670 research outputs found

    Changing Direction:The Irish Republican Movement’s Decision to End Abstention

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    From the beginning, the Irish Republican Movement (IRM) had upheld a commitment to abstaining from taking elected seats in what were viewed as illegitimate government institutions. This commitment, coupled with the use of armed conflict to achieve their stated goals, can be viewed as founding pillars to their strategy for ousting the British from Ireland. In 1986, the abstention policy was abandoned amidst a decades-long war with the British known as the Troubles. This thesis explores the following questions: why did the IRM end abstention during the Troubles and what role did this period of time have in that decision? It is concluded that this decision was the means to realign the IRM’s biographical narrative with the movement’s practices and therefore maintain its ontological security, or stable sense of self. A number of critical events during the Troubles brought this tension between identity and practice into stark contrast. It is argued this tension was alleviated by the ending of the abstention policy and participation in established political processes

    Flexible and stable optical parametric oscillator based laser system for coherent anti-Stokes Raman scattering microscopy

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    The characteristics of a stable and flexible laser system based on a synchronously pumped optical parametric oscillator (OPO) is presented. This OPO can offer very stable operation with both approximately 1 ps and approximately 300 fs outputs over a broad wavelength range, i.e., 920-1200 nm. Combining the pump tuning with the OPO tuning, a total Raman range of 1900-5500 cm(-1) is accessible. For maximum spectral sensitivity, the CARS microsope based on the ps laser system is presented in detail. The lateral resolution of the microscope is diffraction limited to be about 390 nm. Fast wavelength switching (sub-second) between two Raman vibrational frequencies, i.e., 2848 cm(-1) for C--H aliphatic vibrations and 3035 cm(-1) for C--H aromatic vibrations is presented as an example, although this also extends to other Raman frequencies. The possibility of obtaining a multimodal imaging system based on the fs laser system is also discussed

    Validation of the Human Ozone Challenge Model as a Tool for Assessing Anti-Inflammatory Drugs in Early Development

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    This study aimed to test the utility of the ozone challenge model for profiling novel compounds designed to reduce airway inflammation. The authors used a randomized, doubledummy, double-blind, placebo-controlled 3-period crossover design alternating single orally inhaled doses of fluticasone propionate (inhaled corticosteroids, 2mg), oral prednisolone (oral corticosteroids, 50mg), ormatched placebo. At a 2-week interval, 18 healthy ozone responders (>10% increase in sputum neutrophils) underwent a 3-hour ozone (250 ppb)/intermittent exercise challenge starting 1 hour after drug treatment. Airway inflammation was assessed at 2 hours (breath condensate) and 3 hours (induced sputum) after ozone challenge. Compared to placebo, pretreatment with inhaled corticosteroids or oral corticosteroids resulted in a significant reduction (mean [95% confidence interval]) of sputum neutrophils by 62% (35%, 77%) and 64% (39%, 79%) and of sputum supernatant myeloperoxidase by 55% (41%, 66%) and 42% (25%, 56%), respectively. The authors conclude that an optimized ozone challenge model (including ozone responders and ensuring adequate drug levels during exposure) may be useful for testing novel anti-inflammatory compounds in early development

    Nrf2 deficiency influences susceptibility to steroid resistance via HDAC2 reduction

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    Abnormal lung inflammation and oxidant burden are associated with a significant reduction in histone deacetylase 2 (HDAC2) abundance and steroid resistance. We hypothesized that Nrf2 regulates steroid sensitivity via HDAC2 in response to inflammation in mouse lung. Furthermore, HDAC2 deficiency leads to steroid resistance in attenuating lung inflammatory response, which may be due to oxidant/antioxidant imbalance. Loss of antioxidant transcription factor Nrf2 resulted in decreased HDAC2 in lung, and increased inflammatory lung response which was not reversed by steroid. Thus, steroid resistance or inability of steroids to control lung inflammatory response is dependent on Nrf2-HDAC2 axis. These findings have implications in steroid resistance, particularly during the conditions of oxidative stress when the lungs are more susceptible to inflammatory response, which is seen in patients with chronic obstructive pulmonary disease, asthma, rheumatoid arthritis, and inflammatory bowel disease

    People and climate: holocene sediment records of environmental change in Middle Egypt: fieldwork report and initial results

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    The aim of this project is to reveal more about the history of Lake Qarun through a multidisciplinary environmental study. This approach primarily concerns the examination of sediment records, but also includes collection of data from archaeological sites in the Faiyum. The sedimentary history of Lake Qarun will be compared with (i) independent palaeoclimate records for the East African Highlands and the eastern Mediterranean; (ii) local evidence (including Nile alluvial and palaeo-shoreline sequences and Holocene playa deposits); and (iii) the cultural history of the Faiyum. This report describes the fieldwork performed to obtain long sediment cores for palaeolimnological analysis and presents initial results from those cores. Results will be used to construct a Geographical Information System (GIS)

    Safety and feasibility of prostate stereotactic ablative radiotherapy using multi-modality imaging and flattening filter free

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    OBJECTIVE: To investigate feasibility and safety of stereotactic ablative radiotherapy in the management of prostate cancer while employing MR/CT fusion for delineation, fiducial marker seeds for positioning and Varian RapidArc with flattening filter free (FFF) delivery. METHODS: 41 patients were treated for low-intermediate risk prostate cancer with initial prostate-specific antigen of ≤20 ng ml−1, Gleason score 6–7. Patients had MR/CT fusion for delineation of prostate ±seminal vesicles. CT/MR fusion images were used for delineation and planned using flattening filter free modality. Verification on treatment was cone beam CT imaging with fiducial markers for matching. Patients had Radiation Therapy Oncology Group scoring for genitourinary and gastointestinal symptoms at baseline, week 4, 10 and 18. RESULTS: Clinically acceptable plans were achieved for all patients, all plans achieved the objective clinical target volume D99% ≥ 95%, and for planning target volume D95% ≥ 95%. Rectum dose constraints were met for 95.1% for V18 Gy ≤ 35%, 80% V28 Gy ≤ 10%. A total of 32 (78.0%) plans achieved all rectum dose constraints. Grade 1 acute genitourinary symptoms were 53.7% of patients at baseline, 90.2% [95% CI (76.8–97.3%)] (p = 0.0005) at treatment 5, falling to 78.0% (62.4–89.4%) at week 4, and 75.0% (58.8–87.3%) by week 10 and 52.5% (36.1–68.5%) (p = 1.00) at week 18. Acute gastrointestinal symptoms were 5% at baseline, 46.3% [95% CI (30.7–62.6%)] at treatment 5, week 4 43.9% [95% CI (28.5–60.3%)], week 10 25.0% (11.1–42.3%), and declined slightly by week 18 [–20.095% CI (12.7–41.2)] p = 0.039. Overall 75.6% (31/41) of patients experienced Grade 1–2 toxicity during or after treatment. CONCLUSION: This planning and delivery technique is feasible, safe and efficient. A homogeneous dose can be delivered to prostate with confidence, whilst limiting high dose to nearby structures. The use of this technology can be applied safely within further randomized study protocols

    Shell evolution of stable N = 50-56 Zr and Mo nuclei with respect to low-lying octupole excitations

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    For the N = 50-56 zirconium (Z = 40) and molybdenum (Z = 42) isotopes, the evolution of subshells is evaluated by extracting the effective single-particle energies from available particle-transfer data. The extracted systematic evolution of neutron subshells and the systematics of the excitation energy of the octupole phonons provide evidence for type-II shape coexistence in the Zr isotopes. Employing a simplistic approach, the relative effective single-particle energies are used to estimate whether the formation of low-lying octupole-isovector excitations is possible at the proposed energies. The results raise doubts about this assignment

    Effects of cleaning methods upon preservation of stable isotopes and trace elements in shells of Cyprideis torosa (Crustacea, Ostracoda): implications for palaeoenvironmental reconstruction

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    The trace element (Sr/Ca and Mg/Ca) and stable isotope (δ¹⁸O and δ¹³C) geochemistry of fossil ostracod valves provide valuable information, particularly in lacustrine settings, on palaeo-water composition and palaeotemperature. The removal of sedimentary and organic contamination prior to geochemical analysis is essential to avoid bias of the results. Previous stable isotope and trace element work on ostracod shells has, however, employed different treatments for the removal of contamination beyond simple ‘manual’ cleaning using a paint brush and methanol under a low-power binocular microscope. For isotopic work pre-treatments include chemical oxidation, vacuum roasting and plasma ashing, and for trace element work sonication, chemical oxidation and reductive cleaning. The impact of different treatments on the geochemical composition of the valve calcite has not been evaluated in full, and a universal protocol has not been established. Here, a systematic investigation of the cleaning methods is undertaken using specimens of the ubiquitous euryhaline species, Cyprideis torosa. Cleaning methods are evaluated by undertaking paired analyses on a single carapace (comprising two valves); in modern ostracods, whose valves are assumed to be unaltered, the two valves should have identical geochemical and isotopic composition. Hence, when one valve is subjected to the chosen treatment and the other to simple manual cleaning any difference in composition can confidently be assigned to the treatment method. We show that certain cleaning methods have the potential to cause alteration to the geochemical signal, particularly Mg/Ca and δ¹⁸O, and hence have implications for palaeoenvironmental reconstructions. For trace element determinations we recommend cleaning by sonication and for stable isotope analysis, oxidation by hydrogen peroxide. These methods remove contamination, yet do not significantly alter the geochemical signal

    Palaeoenvironmental and diagenetic reconstruction of a closed-lacustrine carbonate system - the challenging marginal setting of the Miocene Ries Crater Lake (Germany)

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    Chemostratigraphic studies on lacustrine sedimentary sequences provide essential insights on past cyclic climatic events, on their repetition and prediction through time. Diagenetic overprint of primary features often hinders the use of such studies for palaeoenvironmental reconstruction. Here the potential of integrated geochemical and petrographic methods is evaluated to record freshwater to saline oscillations within the ancient marginal lacustrine carbonates of the Miocene Ries Crater Lake (Germany). This area is critical because it represents the transition from shoreline to proximal domains of a hydrologically closed system, affected by recurrent emergent events, representing the boundaries of successive sedimentary cycles. Chemostratigraphy targets shifts related to subaerial exposure and/or climatic fluctuations. Methods combine facies changes with δ13C–δ18O chemostratigraphy from matrix carbonates across five closely spaced, temporally equivalent stratigraphic sections. Isotope composition of ostracod shells, gastropods and cements is provided for comparison. Cathodoluminescence and back‐scatter electron microscopy were performed to discriminate primary (syn‐)depositional, from secondary diagenetic features. Meteoric diagenesis is expressed by substantial early dissolution and dark blue luminescent sparry cements carrying negative δ13C and δ18O. Sedimentary cycles are not correlated by isotope chemostratigraphy. Both matrix δ13C and δ18O range from ca −7·5 to +4·0‰ and show clear positive covariance (R = 0·97) whose nature differs from that of previous basin‐oriented studies on the lake: negative values are here unconnected to original freshwater lacustrine conditions but reflect extensive meteoric diagenesis, while positive values probably represent primary saline lake water chemistry. Noisy geochemical curves relate to heterogeneities in (primary) porosity, resulting in selective carbonate diagenesis. This study exemplifies that ancient lacustrine carbonates, despite extensive meteoric weathering, are able to retain key information for both palaeoenvironmental reconstruction and the understanding of diagenetic processes in relation to those primary conditions. Also, it emphasizes the limitation of chemostratigraphy in fossil carbonates, and specifically in settings that are sensitive for the preservation of primary environmental signals, such as lake margins prone to meteoric diagenesis
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