The Surgery Unknotting Number of Legendrian Links

The surgery unknotting number of a Legendrian link is defined as the minimal number of particular oriented surgeries that are required to convert the link into a Legendrian unknot. Lower bounds for the surgery unknotting number are given in terms of classical invariants of the Legendrian link. The surgery unknotting number is calculated for every Legendrian link that is topologically a twist knot or a torus link and for every positive, Legendrian rational link. In addition, the surgery unknotting number is calculated for every Legendrian knot in the Legendrian knot atlas of Chongchitmate and Ng whose underlying smooth knot has crossing number 7 or less. In all these calculations, as long as the Legendrian link of $j$ components is not topologically a slice knot, its surgery unknotting number is equal to the sum of $(j-1)$ and twice the smooth 4-ball genus of the underlying smooth link.Comment: 26 pages, 27 figure

Slavery and jouissance: analysing complaints of suffering in UK and Australian nurses’ talk about their work

Nursing has a gendered and religious history, where ideas of duty and servitude are present and shape its professional identity. The profession also promotes idealised notions of relationships with patients and of professional autonomy both of which are, in practice, highly constrained or even impossible. This paper draws on psychoanalytic concepts in order to reconsider nursing’s professional identity. It does this by presenting an analysis of data from two focus group studies involving nurses in England and Australia held between 2010 and 2012. The studies gave rise to data where extremely negative talk about nursing work seemed to produce, or to be expressed with, a high degree of energy, and a particular kind of enjoyment. In our analysis we focus on the nurses’ apparent enjoyment derived from their expression of a position of powerlessness in which they describe themselves as ‘slaves’ or ‘martyrs’ in the healthcare system. We interpret this as jouissance and suggest that the positions of slave or martyr provide a possible response to what we argue is the impossibility of the nurse’s role. We argue that a remnant of a quasi-religious ethic within the profession makes it acceptable for nurses to talk about self-sacrifice and powerlessness as part of their working subjectivity. We further argue that this analysis offers a new consideration of the issue of power and professional identity in nursing that goes beyond seeing nurses as simply overpowered by, or engaged in a gendered power struggle with other professional groups. We suggest that powerlessness and victimhood hold particular attractions and advantages for nurses and are positions that are more available to nurses than to other occupational groups. This research shows how psychoanalytic theory can help produce new insights into the problems and complexity of nursing and extend existing study of the professions

Incidence and outcome of encapsulating peritoneal sclerosis

Background: Studies report variation in the incidence and outcomes of encapsulating peritoneal sclerosis (EPS). This study reports the incidence and outcome of EPS cases in a national cohort of peritoneal dialysis (PD) patients. Methods: The incident cohort of adult patients who started PD between 1 January 2000 and 31 December 2007 in Scotland (n = 1238) was identified from the Scottish Renal Registry. All renal units in Scotland identified potential EPS cases diagnosed from 1 January 2000 to 31 December 2014, by which point all patients had a minimum of 7 years follow-up from start of PD. Results: By 31 December 2014, 35 EPS cases were diagnosed in the 1238 patient cohort: an overall incidence of 2.8%. The incidence for subgroups with longer PD duration rises exponentially: 1.1% by 1 year, 3.4% by 3 years, 8.8% at 4 years, 9.4% at 5 years and 22.2% by 7 years. Outcomes are poor with mortality of 57.1% by 1 year after diagnosis. Survival analysis demonstrates an initial above-average survival in patients who later develop EPS, which plummets to well below average after EPS diagnosis. Conclusions: The incidence of EPS is reassuringly low provided PD exposure is not prolonged and this supports ongoing use of PD. However, continuing PD beyond 3 years results in an exponential rise in the risk of developing EPS and deciding whether this risk is acceptable should be made on an individual patient basis

EFFECTS OF USING AN IPAD APP WITH EMBEDDED MODELS TO TEACH SIGHT WORDS TO ELEMENTARY STUDENTS WITH DEVELOPMENTAL DISABILITIES

The purpose of the study was to examine the effectiveness of teaching sight words using an iPad app with embedded models to students with developmental disabilities. The experimental design used was multiple probe (conditions) across behaviors replicated across students. All sessions occurred in a one-to-one format. The results showed the iPad app with embedded models were effective in teaching sight words to students with developmental disabilities

The role of HER1-HER4 and EGFRvIII in hormone-refractory prostate cancer

<b>Purpose</b>: The role of the type I receptor tyrosine kinase (HER) family in progression of prostate cancer is controversial. Breast cancer studies show that these receptors should be investigated as a family. The current study investigates expression of HER1-HER4 and EGFRvIII in matched hormone-sensitive and hormone-refractory prostate tumors. <b>Experimental Design</b>: Immunohistochemical analysis was used to investigate protein expression of HER1-HER4, EGFRvIII, and phosphorylated Akt (pAkt) in matched hormone-sensitive and hormone-refractory prostate tumors. <b>Results</b>: Surprisingly, high HER2 membrane expression in hormone-sensitive tumors was associated with an increased time to biochemical relapse (<i>P</i> = 0.0003), and this translated into longer overall survival (<i>P</i> = 0.0021). Consistent with other studies, HER4 membrane expression in hormone-sensitive tumors was associated with longer time to biochemical relapse (<i>P</i> = 0.042), and EGFRvIII membrane expression was associated with shorter time to biochemical relapse (<i>P</i> = 0.015). An increase in pAkt expression was associated with reduced survival (<i>P</i> = 0.0098). Multivariate analysis showed that HER2 was an independent positive predictive marker of time to relapse in hormone-sensitive prostate tumors (<i>P</i> = 0.014). In contrast, high HER2 expression in hormone-refractory tumors was associated with decreased time to death from biochemical relapse (<i>P</i> = 0.039), and EGFRvIII nuclear expression was associated with decreased time to death from biochemical relapse and decreased overall survival (<i>P</i> = 0.02 and <i>P</i> = 0.005). <b>Conclusion</b>: These results suggest that the HER family may have multiple roles in prostate cancer, and that expression of the proteins alone is insufficient to predict the biological response that they may elicit

Engaging perioperative students in online learning: human factors

The aim of this article is to reflect on how a specific approach to teaching and learning – role-play and in particular the ‘radio play’ format – can overcome some of the alienation and barriers to student engagement that the necessity for online teaching can engender. The example used is a post-registration module in perioperative nursing delivered in a London University. Authors reflect on experiences of developing and implementing an activity designed to increase student engagement in an online session focussing on Human Factors in the perioperative setting. The aim of the session was to highlight the factors that potentially lead to clinical error in a way that engaged students and enabled them to relate learning to their own experiences. The challenge was how best to do this in an online setting. This article describes the use of an approach devised by AdvanceHE. Two student participants contribute their reflections to this article and focus on the extent to which the session facilitated a new understanding of the impact of human factors in a perioperative setting. These reflections suggest that the approach to the teaching employed was useful to participants and that it has promise as an online approach. The authors recommend evaluation of this approach

Mesenchymal stem cell response to topographically modified CoCrMo

Surface roughness on implant materials has been shown to be highly influential on the behavior of osteogenic cells. Four surface topographies were engineered on cobalt chromium molybdenum (CoCrMo) in order to examine this influence on human mesenchymal stem cells (MSC). These treatments were smooth polished (SMO), acid etched (AE) using HCl 7.4% and H2 SO4 76% followed by HNO3 30%, sand blasted, and acid etched using either 50 μm Al2 O3 (SLA50) or 250 μm Al2 O3 grit (SLA250). Characterization of the surfaces included energy dispersive X-ray analysis (EDX), contact angle, and surface roughness analysis. Human MSCs were cultured onto the four CoCrMo substrates and markers of cell attachment, retention, proliferation, cytotoxicity, and osteogenic differentiation were studied. Residual aluminum was observed on both SLA surfaces although this appeared to be more widely spread on SLA50, whilst SLA250 was shown to have the roughest topography with an Ra value greater than 1 μm. All substrates were shown to be largely non-cytotoxic although both SLA surfaces were shown to reduce cell attachment, whilst SLA50 also delayed cell proliferation. In contrast, SLA250 stimulated a good rate of proliferation resulting in the largest cell population by day 21. In addition, SLA250 stimulated enhanced cell retention, calcium deposition, and hydroxyapatite formation compared to SMO (p < 0.05). The enhanced response stimulated by SLA250 surface modification may prove advantageous for increasing the bioactivity of implants formed of CoCrMo. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2015

Positive allosteric modulators of the μ‐opioid receptor: a novel approach for future pain medications

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109803/1/bph12599.pd