77 research outputs found

    Techniques in image restoration and enhancement

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    Includes bibliographical references.Image processing in its broad sense pervades many areas but it is convenient to group it into three main sections, viz: image coding, usually for image transmission over telecommunication links; pattern recognition for detecting the presence of a particular distribution in an image which is generally corrupted to some extent by noise; and image restoration, which aims to recover a faithful reproduction of a perfect image which has been degraded, and image enhancement which attempts to present an image in a form which will convey most readily the desired information to the human brain and takes account of the characteristics of vision. It is the object of this thesis to investigate some of the techniques of image restoration and enhancement. There are many different media for implementing the various processes, but digital computation and coherent optics are prevalent

    Enantioselective Synthesis of Sealutomicin C

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    The sealutomicins are a family of anthraquinone antibiotics featuring an enediyne (sealutomicin A) or Bergman-cyclized aromatic ring (sealutomicins B–D). Herein we report the development of an enantioselective organocatalytic method for the synthesis of dihydroquinolines and the use of the developed method in the total synthesis of sealutomicin C which features a transannular cyclization of an aryllithium onto a γ-lactone as a second key step

    Certificates for CCS at reduced public cost: securing the UK's energy and climate future, Energy Bill 2015

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    This Paper concerns the Energy Bill, which starts its Committee stages in the Lords on Monday 7th September and Wednesday 9th September 2015. The Bill is mainly tasked to create the OGA (Oil and Gas Authority). In addition the Bill creates responsibilities for the OGA regarding Carbon Capture and Storage (CCS) licensing. Most importantly, the Bill raises the opportunity for a discussion of how the envisaged development of CCS will be paid for. At present, the funding model involves significant taxpayer support through the CCS competition and levy control framework on electricity. We make a simple proposal that would remove this burden of Government support, and spread the cost of CCS development and deployment across the entire fossil fuel sector through a Certificate scheme that would rely only on data already reported to Government and the OGA, thus minimising the costs of compliance.This Paper concerns the Energy Bill, which starts its Committee stages in the Lords on Monday 7th September and Wednesday 9th September 2015. The Bill is mainly tasked to create the OGA (Oil and Gas Authority). In addition the Bill creates responsibilities for the OGA regarding Carbon Capture and Storage (CCS) licensing. Most importantly, the Bill raises the opportunity for a discussion of how the envisaged development of CCS will be paid for. At present, the funding model involves significant taxpayer support through the CCS competition and levy control framework on electricity. We make a simple proposal that would remove this burden of Government support, and spread the cost of CCS development and deployment across the entire fossil fuel sector through a Certificate scheme that would rely only on data already reported to Government and the OGA, thus minimising the costs of compliance

    Consequentialism about Meaning in Life

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    Ambulance-delivered transdermal glyceryl trinitrate versus sham for ultra-acute stroke: rationale, design and protocol for the Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) trial (ISRCTN26986053)

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    Rationale: Vascular nitric oxide levels are low in acute stroke and donors such as glyceryl trinitrate have shown promise when administered very early after stroke. Potential mechanisms of action include augmentation of cerebral reperfusion, thrombolysis and thrombectomy, lowering blood pressure, and cytoprotection. Aim: To test the safety and efficacy of four days of transdermal glyceryl trinitrate (5 mg/day) versus sham in patients with ultra-acute presumed stroke who are recruited by paramedics prior to hospital presentation. Sample size estimates: The sample size of 850 patients will allow a shift in the modified Rankin Scale with odds ratio 0.70 (glyceryl trinitrate versus sham, ordinal logistic regression) to be detected with 90% power at 5% significance (two-sided). Design: The Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial-2 (RIGHT-2) is a multicentre UK prospective randomized sham-controlled outcome-blinded parallel-group trial in 850 patients with ultra-acute (4 h of onset) FAST-positive presumed stroke and systolic blood pressure 120 mmHg who present to the ambulance service following a 999 emergency call. Data collection is performed via a secure internet site with real-time data validation. Study outcomes: The primary outcome is the modified Rankin Scale measured centrally by telephone at 90 days and masked to treatment. Secondary outcomes include: blood pressure, impairment, recurrence, dysphagia, neuroimaging markers of the acute lesion including vessel patency, discharge disposition, length of stay, death, cognition, quality of life, and mood. Neuroimaging and serious adverse events are adjudicated blinded to treatment. Discussion: RIGHT-2 has recruited more than 500 participants from seven UK ambulance services. Status: Trial is ongoing. Funding: British Heart Foundation. Registration: ISRCTN26986053

    Human α2β1HI CD133+VE epithelial prostate stem cells express low levels of active androgen receptor

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    Stem cells are thought to be the cell of origin in malignant transformation in many tissues, but their role in human prostate carcinogenesis continues to be debated. One of the conflicts with this model is that cancer stem cells have been described to lack androgen receptor (AR) expression, which is of established importance in prostate cancer initiation and progression. We re-examined the expression patterns of AR within adult prostate epithelial differentiation using an optimised sensitive and specific approach examining transcript, protein and AR regulated gene expression. Highly enriched populations were isolated consisting of stem (α(2)β(1)(HI) CD133(+VE)), transiently amplifying (α(2)β(1)(HI) CD133(-VE)) and terminally differentiated (α(2)β(1)(LOW) CD133(-VE)) cells. AR transcript and protein expression was confirmed in α(2)β(1)(HI) CD133(+VE) and CD133(-VE) progenitor cells. Flow cytometry confirmed that median (±SD) fraction of cells expressing AR were 77% (±6%) in α(2)β(1)(HI) CD133(+VE) stem cells and 68% (±12%) in α(2)β(1)(HI) CD133(-VE) transiently amplifying cells. However, 3-fold lower levels of total AR protein expression (peak and median immunofluorescence) were present in α(2)β(1)(HI) CD133(+VE) stem cells compared with differentiated cells. This finding was confirmed with dual immunostaining of prostate sections for AR and CD133, which again demonstrated low levels of AR within basal CD133(+VE) cells. Activity of the AR was confirmed in prostate progenitor cells by the expression of low levels of the AR regulated genes PSA, KLK2 and TMPRSS2. The confirmation of AR expression in prostate progenitor cells allows integration of the cancer stem cell theory with the established models of prostate cancer initiation based on a functional AR. Further study of specific AR functions in prostate stem and differentiated cells may highlight novel mechanisms of prostate homeostasis and insights into tumourigenesis

    Zebrafish Infection: From Pathogenesis to Cell Biology

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    The study of host–pathogen interactions has illuminated fundamental research avenues in both infection and cell biology. Zebrafish (Danio rerio) larvae are genetically tractable, optically accessible, and present a fully functional innate immune system with macrophages and neutrophils that mimic their mammalian counterparts. A wide variety of pathogenic bacteria have been investigated using zebrafish models, providing unprecedented resolution of the cellular response to infection in vivo. In this review, we illustrate how zebrafish models have contributed to our understanding of cellular microbiology by providing an in vivo platform to study host–pathogen interactions from the single cell to whole animal level. We also highlight discoveries made from zebrafish infection that hold great promise for translation into novel therapies for humans

    Prehospital transdermal glyceryl trinitrate in patients with ultra-acute presumed stroke (RIGHT-2): an ambulance-based, randomised, sham-controlled, blinded, phase 3 trial

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    Background: High blood pressure is common in acute stroke and is a predictor of poor outcome; however, large trials of lowering blood pressure have given variable results, and the management of high blood pressure in ultra-acute stroke remains unclear. We investigated whether transdermal glyceryl trinitrate (GTN; also known as nitroglycerin), a nitric oxide donor, might improve outcome when administered very early after stroke onset. Methods: We did a multicentre, paramedic-delivered, ambulance-based, prospective, randomised, sham-controlled, blinded-endpoint, phase 3 trial in adults with presumed stroke within 4 h of onset, face-arm-speech-time score of 2 or 3, and systolic blood pressure 120 mm Hg or higher. Participants were randomly assigned (1:1) to receive transdermal GTN (5 mg once daily for 4 days; the GTN group) or a similar sham dressing (the sham group) in UK-based ambulances by paramedics, with treatment continued in hospital. Paramedics were unmasked to treatment, whereas participants were masked. The primary outcome was the 7-level modified Rankin Scale (mRS; a measure of functional outcome) at 90 days, assessed by central telephone follow-up with masking to treatment. Analysis was hierarchical, first in participants with a confirmed stroke or transient ischaemic attack (cohort 1), and then in all participants who were randomly assigned (intention to treat, cohort 2) according to the statistical analysis plan. This trial is registered with ISRCTN, number ISRCTN26986053. Findings: Between Oct 22, 2015, and May 23, 2018, 516 paramedics from eight UK ambulance services recruited 1149 participants (n=568 in the GTN group, n=581 in the sham group). The median time to randomisation was 71 min (IQR 45–116). 597 (52%) patients had ischaemic stroke, 145 (13%) had intracerebral haemorrhage, 109 (9%) had transient ischaemic attack, and 297 (26%) had a non-stroke mimic at the final diagnosis of the index event. In the GTN group, participants' systolic blood pressure was lowered by 5·8 mm Hg compared with the sham group (p<0·0001), and diastolic blood pressure was lowered by 2·6 mm Hg (p=0·0026) at hospital admission. We found no difference in mRS between the groups in participants with a final diagnosis of stroke or transient ischaemic stroke (cohort 1): 3 (IQR 2–5; n=420) in the GTN group versus 3 (2–5; n=408) in the sham group, adjusted common odds ratio for poor outcome 1·25 (95% CI 0·97–1·60; p=0·083); we also found no difference in mRS between all patients (cohort 2: 3 [2–5]; n=544, in the GTN group vs 3 [2–5]; n=558, in the sham group; 1·04 [0·84–1·29]; p=0·69). We found no difference in secondary outcomes, death (treatment-related deaths: 36 in the GTN group vs 23 in the sham group [p=0·091]), or serious adverse events (188 in the GTN group vs 170 in the sham group [p=0·16]) between treatment groups. Interpretation: Prehospital treatment with transdermal GTN does not seem to improve functional outcome in patients with presumed stroke. It is feasible for UK paramedics to obtain consent and treat patients with stroke in the ultra-acute prehospital setting

    Smoke, curtains and mirrors: the production of race through time and title registration

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    This article analyses the temporal effects of title registration and their relationship to race. It traces the move away from the retrospection of pre-registry common law conveyancing and toward the dynamic, future-oriented Torrens title registration system. The Torrens system, developed in early colonial Australia, enabled the production of ‘clean’, fresh titles that were independent of their predecessors. Through a process praised by legal commentators for ‘curing’ titles of their pasts, this system produces indefeasible titles behind its distinctive ‘curtain’ and ‘mirror’, which function similarly to magicians’ smoke and mirrors by blocking particular realities from view. In the case of title registries, those realities are particular histories of and relationships with land, which will not be protected by property law and are thus made precarious. Building on interdisciplinary work which theorises time as a social tool, I argue that Torrens title registration produces a temporal order which enables land market coordination by rendering some relationships with land temporary and making others indefeasible. This ordering of relationships with land in turn has consequences for the human subjects who have those relationships, cutting futures short for some and guaranteeing permanence to others. Engaging with Renisa Mawani and other critical race theorists, I argue that the categories produced by Torrens title registration systems materialise as race
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