327 research outputs found
Recent Developments in OCL and Textual Modelling
The panel session of the 16th OCL workshop featured a lightning talk session for discussing recent developments and open questions in the area of OCL and textual modelling. During this session, the OCL community discussed, stimulated through short presentations by OCL experts, tool support, potential future extensions, and suggested initiatives to make the textual modelling community even more successful. This collaborative paper, to which each OCL expert contributed one section, summarises the discussions as well as describes the recent developments and open questions presented in the lightning talks
Digital technology and governance in transition: The case of the British Library
Comment on the organizational consequences of the new information and communications technologies (ICTs) is pervaded by a powerful imagery of disaggregation and a tendency for ?virtual? forms of production to be seen as synonymous with the ?end? of bureaucracy. This paper questions the underlying assumptions of the ?virtual organization?, highlighting the historically enduring, diversified character of the bureaucratic form. The paper then presents case study findings on the web-based access to information resources now being provided by the British Library (BL). The case study evidence produces two main findings. First, radically decentralised virtual forms of service delivery are heavily dependent on new forms of capacity-building and information aggregation. Second, digital technology is embedded in an inherently contested and contradictory context of institutional change. Current developments in the management and control of digital rights are consistent with the commodification of the public sphere. However, the evidence also suggests that scholarly access to information resources is being significantly influenced by the ?information society? objectives of the BL and other institutional players within the network of UK research libraries
Mechanical vibrations of pendant liquid droplets
A simple optical deflection technique was used to monitor the vibrations of microlitre pendant droplets of deuterium oxide, formamide, and 1,1,2,2-tetrabromoethane. Droplets of different volumes of each liquid were suspended from the end of a microlitre pipette and vibrated using a small puff of nitrogen gas. A laser was passed through the droplets and the scattered light was collected using a photodiode. Vibration of the droplets resulted in the motion of the scattered beam and time-dependent intensity variations were recorded using the photodiode. These time- dependent variations were Fourier transformed and the frequencies and widths of the mechanical droplet resonances were extracted. A simple model of vibrations in pendant/sessile drops was used to relate these parameters to the surface tension, density and viscosity of the liquid droplets. The surface tension values obtained from this method were found to be in good agreement with results obtained using the standard pendant drop technique. Damping of capillary waves on pendant drops was shown to be similar to that observed for deep liquid baths and the kinematic viscosities obtained were in agreement with literature values for all three liquids studied
Eliminación/Degradación de Triazinas Mediante Biorreactor de Membrana con Post-Tratamiento de Ozonización
The aim of the research was to evaluate the removal of micropollutants in a combined system MBR + ozonation. The research was carried out in a MBR scale laboratory plant which was fed with synthetic wastewater, doped with simazine (SIM), atrazine (ATZ) and terbutilazine (TBZ). The MBR operational conditions were: hydraulic retention time (HRT) of 20 h, organic loading rate (OLR) of 0.23 KgCOD/KgSSV·day, sludge retention time (SRT) of 30 d, and flux of 5.5 LMH. Two ozone doses were tested: low dose (16 mg O3/L) and high dose (45 mg O3/L). The removal eficiency of organic matter was 96%. For the studied triazines, low biodegradation effiencies were reached by biological treatment (MBR): 57%, 53% and 63% for SIM, ATZ and TBZ, respectively. The complementary treatment of ozonation improved the quality of the effluents. At low ozonation dose the overall removal efficiencies increased to 95%, 92% and 96% for SIM, ATZ and TBZ, respectively. At high ozonization dose the overall removal efficiencies were 98%, 97% and 97 % for SIM, ATZ and TBZ, respectively, percentages slightly higher than those obtained at low dose. The results showed the combination of MBR + O3 is effective to remove micropollutants from wastewater, contributing to the preservation of a good ecological state of water bodies.Keywords: Bioreactor, Membrane, Ozone, Triazines, Herbicides
Techniques for measuring aerosol attenuation using the Central Laser Facility at the Pierre Auger Observatory
The Pierre Auger Observatory in Malargüe, Argentina, is designed to study the properties of ultra-high energy cosmic rays with energies above 10(18) eV. It is a hybrid facility that employs a Fluorescence Detector to perform nearly calorimetric measurements of Extensive Air Shower energies. To obtain reliable calorimetric information from the FD, the atmospheric conditions at the observatory need to be continuously monitored during data acquisition. In particular, light attenuation due to aerosols is an important atmospheric correction. The aerosol concentration is highly variable, so that the aerosol attenuation needs to be evaluated hourly. We use light from the Central Laser Facility, located near the center of the observatory site, having an optical signature comparable to that of the highest energy showers detected by the FD. This paper presents two procedures developed to retrieve the aerosol attenuation of fluorescence light from CLF laser shots. Cross checks between the two methods demonstrate that results from both analyses are compatible, and that the uncertainties are well understood. The measurements of the aerosol attenuation provided by the two procedures are currently used at the Pierre Auger Observatory to reconstruct air shower data
The rapid atmospheric monitoring system of the Pierre Auger Observatory
The Pierre Auger Observatory is a facility built to detect air showers produced by cosmic rays above 10(17) eV. During clear nights with a low illuminated moon fraction, the UV fluorescence light produced by air showers is recorded by optical telescopes at the Observatory. To correct the observations for variations in atmospheric conditions, atmospheric monitoring is performed at regular intervals ranging from several minutes (for cloud identification) to several hours (for aerosol conditions) to several days (for vertical profiles of temperature, pressure, and humidity). In 2009, the monitoring program was upgraded to allow for additional targeted measurements of atmospheric conditions shortly after the detection of air showers of special interest, e. g., showers produced by very high-energy cosmic rays or showers with atypical longitudinal profiles. The former events are of particular importance for the determination of the energy scale of the Observatory, and the latter are characteristic of unusual air shower physics or exotic primary particle types. The purpose of targeted (or 'rapid') monitoring is to improve the resolution of the atmospheric measurements for such events. In this paper, we report on the implementation of the rapid monitoring program and its current status. The rapid monitoring data have been analyzed and applied to the reconstruction of air showers of high interest, and indicate that the air fluorescence measurements affected by clouds and aerosols are effectively corrected using measurements from the regular atmospheric monitoring program. We find that the rapid monitoring program has potential for supporting dedicated physics analyses beyond the standard event reconstruction
Investigating the Conformation of HER Membrane Proteins in Cells via Single Molecule and FLIM Microscopy
Refined National Institutes of Health response algorithm for chronic graft-versus-host disease in joints and fascia
Abstract: Implementation of the 2014 National Institutes of Health (NIH) response algorithm for joint/fascia graft-versus-host disease (GVHD) has identified real-world limits to its application. To refine the 2014 NIH response algorithm, we analyzed multicenter prospective observational data from the Chronic GVHD Consortium. The training cohort included 209 patients and the replication cohort included 191 patients with joint/fascia involvement during their course of chronic GVHD. Linear mixed models with random patient effect were used to evaluate correlations between response categories and clinician- or patient-perceived changes in joint status as an anchor of response. Analysis of the training cohort showed that a 2-point change in total photographic range of motion (P-ROM) score was clinically meaningful. The results also suggested that a change from 0 to 1 on the NIH joint/fascia score should not be considered as worsening and suggested that both the NIH joint/fascia score and total P-ROM score, but not individual P-ROM scores, should be used for response assessment. On the basis of these results, we developed an evidence-based refined algorithm, the utility of which was examined in an independent replication cohort. Using the refined algorithm, ∼40% of responses were reclassified, largely mitigating most divergent responses among individual joints and changes from 0 to 1 on the NIH joint/fascia score. The refined algorithm showed robust point estimates and tighter 95% confidence intervals associated with clinician- or patient-perceived changes, compared with the 2014 NIH algorithm. The refined algorithm provides a superior, evidence-based method for measuring therapeutic response in joint/fascia chronic GVHD
Early rise in central venous pressure during a spontaneous breathing trial: A promising test to identify patients at high risk of weaning failure?
Background The spontaneous breathing trial (SBT) assesses the risk of weaning failure by evaluating some physiological responses to the massive venous return increase imposed by discontinuing positive pressure ventilation. This trial can be very demanding for some critically ill patients, inducing excessive physical and cardiovascular stress, including muscle fatigue, heart ischemia and eventually cardiac dysfunction. Extubation failure with emergency reintubation is a serious adverse consequence of a failed weaning process. Some data suggest that as many as 50% of patients that fail weaning do so because of cardiac dysfunction. Unfortunately, monitoring cardiovascular function at the time of the SBT is complex. The aim of our study was to explore if central venous pressure (CVP) changes were related to weaning failure after starting an SBT. We hypothesized that an early rise on CVP could signal a cardiac failure when handling a massive increase on venous return following a discontinuation of positive pressure ventilation. This CVP rise could identify a subset of patients at high risk for extubation failure. Methods Two-hundred and four mechanically ventilated patients in whom an SBT wa
Suppressed basal melting in the eastern Thwaites Glacier grounding zone
This work is from the MELT project, a component of the International Thwaites Glacier Collaboration (ITGC). Support from the National Science Foundation (NSF, grant no. 1739003) and the Natural Environment Research Council (NERC, grant no. NE/S006656/1). Logistics provided by NSF U.S. Antarctic Program and NERC British Antarctic Survey. The ship-based CTD data were supported by the ITGC TARSAN project (NERC grant nos. NE/S006419/1 and NE/S006591/1; NSF grant no. 1929991). ITGC contribution no. ITGC 047.Thwaites Glacier is one of the fastest-changing ice–ocean systems in Antarctica1,2,3. Much of the ice sheet within the catchment of Thwaites Glacier is grounded below sea level on bedrock that deepens inland4, making it susceptible to rapid and irreversible ice loss that could raise the global sea level by more than half a metre2,3,5. The rate and extent of ice loss, and whether it proceeds irreversibly, are set by the ocean conditions and basal melting within the grounding-zone region where Thwaites Glacier first goes afloat3,6, both of which are largely unknown. Here we show—using observations from a hot-water-drilled access hole—that the grounding zone of Thwaites Eastern Ice Shelf (TEIS) is characterized by a warm and highly stable water column with temperatures substantially higher than the in situ freezing point. Despite these warm conditions, low current speeds and strong density stratification in the ice–ocean boundary layer actively restrict the vertical mixing of heat towards the ice base7,8, resulting in strongly suppressed basal melting. Our results demonstrate that the canonical model of ice-shelf basal melting used to generate sea-level projections cannot reproduce observed melt rates beneath this critically important glacier, and that rapid and possibly unstable grounding-line retreat may be associated with relatively modest basal melt rates.Publisher PDFPeer reviewe
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