Low levels of physical activity and sedentary behaviour are a growing health problem globally. Physical inactivity is associated with increased risk of numerous ailments, cardiovascular disease and mortality. Our primary aim was to perform a feasibility study on how to incorporate physical activity among students and teachers in regular teaching activities. The second aim was to investigate how students and teachers perceived the differences between outdoor walking seminars and regular indoor seminars. By transforming an on-campus course into a blended course, we were able to conduct seminars outdoors in nearby nature while walking. These walking seminars were evaluated among 131 students and nine teachers leading the walking seminars. The responses to the student survey and teacher interviews indicate that discussions, sense of well-being and the general quality of the seminar improved, regardless of how physically active participants were the rest of the time. The study shows one way to increase physical activity with small means; in our case, a reorganization of how we prepared for the seminars which allowed for walking discussions. The ancient Greeks walked around outdoors while teaching and learning, both in Plato’s Academia and Aristotle’s Lyceum. Nowadays, however, a large part of the Western population has an indoor, sedentary manner of learning and working. Sedentary lifestyles and low levels of physical activity are two risk factors, increasingly highlighted in medical studies as a major public health problem, with increased risk for numerous ailments ,2,3. TheSedentary lifestyles are also common among students. Students have been reported to be sitting on average around 10 h per day, of which more than 6 h are when they are at their university . They arthe desk as a technology for learning is a contrivance aimed at controlling movement and attention in whichever setting it inhabits. As such, it points to the premise underlying education in many cultures: to learn we must be still’ [In lecture situations, there is an imbalance between teachers’ and students’ physical activity. Teachers are usually physically active during their lectures: they stand up, walk around while talking, point to different parts of presentations, write text on a board, etc. Students are at the same time normally physically passive, confined to their chairs during the same lecture. University settings provide students with a mainly sedentary design. Lectures are normally performed indoors with the professor standing and the students seated. This sedentary design has been taken for granted as the way learning and teaching occur: ‘e still’ .However, the design of the campus of the future focusses on shared space which is more intensively used and of better quality than at present . The camBlended learning, or hybrid courses, can improve the learning situation  but is nAs research results of the negative consequences of sedentary behaviour are becoming increasingly reliable, and the amount of sedentary behaviour on a population level is increasing, there is a need to explore alternative designs of the settings for teaching and learning . DiffereThere are reasons to be physically active also from a learning perspective. For example, ‘mind wandering’ or lack of attention is widespread in learning situations, where studies show that students can focus on average three to five minutes before they lose focus ,28,29. IHowever, one possible occasion where students could be physically active that is common in many educational settings is the seminar, as the purpose of many seminars is active discussion, and these seminars require neither technical aids for presentation nor intense note taking. Discussion seminars are difficult to lead productively  and prevAs an alternative, we have in this study investigated the feasibility of seminars in walking form outdoors. We specifically examined how students experienced these seminars compared to traditional classroom-based seminars with the same purpose, their experiences of communication during the seminars, the quality, and how they felt after the seminars.In the present study, we combined these successful elements: allowing the students to run a part of the seminars themselves, using virtual seminars as a preparation for the physical seminars, and dividing the students into small groups. With these elements in place, it became possible to run the physical seminars outdoors, while walking.The study object in this paper is the mandatory Programme Integrating course for the two 5-year engineering programmes in Media Technology and Computer Science at KTH . The course facilitates students’ perception of connections between courses in their programme and provides a foundation for routines for lifelong learning, through reflection about the conditions of learning as well as by thematic exercises in contemporary cross-boundary subject areas from both within and outside the academy. The readings required before each seminar are not complicated academic texts, but are rather meant to give a brief introduction to the topic (often in the form of one or two videos or a podcast), and provides a backdrop for self-reflection, which is the main purpose of the seminars. The course is spread out over three years of the program and is studied in parallel with other courses .A mandatory mentor-led seminar is given four times per academic year. Before the seminar, the students write a reflection document. Each document consists both of a theme section on a topic relevant to the education, which requires some type of reading and a reflection on this and the courses the students have followed since the last seminar. Examples of themes are ethics, study motivation and procrastination.Students prepare for the seminar by reading and commenting on each other’s reflection documents using a social annotation system , similarIn spring 2014, as an experiment, one of the mentors led one of his groups in an outdoor walking seminar. The oral evaluation after the seminar was positive, weather permitting. For the next round of seminars, all four groups by the same mentor had walking seminars, this time evaluated by an anonymous online questionnaire (response frequency 85%) on their experiences, comparing the walking seminar to the previous indoor seminars with the same group in the same course. The results were in favour of the walking seminars: the students reported improved communication, sense of wellbeing, and quality of the seminar, and 83% reported they would like more walking seminars .The seminar group gathers in the scheduled seminar room. A blind vote on whether the seminar should be held indoors or outdoors is performed. We have used both veto  and grouping based on the vote . This handles challenging weather/poor clothing and physical ability issues. At the time of the study, the students had during that academic year on average participated in two indoor seminars and two outdoor seminars. While walking, the teacher walked between the groups to listen in and make notes of particularly interesting discussions or arguments. About two to three times during the seminar, the teacher gathered the subgroups to briefly discuss these particularly interesting issues with the whole group.The questions in the survey in the pilot study were based on the feedback from the first group of students and a discussion with the course responsible teacher. For the present study, some of the questions were clarified (based on the comments and answers to the open-ended questions from students in the pilot study).During the following academic year, the idea of walking seminars was disseminated to more teachers, and in the spring of 2015 a refined version of the survey used in 2014 was distributed to 176 students enrolled in either the Computer Science or the Media Technology programme who were likely to have participated in at least one walking seminar. Besides the above-mentioned programme integrating courses, 10 students were invited from the Degree Project course for Computer Science students. The group sizes varied from 3–5 for the Degree course, 6–9 for the Media course and 11–15 for the Computer Science course. All seminar questions had a seven-item Likert scale. As the participants’ views on physical activity could vary depending on how physically active they were otherwise; for this study, we also included the Active-Q questionnaire  to invesThe nine interviewed teachers were teachers on at least one of the three courses mentioned above, or a Master’s level course in Philosophy of Science and Research Methodology for Computer Scientists. The interviews were structured and followed the same order as the questionnaire to the students. All interviews were recorded and transcribed. All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the Declaration of Helsinki. As this work was made as a part of the course development and no sensitive data was collected, it did not require further ethics approval. Of the 176 invited students, 131 answered (74.4%) the questionnaire on the walking seminars: 49 women and 82 men. The invited students were highly likely to have participated in a walking seminar. We know which groups of students participated, but we have not kept a record of students who temporarily switched to another group. A few of the invited students might not have participated in a walking seminar, and hence declined to answer.n>”, where n is 1–7. In summary, 78% answered that the discussions improved, 82% felt better after the seminar, 71% thought that the quality of the seminars had improved, 72% thought the possibilities to speak had improved. Very few students reported deterioration on any of these questions. The possibilities to hear what others had to say was on average unaffected, but with individual variations, as were the score for stay on topic and seriousness. In t-test p-value < 0.05) than the Media students . This effect might be explained by the larger group size for the CS students, making the effect of splitting up into smaller groups greater than for the media students.Comparing the Computer Science (CS) and the Media students, the CS students thought that their possibility to speak (Q4) improved significantly more . Would become angry if anyone tried to counteract more walking seminars.Some answers in the general comment field were as follows:Thumbs up for walking seminars! So nice to be active instead of sitting indoors!Walking seminars I think make more people discuss actively and it also become less stiff than in a seminar room. Besides it is healthy and fun to be outdoors and be active.In This mentioning of stiffness was confirmed in a separate question on whether the respondents found the walking seminar more relaxed; 91% said so, and 83% thought this was an improvement . There is a Pearson correlation of 0.7 between those two questions, significant at the 0.01 level.n = 115) had experienced a reshuffle of the subgroups. Of these, 4% thought this was a bad idea, 59% were positive and the rest neutral. When asked whether their university should offer walking seminars in more courses, 9% were negative, 71% positive and the rest neutral.When asked about the ideal size of the subgroups, 3% answered two people, 59% three people, and 39% answered four people. Some of the students  also answered Active-Q, a detailed questionnaire on physical activity in general . The totThere were no significant differences between registered genders on any of the seminar questions, but as expected there were differences in weight, height and 24-h energy expenditure.t-test p-value < 0.05) and also thought that the quality had improved more  compared to those who did not answer Active-Q. However, there is no other correlation between any of the seminar questions and the level of physical activity, or Body-Mass Index (BMI). That is, the students were approximately equally positive to the walking seminars regardless of their normal physical activity level and BMI.Those who answered Active-Q felt significantly better after the seminar :It worked well, and better, in this context <outdoors> probably because it defuses the stress of “now I am going to talk in front of the group”. When you walk and talk <...> it is less official.After the first <outdoor> seminar there was a male student that said this was really great, because he was very shy and on top of it all you must speak English and he thought he would not have said anything if it had been an indoor seminar in a classroom.Regarding the quality of the seminar (average 5.5):When it comes to the possibilities to speak their mind, the average score was 5. The two teachers who answered “somewhat worse” elaborated on that:The possibilities for me to speak my mind became somewhat worse, but that is really an improvement, because I have a tendency to talk too much during the seminars.It became easier for me to shut up!The possibilities to hear what others had to say was, on average, unaffected (4.1). However, just as with the possibilities to speak their mind, those who scored low did not consider this a disadvantage:As seminar leader, I cannot hear everything because I walk between the groups so I no longer know everything nor hear everything, but that is not important as it is more important that the students talk.The teachers thought the outdoor seminars were on a par with the indoor seminars when it came to staying on topic (3.9) and the seriousness (4.3). On the last account, one teacher explained: Better. For some students, the difference was huge.Two other observations from the interviews were that one teacher was really surprised by clear differences between the outdoor and indoor seminars, especially the positive qualitative differences. Another teacher proposed:Start with walking seminars in the beginning of program to enable all to get to know each other. We have performed an intervention study where students who were accustomed to traditional indoor seminars in a course were taken for a walk outdoors while performing a seminar. Surveying the students and interviewing the teachers, it was indicated that walking outdoors was in general perceived as an improvement on several accounts  and a slight deterioration on other accounts (staying on topic and seriousness). There are several limitations to this study. We have no objective measure of the results of these seminars, regardless of performing them indoors or outdoors. Nor do we know if it would be possible to perform similar outdoor seminars at other venues, as not all seminars are located next to a park as in the studied case. When it comes to the lack of objective measures, we make the assumption (as we did for the indoor seminars) that reflecting in your own words, discussing and arguing over a topic will lead to a deeper understanding. Regarding the location, it is obvious that noise pollution would be a serious impediment to hearing. The location we used was particularly suited for this purpose. However, it had its challenges: construction work at the university, park maintenance and outings by nearby schools and daycare facilities, but despite this, the students were positive. A 60-min indoor seminar with nine students will result, on average, in 7 min talking and 53 min listening for the students. A 60-min outdoor seminar with three sub-groups will result in 20 min talking and 40 min listening. This would be a tripling of the time talking but, in reality, when the discussions become intense in the sub-groups, much more will be said in the same time, which could explain the perception students report about being more active, more relaxed, and more open. The teachers’ role in these seminars is not teaching, but facilitating the discussion among the students; there is therefore no loss of “teaching time” for the teachers.We have introduced two new items at the same time: walking and being outdoors. We have no way of determining whether the positive effects came from either aspect of the combination. One could envision a study where two groups of students were outdoors, one walking and one sitting, to separate these effects. However, due to the health benefits associated with walking, that outdoor walking “produced the most novel and highest quality analogies”  and spenStudents are the office workers of the future and getting them to adapt to healthy ways of working during their education may have important public health advantages. We acknowledge that a huge body of work and knowledge are developed, e.g., within the domain of occupational health when it comes to how to address low levels of physical activity and sedentary work-postures in many settings, including contexts in schools and universities. Nevertheless, we are motivated to continue to explore the benefit of introducing walking outdoors as an alternative to redesigning classrooms. Previous research suggests that physical activity should be recognised as a legitimate activity at work, embedded within the university culture and endorsed using a top-down approach. Further, it is important to recognise physical activity as a legitimate health-promoting activity that is supported and encouraged during working hours . Based on this study and our experience of walking seminars, we argue that similar walking seminars could be used in other venues, as long as the goal of the seminar is the discussion and the deepened understanding of the discussed topics that follows (in contrast to information distribution). We have performed walking seminars with classes of up to 40 students at the same time. The ideal subgroup size seems to be three. Four is possible, but requires wide walking paths and strong voices. These seminars where themes are only discussed is one subgroup of all seminars. We therefore aim to include more types of seminars in the future, for example, seminars that do require notes to be taken and studies on requirements for those tools that must be added to those seminars. Also, the method described here would benefit from being tested in different venues, e.g., ordinary city parks.We have conducted a study of the possibility of conducting seminars while walking outdoors. This seminar form was made possible by using three previously identified elements for improving seminars: virtual seminars, small groups, and student involvement. The study shows that a sense of wellbeing can be achieved at the same time as the perceived quality of the seminars increased according to both the students and the teachers who led the seminars. Including outdoor walking in similar ways into ordinary workdays could have many possible benefits both for health and learning ,33,34,35


In this case report, we discuss the microsurgical management of a Spetzler-Martin grade 5 arteriovenous malformation (AVM) in a young boy who presented with a hemorrhagic episode and had a high calculated risk of rebleeding. We also outline the rationale for choosing the management option. Herein, we report a microsurgical management of a grade 5 arteriovenous malformation (AVM) in a young patient with a high predicted risk for rebleeding.As of now, many tenets exist regarding management of high grade cerebral arterio-venous malformation (AVM) management, making a rigid algorithm impossible to create. In experienced hands, microsurgery proved to have better results, compared to other treatmentsA 22-year-old Brahmin male from Khaireni, a remote village in Nepal, presented to our emergency room with a sudden-onset severe headaches and left-sided weakness over the last 24 hours. Physical examination revealed a Glasgow coma scale (GCS) of 14/15 with left-sided hemiparesis of 3+/5. Medical history was significant for a few episodes of paroxysmal headaches since last couple of years, which improved after taking 500 mg Paracetamol tablet on an ‘as needed’ basis. The frequency and intensity of the headache had worsened in the last few months. There was no significant family history. An urgent head computerized tomogram (CT) revealed evidence of a hyperdense lesion with peripheral stippled calcification on the right side in the territory of posterior limb of internal capsule and the retro-thalamic region . There wMultiple factors such as young age at presentation, the fact that the lesion had bled, presentation of patient with deficits associated with the lesion on the non-dominant side, presence of deep venous drainage and intra-nidal aneurysm led to a high calculated risk for rebleeding in the patient. We therefore decided on surgical management, despite the high grade of the lesion. After explanation of the risks of the treatment and role of adjuvants in the form of radiosurgery and embolisation the patient was taken up for microsurgical excision. Since the facility of radiosurgery is not available in the country, we only had the option of embolisation of the feeders prior to the surgical excision of the lesion. However, since the lesion had only low velocity feeders from the lenticulostriate vessels, we opted for direct microsurgical management. After a liberal craniotomy, basal cisterns were opened to gain access to the M1 branch of the MCA. We identified the major deep draining vein that was looping over the MCA bifurcation with the help of Indocyanine Green (ICG) venography. We placed a temporary clip on M1, then made a minimal corticostomy over the parietal cortex and continued our dissection over the gliotic tissue surrounding the AVM taking care of the minimal bleeders with the help of bipolar cauterization and avoiding inadvertent entry to the nidus. Lastly a clip was applied to the draining vein after completely dissecting the AVM nidus. The lesion was finally excised . CompletTH post-operative day after removal of sutures. Patient came for follow-up 2 weeks later walking on his own with left upper limb weakness of grade 3+/5. The Nimodipine was tapered off in the subsequent three weeks. The patient was advised to continue Na Valproate 300 mg orally three times a day for at least a year. Post operative angiography revealed complete excision of the AVM with no remaining feeders  and Nimodipine (60 mg 4 hourly via nasogastric tube) for seizure and vasospasm prophylaxis, respectively. Repeat head CT scan the following morning revealed no cavity hematoma or any evidence of vasospasm . Patientfeeders . The pat3. Studies have verified that the risk of rebleeding under these circumstances is as high as 34.4% compared to just 0.9% per year in patients without these risk factors5. Another important factor to be considered while calculating the risk of rebleeding is the presence of concurrent aneurysm within the AVM (6.93% with aneurysm Vs 3.99% without aneurysm)3.Bleeding within the AVM is considered a significant predictor of rebleeding. Other important factors moderating risk of rebleeding include deep venous drainage6, mostly attributable to hemorrhage. A minority of only 5% to 15% of such deficits are related to factors such as coronary steal phenomenon and venous hypertension9.Up to 40% of cases with AVM manifest neurological deficits10. Multivariate studies have shown this grading system to reliably predict permanent major morbidity or mortality at the following levels: Grade I (4%), Grade II (10%), Grade III (18%), Grade IV (31%), and Grade V (37%)11. This data has been further validated prospectively, and this grading system remains the most widely used among neurosurgeons and neurointerventionalists12.The Spetzler-Martin Scale is used to estimate the risk of surgical resection of an AVM with higher grades being associated with greater surgical morbidity and mortalityet al. reported the management of 73 grade 4 and 5 lesions and found the annual hemorrhage rate for untreated lesions to be only 1.5% versus 10.4% for partially treated lesions13. Grade IV or V lesions are only treated in circumstances of progressive neurological deterioration from hemorrhage, vascular steal, or seizure as seen in our case, which had a high risk of rebleeding because of presentation at young age with hemorrhagic episode, large size of the nidus, deep venous drainage pattern and associated aneurysm within the AVM.Han14 which parallels the natural history of the lesion after bleeding. However there is a risk of inadvertent radiation injury to the adjacent eloquent brain area15 and also a risk of symptomatic radiation necrosis in around 9% of cases16.There is time-lag of about two years following radiosurgery for complete obliteration of the nidus in the lesion. The risk of hemorrhage in this time period is around 4.8% per year17. One study has shown that the deep venous drainage, higher grade of the lesions and the periprocedural hemorrhage are predictors of post procedural complications following the embolisation treatment17.The main indication for other embolisation options in such a high grade of AVM is in order to downgrade the lesion and to minimise the intraoperative blood loss so as to make the lesion amenable for microsurgical excision, which bears an acceptable complication rate of around just 6.5%3. Partial embolisation of the high grade lesions are only justified in few circumstances, such as in vascular steal phenomenon or an AVM with associated aneurysm18.In our case there were only few feeders from the lenticulostriate branches from MCA: not ideal for embolization. Partial embolisation of the lesion will not reduce the risk of hemorrhage to zeroIn a few selected cases who have a high calculated risk of rebleeding, microsurgical excision remains a therapeutic option even for a high grade AVM especially in centers with limited resources for intervention and radiosurgery. However, all the patients should be well counseled about the available alternative mode of intervention and the associated risks. The management plan in each patient should be tailored addressing factors such as age of the patient, mode of presentation, grade of the lesion, treatment modalities and expertise availability etc.Written, informed consent was sought and attained from the father of the patient as per medical protocol in Nepal. This is a very successful case of surgical removal of high grade AVM which is not ideal for embolism. The experiences of decision making and surgical strategy are both beneficial to the readers.I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. I have seen the revised manuscript. I still see that the AVM appears overgraded as the size and eloquence appear doubtful, in absence of measurements.I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. This is an interesting paper but I do not agree that it was grade 5 AVM. The size is probably over 6cm, and deep drainage can also be confirmed, but it is unclear whether this AVM is located in an eloquent area or not.  I think the authors should answer this question before the article is indexed.I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. Grading appears faulty as size of nidus, eloquence and drainage are suspicious on single images. more images might have been helpful. The AVM at best appears to be grade 3.As such, it would be a routine microsurgical excision of an AVMIt is a well written case report and the discussion is precise. Main points for not approving this article are:I have read this submission. I believe that I have an appropriate level of expertise to state that I do not consider it to be of an acceptable scientific standard, for reasons outlined above. How did the authors measure the size of AVM. How did they distinguish hematoma from AVM?  Was the AVM alone really above 6 cm in diameter? The authors should show the image such as T2-weighted images of MRI or enhanced CT clearly indicating the size of AVM.Was the AVM really located in the eloquent area? The authors should show the location of nidus clearly. I think not nidus but only hematoma was located in the insult.Magnification of  figures 3 and figures 4 was too high. The authors should show angiograms of  A-P view and lateral view with less magnification.Why didn’t the authors perform preoperative embolization? I think it would be helpful in cases of high-grade AVMs. The authors reported a case of S-M grade 5 AVM successfully treated by microsurgical resection. I have some questions about as below.I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above.


The increase of hepatocyte lincRNA-p21 was associated with the loss of miR-30, which can inhibit TGF-β signaling by targeting KLF11. We revealed that lincRNA-p21 modulated miR-30 availability by acting as a competing endogenous RNA (ceRNA). The physiological significance of this interaction is highlighted by the feedback loop, in which lincRNA-p21 works as a downstream effector of the TGF-β signaling to strengthen TGF-β signaling and mediate its role in promoting liver fibrosis by interacting with miR-30. In vivo results showed that knockdown of hepatocyte lincRNA-p21 greatly reduced CCl4-induced liver fibrosis and inflammation, whereas ectopic expression of miR-30 in hepatocyte exhibited the similar results. Mechanistic studies further revealed that inhibition of miR-30 impaired the effects of lincRNA-p21 on liver fibrosis. Additionally, lincRNA-p21 promoted hepatocyte apoptosis in vitro and in vivo, whereas the proliferation rate of hepatocyte was suppressed by lincRNA-p21. The pleiotropic roles of hepatocyte lincRNA-p21 suggest that it may represent an unknown paradigm in liver fibrosis and serve as a potential target for therapy.Hepatocyte death, as well as the following inflammatory and fibrogenic signaling cascades, is the key trigger of liver fibrosis. Here, we isolated hepatocytes from CCl Following continued liver injury, quiescent hepatic stellate cells (HSCs) are exposed to apoptotic hepatocytes, inflammatory and profibrogenic factors, and transdifferentiate into myofibroblasts that synthesize large amounts of ECM proteins3. Despite the fact that HSCs play a pivotal role in hepatic fibrogenesis, hepatocytes are the dominant cell type residing in the liver and actively orchestrate the profibrogenic responses. In different animal models, as well as various liver diseases, development of liver fibrosis is associated with significant hepatocyte injury. Increased hepatocyte death promotes inflammatory cell recruitment, and subsequently triggers activation of inflammatory and fibrogenic signaling cascades4. There is ample evidence that apoptotic hepatocytes promote the secretion of pro-inflammatory and profibrogenic cytokines and trigger HSC activation6. Hepatocyte-specific deletion of Bcl-xl, Mcl-1 or TAK1 leads to selective increase of hepatocyte apoptosis and triggers liver fibrosis, thus providing a direct link between hepatocyte apoptosis and fibrogenesis9. Among the profibrogenic cytokines released by hepatocyte, TGF-β plays pleiotropic roles in the progression of liver fibrosis. Enhanced TGF-β signaling has been implicated during hepatic fibrosis in different animal models and human patients10. In hepatocyte, TGF-β signaling promotes cell damage, profibrogenic and inflammatory cytokine production, leads to cellular apoptosis and growth inhibition, and thus contributes to hepatic fibrogenesis12.Hepatic fibrosis occurs during most chronic liver diseases and is characterized by the excessive production of extracellular matrix (ECM)14. So far, the deregulations of lncRNA have been shown in various disease states. Kinds of lncRNAs are involved in liver regeneration, neoplasia and other liver diseases17. However, the involvement of lncRNA in liver fibrogenesis, especially the deregulation of lncRNA in hepatocyte upon liver injury, remains elusive. Here, we isolated hepatocytes from carbon tetrachloride (CCl4)-induced fibrotic liver and found that hepatocyte lincRNA-p21 (long intervening noncoding RNA-p21) significantly increased during liver fibrosis. LincRNA-p21 was initially identified as a transcriptional target of p53, and was characterized to mediate p53-dependent apoptosis but not cell cycle arrest in doxorubicin-treated mouse embryo fibroblasts19. However, there are conflicting reports on the role of lincRNA-p21 in apoptosis22.Long noncoding RNAs (lncRNAs) are defined as greater than 200 nt and unable to be translated into proteins. Accumulating data show that lncRNAs are involved in regulating gene expression through various mechanisms and participate in the regulation of a variety of cellular events24. LncRNA transcripts can regulate microRNA activity by acting as either competitive endogenous RNAs (ceRNA) or as microRNA sponges, thereby alleviating the inhibitory effect of microRNAs on their respective mRNA targets27. In the present study, we find that hepatocyte lincRNA-p21 can function as a ceRNA by binding miR-30, and therefore participating in the regulation of TGF-β signaling and liver fibrosis. Moreover, our results reveal that lincRNA-p21 contributes to promoting hepatocyte apoptosis and suppressing hepatocyte growth in the fibrotic liver. Knockdown of hepatocyte lincRNA-p21 in vivo blunted CCl4-induced hepatocyte apoptosis and therefore reduced the infiltration of inflammatory cells and the secretion of pro-inflammatory and profibrogenic cytokines in the CCl4-induced fibrotic liver.The MicroRNA (miRNA) profiling of fibrotic liver has identified a panel of deregulated miRNAs that contributes to liver fibrogenesis4-induced fibrotic liver and 5 oil-treated sham liver. Total RNA were prepared and used to conduct transcriptome RNA sequencing (RNA-seq). Basing on an absolute fold change cutoff value of 1 in log2 scale, we identified 111 aberrantly expressed lncRNA transcripts (63 upregulated and 48 downregulated) in the hepatocytes from fibrotic liver compared with those from oil-treated liver . Among them, RNAhybrid analysis (http://bibiserv.techfak.uni-bielefeld.de/rnahybrid/) further revealed a healthy minimum free energy of hybridization between lincRNA-p21 and miR-30 family members  pulled down by biotinylated lincRNA-p21, but not by biotinylated lincRNAp21 mutant , were intravenously injected into CCl4-treated mice weekly during the liver fibrosis development. AdH-shlincp21 was injected in the tail vein two days before the first treatment of CCl4. In SCR-injected group, AdH-shlincp21 significantly inhibited liver fibrosis. However, in anti-miR-30 group, AdH-shlincp21 failed to exert the inhibitory effects , and found 3 conserved binding sites at −1520 bp, −944 bp and −530 bp upstream of lincRNA-p21 in mouse genome. The predicted murine lincRNA-p21 promoter includes the 1400 bp upstream and 200 bp downstream of the first exon34. To identify the cis-element responsible for TGF-β induction, we constructed a set of pGL3-Basic luciferase reporters carrying various genomic sequences spanning from −1,825 to + 115 (relative to transcription start site), and subjected them to luciferase assays. The construct encompassing −1825 to +115 bp had a higher promoter activity in response to TGF-β1  and the decrease of antiapoptotic Bcl-XL, and enhanced hepatocyte apoptosis -positive hepatocytes. However, knockdown of lincRNA-p21 blunted the increase of hepatocyte apoptosis . The percentage of apoptotic cells was determined by a FACScan flow cytometer .31. Briefly, mice were intraperitoneally injected with of 20% CCl4 solution in sterile mineral oil at a dose of 2.5 ml CCl4 per kilogram body weight twice per week for three or four weeks. The adenovirus was injected only one time via tail vein at two days before the first CCl4 injection (1 × 109 pfu/mouse).Animal protocols were reviewed and approved by the Animal Care and Use Committee of Nanjing University, and conformed to the Guidelines for the Care and Use of Laboratory Animals published by the National Institutes of Health. Five-week old male C57 mice (20 ± 2 g) were obtained from the Animal Center of Yangzhou University . Animals were maintained under pathogen-limited conditions and had free access to rodent chow and water. Mouse liver fibrosis was induced according to previously described mothed31 in Supplementary Materials and Methods.Histological examinations of liver were performed as described before260/A280 reading . Quantitative real-time PCR was performed as described in Supplementary Materials and Methods. Primers are listed in Supplementary Table Total RNA was extracted from the cells or liver tissues using TRIzol Reagent (Invitrogen) and checked for purity and concentration with ALincRNA-p21 probe was labelled with digoxigenin (DIG) using a DIG DNA Labelling Kit (Roche). Total RNA extracted from AML12 cells and run on a 1% denatured agarose gel, transferred to positively charged nylon membranes (Millipore) followed by cross-linking through UV irradiation. The membrane was then hybridized with (DIG)-labelled probe overnight. The detection was performed using a DIG luminescent detection kit (Roche) according to the manufacturer’s instructions.31. In brief, the cell lysates were separated by SDS-PAGE and then transferred onto PVDF membranes. After incubation with primary antibody, the membranes were washed with PBST and then probed with horseradish peroxidase-conjugated secondary antibody at room temperature. The immunoreactive bands were detected by fluorography using an enhanced chemiluminescence system .Western blot was performed as described beforeResults in this study are expressed as the means ± standard error of the mean (SEM). The data were analyzed for normal distribution. Differences between multiple groups were checked using one-way ANOVA with post-hoc Bonferroni correction. Differences between two groups were analyzed by a two-tailed unpaired Student’s t test. A value of P < 0.05 was considered statistically significant, and P < 0.01 indicated strongly significant difference.Other methods used in this study are described in the Supplementary Materials and Methods.Supplementary file


With normal Mg2+ intake, homeostasis is maintained primarily through the regulated reabsorption of Mg2+ by the thick ascending limb of Henle’s loop and distal convoluted tubule of the kidney. Inadequate reabsorption results in renal Mg2+ wasting, as evidenced by an inappropriately high fractional Mg2+ excretion. Familial renal Mg2+ wasting is suggestive of a genetic cause, and subsequent studies in these hypomagnesemic families have revealed over a dozen genes directly or indirectly involved in Mg2+ transport. Those can be classified into four groups: hypercalciuric hypomagnesemias , Gitelman-like hypomagnesemias , mitochondrial hypomagnesemias  and other hypomagnesemias . Although identification of these genes has not yet changed treatment, which remains Mg2+ supplementation, it has contributed enormously to our understanding of Mg2+ transport and renal function. In this review, we discuss general mechanisms and symptoms of genetic causes of hypomagnesemia as well as the specific molecular mechanisms and clinical phenotypes associated with each syndrome.Magnesium is essential to the proper functioning of numerous cellular processes. Magnesium ion (Mg Accordingly, hypomagnesemia is defined as a serum [Mg2+] < 0.70 mM (<1.7 mg/dL) and hypermagnesemia as a serum [Mg2+] > 1.1 mM (>2.5 mg/dL). A shortage of Mg2+ can have direct consequences, some well-established, others less clear, but it is also associated with several other diseases. Direct consequences or symptoms that might arise from hypomagnesemia are variable in severity and may correlate to the extent and duration of the Mg2+ shortage, ranging from leg cramps and tiredness to seizures, coma and eventually death  during pregnancy is a treatment for pre-eclampsia urine × [creatinine]plasma)/ (0.7 [Mg2+]plasma × [creatinine]urine)} × 100 %. The factor of 0.7 is included to adjust the total plasma Mg2+ concentration to the freely filtered fraction. A FEMg of >4 % in a hypomagnesemic patient is consistent with renal Mg2+ wasting, while a patient with a FEMg of <2 % will likely have an extra-renal origin of their hypomagnesemia [2+ wasting. First, a low glomerular filtration rate may result in a lower filtered load of Mg2+. If the absorptive capacity of the kidney for Mg2+ is sufficient to cope with this lower load, the result may be a normal or even low FEMg. By the same mechanism, severe  hypomagnesemia may result in a lower filtered load of Mg2+ and thus a normal or low FEMg. To account for these confounding factors, the serum Mg2+ levels of hypomagnesemic patients should be increased by means of intravenous Mg2+ supplementation before the FEMg is measured [The most important clinical diagnostic tool for differentiating hypomagnesemia of renal origin from intestinal hypomagnesemia is determination of the fractional excretion of magnesium (FEMg) , which cgnesemia . Howevermeasured .The genetic causes of hypomagnesemia are heterogeneous and comprise both recessive and dominant disorders Table . The loc2+ and Mg2+ reabsorption takes place via paracellular pathways in the TAL and is therefore strongly dependent on the lumen positive transepithelial potential difference. Consequently, disruption of this voltage difference or of the integrity of this paracellular pathway will impair both Ca2+ and Mg2+ transport . In twofference . Compensfference . This onfference ), as meefference , 15.CLDN16 (encoding claudin-16) and CLDN19 (encoding claudin-19) are the most frequent cause of hypercalciuric hypomagnesemia [2+ and Mg2+ reabsorption in the TAL (reviewed in [+) and volume loss [CLDN19 mutations will also exhibit ocular anomalies [Recessive mutations in gnesemia . These ciewed in ). Conseqnomalies . The rennomalies . The cauCASR) are associated with hypercalciuric hypocalcemia and occasionally with hypomagnesemia [2+ and Mg2+ sensor in the TAL and other tissues  and water can also occur [Gain-of-function mutations in the gene encoding the calcium sensing receptor CaSR . Gain-oiewed in ). Hyperciewed in ). MoreovCLCNKB, which encodes the chloride ion (Cl−) channel ClC-Kb, cause Bartter syndrome type III. ClC-Kb is expressed basolaterally in the TAL and DCT, providing a pathway for (Cl−) to exit the cell. Mutations in the channel therefore interfere with regulation of intracellular chloride levels and the function of NCC (thiazide-sensitive NaCl cotransporter) and NKCC (Na+-K+-Cl− cotransporter) . Patiennd water . The CLC+, K+ and/or Cl− in the DCT. Adequate transcellular Mg2+ reabsorption in the DCT is dependent on the apical membrane potential, which is lumen positive when compared to the cytoplasm . Therefsymptoms , althougsymptoms . Regardlsymptoms ). This osymptoms ). Lastlysymptoms –34, justsymptoms .SLC12A3, the gene encoding the Na+-Cl−-cotransporter (NCC) that is expressed on the apical membrane of the DCT [+/H+ exchanger)-mediated Na+ reabsorption in the DCT as a means to compensate for the NCC dysfunction.With an estimated prevalence of 1:40 000 , Gitelma the DCT  (reviewe the DCT ). Sympto the DCT . Affecte the DCT , 37. In  the DCT . AdditioBSND gene, is expressed in the ascending thin limb, TAL, DCT and inner ear as a subunit of the ClC-Kb and ClC-Ka Cl− channels . Coiewed in , 26). Moiewed in . Long-laiewed in  and that+ channel Kir4.1 encoded by KCNJ10 [+ channel that conducts outward K+ currents, thus recycling the K+ imported by the Na+-K+-ATPase. To aid in diagnosis, magnetic resonance imaging of the brain might show subtle changes, especially in the dentate nuclei of the cerebellum [This syndrome, characterized by epilepsy, ataxia, sensorineural deafness and tubulopathy (referred to as EAST syndrome), is a rare recessive genetic disease affecting the Ky KCNJ10 . This pry KCNJ10 , 42). Inrebellum . Patientrebellum , it is drebellum .FXYD2 mutation. The FXYD2 gene encodes the γ-subunit of the Na+-K+-ATPase [+-K+-ATPase [Only three families, all Belgian or Dutch, putatively descendants from a common founder , have be+-ATPase . The spe+-ATPase . Virtual+-ATPase .HNF1B gene are associated with a multi-system disorder and considered to be the most common genetic cause of congenital anomalies of the kidney and urinary tract (CAKUT) . Th defects . Mutatio defects , thus giHNF1B mutations are the most common cause of genetic hypomagnesemia for pediatric nephrologists. The current view is that HNF1B dysfunction leads to inadequate transcription of the FXYD2 splice-isoform FXYD2a, which encodes the γa-subunit of the Na+-K+-ATPase [HNF1B have been properly excluded.Hypomagnesemia is also one of these symptoms, occurring in up to 50 % of affected children  and some+-ATPase . The dia+-ATPase . If a paPCBD1 had long been identified to be responsible for transient neonatal hyperphenylalaninemia and primapterinuria (HPABH4D) [PCBD1 mutations [PCBD1 mutations) if screening for mutations of PAH  is negative after a positive result for the Guthrie test.Recessive mutations in HPABH4D) , but no utations , 54. ThiFXYD2 transcription, causing hypomagnesemia. It should be noted, however, that the CAKUT phenotype often observed in HNF1B patients is not seen in PCBD1-disease due to a different expression pattern of these two proteins. Lastly, hypokalemia and hypocalciuria have not been reported in these patients. Still, it is placed here with the Gitelman-like hypomagnesemias based on the pathophysiological mechanism.The neonatal phenotype can be explained by the failure of PCBD1 to fulfil its role as an enzyme in the metabolism of aromatic acids. The complications appearing later in life are explained by the additional role of PCBD1 as a dimerization factor for HNF1A and HNF1B, regulating their transcriptional activity (reviewed in ). This i2+ homeostasis: is it the ATP that is necessary to drive the Na+-K+-ATPase and to activate CNNM2 [2+-signaling be key here?The mitochondrial hypomagnesemias, of which the pathophysiological mechanism is still unexplained, have a highly variable presentation. Their phenotype depends both on the nature of the mutation and the fraction of mitochondria affected in each tissue (reviewed in ). Some ote CNNM2 ? Or coulSARS2 [Ile gene MT-TI causing a syndrome with hypertension, hypercholesterolemia and hypomagnesemia [POLG1 and the mitochondrial Pearson’s syndrome [2+ concentrations is not regular clinical practice, it would be interesting to investigate the genuine frequency of hypomagnesemia in patients with mitochondrial disease.Impaired mitochondrial function might be associated with hypomagnesemia much more frequently than is currently realized. At least three distinct mitochondrial syndromes are accompanied by hypomagnesemia: (1) deletions in the mitochondrial genome as seen in Kearns–Sayre syndrome  (2) receSARS2  and (3) gnesemia . An addisyndrome , 64). SiTRPM6, which encodes the DCT-specific apical Mg2+ transporter TRPM6, resulting in an isolated hypomagnesemia (i.e. no other symptoms except secondary to the hypomagnesemia). Others, such as mutations in EGF and EGFR affect the activity and expression of this channel [FAM111A is the only gene in this group of which the pathophysiological mechanism underlying the hypomagnesemia has received no attention at all.The remaining disorders associated with hypomagnesemia are classified in this review as “other hypomagnesemias’” due to their heterogenic nature. One of these is caused by mutations in 2+ channel, TRPM6, cause the most profound genetic hypomagnesemia [2+ concentration as low as 0.2 mM or even lower, as low as immeasurable levels, is not uncommon in these patients [2+ resorption in the colon and DCT, thereby inhibiting uptake and stimulating wasting of Mg2+, causing significant hypomagnesemia [Mutations in the gene for the DCT- and colon-specific apical Mggnesemia , 66. A mpatients . Consequpatients . A defecgnesemia . The secgnesemia .CNNM2 is most highly expressed in the TAL, DCT and brain [CNNM2 mutations [2+ transporter itself, it is now thought to fulfill the role of intracellular Mg2+ sensor by undergoing a conformational change upon binding of Mg-ATP [2+ transport, however, remains unclear, as is the precise basis of the neurological symptoms.nd brain , 70, whiutations . Althougf Mg-ATP . How thiEGF) has been associated with a recessive form of hypomagnesemia with an additional neurological phenotype  [2+ transport [One mutation in the epidermal growth factor gene (ability) . The onlability) . Subsequransport . The intEGF mutations and cetuximab (an EGFR inhibitor) both cause hypomagnesemia [EGFR have also been found to cause hypomagnesemia. Only one patient has been diagnosed to date with loss-of-function of the EGFR. This mutation resulted in severe symptoms comparable to those observed with full EGFR blockade, including skin rash, inflammation of the lungs and bowel and hypomagnesemia [Since gnesemia , it is ngnesemia .KCNA1 has been associated with hypomagnesemia [KCNA1 mutations known to date cause episodic ataxia type 1 without hypomagnesemia  in gnesemia , while aiewed in ). The KCel Kv1.1 , which iel Kv1.1  and reviel Kv1.1 ). In neuel Kv1.1 . Followiel Kv1.1 . HoweverFAM111A are associated with two distinct dominant diseases: a perinatally lethal disorder called gracile bone dysplasia (GLCEB) and Kenny–Caffey syndrome type 2 (KCS2) [TBCE [Mutations in 2 (KCS2) . To date2 (KCS2) –85. Othe2 (KCS2) ). FAM1112 (KCS2)  and show2 (KCS2) –89. Howe2) [TBCE , the cau2) [TBCE .2+ supplementation is the only treatment available for hypomagnesemia of genetic origin. In the acute situation of a (severely) symptomatically hypomagnesemic patient, intravenous Mg2+ supplementation can be very important. For adults, a dose of 8–12 g of MgSO4 (containing 0.8–1.2 g of Mg2+) in the first 24 h is recommended, followed by 4–6 g/day for 3 or 4 days [2+ supplementation of 3 × 120 mg/day is more convenient while being sufficiently effective [2+ supplementation is therefore recommended in many of the hypomagnesemias, including Gitelman syndrome, Bartter syndrome, EAST syndrome and those caused by TRPM6 mutations [2+ concentration often alleviates symptoms, such as seizures and secondary hypocalcemia, even though normal Mg2+ values are rarely reached [2+ supplementation. Paradoxically, higher doses of oral Mg2+ might even be detrimental because of the resulting diarrhea [2+ supplementation given since some preparations have a better bioavailability than others. For this reason, we recommend magnesium chloride or magnesium glycerophospate rather than magnesium oxide or magnesium sulfate for oral Mg2+ supplementation [Oral or intravenous Mgr 4 days . For theffective . Parenteutations , 31, 41. reached , 75. Fur+ channel ENaC or aldosterone blockers. However, care should be taken, especially in the young child, since this treatment will interfere with the distal compensatory salt reabsorption of the kidney [2+ deficiency. In both cases, treatment with anticonvulsants such as valproate or phenobarbital might be beneficial [Since hypokalemia is commonly associated with hypomagnesemia, especially in the Gitelman-like hypomagnesemias, one might consider treatment with the epithelial Nae kidney . Lastly,neficial .2+ homeostasis. Based on the combination of increased fractional renal Mg2+ excretion with familial occurrence and a variety of additional symptoms, it is possible to recognize cases with a genetic cause and differentiate between them to a certain extent . Additi complex . The pat complex . However the DCT  could al


The ability to record and stream neurosurgery is an unprecedented opportunity to further research, medical education, and quality improvement. Here, we appraise the ease of implementation of existing point-of-view devices when capturing and sharing procedures from the neurosurgical operating room and detail their potential utility in this context.Our neurosurgical team tested and critically evaluated features of the Google Glass and Panasonic HX-A500 cameras, including ergonomics, media quality, and media sharing in both the operating theater and the angiography suite.Existing devices boast several features that facilitate live recording and streaming of neurosurgical procedures. Given that their primary application is not intended for the surgical environment, we identified a number of concrete, yet improvable, limitations.The present study suggests that neurosurgical video capture and live streaming represents an opportunity to contribute to research, education, and quality improvement. Despite this promise, shortcomings render existing devices impractical for serious consideration. We describe the features that future recording platforms should possess to improve upon existing technology. The ability to record and stream neurosurgery is an unprecedented opportunity to further research, medical education, and quality improvement. Individual cases may often be performed using one of several strategies that, combined with continuous technological advances, means the operating room (OR) is in constant flux. Capturing and compiling video of these surgeries is a teaching tool that can prepare medical students, residents, and accomplished surgeons alike by providing knowledge and useful expectations of procedures, which together improve success and patient outcomes in neurosurgery. This concept is exemplified by online archives, such as The Neurosurgical Atlas, which provide high-quality video of neurosurgical procedures conducted by experienced surgeons .Modern OR video recording is generally accomplished by means of specialized equipment, such as in-light cameras or modified commercially available cameras. However, existing solutions often lack utility or are impractical by nature of their design. Cameras are often unable to replicate the surgeon’s perspective during surgery and consequently, the viewer is unable to visualize the procedure in the context of complete anatomy; this is especially true of neurosurgery where the surgeon must work in relatively small spaces that obscure most recording angles. The advent of point-of-view (POV) cameras, such as the Google Glass and GoPro Hero series, now permit the recording of high-definition video captured from the surgeon’s perspective –4.Google Glass is a unique POV experience because it can be operated in a hands-free manner to stream video content and communicate with remote individuals. Therefore, this device can be used to provide the surgeon’s perspective to a colleague for live consultation or education without compromising the sterile field. In 2013, the first live stream of surgery using Google Glass was performed, and this concept has since expanded to include virtually augmented surgery . In 2014These reports of surgical video streaming and capture using POV devices suggest that there is utility in their more widespread application into specialties, such as neurosurgery. The existence of video archives dedicated solely to the dissemination of knowledge reflects the desire and the need for neurosurgeons to expand and share their knowledge. The employment of POV cameras capable of streaming video while permitting communication is an opportunity to enrich the learning opportunities provided by previous recording technology. Despite this promise, modern POV cameras are not optimized for use in the OR. Consequently, video quality may not be optimal for capturing the level of detail required to appreciate neurosurgical anatomy. Furthermore, the device must be streamlined for use in the OR so as not to detract from the surgeon’s focus.Our neurosurgical team performed a market analysis of available recording solutions for the OR and selected those devices representing the most promising candidates. We chose the Google Glass on the basis of its popularity and precedent in surgical streaming  and the Our team tested the Panasonic HX-A500 during a Chiari decompression using 1,820 × 1,080/60 pixel resolution settings and during a VP shunt revision at 1,280 × 720/30 pixel resolution; both procedures were recorded under Berchtold Chromophare E558 lighting with a Luxtec headlamp also in use. We tested Google Glass during two procedures: an external carotid–internal carotid bypass performed under Berchtold Chromophare E558 lighting and a craniotomy for cavernous malformation with intraoperative angiogram performed under Berchtold Chromophare E650 BRITE halogen lighting. We critically evaluated features pertaining to ergonomics, in-context image quality, and privacy-sensitive media acquisition and sharing capacity in both the operating theater and the angiography suite. We herein refer to ergonomics as those features of a device that affect the comfort, efficiency, and safety of the neurosurgeon and patient during a procedure.Regarding ergonomics, the HX-A500 is compatible with loupes but is mounted laterally on the head and therefore does not align well with the surgeon’s natural gaze. The camera angle can be adjusted through 160° to mitigate this problem. However, when working in deeper tissue layers, it becomes difficult to fully appreciate the anatomy. The main unit of the HX-A500 was secured to the surgeon’s arm with the cord connecting to the camera running across the shoulder and up the neck. This was not a hindrance to mobility, but it did mean that our surgeon could not handle the device once in sterile gown. The battery captured ~144 min of footage during surgery. Given that many surgical procedures may last beyond this amount of time, a surgeon utilizing the HX-A500 must be selective with respect to what portion of a procedure to record. Given the inaccessibility of the main unit once gowned, the only means of camera control would be through the Panasonic smartphone application that enables remote control. However, micromanaging the camera’s function in this manner is undesirable as it represents a disruption to surgical workflow.The video resolution was excellent when recording with the HX-A500’s high-quality setting  and did not experience washout from halogen lighting save for short portions at the beginning and end of recordings. The device’s image stabilization aided in capturing smooth video that translated to a better appreciation for detail but was limited by a lack of zoom. Figure The HX-A500 is capable of microSD/HC memory card media storage of up to 32 GB. In practice, we found this to be ~2 h and 47 min of recording high-quality video and 8 h and 40 min of recording on the lower quality setting. The HX-A500 can stream media through the use of a Panasonic application for smartphones but is not capable of voice communication. Setting up and ultimately using the HX-A500’s streaming capabilities proved cumbersome and ultimately was not tested in the OR due to institutional privacy regulations surrounding Wi-Fi use.The Glass device excelled namely in two aspects: the fact that it is self-contained and that it can be controlled solely by the surgeon in a hands-free manner. These qualities ensure that the apparatus is not a distraction in the OR environment where the ability to focus is crucial. The heads-up-display of Glass proved to be an important complement to photography in the OR as it ensured optimal focus and positioning of the camera with minimal disruption to workflow. However, Glass was incompatible with loupes meaning that it could only be utilized for parts of the surgery. Our surgeon was able to hold the Glass device in place while wearing loupes by taping it to a surgical headlamp. This impractical solution was further complicated by the camera’s view, which is directed straight-ahead and therefore does not align with the surgeon’s natural gaze during procedures. To capture the surgical field, our surgeon was forced to look straight down so that the device was pointed in the correct direction.By default, Glass records 10-s clips of video, and to circumvent this limitation, the user must manually swipe the device to override the default clip length. To maintain sterility, our surgeon asked an assistant to perform the manual override each time a video recording commenced. Constant recording with Glass during a procedure led to frequent overheating and a battery life of ~45 min. This was without concurrent live streaming of video content, which would likely further shorten the battery life. Like the HX-A500, the limited battery life of Glass forces the surgeon to be selective with respect to what portions of a procedure are captured if no external power source is available. The hands-free control of Glass made micromanaging recording times less of a distraction. Should the surgeon choose to circumvent the battery life limitation by maintaining power through an external source, then cables must be routed behind the surgeon, which can pose a tripping hazard.Google Glass has a 5-MP camera, which is less than many new smartphones that feature an 8-MP camera. Footage that we captured during surgical procedures was comparable to that acquired by the average smartphone. The media also suffered from washout due to the halogen lighting. The Glass’ lack of native image stabilization also led to choppy video even when the surgeon was stationary. The Glass is also unable to zoom which, combined with other concerns over media quality renders the device suboptimal for use in procedures requiring appreciation of detailed neurosurgical anatomy. Figure The Glass’ ability to capture and share media in a hands-free manner during a procedure is an important opportunity for improving communication in and out of the OR. Our surgeon had no issue using hands-free gestures to initiate capture of a photo or video clip during a procedure. As mentioned, this functionality is limited by the need for a manual override of the default 10-s clip length. The surgeon may also choose to call individuals through audio alone to provide notifications or receive a consultation. We did not stream live video from the OR with Glass due to institutional privacy regulations surrounding Wi-Fi use.The present study suggests that neurosurgical video capture and live streaming through POV devices are applications through which improvements to medical education, quality improvement, and research, among other possibilities, may be improved. Despite this promise, a number of shortcomings render existing devices impractical for serious consideration. Concerns not unique to a particular device are described in the context of our evaluation categories: ergonomics, media quality, and media acquisition and sharing. Table Considering the amount of time neurosurgeons spend utilizing loupes, the inability for devices, such as Google Glass, to be worn simultaneously means that a significant portion of operations cannot be captured. The utility of existing cameras is also diminished by concerns for sterility; once gowned, a surgeon may not physically interact with a camera and in our experience, requires the aid of other OR staff for controlling basic functions. Google Glass partially mitigates this drawback by allowing the use of voice commands and head gestures, such as nods or winks, to control video recording. However, it is also reliant on the ability to swipe on the device for navigating menus. The Panasonic HX-A500 can be controlled by a remote control application used on a smart phone but does not permit head voice commands and head gestures. Battery life is a significant barrier to capturing video for significant amounts of time as it means that the surgeon is forced to be selective with respect to what portion of a surgery will be captured. When live streaming video, both the Google Glass and Panasonic HX-A500 battery life are consumed at an enhanced rate thus further constraining recording time. The fact that a surgeon must be prudent with battery life necessitates being able to control recording function, but this is made difficult by the aforementioned issue of sterility. The surgeon may opt to leave devices connected to an external power supply, but extra cords pose a tripping hazard. Furthermore, the need to micromanage any recording device is a distraction in the already hectic OR.We also found that neither the Panasonic HX-A500 nor the Google Glass capture the same level of image quality obtainable by in-light camera solutions designed for the OR. This limitation significantly impedes the utility of existing POV devices because neurosurgery requires the ability to appreciate the fine anatomical detail. These devices are also unable to capture neurosurgical procedures requiring microsurgery. The image quality of the Panasonic HX-A500 was better than that of Glass owing to its greater resolution and image stabilization capabilities, but without the ability to zoom, a surgeon cannot target specific areas of the surgical field for selective recording. Furthermore, even if the Panasonic HX-A500 was capable of zooming, the surgeon would not be able to control this function in a sterile fashion and would require remote assistance from an individual controlling the camera from a smartphone.The final limitation we found is that of streaming video and patient privacy. When streaming through Google Glass, the device must communicate with Google’s public servers to broadcast the signal, which is in violation of HIPAA’s standards for protecting wireless local area networks . PrivateDespite the reported shortcomings of commercially available devices for POV recording in the neurosurgical OR, we have identified clear, achievable specifications that any future platform should possess. In the context of neurosurgery, it is especially important that cameras are optimized for maximal ergonomics, image quality, and protection of patient privacy. An ergonomic recording platform should be self-contained and operable in a hands-free manner, much like the Google Glass. There are several reasons for this, including the issue of sterility, which could be addressed through the use of an aseptic, disposable housing. The camera should require minimal time and energy investment from the surgeon. To achieve this, improved battery life and memory become critical. POV cameras used in the OR must not require a surgeon to be selective with respect to recording due to limited battery life or memory capacity – a limitation of all devices.In this vein, future recording platforms must also be compatible with eyewear, loupes, and headlamps in such a manner that it captures the surgeon’s natural gaze without obstructing vision. The capacity for mounting the Panasonic HX-A500 to existing loupes meant that the device could be dynamically adjusted with relative ease to the surgeon’s gaze, as compared to the Glass. This is especially important given the relatively small area that a neurosurgeon must often work in – should a camera not be aligned with gaze then landmarks critical to appreciating the procedure will be missed. In addition to gaze alignment, the camera must also maintain focus on the field of view and should do so in a dynamic fashion that can account for natural movements of the surgeon’s head. We have not found dynamic gaze alignment to be a readily available feature of POV devices. The field of view should be adjustable so that either wide or narrow perspectives can be captured depending on the neurosurgeon’s needs. For the viewer, information, such as axis and angle, should be incorporated into video feed to provide orientation as the surgeon’s head moves. The relative size of structures could also be appreciated through a scale that adapts to the camera’s zoom. The wavelength response of the camera should also be optimized for function under the halogen lighting of the OR so as to avoid the media washout experienced by the Google Glass and Panasonic HX-A500.The final specification that any successful device will feature is the ability to maintain patient privacy while allowing media streaming and communication through secure networks. The ability to receive consultation or provide viewing for educational purposes during a neurosurgical procedure is a tremendous opportunity that must remain prudent to patient privacy. Access to neurosurgical knowledge should not be restricted on the basis of geographic location, and resources, such as The Neurosurgical Atlas, demonstrate that high-quality learning materials for highly specialized fields, such as neurosurgery, can be made ubiquitous through the internet. However, bridging individuals and their knowledge and experience through the use of live video streaming can be seen as a next step in leveling access to neurosurgical consultation and medical education.The present study is limited by the number of devices we tested. There are numerous alternative solutions available each with different technical specifications that may make them more suitable for certain OR contexts. Our study is also limited by its qualitative nature. Each camera was evaluated by our study’s own neurosurgeons. When assessing the quality of recorded media, we did not perform a blinded appraisal of the media quality and relied on our own qualitative assessment. Future studies should consider comparing more devices and blinding the device testers and those who appraise the media quality.In summary, we identify the strengths and weaknesses of a selection of commercially available POV cameras in the neurosurgical OR. We elaborate on how these aspects of existing devices can be incorporated or improved upon in future recording platforms to improve research, education, and quality in patient care.JP – paper concept development, manuscript preparation and writing, supplementary footage editing, device testing, and manuscript submission; SK – paper concept development and manuscript preparation and writing; BR and IK – paper concept development, manuscript preparation and writing, supplementary footage editing, and device testing; RS – paper concept development, manuscript preparation and writing, supplementary footage editing, device testing, and project sponsor.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.


We argue that the generalisation of Ward’s linkage method to incorporate Manhattan distances is theoretically sound and provide an example of where this method outperforms the method using Euclidean distances. As an application, we perform statistical analyses on languages using methods normally applied to biology and genetic classification. We aim to quantify differences in character traits between languages and use a statistical language signature based on relative bi-gram (sequence of two letters) frequencies to calculate a distance matrix between 32 Indo-European languages. We then use Ward’s method of hierarchical clustering to classify the languages, using the Euclidean distance and the Manhattan distance. Results obtained from using the different distance metrics are compared to show that the Ward’s algorithm characteristic of minimising intra-cluster variation and maximising inter-cluster variation is not violated when using the Manhattan metric.The claim that Ward’s linkage algorithm in hierarchical clustering is limited to use with Euclidean distances is investigated. In this paper, Ward’s clustering algorithm is generalised to use with  Whereas  mapped eThe probability of observing a certain character in a linguistic sequence is highly dependent on the previous characters in the sequence as well as the language under consideration . Based onαβ denote the number of times the bi-gram ‘αβ’ is observed in the document. The table consisting of the relative bi-gram frequencies is defined as matrix RF with cells:n is the number of characters in the document (including blank spaces)We let RF is size 65 × 65. In order to avoid complications when performing cluster analysis, we henceforth describe our data as a set of 32 observations, (for the 32 languages) where each observation is the SLS in vector form. Each observation is a vector of p = 65 × 65 = 4225 elements.Matrix R4225. investigR  su suConnectogether  define tnni(j) is defined as the jth nearest neighbour of item i, and xinni(j) is defined as below:M containing m rows and n columns with a clustering solution C1, C2, …Ck, the connectivity is defined as:If  desired .Based on these validation techniques, we compare clustering using Euclidean distances with clustering using Manhattan distances. Although the values for the Euclidean and Manhattan distances in l1 norm distance such as the Manhattan distance. Ward’s method is generalised to include Manhattan distances.This paper investigated the use of Manhattan distances with Ward’s clustering algorithm. An important component of this research was the generalisation of Ward’s method for use with a In the application Ward’s clustering algorithm is used to classify a set of Indo-European languages. The results from using Ward’s method with Euclidean distances was compared to the results from using Ward’s method with Manhattan distances. This classification in the form of hierarchical cluster analysis successfully reproduced the phylogenetic classification of the languages. Validation was not only based on comparing the two clusterings with a tree constructed based on the linguistic ancestry, but also on measures such as cluster compactness, separation and connectedness.The Manhattan distance method yielded the most. The Robinson-Foulds distance between the tree constructed as benchmark and the tree resulting from Ward’s method with the Manhattan distance was less than the distance from the benchmark tree to the tree using Euclidean distances. Using measures like the Dunn Index, Silhouette width and connectivity, it was also shown that intra-cluster distances were minimised and inter-cluster distances were maximised. In our situation, the use of an alternative objective function (in this case least absolute error) with Ward’s function produces more accurate results than Ward’s method with the Euclidean distance metric.The proposed methodology can not only be applied to other language families beyond Indo-European languages, but also to other languages within this family. Because many other Indo-European languages do not make use of the Latin alphabet, further research could be done on how to compare languages with different alphabets. This could be done by transliterating or using single units of sound from languages with different scripts and map these to their counterparts in the Latin alphabet.Another possibility for further research is the use of tri-gram frequencies to form the SLS. This would mean having a three-dimensional SLS. The Manhattan metric could still be used in this case, as well as Ward’s method of linkage within the hierarchical clustering process, making this adaptation a natural extension of this research.Ultimately, we established that Ward’s clustering algorithm can be used in conjunction with Manhattan distances, without the characteristic of minimising within-cluster variation and maximising between-cluster variation being violated, and that for this specific case it produced better results than using Euclidean distances.