Cosmetic crossings and Seifert matrices

We study cosmetic crossings in knots of genus one and obtain obstructions to such crossings in terms of knot invariants determined by Seifert matrices. In particular, we prove that for genus one knots the Alexander polynomial and the homology of the double cover branching over the knot provide obstructions to cosmetic crossings. As an application we prove the nugatory crossing conjecture for twisted Whitehead doubles of non-cable knots. We also verify the conjecture for several families of pretzel knots and all genus one knots with up to 12 crossings.Comment: 16 pages, 5 Figures. Minor revisions. This version will appear in Communications in Analysis and Geometry. This paper subsumes the results of arXiv:1107.203

Aortoiliac reconstructive surgery based upon the results of duplex scanning

Objective:to evaluate whether duplex scanning can replace angiography in patients operated for aortoiliac obstructive disease.Design:retrospective.Materials and methods:between January 1995 and October 1996, 44 patients underwent vascular surgery of the aortoiliac tract. The study population was divided into two groups; patients operated upon the results of duplex scanning only and patients who also underwent angiography prior to surgery. The additional value of angiography and the differences between both groups concerning unexpected peroperative findings, early postoperative failures and the need for additional radiological or surgical interventions in the first three postoperative months were studied.Results:Duplex scan group: 22 patients were operated upon the results of duplex scanning only. In two patients surgical strategy had to be changed. Early postoperative graft occlusion occurred in one case. A haemodynamically significant graft stenosis within 3 months of surgery occurred in one patient. Duplex/angiography group: 22 patients underwent both duplex scanning and angiography. Six patients underwent diagnostic angiography after failed duplex scanning. In 10 patients angiography was part of percutaneous transluminal angioplasty prior to surgery. In six patients angiograms were performed after successful duplex scanning. Angiography failed in two patients and added information in four of 16 patients. Unexpected findings at operation occurred in four patients. Graft stenosis within 3 months was detected in three patients.Conclusion:after successful duplex scanning information obtained by angiography has only a limited impact on therapeutic decision-making. In the majority of patients vascular reconstructive surgery of aortoiliac arteries can be planned based on duplex scanning only

Community? What do you mean? An investigation into how differing understandings of the term ‘community’ shapes care-leavers’ move to independence

We explored the ways in which a performance-led approach to community formation and personal development can inform care-leavers’ move to independence. We adopted a case study approach, working with two groups of participants: young people leaving care and their support workers in Devon County Council’s Children in Care team (DCCCCS). The project was co-designed and co-developed with participants from both groups and our colleagues from Exstream Theatre Company. In this action–research project all researchers acted as participant-observers. It had two key objectives: first, to better understand how the term ‘community’ shaped the processes that the participating young people engaged with, and second, to take a practice-led approach to explore if, and how, performance-based methods and principles could be used to support the participants as they left care. A number of findings challenged our early assumptions, in particular the complexity of working with people with unstable and unpredictable lives. By working with the young people and DCCCCS managers and support workers, we developed a new way of using the creation of a theatrical performance, a deeply-supportive, peer-enabled environment and a theatre company, to enable a space in which participants could reimagine both their sense of self and community. The development and implementation of this model raises further research questions relating to how new communities might be formed, as well as suggesting a number of uses that may inform the future development of the Connected Communities community engagement strategy

Cortisol increases Na+/K+-ATPase density in plasma membranes of gill chloride cells in the freshwater tilapia Oreochromis mossambicus

Contains fulltext : Wendelaar45.pdf ( ) (Open Access

Protective effect of aqueous extract of the rhizomes of Sansevieria liberica Gérôme and Labroy on carbon tetrachloride induced hepatotoxicity in rats

The ability of an aqueous extract of the rhizomes of Sansevieria liberica to protect against carbon tetrachloride induced liver injury was investigated in Wistar albino rats. The carbon tetrachloride was prepared 1:5 (v:v) in olive oil, and administered subcutaneously at 1 mL/kg body weight. The extract was administered to both normal and carbon tetrachloride treated rats at 100, 200 and 300 mg/kg. On gas chromatographic analysis of the extract, twenty nine known flavonoids were detected, consisting mainly of 31.94 % apigenin, 20.66 % quercetin, 11.28 % kaempferol, 5.99 % naringenin, 5.83 % (-)-epicatechin, 3.69 % biochanin, 3.58 % (+)-catechin, 2.72 % diadzein, 2.20 % ellagic acid, 2.04 % butein. Compared to test control, the treatment dose dependently produced significantly (P<0.05) lower alkaline phosphatase, aspartate transaminase and alanine transaminase activities. The plasma total bilirubin and total protein levels of the test animals were lower though not significantly. The hepatic histo-pathological studies showed that carbon tetrachloride caused fatty degeneration of hepato-cytes, which was inhibited by pre-treatment with the extract; thus, confirming the results of the biochemical studies. The results of this study indicated that treatment with the plant ex-tracts protects the liver against carbon tetrachloride induced hepatotoxicity. This supports the use of Sansevieria liberica in traditional health care for managing liver problems

Predictive model for functional consequences of oral cavity tumour

The prediction of functional consequences after treatment of large oral cavity tumours is mainly based on the size and location of the tumour. However, patient specific factors play an important role in the functional outcome, making the current predictions unreliable and subjective. An objective prediction is necessary for better patient oriented care, where the choice between surgery or chemo- and radiotherapy could be made according to more reliable measures. In this project, work is being performed to create a tool to obtain this objective prediction. The aim is to develop a virtual biomechanical patient-specific model of the oral cavity for virtual surgery. By adjusting the model, so as to mimic the performed surgery, an accurate preoperative assessment of the postoperative functional consequences can be made for each individual patient

The ERE of the "Red Rectangle" revisited

We present in this paper high signal-to-noise long-slit optical spectra of the Extended Red Emission (ERE) in the "Red Rectangle" (RR) nebula. These spectra, obtained at different positions in the nebula, reveal an extremely complex emission pattern on top of the broad ERE continuum. It is well known that three features converge at large distance from the central object, in wavelength and profile to the diffuse interstellar bands (DIBs) at 5797, 5849.8 and 6614 ang., (e.g. Sarre et al., 1995). In this paper we give a detailed inventory of all spectral subfeatures observed in the 5550--6850 ang. spectral range. Thanks to our high S/N spectra, we propose 5 new features in the RR that can be associated with DIBs. For the 5550--6200 ang. spectral range our slit position was on top of the NE spike of the X shaped nebula. A detailed description of the spatial profile-changes is given of the strongest features revealing that even far out in the nebula at 24 arcsec from the central star, there remains a small shift in wavelength of 1 respectively 2 ang between the ERE subfeatures and the DIB wavelengths of 5797.11 and 5849.78 ang.Comment: 8 pages, 9 figures accepted by Astronomy and Astrophysic

Value of risk scores in the decision to palliate patients withruptured abdominal aortic aneurysm

Background: The aim of this study was to develop a 48‐h mortality risk score, which included morphology data, for patients with ruptured abdominal aortic aneurysm presenting to an emergency department, and to assess its predictive accuracy and clinical effectiveness in triaging patients to immediate aneurysm repair, transfer or palliative care. Methods: Data from patients in the IMPROVE (Immediate Management of the Patient With Ruptured Aneurysm: Open Versus Endovascular Repair) randomized trial were used to develop the risk score. Variables considered included age, sex, haemodynamic markers and aortic morphology. Backwards selection was used to identify relevant predictors. Predictive performance was assessed using calibration plots and the C‐statistic. Validation of the newly developed and other previously published scores was conducted in four external populations. The net benefit of treating patients based on a risk threshold compared with treating none was quantified. Results: Data from 536 patients in the IMPROVE trial were included. The final variables retained were age, sex, haemoglobin level, serum creatinine level, systolic BP, aortic neck length and angle, and acute myocardial ischaemia. The discrimination of the score for 48‐h mortality in the IMPROVE data was reasonable (C‐statistic 0·710, 95 per cent c.i. 0·659 to 0·760), but varied in external populations (from 0·652 to 0·761). The new score outperformed other published risk scores in some, but not all, populations. An 8 (95 per cent c.i. 5 to 11) per cent improvement in the C‐statistic was estimated compared with using age alone. Conclusion: The assessed risk scores did not have sufficient accuracy to enable potentially life‐saving decisions to be made regarding intervention. Focus should therefore shift to offering repair to more patients and reducing non‐intervention rates, while respecting the wishes of the patient and family