998 research outputs found

    The dehydration, rehydration and tectonic setting of greenstone belts in a portion of the northern Kaapvaal Craton, South Africa

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    High-grade gneiss terranes and low-grade granite-greenstone terranes are well known in several Archaean domains. The geological relationship between these different crustal regions, however, is still controversial. One school of thought favors fundamental genetic differences between high-grade and low-grade terranes while others argue for a depth-controlled crustal evolution. The detailed examination of well-exposed Archaean terranes at different metamorphic grades, therefore, is not only an important source of information about the crustal levels exposed, but also is critical to the understanding of the possible tectonic and metamorphic evolution of greenstone belts with time. Three South African greenstone belts are compared

    Steady-state and transient-state performance of a biotrickling filter treating chlorobenzene-containing waste gas

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    Biotrickling filter (BTF) technology was applied for the treatment of waste gas containing a mixture of chlorobenzene and 1,2-dichlorobenzene. An adapted microbial community was immobilised on a structured packing material. The strategy followed was to reach high removal efficiencies at initially low mass loading rates followed by an increase of the latter. This procedure was successful and resulted in a short start-up period of only 2weeks. A 3-month operation under steady-state conditions showed good performance, with >95% removal efficiency at a mass loading rate of 1,800gm−3day−1. Dimensionless concentration profiles showed that the chlorobenzenes were simultaneously degraded. Low dissolved organic carbon of 15mgl−1 and stoichiometric chloride concentrations in the trickling liquid indicated complete mineralisation of the pollutant. Transient-state experiments with five times higher mass loading rates caused a decrease in the removal efficiency that recovered rapidly once the mass loading rate returned to its original steady-state level. A progressive increase of the mass loading rate in a long-term performance experiment showed that the removal efficiency could be kept stable between 95 and 99% at loads of up to 5,200gm−3day−1 over several days. Above this mass loading rate, the elimination capacity did not increase any further. These results demonstrated that with a well-adapted inoculum and optimal operation parameters, a BTF system with excellent performance and stability that efficiently removes a mixture of cholorobenzene vapours from air can be obtaine

    A large eddy simulation of the dispersion of traffic emissions by moving vehicles at an intersection

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    Traffic induced flow within urban areas can have a significant effect on pollution dispersion, particularly for traffic emissions. Traffic movement results in increased turbulence within the street and the dispersion of pollutants by vehicles as they move through the street. In order to accurately model urban air quality and perform meaningful exposure analysis at the microscale, these effects cannot be ignored. In this paper we introduce a method to simulate traffic induced dispersion at high resolution. The computational fluid dynamics software, Fluidity, is used to model the moving vehicles through a domain consisting of an idealised intersection. A multi-fluid method is used where vehicles are represented as a second fluid which displaces the air as it moves through the domain. The vehicle model is coupled with an instantaneous emissions model which calculates the emission rate of each vehicle at each time step. A comparison is made with a second Fluidity model which simulates the traffic emissions as a line source and does not include moving vehicles. The method is used to demonstrate how moving vehicles can have a significant effect on street level concentration fields and how large vehicles such as buses can also cause acute high concentration events at the roadside which can contribute significantly to overall exposure

    The CMS Global Calorimeter Trigger Hardware Design

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    An alternative design for the CMS Global Calorimeter Trigger (GCT) is being implemented. The new design adheres to all the CMS specifications regarding interfaces and functional requirements of the trigger systems. The design is modular, compact, and utilizes proven components. Functionality has been partitioned to allow commissioning in stages corresponding to the different capabilities being made operational. The functional breakdown and hardware platform is presented and discussed. A related paper discusses the firmware required to implement the GCT functionality

    Diagnosis and workup of 522 consecutive patients with neuroendocrine neoplasms in Switzerland.

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    BACKGROUND: Neuroendocrine neoplasms (NENs) are difficult to diagnose. We used SwissNET data to characterise NEN patients followed in the two academic centres of western Switzerland (WS), and to compare them with patients followed in eastern Switzerland (ES) as well as with international guidelines. METHOD: SwissNET is a prospective database covering data from 522 consecutive patients (285 men, 237 women) from WS (n = 99) and ES (n = 423). RESULTS: Mean ± SD age at diagnosis was 59.0 ± 15.7 years. Overall, 76/522 experienced a functional syndrome, with a median interval of 1.0 (IQR: 1.0-3.0) year between symptoms onset and diagnosis. A total of 51/522 of these tumours were incidental. The primary tumour site was the small intestine (29%), pancreas (21%), appendix (18%) and lung (11%) in both regions combined. In all, 513 functional imaging studies were obtained (139 in WS, 374 in ES). Of these, 381 were 111In-pentetreotide scintigraphies and 20 were 68Ga-DOTATOC PET. First line therapy was surgery in 87% of patients, medical therapy (biotherapy or chemotherapy) in 9% and irradiation in 3% for both regions together. CONCLUSION: Swiss NEN patients appear similar to what has been described in the literature. Imaging by somatostatin receptor scintigraphy (SRS) is widely used in both regions of Switzerland. In good accordance with published guidelines, data on first line therapy demonstrate the crucial role of surgery. The low incidence of biotherapy suggests that long-acting somatostatin analogues are not yet widely used for their anti-proliferative effects. The SwissNET initiative should help improve compliance with ENETS guidelines in the workup and care of NEN patients

    An Automated Machine-Learning Approach for Road Pothole Detection Using Smartphone Sensor Data.

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    Road surface monitoring and maintenance are essential for driving comfort, transport safety and preserving infrastructure integrity. Traditional road condition monitoring is regularly conducted by specially designed instrumented vehicles, which requires time and money and is only able to cover a limited proportion of the road network. In light of the ubiquitous use of smartphones, this paper proposes an automatic pothole detection system utilizing the built-in vibration sensors and global positioning system receivers in smartphones. We collected road condition data in a city using dedicated vehicles and smartphones with a purpose-built mobile application designed for this study. A series of processing methods were applied to the collected data, and features from different frequency domains were extracted, along with various machine-learning classifiers. The results indicated that features from the time and frequency domains outperformed other features for identifying potholes. Among the classifiers tested, the Random Forest method exhibited the best classification performance for potholes, with a precision of 88.5% and recall of 75%. Finally, we validated the proposed method using datasets generated from different road types and examined its universality and robustness

    QTc interval and resting heart rate as long-term predictors of mortality in type 1 and type 2 diabetes mellitus: a 23-year follow-up

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    Aims/hypothesis: We evaluated the association of QT interval corrected for heart rate (QTc) and resting heart rate (rHR) with mortality (all-causes, cardiovascular, cardiac, and ischaemic heart disease) in subjects with type 1 and type 2 diabetes. Methods: We followed 523 diabetic patients (221 with type 1 diabetes, 302 with type 2 diabetes) who were recruited between 1974 and 1977 in Switzerland for the WHO Multinational Study of Vascular Disease in Diabetes. Duration of follow-up was 22.6 ± 0.6years. Causes of death were obtained from death certificates, hospital records, post-mortem reports, and additional information given by treating physicians. Results: In subjects with type 1 diabetes QTc, but not rHR, was associated with an increased risk of: (1) all-cause mortality (hazard ratio [HR] 1.10 per 10ms increase in QTc, 95% CI 1.02-1.20, p = 0.011); (2) mortality due to cardiovascular (HR 1.15, 1.02-1.31, p = 0.024); and (3) mortality due to cardiac disease (HR 1.19, 1.03-1.36, p = 0.016). Findings for subjects with type 2 diabetes were different: rHR, but not QTc was associated with mortality due to: (1) all causes (HR 1.31 per 10 beats per min, 95% CI 1.15-1.50, p < 0.001); (2) cardiovascular disease (HR 1.43, 1.18-1.73, p < 0.001); (3) cardiac disease (HR 1.45, 1.19-1.76, p < 0.001); and (4) ischaemic heart disease (HR 1.52, 1.21-1.90, p < 0.001). Effect modification of QTc by type 1 and rHR by type 2 diabetes was statistically significant (p < 0.05 for all terms of interaction). Conclusions/interpretation: QTc is associated with long-term mortality in subjects with type 1 diabetes, whereas rHR is related to increased mortality risk in subjects with type 2 diabete

    Fuel metabolism during exercise in euglycaemia and hyperglycaemia in patients with type 1 diabetes mellitus—a prospective single-blinded randomised crossover trial

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    Aims/hypothesis: We assessed systemic and local muscle fuel metabolism during aerobic exercise in patients with type 1 diabetes at euglycaemia and hyperglycaemia with identical insulin levels. Methods: This was a single-blinded randomised crossover study at a university diabetes unit in Switzerland. We studied seven physically active men with type 1 diabetes (mean ± SEM age 33.5 ± 2.4years, diabetes duration 20.1 ± 3.6years, HbA1c 6.7 ± 0.2% and peak oxygen uptake [ V.O2peak\mathop {\text{V}}\limits^{\text{.}} {\text{O}}_{2{\text{peak}}} ] 50.3 ± 4.5ml min−1 kg−1). Men were studied twice while cycling for 120min at 55 to 60% of V.O2peak\mathop {\text{V}}\limits^{\text{.}} {\text{O}}_{{\text{2peak}}} , with a blood glucose level randomly set either at 5 or 11mmol/l and identical insulinaemia. The participants were blinded to the glycaemic level; allocation concealment was by opaque, sealed envelopes. Magnetic resonance spectroscopy was used to quantify intramyocellular glycogen and lipids before and after exercise. Indirect calorimetry and measurement of stable isotopes and counter-regulatory hormones complemented the assessment of local and systemic fuel metabolism. Results: The contribution of lipid oxidation to overall energy metabolism was higher in euglycaemia than in hyperglycaemia (49.4 ± 4.8 vs 30.6 ± 4.2%; p < 0.05). Carbohydrate oxidation accounted for 48.2 ± 4.7 and 66.6 ± 4.2% of total energy expenditure in euglycaemia and hyperglycaemia, respectively (p < 0.05). The level of intramyocellular glycogen before exercise was higher in hyperglycaemia than in euglycaemia (3.4 ± 0.3 vs 2.7 ± 0.2 arbitrary units [AU]; p < 0.05). Absolute glycogen consumption tended to be higher in hyperglycaemia than in euglycaemia (1.3 ± 0.3 vs 0.9 ± 0.1 AU). Cortisol and growth hormone increased more strongly in euglycaemia than in hyperglycaemia (levels at the end of exercise 634 ± 52 vs 501 ± 32nmol/l and 15.5 ± 4.5 vs 7.4 ± 2.0ng/ml, respectively; p < 0.05). Conclusions/interpretation: Substrate oxidation in type 1 diabetic patients performing aerobic exercise in euglycaemia is similar to that in healthy individuals revealing a shift towards lipid oxidation during exercise. In hyperglycaemia fuel metabolism in these patients is dominated by carbohydrate oxidation. Intramyocellular glycogen was not spared in hyperglycaemia. Trial registration: ClinicalTrials.Gov NCT00325559 Funding: This study was supported by unrestricted grants from the Oetliker-Stiftung für Physiologie, from the Swiss Diabetes Foundation, from NovoNordisk, Switzerland, and from the Swiss National Science Foundatio
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