2,804 research outputs found
Sigtuna Think Piece 4: Climate Change Education in Relation to Selective Traditions in Environmental Education
In this paper the development of climate change education is related to three traditions of environmental education in Swedish schools: fact-based, normative and pluralistic traditions. These traditions are discussed from two perspectives; first that climate change is a political concept connected to different interests, ideologies, priorities and strategies; and second that compulsory education has democratic responsibility and should be carried out using democratic working methods to prepare pupils for active participation in civic life. It is stressed that the pluralistic approach has many advantages as it recognises the political dimension of environmental and sustainability issues and the same time, strives to avoid the risks of indoctrination by promoting students’ critical thinking and their democratic action competence. Finally the paper recognises a number of questions important to address in further research such as the relativistic attitude of a pluralistic approach and the meaning of such an approach in educational practice
False-negative upper extremity ultrasound in the initial evaluation of patients with suspected subclavian vein thrombosis due to thoracic outlet syndrome (Paget-Schroetter syndrome)
OBJECTIVE: To assess the utilization and consequences of upper extremity Duplex ultrasound in the initial diagnostic evaluation of patients with suspected subclavian vein (SCV) thrombosis and venous thoracic outlet syndrome (VTOS).
METHODS: A retrospective single-center review was conducted for patients that underwent primary surgical treatment for VTOS between 2008 and 2017, in whom an upper extremity ultrasound had been performed as the initial diagnostic test (n = 214). Clinical and treatment characteristics were compared between patients with positive and false-negative ultrasound studies.
RESULTS: There were 122 men (57%) and 92 women (43%) that had presented with spontaneous idiopathic arm swelling, including 28 (13%) with proven pulmonary embolism, at a mean age of 30.7 ± 0.8 years (range 14-69). Upper extremity ultrasound had been performed 23.8 ± 12.2 days after the onset of symptoms, with confirmation of axillary-SCV thrombosis in 169 patients (79%) and negative results in 45 (21%). Of the false-negative ultrasound study reports, only 8 (18%) acknowledged limitations in visualizing the central SCV. Definitive diagnostic imaging (DDI) had been obtained by upper extremity venography in 175 (82%), computed tomography angiography in 24 (11%), and magnetic resonance angiography in 15 (7%), with 142 (66%) undergoing catheter-directed axillary-SCV thrombolysis. The mean interval between initial ultrasound and DDI was 48.9 ± 14.2 days with no significant difference between groups, but patients with a positive ultrasound were more likely to have DDI within 48 hours than those with a false-negative ultrasound (44% vs 24%; P = .02). At the time of surgical treatment, the SCV was widely patent following paraclavicular decompression and external venolysis alone in 74 patients (35%). Patch angioplasty was performed for focal SCV stenosis in 76 (36%) and bypass graft reconstruction for long-segment axillary-SCV occlusion in 63 (29%). Patients with false-negative initial ultrasound studies were significantly more likely to require SCV bypass reconstruction than those with a positive ultrasound (44% vs 25%; P = .02).
CONCLUSIONS: Duplex ultrasound has significant limitations in the initial evaluation of patients with suspected SCV thrombosis, with false-negative results in 21% of patients with proven VTOS. This is rarely acknowledged in ultrasound reports, but false-negative ultrasound studies have the potential to delay definitive imaging, thrombolysis, and further treatment for VTOS. Initial false-negative ultrasound results are associated with progressive thrombus extension and a more frequent need for SCV bypass reconstruction at the time of surgical treatment
The Anti-Sigma Factor MucA of Pseudomonas aeruginosa: Dramatic Differences of a mucA22 vs. a ΔmucA Mutant in Anaerobic Acidified Nitrite Sensitivity of Planktonic and Biofilm Bacteria in vitro and During Chronic Murine Lung Infection
Mucoid mucA22 Pseudomonas aeruginosa (PA) is an opportunistic lung pathogen of cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD) patients that is highly sensitive to acidified nitrite (A-NO2-). In this study, we first screened PA mutant strains for sensitivity or resistance to 20 mM A-NO2- under anaerobic conditions that represent the chronic stages of the aforementioned diseases. Mutants found to be sensitive to A-NO2- included PA0964 (pmpR, PQS biosynthesis), PA4455 (probable ABC transporter permease), katA (major catalase, KatA) and rhlR (quorum sensing regulator). In contrast, mutants lacking PA0450 (a putative phosphate transporter) and PA1505 (moaA2) were A-NO2- resistant. However, we were puzzled when we discovered that mucA22 mutant bacteria, a frequently isolated mucA allele in CF and to a lesser extent COPD, were more sensitive to A-NO2- than a truncated ΔmucA deletion (Δ157–194) mutant in planktonic and biofilm culture, as well as during a chronic murine lung infection. Subsequent transcriptional profiling of anaerobic, A-NO2--treated bacteria revealed restoration of near wild-type transcript levels of protective NO2- and nitric oxide (NO) reductase (nirS and norCB, respectively) in the ΔmucA mutant in contrast to extremely low levels in the A-NO2--sensitive mucA22 mutant. Proteins that were S-nitrosylated by NO derived from A-NO2- reduction in the sensitive mucA22 strain were those involved in anaerobic respiration (NirQ, NirS), pyruvate fermentation (UspK), global gene regulation (Vfr), the TCA cycle (succinate dehydrogenase, SdhB) and several double mutants were even more sensitive to A-NO2-. Bioinformatic-based data point to future studies designed to elucidate potential cellular binding partners for MucA and MucA22. Given that A-NO2- is a potentially viable treatment strategy to combat PA and other infections, this study offers novel developments as to how clinicians might better treat problematic PA infections in COPD and CF airway diseases
Resilience and stability of a pelagic marine ecosystem
The accelerating loss of biodiversity and ecosystem services worldwide has accentuated a long-standing debate on the role of diversity in stabilizing ecological communities and has given rise to a field of research on biodiversity and ecosystem functioning (BEF). Although broad consensus has been reached regarding the positive BEF relationship, a number of important challenges remain unanswered. These primarily concern the underlying mechanisms by which diversity increases resilience and community stability, particularly the relative importance of statistical averaging and functional complementarity. Our understanding of these mechanisms relies heavily on theoretical and experimental studies, yet the degree to which theory adequately explains the dynamics and stability of natural ecosystems is largely unknown, especially in marine ecosystems. Using modelling and a unique 60-year dataset covering multiple trophic levels, we show that the pronounced multi-decadal variability of the Southern California Current System (SCCS) does not represent fundamental changes in ecosystem functioning, but a linear response to key environmental drivers channelled through bottom-up and physical control. Furthermore, we show strong temporal asynchrony between key species or functional groups within multiple trophic levels caused by opposite responses to these drivers. We argue that functional complementarity is the primary mechanism reducing community variability and promoting resilience and stability in the SCCS
The Effect of Extremity Vascular Complications on the Outcomes of Cardiac Support Device Recipients
ObjectiveTo assess the effect of extremity vascular complications (EVCs, including ischemia or vessel trauma) on the outcomes of patients receiving cardiac support devices (CSDs, including ventricular assist device [VAD] and extracorporeal membrane oxygenation [ECMO]).MethodsInstitutional Review Board-approved, retrospective review of a prospectively maintained database of all temporary and permanent CSD recipients from 7/1/10 to 6/30/12. Patient demographics, procedural data, and outcomes were analyzed. The primary endpoint was all-cause mortality at 30-days post-CSD initiation.ResultsOf 208 patients who received CSDs, 31 (14.9%) experienced EVC: 13 (8.9%) of the 146 permanent VADs, 10 (26.3%) of the 38 temporary VADs, and 8 (33.3%) of the 24 ECMO patients. The 30-day mortality for CSD-EVC patients was not significantly higher than that of the CSD patients who did not experience EVC for permanent VAD (15.4% vs 4.5%; PÂ = .15) and ECMO patients (50.0% vs 68.75%; PÂ = 1.00), but was significantly higher for temporary VAD patients (80.0% vs 35.7%; PÂ = .03). Within the CSD-EVC cohort, patients who received a temporary VAD had a significantly higher 30-day mortality and decision to withdraw care after EVC compared with those who received a permanent VAD (PÂ = .01 and PÂ < .01, respectively). Looking beyond the 30-day window, EVC was associated with higher mortality rates in the permanent VAD population (53.8% vs 25.6%; PÂ = .025) but not the temporary VAD or ECMO groups.ConclusionsIn temporary VAD recipients, EVCs result in higher 30-day mortality, more frequent withdrawal of care, and shortened survival time relative to the global temporary VAD group. EVC in permanent VAD recipients did not affect early (30-day) mortality rates, but strongly predicted a higher cumulative mortality risk for the 2-year study period. Overall ECMO mortality rates were high, and not significantly impacted by the occurrence of EVC. The nature of the EVC (cannulation site complication vs embolic injury) did not impact mortality. This data provides quality improvement targets for VAD programs
Reoperative brachial plexus neurolysis after previous anatomically complete supraclavicular decompression for neurogenic thoracic outlet syndrome: A 10-year single-center case series
BACKGROUND: Optimal management of recurrent neurogenic thoracic outlet syndrome (NTOS) remains a considerable challenge.
OBJECTIVE: To assess the safety and effectiveness of reoperative brachial plexus neurolysis in patients with recurrent NTOS.
METHODS: From 2009 to 2019, 85 patients underwent reoperative supraclavicular brachial plexus neurolysis for recurrent NTOS after a previous anatomically complete supraclavicular decompression. Data from a prospectively maintained database were analyzed retrospectively.
RESULTS: The mean patient age at reoperation was 36.9 ± 1.3 (range 15-64) years, 75% were female, and the interval after previous primary operation was 2.5 ± 0.2 years. Intervening injury had precipitated recurrent NTOS in 14 patients (16%), and the mean Disability of the Arm, Shoulder, and Hand (QuickDASH) score before reoperation was 65.2 ± 2.6, reflecting substantial disability. Operative findings consisted of dense fibrous scar tissue surrounding/encasing the brachial plexus. Compared with the previous primary operations, reoperations had a shorter operative time (198 ± 4 vs 161 ± 5 minutes, P \u3c .01) and hospital stay (4.4 ± 0.2 vs 3.6 ± 0.1 days, P \u3c .01), but there were no significant differences in the frequency of prolonged hospitalization (7.1% vs 4.7%), early reoperation (3.5% vs 1.2%), or 30-day hospital readmission (8.2% vs 7.1%). During a median follow-up of 4.8 years, QuickDASH scores improved by 23.3 ± 2.6 (34.2% ± 3.6%; P \u3c .01) and patient-rated outcomes were excellent in 24%, good in 42%, fair in 26%, and poor in 8%.
CONCLUSION: Reoperative supraclavicular brachial plexus neurolysis is technically challenging but safe and effective treatment for recurrent NTOS, with significant improvements in symptoms and function. Diminishing perineural scar tissue development and avoiding secondary injury would likely decrease the need for reoperations
Ecological Transitions in a Coastal Upwelling Ecosystem
The southern California Current Ecosystem (CCE) is a dynamic eastern boundary current ecosystem that is forced by ocean-atmosphere variability on interannual, multidecadal, and long-term secular time scales. Recent evidence suggests that apparent abrupt transitions in ecosystem conditions reflect linear tracking of the physical environment rather than oscillations between alternative preferred states. A space-for-time exchange is one approach that permits use of natural spatial variability in the CCE to develop a mechanistic understanding needed to project future temporal changes. The role of (sub)mesoscale frontal systems in altering rates of nutrient transport, primary and secondary production, export fluxes, and the rates of encounters between predators and prey is an issue central to this pelagic ecosystem and its future trajectory because the occurrence of such frontal features is increasing
RELATIONSHIP BETWEEN ATOPIC DERMATITIS AND IMMUNOGLOBULIN E
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66225/1/j.1365-4362.1976.tb00705.x.pd
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