-quality educational resources .Its students fully eager to) expresses a feeling of eagerness, and that in Extract 18  indicates satisfaction. Third, informal features were observed in the 2021 corpus. For example, the use of personal pronouns such as we, you, your, us in Extract 19 helps to construe a conversational tune, which suggests an attempt to talk directly with readers of the texts and to establish a close relation with stakeholders of the universities.However, a close examination of the Affect extracts from the two corpora revealed three differences in the use of this sub-type of Attitude markers. First, the Phase II (2021) corpus contained more instances that positively appraised students than did the Phase I (turn-of-the-century) corpus. Second, the Phase II corpus showed a more diverse use of Affect markers than the other corpus did. For example, aside from Happiness manifested by the Extracts 15 and 16, instances of Desideration and Satisfaction were found in the Phase II corpus. The bolded segment in Extract 17 eager to serve their country .The goal of talent cultivation is to nurture students who have both ability and moral integrity, able to cultivate charisma and (18)take pride in its unique culture”, our university aims to become a high-level research university .With the development strategy to “pillar our university with academic achievements, empower it with talents, make it prosper through innovation, enliven it with an open atmosphere, and (19)welcome your cooperation in meeting the challenges of an ever-changing world and invite you to join us in building a world-class university and promoting excellence in higher education .We M = 7.57, SD = 1.06) and Phase II corpora , Z = −0.149, p = 0.139. Judgement markers were used in both corpora to highlight faculty’s and students’ academic and research capacities (Extract 20), tenacity in their pursuit of academic excellence (Extract 21), and commitment to virtue ethics (Extract 22).The test on Judgement also showed a non-significant difference between Phase I ((20)high-quality faculty .MUC has always had (21)making every endeavour to build the university into a highly advanced institution of educational science and other sciences .The staff members are (22)well-qualified in both academic and ethical aspects, making remarkable contributions to the construction of our socialist modernisation .Many others are It should be noted that when people’s virtue ethics or moral standards were evaluated in the texts, as illustrated in the last extract, they were often associated with patriotism and ideological perspectives. In other words, political correctness and loyalty to the Communist Party of China (CPC) and the Socialist cause are considered indispensable to the virtue ethics in the Chinese higher education context.Z = −2.113, p = 0.035. The About Us texts posted in 2021  used significantly more Appreciation markers than the texts posted at the turn of the century . As shown in Finally, the Wilcoxon signed-rank test on Appreciation indicated a significant difference between the two corpora, (23)majestic Yuelu Mountain and facing the grand Xiangjiang River, CSU has pleasing scenery and is ideal for study and research .Backed by the (24)prestigious teacher training institution, influential both at home and abroad .40 years’ development has shaped East China Normal University into a (25)great progress in its overall strength through teamwork, innovation and commitment to excellence .CSU has made (26)outstanding tradition dates back to the early 20th century, when modern democracy and science were emerging and developing quickly in Guangdong province .The About Us texts in 2021.There seemed to be a growing number of Appreciation markers that positively evaluated the external and internal environment in the texts over the past 20 years. Such markers, though appraising things and entities, are related to human perception and can invoke people’s Affect. The increase in their frequency in the Phase II corpus indicates more human involvement in the creation of the From both the major themes evaluated and the diachronic difference over the past two decades summarised above, it is not difficult to realise that positive evaluation has been strategically employed by the top-tier Chinese universities to extensively conduct self-promotion, to aggressively attract potential students, and to actively compete in the higher education market.About Us texts, more students-related evaluations were deployed, more diverse and informal Attitude instances were utilised, and more Attitude instances were employed to boast a cosy and comfortable environment that students could enjoy in and outside of the campus. All these discursive strategies jointly pointed to a clear tactic on the part of the universities: to gain the students’  favour and to influence their choices and decisions. This, in part, reflects an ongoing transition to marketisation within the context of Chinese higher education over the two decades.More specifically, these universities like market vendors are explicitly promoting what they have to offer, such as educational resources, facilities, environments, products and services, to prospective students who, like consumers in the market, have free choices and decisions to make. Over the past 20 years or so, more and more Attitude markers were used in the About Us texts in the Phase II corpus. Relatedly, the presence of conversational and informal style in the Phase II corpus could be attributed to the fact that the top-tier Chinese universities are pulling down their poker faces and vying for quality students in the competitive higher education market. The marketisation logic also endows universities with relatively higher institutional autonomy as compared to decades ago contribute significantly to the nation construction and development .They all play important roles in their own fields and (28)for the country .In the past 58 years since its founding, BIT has turned out more than 60,000 scientists and technologists The negative Attitude markers provide an interesting perspective on this point. Both Extracts 29 and 30 are instances of negative evaluation. However, these negative Attitude markers are not directed at the universities but at the foreign invaders in the first extract and at the historical situation of the nation in the second. The negative markers in the extracts function to arouse a sentiment of patriotism, which seldom fails to evoke solidarity and empathy among the Chinese readers.(29)devastating damage at the hands of the invading Japanese army .In 1937, the University experienced (30)a life–and–death crisis .Nankai University (NKU) was founded in 1919, by the famous patriotic educators Zhang Boling and Yan Xiu, when the thunder of the May Fourth Movement was just about to explode and the whole China had fallen into About Us texts targets primarily at international readership, these Chinese universities need to examine the effectiveness of this promotional strategy in attracting international prospective students. In our comparison of the Chinese and English versions of the About Us texts of the same universities, it was clear that the English versions of some universities’ About Us texts were translated word-for-word from the Chinese versions. Considering the fact that what works for attracting Chinese students may not necessarily work for attracting international students, it stands to reason that Chinese universities should tailor their About Us texts specifically to international prospective students so as to better suit their reading habits and expectations as consumers of higher education.It should be acknowledged, however, that little is known about international students’ views on such ideology and revolutionary spirit. Given that the English version of the About Us corpus.Another factor is associated with Confucianism which has long penetrated into the education sphere in China. The Confucian doctrine stresses five integral virtues of man: benevolence (仁), righteousness (义), trustworthiness (信), propriety (礼), and wisdom (智) . The thiAbout Us texts are meant to be interpreted by student audience with shared mental models, knowledge, and attitudes situated in a specific epistemic community. In this process, positive Attitude markers predispose the top-tier universities to be perceived by student audience as authoritative, trustworthy, or credible agents, whose beliefs, claims, knowledge, and opinions inscribed in the texts tend to be accepted by the students  shape Chinese higher education in its recent massification process. The reverse order of “governments” and “markets” in the two article titles is, in a sense, indicative of the relative weighting of the two major driving forces that shape modern higher education in their respective socio-political contexts. Correspondingly, the motivation to serve the national interest seems to outweigh the aspiration to satisfy students’ personal needs in the Chinese higher education system. The opposite seems to be true in the Western context, where investment-return logic is celebrated and personal development tends to be prioritised over other social agendas.The differences between the Chinese and the Western higher education systems, in particular, are rooted in a series of socio-political imperatives, socio-economic constraints and socio-cultural norms that are in constant dialogue with each other ,b. WhileThis difference is related to another observation clearly seen in the extracts presented earlier: Chinese graduates are encouraged by the universities to serve their country and take pride in their traditional culture. In contrast, many Western universities endorse the individualistic spirit and encourage students to challenge orthodoxy and bring about change. This difference can be attributed to the collectivism-individualism distinction between China and the West . China iMirroring market economy with Chinese characteristics, we can come up with a term to capture the ground reality in the domain of higher education in China: higher education with Chinese characteristics. In this emerging model, while the effect of neoliberalism has been tempered and that of the marketisation logic mediated, the role of the government has been administratively effective and financially supportive.About Us texts posted on the official websites of 35 top-tier Chinese universities at the turn of the century and in the year 2021. A high density of positive Attitude markers revealed the promotional nature of the texts and the seven major themes positively appraised in the texts during the past two decades, which reflects in part the discursive strategies employed by top-tier Chinese universities to attract prospective students and engage in competition in the higher education market.This study investigated the marketisation process of Chinese higher education by comparing the use of Attitude markers in the Quantitative and qualitative analysis of the texts also showed some mild changes in the use of the markers during the timeframe. The analysis of the Attitude markers uncovered that the strategic promotion of China’s top universities seems to be positioned in a constant paradox between marketisation paralleling that in the Western world and government guidance and support unique in China. The equilibrium between the two forces appears to have generated some motives for the progress made by the top-tier Chinese universities so far. The confrontation and interaction of the two are further compounded by the patriotism and traditional Chinese values most typically represented by Confucianism. As an idiosyncratic model, Chinese higher education, as well as the way it is promulgated, deserves more scholarly attention.This study can offer some implications for examining the discoursal construction for institutional promotional purposes. First, as demonstrated in this study, attitude markers constitute an integral part of the self-evaluation and self-promotion process. By focussing on the attitude dimension in given texts, the discursive strategies for constructing institutional images and university-reader relationships can be unveiled. Second, this study adopted a mixed method research design, where both detailed analysis of textual features and statistical procedures were performed to explore the discursive strategies utilised by the universities. The integration of both research paradigms can be expected to yield a more holistic understanding of the working mechanism where linguistic features constitute, and at the same time are shaped by, the social reality, in this case the Chinese higher education. One possible option for future research in this line of inquiry might be an empirical investigation into the similarities and differences between public and private universities in discursively forging their institutional images and establishing university-audience relationships.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.CX and JL conceived the idea and decided on the research design. LX collected and analysed the data. CX and LX drafted the manuscript. JL revised, proofread, and finalised the manuscript for submission. All authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Extensive practice and knowledge of the methods and effects of castration of male livestock and even humans has been widespread since ancient times, but only a few decades ago did neutering (including spaying) become a routine part of canine husbandry. In the US, the 6-month neuter became standard practice. Only recently, however, have some of the consequences of this major physiological alteration become evident. As the data-based study on 35 breeds reveals, there are major breed differences associated with effects of neutering, especially with early neutering, including increased risks of joint disorders and some cancers. The study of mixed-breed dogs reveals that the risk of joint disorders is increased in the large dogs. Implications of breed-specific and sex-specific effects for age of neutering have prompted the consideration of a new paradigm with regard to this practice. This involves focusing on each individual dog when deciding upon the appropriate age of neutering to avoid increasing the risk of a joint disorder or cancer above that inherent for the breed. For many breeds, particularly the smaller dogs, no effects were found for the age of neutering on joint disorders and the cancers followed. In these cases, the caregiver has a wide range of choice for neutering without increasing the dog's risk for these diseases. In the future, additional research may reveal more about other increased risks for age-related cognitive dysfunction or elevated levels of luteinizing hormone caused by gonad removal, and lead to revised guidelines. Having dogs as companions to humans dates back to prehistoric times: recent archeological studies of dental microwear of canine skeletons suggest that early protocols differed in their diets from wolves, were behaviorally and morphologically distinct, and already were companions to humans in the Paleolithic age, over 28,000 years ago .As farming by early humans came to include husbandry of cattle, horses, sheep, and goats, castration of male livestock animals became commonplace, and was practiced at least 8,000 years ago . GonadecCastrating male livestock, a relatively easy procedure, was commonly practiced in Egypt . AncientIn ancient Greece, most cattle, sheep, goats, and pigs were castrated, except for a few males needed for breeding . As wellIn Asia Minor, castration sometimes was incorporated into religious or sacrifice ceremonies. Around the world and throughout ages, people were making decisions on specifically which males to neuter and which method to use, while also choosing not to castrate certain individuals. Spaying females, or ovariohysterectomy, did not come into practice until much later, undoubtedly because of the greater surgical complexity and risks of infections. Even now, spaying females is not common in the husbandry of livestock or horses.The prevalent practice in major ancient cultures of castrating boys and men was a practice that produced eunuchs who had special roles in several ancient societies; awareness of the methods, purposes, and effects of human castration was inevitable. Studies of eunuchs in Late Antiquity and the court cultures of Byzantium, Islam, and China are available, outlining their important integrated roles in society; less is known about the worldwide slave trade in eunuchs in the Afro-Euro-Asian world , 11. AlsIn recent times, castrated cattle were selected to be the special display bulls of the Dinka people, as was done in ancient Egypt, and they also would be the ones selected for sacrifice . The DinIn the twentieth century, when many animals were living on farms, people still were well aware of options of neutering livestock animals. Pet dogs were typically living outside of homes, often in their dog houses. Gradually there was a movement toward having the dogs inside homes where they came to be considered members of the family . As closAlthough neutering is thought of as a means of rendering the male or female infertile by removing the source of sperm and ova, neutering also removes the primary source of testosterone (T) or estrogen (E) which acts on the basal brain hypothalamus and suprachiasmatic nucleus to facilitate some behaviors. People often believe that after neutering, males will no longer have an interest in mating and will be less aggressive toward other male dogs and people. However, these behaviors are mediated by a neural circuitry, and testosterone simply facilitates the neural circuitry. Even with little T available, the male-like behaviors can still be activated in many male dogs . In femaWhat is less well known is that production of the gonadal hormones is under the control of gonadotropic hormones produced by the pituitary, the luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In intact males, T levels are controlled by means of a feedback mechanism which maintains T at a consistent level. The T production acts on the hypothalamus which produces the gonadotropin releasing hormone (GnRH); if T levels are low, GnRH induces the pituitary to produce more LH until T levels return to normal. The rising LH in an intact male causes more T to be produced, and then LH drops. Following removal of the gonads in males, the production of LH is not suppressed by T working on the feedback loop. LH levels rise—and remain permanently high. A similar process occurs in females; removal of the ovaries results in low estrogen and this causes consistently high levels of LH.If there are physiological effects of high levels of LH, these could occur wherever there are receptors for LH. Until recently, little was known about this topic. The various LH receptor sites are now better understood, although what functions might be affected remain to be clarified . SeveralA perusal of the diseases associated with neutering in some breeds or sexes reveals that the diseases listed in The data-based findings on 35-breeds of dogs reveal wide differences among breeds with regard to increased risks of joint disorders and/or cancers . Given tKnowing about increased risks of disabling joint disorders with neutering, and avoiding the increased risks, is important not just in companion canines but also in working dogs used in police and military work, service dogs working in assisting people in wheelchairs, and dogs used in hunting, herding and agility trials. This emphasizes that the age of neutering should be chosen to avoid the vulnerable period which in some breeds is up to 2 years of age. Avoiding increasing the risk of cancer is important for every role that companion dogs have. There is a range of vulnerabilities to cancers associated with neutering, differing among various breeds, just as is true with joint disorders.The data also reveal that for most breeds, there is no increased risk of joint disorders or cancers associated with neutering. Thus, from the standpoint of these two disease categories there is no generally recommended age for neutering across all breeds where these diseases were not associated with age of neutering. The caregiver and/or veterinarian can make a personal choice after assessing their own context and situation without adversely increasing risks of these diseases. Veterinarians may wish to provide their own guidelines.For female dogs, the occurrence of mammary cancer is a concern. Some evident differences were found among the 35 breeds in the proportion of females left intact that developed mammary cancer; in some breeds, as many as 6 percent of intact female dogs had mammary cancer, while other breeds were at 0 percent . In one Two large studies have examined the relationship between neutering and lifespan. One was based on the Veterinary Medical Database of over 40,000 dogs, and another involved over 20,000 dogs from three separate veterinary hospitals in the US. Both studies found that neutered dogs lived significantly longer than those left intact , 27. TheAn extensive literature documents the relationship between a decline of gonadal hormones with aging in humans and the increased risk of Alzheimer's disease –31. ThesAlthough the authors do not necessarily recommend that caregivers completely avoid neutering their male or female dogs, in many cases this is the choice of the caregivers. This may or may not present problems to work out. For those with dogs of large body size the pursuit of females in estrus may present challenges. With large females, managing the proestrus bleeding may require doggy diapers and housing management. These are issues of less concern in small dogs.The behavior issues for intact males, such as roaming, urine marking in the house or aggression to another family dog or human family member, sometimes can be reduced by neutering. However, research has revealed that neutering may resolve these behaviors only in a minority of neutered dogs  . Recent For dogs used in service or assistance roles it may not be acceptable to have an intact dog because of the discipline required and the risk of an intact dog being attracted to, or attracting, dogs of the opposite sex. This is usually not an issue with police or military dogs, and intact German Shepherd males and females were found to be more trainable than neutered dogs for police dog narcotics olfaction performance and behavior; males performed better than females . For theIn general, the idea is to replace the long-standing practice of expecting that the puppy should be spayed or neutered before or at 6 months, or in the case of some females, before the first estrus. Others also raise questions about this across-the-board timing that has been favored the past few decades . InsteadThe above background is intended to provide the veterinarian or the caregiver of the puppy some information with which to decide on the best age for neutering on a case-by-case basis. Generally, one would focus on the breed and sex of the puppy. If the breed is one of the 35 breeds covered in our study , this isSince ancient times, humans have altered the hormonal status of animals and men with castration, making choices as to which individuals would have these procedures. Emphasizing the concept of personal choice, the idea inherent in the paradigm shift is to take each puppy as a separate case and consider all the relevant factors of the living context when deciding upon the age for neutering. As we learn more about some aspects of neutering such as age-related cognitive decline, there may be some additional considerations that may impact some breeds. The idea of a paradigm shift is that additional relevant information may come about and influence decisions made by puppy owners and their veterinarians.The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author/s.LH and BH: concept, draft, and edits shared equally. Both authors contributed to the article and approved the submitted version.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


During the development of a pharmaceutical formulation, a powerful tool is needed to extract the key points from the complicated process parameters and material attributes. Artificial neural networks (ANNs), a promising and more flexible modeling technique, can address real intricate questions in a high parallelism and distributed pattern in the manner of biological neural networks. The data mined and analyzing based on ANNs have the ability to replace hundreds of trial and error experiments. ANNs have been used for data analysis by pharmaceutics researchers since the 1990s and it has now become a research method in pharmaceutical science. This review focuses on the latest application progress of ANNs in the prediction, characterization and optimization of pharmaceutical formulation to provide a reference for the further interdisciplinary study of pharmaceutics and ANNs. The development of artificial intelligence (AI) undoubtedly has revolutionary significance since AI uses big data as a more effective human substitute. To be factual, AI is a field focused on intellectual tasks that are generally performed by humans . One subThe design of ANNs simulates the structure of the actual neural networks of the brain’s central nervous system to a certain extent , so ANNsANNs, a machine learning technology, have a similar learning pattern. Their architecture is changed according to the information provided during the learning phase, i.e., an ANN learns from past experiences and mistakes to achieve target values, in the manner of mammalian neurons . ConsequThe progress of artificial intelligence has brought a positive impact on pharmaceutical formulation development as well. The field of pharmaceutics has the characteristics of strong practicality and application comprehensiveness. It is a technology that studies the basic theory, prescription design (main drug and excipients), preparation process, quality control  and rational application of drug dosage forms. The research and development of drug formulations demand huge amounts of time and cost, which spurs us on to apply more innovative and interdisciplinary strategies and technologies. Integrating multiple research perspectives in different disciplines can produce more novel, efficient and systematic solutions. Hussain et al. put forward the idea of introducing artificial neural network in pharmaceutical science for the first time in 1991 ,18. CompSo far, many researchers have introduced the work of artificial neural networks into the modern pharmaceutical industry, especially for dealing with data and the vague relationships often faced in the process of research and development. This article introduces and summarizes the structures of ANN models and discusses the application advances of ANNs in the prediction, characterization and optimization of pharmaceutical formulation.The applicability of ANNs can be enhanced by combining distinct model structures and optimization algorithms. Hence, the learning performance of ANNs depends on the network structures, to a large extent . ArtificFor an image, the number of learning parameters is usually more than imagined. The CNN is the most commonly used supervised learning technique for images and has made many breakthroughs in image recognition and computer vision. Its typical application is to recognize handwritten characters, authentic color photographs, etc. The introduction of CNNs in many other fields should also be proposed, including object detection, scene labeling, visual saliency detection and pose estimation .Kohonen networks with an unsupervised learning mode are also called self-organizing map (SOM) neural networks. A SOM is composed of the input layer and competition layer (the output layer), and it uses competition learning to classify data. The basic concept is that each neuron in the competition layer competes to respond the input data and one neuron ultimately wins, which represents the classification of input patterns. Hence, SOMs are widely used in many information processing fields, such as speech recognition, classification, clustering, etc.RNNs are often recommended in voice recognition, language translation, natural language understanding and music synthesis, on account of it being suitable for handling time-series data. That means that the output of a neuron is not only related to the current input but is also related to the output of certain neurons at a previous time or several previous moments. Consequently, an RNN is a network with “memory” and that “memory” plays a pivotal role in the modeling of sequential data.On one hand, the MLP is the basis of ANN modeling and brings ANN universality. After understanding MLPs thoroughly, the whole framework of artificial neural networks will be easily connected. On the other hand, most ANN models introduced to pharmaceutical science are static neural networks, especially MLPs and GRNNs . Hence, starting from the MLP, the components and elements of the MLP and GRNN models are introduced in detail.As it is a typical feedforward ANN model, the multilayer perceptron contains an input layer, several hidden layers and an output layer . From a The universal approximation theorem has proven that, for an MLP, if the number of hidden layer neurons and the form of activation functions are not limited, then function ,26,27. Hfunction . Additiofunction .Another major concept is the backpropagation (BP) algorithm. It is a parameter update type of supervised learning, which is easy to use and has a high level of accuracy. Since the 1980s, the BP algorithm has been the core training method of ANNs . The traA concept that needs to be distinguished is that the BP algorithm refers to the method used to obtain the parameter gradient of the error of each layer in the network, and the GD method utilizes that gradient for learning. In detail, the gradient of the training error of each neuron parameter is calculated and moved forward, layer by layer, from the output layer. Then, according to the principle of gradient descent, the weights are adjusted and updated appropriately along the negative gradient direction. A multilayer feedforward neural network trained by the BP algorithm is called a BP neural network (BPNN) . The tra2 of the experimental value and predicted value were 0.9811 (ANN 1) and 0.9960 (ANN 2). In this study, MLPs can offer a guide to ibuprofen dissolution behavior effectively, based on the excipients and process parameters.Madzarevic et al.  optimizeA GRNN, an ANN using the radial basis function as the activation function, has a strong nonlinear mapping capacity and possesses additional advantages over RBFNNs in some respects . The strGeneralized regression neural networks have four layers: the input layer; the radial layer; the regression layer; and the output layer  22]. Th. Th22]. The difference between a GRNN and classic neural networks is that each weight of the GRNN is represented by the weight distribution, which allows more parameter combinations to be considered at the same time . Since tGRNNs are involved in many aspects of pharmaceutical science research ,35,36,37The application conditions for each type of ANN are different, so we are able to select the best one by testing several models. Behzadi et al.  comparedThe superiority of ANNs in handling noisy and nonlinear data allows it to be suitable for dealing with many formulation tasks ,40. WhenA variety of ANN functions can be generalized for classification, prediction and modeling . Based oANNs reflect an uncomplicated and dependable system that may tackle varied issues related to data analysis and behavior prediction . ReleaseOn one hand, selecting an appropriate formulation with various compositions to obtain the required release/dissolution behavior is a vastly laborious method of developing pharmaceutical products. Based on a great number of tests and the experiences of researchers, a familiar way is to carry out a series of physicochemical methods to obtain a better profile. On the other hand, especially for sustained release dosage forms, such as nanoparticles, microspheres and liposomes, the property of long-term release under conditions simulating body temperature in vitro is inconvenient for the necessary testing in each period. Although accelerated release tests in vitro are often used in labs to obtain the release behaviors of sustained release dosage forms, this strategy produces variant release profiles due to the different methods and may produce some undesirable results attributed to the severe conditions , for example, profile fragments are difficult to distinguish or are missing and release mechanisms are changed at various release phases.Therefore, tools used to assist the prediction of the release profiles of drugs that are high-speed and effective are very feasible. For instance, developing an ANN model that has the capability to predict drug release would reduce the workload greatly in the pre-prescription stage, and the adequacy of the predictions has been confirmed ,92,93,94In the case of drug release models, the input variables of the ANNs are the formulation characteristics, such as drug content, pH or composition, while the output neurons represent the dissolution performances of the formulation . Additioy et al.  compared−4 and 0.0179, respectively), it was shown that the ANN was more appropriate for the prediction of the release of riboflavin hydrogels and had great generality over the release behavior of the hydrogels.Obeid et al.  establisa et al.  used an In addition, some dynamic neural networks, such as Elman neural networks (ENNs), can be applied to predict drug dissolution profiles ,100,101.Petrović et al.  used botIn some studies, ANNs were proposed to optimize the ultrasonic release of APIs in preparations (such as liposomes and micelles) to maintain a constant therapeutic concentration at specific sites ,105. ForTherefore, it is feasible to determine drug release behavior using ANNs according to critical formulation factors, process parameters and API properties. To some degree, ANNs have shown better prediction capabilities compared to others. Furthermore, ANNs can not only accurately predict release properties from formulations but should also be highlighted as a data analysis tool for product quality control in the process of experimentation and production.Formulation development involves a vast number of variable factors, which makes it hard to select and design formulations with APIs of different natures and leads to the need for time-consuming trial and error experiments and complex statistical analysis. Where the critical material properties (CMAs) have been changed, the formulation may need to be adjusted accordingly. Indeed, this is an overloaded and laborious task. Amasya et al.  optimizeDue to their simplicity and easy implementation, some computer-based design of experiments (DoE) methods have been proposed. RSMs have a high sensitivity to independent variable composition and constitute one of the most widely used methods ,107,108.Koletti et al.  comparedConsidering CMAs and critical process parameters, Sansare et al.  used two2 in the emulsion; the concentration of Tween 85 in the emulsion; the concentration of Tween 85 in the receptor bath; the alginate flow rates; the emulsion flow rates; and the vibration frequency. Meanwhile, 39 pieces of data were used for training and 4 for testing the error. The optimized core-shell microparticles formulation by the MLP successfully obtained a narrow size distribution and uniform oil distribution in the particle core and it had the highest mechanical resistance to maintain the stability of the microparticles. The results demonstrated that the use of an ANN facilitated the understanding and optimization of complex manufacturing processes through reducing preliminary experiments.The microencapsulation of hydrophobic API with a hydrophilic matrix can improve the stability of a drug. As shown in In general, where the relationship between the independent and dependent variables is straightforward and of a lower dimensionality, response surface methodology and artificial neural networks can both present valuable outcomes ,108. HowDue to the complex nature of formulation development, ANNs have certain uses for modeling and analyzing the process of formulation selection and optimization, which can greatly lighten the workload and reduce the required time. By and large, ANNs have better prospects as valuable pre-formulation tools and they are also suitable for the optimization of some manufacturing process parameters ,122,123.In recent years, drug candidates have increased substantially and the number of clinical studies has doubled, resulting in high development and supervision costs. Therefore, ethical reasons and the purpose of more effective drug research and supervision promote the establishment of validated IVIVC. The primary aim of IVIVC is to predict drug plasma concentration–time profiles by relating the drug dissolution behavior in vitro  to the pharmacokinetic process in vivo ,125,126.G. Fatouros et al.  introducAt the same time, an ANN can also be applied to pharmacokinetic study ,132,133.Although PLS regression analysis indicates the simplest behavior, it is intelligible that IVIVC should not be limited to a linear relationship . An IVIVIn addition to the applications mentioned above, ANNs can be used to determine drug concentration ,80, predIn a recent study , an ANN 2 = 0.998). The results showed that a more general ANN was developed and could predict drug solubility for a range of hydrotropic systems. In another study, Chiappini et al. used an MLP to explore the relationship between fluorescent signals and etanercept concentration (the dependent variable of the output layer) [Damiati et al.  utilizedt layer) . The num2 = 0.90 for the testing data).For microparticle formulations, the problems of needle blockages and microparticle residue caused by the micron level size and a faster sedimentation rate during injection is still a challenge today. Sarmadi et al.  used an For implants, a cumulative drug concentration is hardly detected at the implantation site because with the extrinsic/intrinsic hydrodynamic conditions, some factors also play a vital role in drug release in addition to formulation factors. In one study, researchers used an ANN to clarify the physicodynamic phenomenon controlling the diffusion coefficient of a sodium dodecyl sulphate (SDS) gel and to find the greatest influential factor on the diffusivity from formulation variables (SDS loading dose and gel weight), intrinsic variables (flow rate and pH of vagina fluids) and extrinsic variables (application site) . The resAs an important property of a solid dosage form, porosity can indirectly characterize its form dissolution capability and rate. Khalid et al.  selectedAdditionally, 3D printing, an automated and digitalized technology, has exceptional advantages in many fields and is also used in the pharmaceutics industry to drive personalized medicine . With 3D10, D50 and D90) of wet granulation. The best model had two hidden layers containing two neurons per layer. The ANN produced a high correlation level between the experimental and predicted data for the size distribution (R2 > 0.99). Therefore, the developed model could offer accurate predictions for the twin-screw granulation process in this study. Damiati et al. [2 > 0.98 for all validation datasets), but the joint ANNs comprising two and three microfluidic devices can also predict the size of droplets and microparticles with a high degree of accuracy . In another research [The particle or granule size (distribution) is a critical quality attribute for drug dosage forms and even subtle differences may generate significant impacts. ANNs provide a useful tool for the prediction of particle/granule size ,165,166.research , an ANN Youshia et al.  predicteDrug stability is the main research content of quality control, which runs through the whole process of formulation research and development, such as the guidance of formulation design, the determination of storage conditions and validity term. Ajdarić et al.  used a fThe applications of ANNs in pharmaceutical science are broad, ranging from the design of dosage forms and characterization of formulation to the prediction of API release, the interpretation of analyzed data and the establishment of IVIVC, etc. Based on these findings, ANNs have been applied to evaluate the relationship between data and to guide the traditional experiments, which could minimize the number of required experiments. Hence, it has practical guidance and optimization significance for pharmaceutical sciences.Alan Turing introduced the concept of a machine that could think in 1950. “Artificial intelligence” as a term was proposed by John McCarthy in 1956, and AI began to take shape. In recent years, the popularity and practicability of AI have been developed tremendously. With their powerful functions, artificial neural networks (ANNs) and other artificial intelligence technologies have gradually penetrated into many aspects of pharmaceutical science. Among these, the ANN is the most frequently applied modeling technique.An artificial neural network is the integration and development of various methods, which has the characteristics of comprehensiveness and interdisciplinarity. Although current pharmaceutical development still mainly relies on the traditional trial and error methods of pharmaceutical researchers, we believe that the integrated experimental, theoretical and task-driven/data-driven AI methodology will vastly promote the betterment of pharmaceutical science. It is clear that the communication between ANNs and pharmaceutics can avoid repetitive work, such as greatly reducing the demand for animal research, predicting drug pharmacokinetic profiles, optimizing formulation designs, simplifying quality control, accelerating consistency evaluations, etc. Thus, the time and cost of fundamental research and product development can be reduced and the burden of drug evaluation and supervision could be decreased. Moreover, ANNs can generalize correlation tendencies using limited input data so as to carry out specific tasks quickly and efficiently. In short, ANNs have the possibility of becoming a key step in the research process of pharmaceutics and the associated data mining by ANNs could provide us with the capacity to predict outcomes and discover new relationships.The application of ANNs in pharmaceutical formulation emphasizes the importance of model selection and construction. In general, the successful establishment of ANN-based models is measured by its predictive ability, which is dependent on the selection of inputs, the time spent on training and the construction of the ANN architecture. Thus, before constructing an ANN model, some theoretical knowledge is required and the whole ANN framework needs to be considered seriously. Additionally, a universal learning method, optimization algorithm or network configuration are impossible for ANN application in pharmaceutics, and many attempts are required to choose an appropriate network structure when facing a new problem. The ultimate goal of introducing ANNs into pharmaceutical science is to solve problems in practical applications, so some factors, such as running time and running memory, should be considered to create ANN models of more practical value.For the specific applications of ANNs in pharmaceutical formulation, some traditional release models are not applicable in all cases and ANNs based on ML have good data processing capabilities, so ANNs are expected to be advantageous in the establishment of drug release models. We think that ANNs will be used in the study of drug release mechanisms in the human environment when more physicochemical and physiological factors are taken into consideration.We also hope that ANNs can promote drug industrialization and be applied to preparation production and analysis. In recent years, pharmaceutical companies have been encouraged to adopt continuous manufacturing technology, which demands product understanding, process understanding and process control based strongly on the concept of Quality by Design. The various superiorities of ANNs can contribute to the design of better formulations and the development of more robust manufacturing processes. At the same time, process analysis technology has also begun to be proposed to help confirm the product quality in real time. It is conceivable that, to some extent, it is feasible to predict the CQAs of products based on ANNs for quality assurance purposes. These worthy attempts are expected to have a real positive impact on the pharmaceutical industry.Although ANNs are expected to be a powerful tool in pharmaceutical research, it does not mean that some conventional experimental methods should be abandoned. The superiorities of conventional and emerging techniques should be integrated. In addition, it is feasible to extend the application of ANNs to the problems of the prediction, characterization and optimization of pharmaceutical formulation only on the basis of understanding the prescription ingredients, processing parameters and target properties. However, there are some limitations for ANN applications. For example, the amount of workable data in pharmaceutics is too small compared to the enormous amount of information available in natural language processing, image processing, etc. and open data sharing in the field of pharmaceutics is not common. Moreover, the accuracy of ANNs in drug and formulation analysis ought to be improved and new modeling tools also need to be raised. In the future, advances in optimization algorithms, model design and upstream disciplines will further improve the performance of ANNs, and then more potential applications of ANNs in pharmaceutics can be explored.At present, the ANNs commonly used in pharmaceutical science mainly includes the aforementioned multilayer perceptron, generalized regression neural network, etc. In the future, we should conduct more in-depth explorations of ANNs and continue to mine their value in our research field. It can also be said that we should use ML and AL technologies in the field of pharmaceutics more widely, so as to encourage the communication among these disciplines and create more innovation and breakthrough sparks.


Antarctica is contaminated by anthropogenic pollution. Due to the persistent low temperatures, the toxic impacts of pollution to the environment can be extensive. The severity of the effects varies according to the animal species, chemical type and level of exposure. Penguins are at major risk as they are the most prominent group of animals in Antarctica. This review highlights the background of penguins in Antarctica, the anthropogenic pollution and cases, as well as the toxic effects of diesel, heavy metals and microplastics toward penguins. A bibliometric analysis is also included.Antarctica is a relatively pristine continent that attracts scientists and tourists alike. However, the risk of environmental pollution in Antarctica is increasing with the increase in the number of visitors. Recently, there has been a surge in interest regarding diesel, heavy metals and microplastics pollution. Contamination from these pollutants poses risks to the environment and the health of organisms inhabiting the continent. Penguins are one of the most prominent and widely distributed animals in Antarctica and are at major risk due to pollution. Even on a small scale, the impacts of pollution toward penguin populations are extensive. This review discusses the background of penguins in Antarctica, the anthropogenic pollution and cases, as well as the impacts of diesel, heavy metals and microplastics toxicities on penguins. The trends of the literature for the emerging risks of these pollutants are also reviewed through a bibliometric approach and network mapping analysis. A sum of 27 articles are analyzed on the effects of varying pollutants on penguins in Antarctica from 2000 to 2020 using the VOSviewer bibliometric software, Microsoft Excel and Tableau Public. Research articles collected from the Scopus database are evaluated for the most applicable research themes according to the bibliometric indicators . Although bibliometric studies on the present research theme are not frequent, our results are sub-optimal due to the small number of search query matches from the Scopus database. As a result, our findings offer only a fragmentary comprehension of the topics in question. Nevertheless, this review provides valuable inputs regarding prospective research avenues for researchers to pursue in the future. Antarctica is the most isolated continent and is located at the southernmost part of the globe. It endures extreme cold temperatures and is a popular destination for scientists, explorers and visitors. The number of visitors to the continent from around the world showed an exponential increase from 35,000 visitors in 2012–2013 to 73,991 visitors in 2019–2020 .The extreme ambient temperatures of Antarctica negatively affect the natural recovery process. Under constant low temperatures, the natural remediation processes on the continent are slower compared to those in warmer regions or the tropics. Organic chemical pollutants such as oil-based products tend to be more persistent and harder to remediate in low-temperature regions due to the slower biodegradation rate ,6,7,8. HPygoscelis antarcticus) has been reduced by up to 77%—from 122,550 breeding pairs in 1971 down to 52,786 in January 2020 [Anthropogenic environmental pollution in Antarctica has led to a recognition of the potential negative impacts on the organisms living there. Penguins are of particular interest to researchers due to their utility as an indicator species for pollution and climate change. Unlike many other indigenous Antarctic vertebrates, penguins are widely distributed, non-cryptic and non-secretive animals that are also easy to observe . In addiary 2020 . It is sary 2020 . Due to ary 2020 . In addii.(diesel fuel) AND “penguins” AND (“Antarctic” OR “Antarctic”).ii. AND “penguins” AND (“Antarctic” OR “Antarctic”).iii.microplastic AND “penguins” AND (“Antarctic” OR “Antarctic”).The use of bibliometric indicators as a framework for assessing research performance is gaining more attention among students, academicians, professionals, scientific regulators and innovation managers. Bibliometrics offer a platform that can be effortlessly scaled up from the institute level to the global scale. The implementation of a bibliometric analysis at the onset of new research can confirm that important references from the literature are taken into account when developing the research. Furthermore, bibliometric analysis can reveal knowledge gaps, emphasizing the scientific scarcity and novelty of the suggested study . The goaThe search was limited to articles pertaining to only these keywords in order to avoid the recurrence of similar research in other forms of documents published. Based on the Scopus database query results, the total publications obtained were 3 documents on diesel, 22 articles related to heavy metals and 2 documents on microplastic research. To provide a comprehensive and in-depth overview, bibliometric software , interactive mapping software (Tableau Public) and an online chart illustrator (Datawrapper) as well as Microsoft Excel for data organization were used. These tools provide a visual mapping of the current trends and research development, focusing on the analysis of the link strength of networks based on the topographical distribution, chronological research trends, subject areas, source journals and network of keyword occurrences .Articles published on the effects of diesel, heavy metals and microplastics pollution towards penguins in Antarctica are illustrated in In this review article, the background of penguins in Antarctica, the anthropogenic pollution and cases as well as diesel, heavy metals and microplastics toxicities and their impacts on penguins, together with the bibliometric analysis, are discussed to highlight the research gaps that need to be addressed in the future.Pygoscelis adeliae), chinstrap (Pygoscelis antarcticus), gentoo (Pygoscelis papua) and emperor (Aptenodytes forsteri) penguins. According to Sander et al. [There are four main species of penguins that breed in Antarctica, which are the Adelie  and Marine Gas Oil (MGO) . The typThe SAB, MGO and IFO 180 diesel fuel contain varying hydrocarbon compositions that result in varying toxicity levels towards the ecosystem. When in contact with water, different hydrocarbon compositions of diesel fuel can result in different degrees of water-accommodated fraction (WAF) ability . The impPenguins are flightless seabirds that swim but often need to resurface to breathe, usually in a group and, thus, are at risk of harm due to diesel pollution. However, the severity of the effects depends on the species, amount of exposure and type of oil. In addition, penguins can accumulate polycyclic aromatic hydrocarbons (PAHs) through the food chain and during preening ,64. PengMeanwhile, Troisi et al.  detectedThe survival rates of oiled seabirds after being affected by oil spills depends on the degree of oiling, condition of plumage and duration of oil exposure . AccordiHeavy metals are a natural component in the environment but are also released through human activities. In Antarctica, high levels of heavy metals have been detected in biotic samples from terrestrial and aquatic organisms, as well as in abiotic samples such as soil, snow and atmosphere . The AntPrevious research suggested that heavy metals can be transported from other continents in the southern hemisphere to Antarctica via long-range atmospheric transport . In DeceIn addition, ornithogenic soils that result from the deposition of guano by marine birds can be a source of heavy metal pollution . Heavy mThe presence of high concentrations of heavy metals in Antarctica is an emerging issue . AlthougThere are many adverse effects of heavy metals on penguins. The toxicity of heavy metals can lead to severe damage of the penguin’s kidneys, liver and central nervous system . The bioThe effects of the accumulation of heavy metals in penguins can spread to the environment as well. Chu et al.  mentioneThroughout the globe, plastic pollution is ubiquitous. Evidence of plastic pollution also has been found across the most remote islands and beaches in Antarctica, which have never been visited before ,97,98. TAs a pollutant, microplastics have gained much notoriety in recent years as they are pervasive and persistent. Microplastics are defined as plastic particles that are smaller than 5 mm, either originally manufactured as such (primary source) or as the fragmentation products of larger plastics (secondary source) . MicroplIn Antarctica, the sources of plastic pollution are fishing activities, tourism and research stations . RecentlMicroplastics can be ingested via direct ingestion or indirect ingestion. For direct plastic debris ingestion, penguins are not strongly impacted as they target live prey and do not pay attention to the floating plastic . When thEuphausia superba, which was shown to ingest microplastics available in the sea. A recent laboratory study has proven that Antarctic krill are able to convert microplastic particles into nanoplastics through digestive fragmentation [P. adeliae, P. antarcticus and P. papua  and nylon were reportedly found among the penguins that breed along the coastline and feed on fish contaminated by microplastics.The keyword analysis formed three clusters based on the impacts of diesel on penguins in Antarctica, with 1701 links and a TLS of 1723 B. The keAdelie, chinstrap, gentoo and emperor penguins are the main species of penguins that breed in Antarctica. Due to these three species being widely distributed in Antarctica, they are prone to exposure to environmental pollutants such as diesel, heavy metals and microplastics. The bibliometric output showed that 27 articles related to the toxicity of pollutants  were published and indexed in the Scopus database from the year 2000 to 2020. The topic of heavy metal toxicity was the most emerging research area regarding its risks among penguins. Several limitations contributed to the low number of articles retrieved since our search was limited to the Scopus database for the analysis. The use of other journal databases such as the Web of Science and Google Scholar might return a higher number of articles. Nevertheless, the low number of published articles on the topic of diesel and microplastics in comparison to heavy metal pollution indicates that they are relatively unexplored research topics for emerging contaminants in Antarctica that arise from growing human activities. With the adverse toxicity effects of pollution towards penguins, these pollutants should be monitored and their use restricted. Therefore, studies about the toxicity of pollutants toward penguins are highly encouraged in order to preserve the delicate ecosystem balance in Antarctica.


Virtual reality (VR) and augmented reality (AR) have been proposed as novel methods to enhance cardio-pulmonary resuscitation (CPR) performance and increase engagement with CPR training. A scoping review was conducted to map the global evolution of these new approaches to CPR training, to assess their efficacy and determine future directions to meet gaps in current knowledge.A standardised five-stage scoping methodology was used to (1) identify the research question, (2) identify relevant studies, (3) select the studies, (4) chart the data and (5) summarise the findings. The Kirkpatrick model levels of evidence were used to chart and assess the efficacy of each intervention reported. A multi-pronged search term strategy was used to search the Web of Science, PubMed, CINAHL and EMBASE databases up to June 2020.A total of 42 articles were included in this review. The first relevant paper identified was published in 2009 and based on VR, from 2014 onwards there was a large increase in the volume of work being published regarding VR and AR uses in CPR training. This review reports Kirkpatrick level one to three evidence for the use of VR/AR–CPR. Inconsistencies in the specific language, keywords used and methodologies are highlighted.VR and AR technologies have shown great potential in the area of CPR, and there is continuing evidence of new novel applications and concepts. As VR/AR research into CPR reaches an inflection point, it is key to bring collaboration and consistency to the wider research community, to enable the growth of the area and ease of access to the wider medical community.The online version contains supplementary material available at 10.1186/s41077-021-00158-0. As a society, we currently face two significant problems with cardiopulmonary resuscitation (CPR). The first challenge centres on the quality of CPR performed during both out-of-hospital and in-hospital cardiac arrests. The second challenge lies in trying to engage the general public in CPR training. Effective CPR, with appropriate rate and depth of compressions, is vital for survival after cardiac arrest . Even wiVirtual reality (VR) has been proposed as potentially a powerful tool to enhance interaction and performance with manikin simulators . AugmentFor the purposes of this review, a training device had to provide an immersive experience to be classed as using virtual reality techniques. This is in agreement with Cant et al  who suggIdentify the research questionIdentify relevant studiesSelect the relevant studiesChart the dataSummarise and report the resultsA scoping review provides an initial insight into the content and breadth of developing heterogeneous data from diverse sources, prior to embarking on a systematic review on deeper established datasets , 13. ThiAs technologies including VR and AR continue to evolve, become less expensive and within the reach of researchers, the next step to potential applications in healthcare staff training comes in to sight. Globally, CPR training inside and outside of healthcare remains challenging and the evidence base for the application of VR and AR to CPR is beginning to grow. This growth has led to the proposal of the question ‘Can VR and/or AR improve CPR training?’ This in turn was developed further to focus upon the educational outcomes of basic life support training, using the Kirkpatrick model. The resultant research question of ‘Can VR and/or AR enhance learning, knowledge, skills or attitudes and if applied, was there an outcome concerning basic life support skills?’ This question was deemed broad enough to capture the current evidence base yet focused enough to indicate areas and direction for development of the literature further.In order to be included, the identified article had to be on the topic of life support training or performance and use of VR and/or AR as a teaching or feedback tool. No limitations on date or language were filtered for this search; English-language translations were procured for those written primarily in a different language.Articles were excluded if they were opinion pieces rather than unbiased reviews/studies, or did not use VR or AR methods for CPR. To be classed as virtual reality, the methodology had to include an immersive element.heart massage, artificial respiration, cardiopulmonary resuscitation, CPR, basic life support, heart stoppage, cardiac massage, heart massage, circulatory arrest. VR/AR terms included computer simulation, user-computer interface, virtual reality, augmented reality, computer simulation, computer assisted therapy ; study selection was confirmed by discussion and consensus by all the authors.Microsoft Excel 2013  was used to gather and display relevant information regarding each of the selected studies. The data-charting matrix was developed collaboratively by two authors (RM and TC) to determine which metrics and data to collect. This included subject of study , year of publication, geography of study, source of publication and impact factor (June 2020).The findings of the studies were assessed and reported based on the Kirkpatrick model, which is used to assess the efficacy of a specified training or intervention. The Kirkpatrick model can be used to evaluate how likely a training programme is to meet the needs of both the organisation and the trainees. It consists of four levels of evidence, assessing the reaction to training, skills learnt, behaviours and outcomes  Table 22.Table Studies were grouped according to the main method used/reported, that of VR or AR. Also, studies were stratified according to the Kirkpatrick model, and which level of evidence they supplied. The information collated in this literature search was reviewed to provide an overview of the existing knowledge and findings on this topic and identify gaps in the literature.The search resulted in 696 articles, of which 534 were excluded by title, and 71 were excluded on review of the abstract. An additional 49 studies were identified as duplicates and removed. Forty-two articles were included in this review  . The folPublications were identified from twelve different countries  evaluated the acceptance of the VREM (VR enhanced manikin) prototype, 85% of participants stated the VR experience was interesting and believed it could be very useful for healthcare training . Howevern = 51) had real-time feedback, via a holographic overlay of blood flow to vital organs, which was dependent on the quality of chest compressions being performed. Ninety-eight percent of the participants felt the visualizations were helpful for training, and 94% were willing to use the application in future CPR training [Wong et al (2018) surveyed 30 CPR instructors regarding their views on the use of VR in CPR training, reporting that VR was viewed by the instructors as having potential as a blended learning tool, for both novice and experienced healthcare professionals . Additiotraining .The second level of evidence in the Kirkpatrick model is evidence of participants learning new knowledge or skills. Multiple studies found that the use of VR and AR during CPR training led to an increased in the practical skills of CPR , 29, 32.Multiple studies , 37 wentThe highest level of evidence for a teaching/intervention using the Kirkpatrick model is an improvement in patient/cardiac arrest victim outcomes. The authors were not able to identify any published work on the influence of VR and AR training on patient outcomes.The aim of the study was to evaluate the development of research into the use of VR and AR to enhance CPR training and provision. The findings of this review indicate that this field of VR and AR CPR is both diverse and immature. There is also evidence that the field is growing and evolving with increasing publications and subsequent citations stimulating the growth. Geographically, there is a spread of activity across developed countries, as expected of a new field that is highly dependent on advances in technology. The high number of novel innovations and experimental studies presented indicate that the field is ripe for future research and development. The higher proportion of VR studies may be reflective of the state of current technology. It is expected that the number of research articles regarding the use of AR in CPR may increase in coming years.Several of the papers identified in this search were abstracts or details of innovative designs where the testing and results had not yet been published. This illustrates the growth and potential of this area of study, and reflects the development and incorporation of high fidelity manikins into emergency medicine . InnovatThe reviewed publications show a wide range of methodologies to assess the use of VR and AR. Overall, the studies illustrated that virtual technologies have been well received by instructors and those undergoing training . There is evidence to show that VR and AR technologies are particularly well received by the ‘technology natives’ of the younger generation , 32. By The high rigor of the science generated to date is reflected by the number of publications in high impact peer reviewed journals. This may also indicate that the novelty of VR is of interest as of this writing, to editors and readerships. Reviewing the authorship of the included publications, it can be seen that there are emerging research groups; where the same team have several publications in the field of VR/AR CPR based in both Italy and the USA.A lack of systematic reporting in terms of author keywords and lack of agreed-upon terminology was identified, which has led to a lack of cohesion in how work is categorised within repositories. Of note, it was apparent that there is a lack of consensus of what constitutes VR. Does virtual reality have to be a fully immersive experience, or can you class any situational-based learning using technology as VR? Kardong-edgren et al  discusseThese factors are likely to be limiting the visibility of VR and AR research, both internally within the simulation medicine community, and externally to the wider reader and clinician. Standardization of keywords and terminology has been used in simulation-based education  and woulCurrently, the field of AR/VR CPR research is likely to be at an inflection point in terms of publications as researchers within this topic span both experts in the digital innovation and resuscitation science and the technology continues to rapidly advance. However, to enable successful growth, it is vital to collaborate as a community of practice that mutually engages, shares resources and has joint accountability to shape this field of research and yield potential solutions to improve CPR quality and bystander CPR engagement. The International Network for Simulation-based Pediatric Research, Innovation & Education (INSPIRE network) is an example of where this has been achieved . It was The COVID-19 pandemic has led to a ‘new-normal’ that poses significant challenges on how to learn and maintain CPR skills. Gatherings of large groups are strongly discouraged and, in many organisations, not allowed at all, the majority learning has been converted to a socially distant or virtual format, and people are encouraged to keep a distance of 2-metres or more unless wearing suitable persona protective equipment. Further collaborative exploration of the value of VR and AR CPR may provide important insights on potential solutions to these challenges, and the changing landscape of CPR training.The analytical methodology chosen was not a systematic review, therefore the quality of the papers was not reviewed in-depth, and all were treated with equal weighting. Furthermore, our search terms selected may have missed other unique articles that could have otherwise met inclusion criteria, as the keywords for new technologies may still be evolving.From 2009 to 2019, the number of peer-reviewed articles and conference proceedings about VR and AR on CPR has grown slowly but now exponentially, with geographical diversity and high impact. Published work has demonstrated that VR and AR technologies met level one and two in the Kirkpatrick model to assess a teaching method. Early evidence suggests that trainees apply the knowledge they learn during VR and AR training sessions, but further evidence is needed, along with data regarding the outcome of the application of skills. Now is the time to look to the future, building on the work reviewed in this paper, and grasping the opportunity for new innovations to improve how healthcare professionals and the general public provide CPR.Additional file 1. The studies included in the scoping review.Additional file 2. The impact factor of the journals publishing VR AR CPR studies, in this review.