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COVID-19 was declared a pandemic by the WHO in 2020. In light of the global shortage of PPE and concerns regarding the safety of healthcare providers, clinicians have resorted to the use of novel protective barriers, such as aerosol boxes and plastic sheets, during aerosol generating procedures, especially tracheal intubation. We compared the effect of these barriers on the tracheal intubation of simulated patients with severe COVID-19 in a crossover study. The study was approved by the Ethics Committee of King Faisal Specialist Hospital, and the procedures were compliant with the COVID-19 airway management guidelines of the Saudi Anesthesia Society. The time to intubation was our primary outcome. Secondary outcomes included number of optimization maneuvers, number of intubation attempts, time to glottic view and ventilation of the lungs, and damage to PPE. Thirteen consultant anesthetists performed 39 tracheal intubations on a manikin using each of three approaches (aerosol box, plastic sheet, and no-barrier). Data were collected via direct and video observation. The plastic sheet approach demonstrated the highest time to intubation (mean ± StE [95% CI]: 33.3s ± 3.5 [25.8– 40.9]) compared to the aerosol box (22.0s ± 2.5 [16.5 – 27.5], P < 0.01) and no-barrier approaches (16.1s ± 1.1 [13.7 – 18.4], P < 0.0001). Similarly, the plastic sheet approach had the highest time to glottic view, and ventilation intervals compared to the other two approaches, while the no-barrier approach had the shortest time intervals. There were no failed intubations or damage to the PPE sustained during the use of any of the three approaches. The aerosol box does not impose a significant delay in tracheal intubation using video laryngoscopy, unlike the plastic sheet barrier. Further research on the aerosolization risk is warranted before these protective barriers can be considered as mainstay approaches during aerosol generating procedures.

In this essay I ask what Wittgenstein means when he writes in the introductory section of his “Remarks on Frazer’s Golden Bough,” “I must plunge into the water of doubt again and again.” This comment is both significant and obscure. Although Wittgenstein did not himself publish the “Remarks,” he took care to organize them, and rejected other introductory comments in favor of the ones that now open the “Remarks” and which conclude with this sentence. But it is not clear what role doubt plays in the “Remarks,” as Wittgenstein neither mentions it again not assumes a doubtful posture towards what he describes as Frazer’s errors. I argue that the sentence is meant to apply first and foremost not to Frazer but to Wittgenstein himself, and that, when read carefully, it refers to a kind of baptism. Appreciating this should decisively shape our understanding of the “Remarks” and has implications for our understanding of the Philosophical Investigations, which echoes and repeats many of the central ideas and even formulations of the earlier text. In particular, it underscores the importance of the idea of disorientation to Wittgenstein’s later work. Being doubtful or disoriented is not just a difficulty to be solved or avoided, but a beneficial process through which one must pass, as Wittgenstein says, again and again.

‘Demonstration reaches’ are sections of river where multiple threats to native fish are addressed through river rehabilitation and strong community participation. They are an important way of promoting the key driving actions of the Murray-Darling Basin Authority's Native Fish Strategy (NFS) by using on-ground community-driven rehabilitation. Measuring rehabilitation success against well-defined targets and using this information to adaptively mange activities is fundamental to the demonstration reach philosophy. Seven years on from the establishment of the first demonstration reach, there are now seven throughout the Murray-Darling Basin (MDB), all in differing states of maturation and but all applying a standardised framework for monitoring native fish outcomes. In this study, we reflect on the role that demonstration reaches have played within the NFS, synthesise some key findings from 32 monitoring and evaluation outputs, and highlight some of the successes and barriers to success. We make recommendations as to how to strengthen the demonstration reach model to ensure it remains a relevant approach for fish habitat rehabilitation beyond the NFS and MDB.

By pulsing the tunneling voltage between the Tungsten (W) tip of a Scanning Tunneling Microscope (STM) and a graphene-covered metal surface, a superconducting (SC) nanostructure is formed at the apex of the STM tip. We have characterized the SC properties of the resulting nanotip as a function of temperature and magnetic field, obtaining a transition temperature of 3.3 K and a critical field well above 3 T. The SC nanotip is robust and stable and achieves atomic resolution. A non-SC tip can be easily recovered by controlled voltage pulsing on a clean metal surface. The present result should be taken into account when studying zero-bias features like Kondo resonances, zero-bias-conductance peaks, or superconductivity on graphene-based systems by means of STM using tungsten tips.

The disruption of endocrine systems due to environmental contaminants potentially impacts on developmental, behavioural, regulatory, and reproductive systems of wildlife. A major source of exposure of wildlife (terrestrial and aquatic) to endocrine disrupting compounds is through contact with contaminated surface waters. Current testing routines in aquatic systems have not been designed specifically to assess endocrine disruption properties or, alternatively, methods tend not to be fully developed. An alternative approach is to use a response sensitive to these chemicals such as gonopodium length in the pest species Gambusia holbrooki as an indicator. This species was used as a surrogate for native aquatic species to assess endocrine disruption in wetlands that are used for the storage of stormwater or treated sewage effluent. These were compared with adjacent wetlands used for watering stock (farm dams) that were not contaminated with these pollutants. Deformities in the mosquito fish were found that wer...

The disruption of endocrine systems due to environmental contaminants potentially impacts on the developmental, behavioural, regulatory and reproductive systems of animals. A major source of exposure of animals (terrestrial and aquatic) to endocrine-disrupting compounds is through contact with contaminated surface waters contaminated with sewage effluent and/or stormwater discharge. We studied the response to endocrine-disrupting compounds of Gambusia holbrooki mosquito fish resident of wetlands that were used for the storage of either treated sewage effluent or stormwater runoff. We found that fish from wetlands that received polluted waters directly from the source (treated sewage effluent or stormwater runoff) demonstrated a morphological response consistent with endocrine disruption. In contrast, fish in the second in the series of wetlands that housed treated sewage effluent did not show evidence of such response. However, those from the second in the series of stormwater receiving wetlands did display a morphological response, although it could be considered milder than was observed in fish from the first in this effluent stream. Fish were also smaller in the wetland that received sewage effluent directly from the sewage treatment plant than elsewhere. Although the differences were not statistically significant, the average size of fish in the first in the series of stormwater wetlands were also small and second only to those in the first sewage effluent wetland.

Alligator weed, Alternanthera philoxeroides (Martius) Grisebach, of the family Amaranthaceae, has become a weed in many countries outside of its natural range in South America. In Australia, it is classified as a weed of national significance because of its potential to devastate agricultural and natural ecosystems. In New South Wales, the weed management officers of local government areas are charged with its control. In 2007, we surveyed this group to determine the status of alligator weed in each jurisdiction and to determine the methods and resources used in its control. Half of the local government area officers who responded reported its presence. The age, number, and size of the infestations indicated that the weed continues to spread into new areas, and is well established in others, at least within local government areas. The resources provided for the weed's management across the local government areas was less than had been expended annually on its removal from a single swamp. The respondents acknowledged that the current approach was inadequate and the need for research into its management was identified. We conclude that, with current management, the weed will continue to spread and recommend that the community should be mobilized to identify new areas of infestation and appropriately train people (e.g. bush restoration consultants, Landcare groups) to remove the weed.

Infections of the ear, nose and throat are common and may threaten life. Intracranial complications may arise from infections of the ear and paranasal sinuses. Orbital complications (loss of vision) may arise from infection of the paranasal sinus. Respiratory embarrassment may result from infections of the upper aerodiogestive tract. The clinical presentation, implications and management of foreign bodies in the ear, nose and throat depend on the nature of the foreign body and the site at which it becomes lodged.

We report the case of a professional scuba diver who was unable to dive because he began experiencing severe frontal pain on descent. Following endoscopic surgery to open the frontal recess, the man was able to resume diving unrestricted by pain. We discuss the causes and treatment of this complaint, and we suggest that this might be considered a new indication for surgery in a limited number of cases.

Introduction The 3-dimensional flow in the primary flow path of the GE90-94B high bypass ratio turbofan engine has been achieved. The simulation of the compressor components, the cooled high pressure turbine and the low pressure turbine was performed using the APNASA turbomachinery flow code. The combustor flow and chemistry were simulated using the National Combustor Code, NCC. The engine simulation matches the engine thermodynamic cycle for a sea-level takeoff condition. The fan, booster and OGV are corrected to the cycle condition from component simulations, whereas the high pressure compressor and turbines have been simulated at the cycle condition and coupled to the NCC code by passing profiles. Details of this coupling are presented. Significant gains in parallel computing are demonstrated which allow simulations to take place that can impact design. One of the goals of the Numerical Propulsion System Simulation (NPSS) Program at NASA Glenn Research Center has been to demonstrate a high-fidelity 3D Turbofan Engine Simulation. This simulation will support the multi-dimensional, multi-fidelity, multidiscipline concept of the design and analysis of propulsion systems for the future. This paper describes the current status of one major part of that goal: the complete turbofan engine simulation using an advanced 3-D Navier-Stokes turbomachinery solver, APNASA, coupled with the National Combustion Code, NCC. A production engine has been chosen for this demonstration: the GE90 turbofan engine shown in Fig. 1. A sea level, Mach 0.25, takeoff condition has been chosen for the simulation. The main reason is that detailed cooling flows for the turbine are well known at takeoff since this represents the cooled turbine design condition. Since the cooling flow represents a significant amount of the boundary condition information required for the simulation, it was felt this was a good point for the simulation. It also represents a condition where there are the highest temperatures and most stress in the engine, and is therefore a practical point to gain further understanding. _ C A S b A The GE90 development program included component testing of all the turbomachinery as well as the combustor. The full engine simulation effort has taken advantage of this. All the turbomachinery components 38th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 7-10 July 2002, Indianapolis, Indiana AIAA 2002-3769 Copyright © 2002 ___________________________________________ * Professor, Senior Member AIAA. † Member AIAA. ‡ Aerospace Engineer, Senior Member AIAA. § Senior Research Scientist, Associate Fellow AIAA. opyright  2002 by Mark G. Turner, Rob Ryder, ndrew Norris, Mark Celestina, Jeff Moder, Nanuey Liu, John Adamczyk and Joe Veres. Published y the American Institute of Aeronautics and stronautics, Inc. with permission. 1 American Institute of Aeronautics and Astronautics by the author(s). Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. The GE90 Turbofan Engine have been analyzed and compared to component test data to validate and calibrate the approach. These efforts have been presented by Turner, Turner et al., and Adamczyk. Also presented by Turner et al. was the coupled high and low pressure turbine run at engine conditions. Temperature profile test data does not exist for the combustor running at takeoff conditions so that validation could not be made. The GE90-94B is a production engine offered on the Boeing 777-200ER as shown in a cutaway schematic in Fig. 1. It is a 94,000 pound thrust version of the GE90 with a bypass ratio of 8.4. The fan is 120 inches in diameter comprising 22 composite wide-chord blades. The fan outlet guide vane (OGV) has several types with different camber to guide the bypass flow around the pylon. Only the nominal type is modeled in the simulation. The efforts presented in this paper have built on the successful component simulations by running or correcting each component to the engine condition. A cycle analysis of the GE90 at the takeoff condition has been run. This cycle point is used to help ground the simulation and to compare with the full 3D simulation. The profiles have been passed from the high pressure compressor (HPC) to the combustor and from the combustor to the high pressure turbine (HPT). The booster, or low pressure compressor, consists of three stages and rotates on a common shaft with the fan and low pressure turbine (LPT). The three stages comprise 7 blade rows. A fan frame strut separates the booster from the high pressure compressor (HPC). The 10 stage HPC has a 23-to-1 pressure ratio and has been redesigned using three-dimensional aerodynamic (3-D Aero) technology. The original GE90 HPC was a scale of the HPC developed for the NASA/GE Energy Efficient Engine (E) program. The HPC is on a common shaft with the high pressure turbine (HPT). The full engine simulation project has produced improved component simulations in computer run times that are now short enough to impact design. The coupled high and low pressure turbine presented in Turner et al. was the first dual spool turbine simulation published. As engines are pushed to higher pressure ratios with reduced part counts, component coupling is becoming even more important. The work presented in this paper demonstrates the coupling of the high fidelity turbomachinery and combustor simulations. The combustor is a dual dome annular design for reduced NOX emission levels and reduced unburned hydrocarbon, carbon monoxide and smoke levels. There are 30 pairs of fuel nozzles around the annulus. The HPT has two stages comprising 4 blade rows. There is a turbine mid frame strut separating the HPT and LPT. It diffuses the flow through a high angle outer diameter casing to a high diameter for an improved efficiency LPT. The LPT has 6 stages comprising 12 blade rows. A turbine rear frame strut follows this. One other important aspect of this effort is to reduce the wall clock time to obtain a simulation by exploiting parallel processing as much as possible. Reduced solution times are necessary to efficiently explore the physics of a problem, to validate a code, and most importantly, to impact design. The simulation consists of 49 blade rows of turbomachinery and a 24-degree sector of the combustor. The 49 blade rows include the fan, bypass splitter, nominal OGV (the pylon and different OGV types are not modeled), the 3 stage booster (7 blade rows), the fan frame strut, the 10 stage HPC (21 blade rows), the 2 stage HPT (4 blade rows), the turbine midframe strut, the 6 stage LPT (12 blade rows), and the turbine rear frame strut. Although there are 30 pairs of fuel nozzles, actual periodicity of the geometry requires the modeling of 2 pairs of fuel nozzles, or a 24-degree sector. Unique cooling arrangements make one pair of fuel nozzles a-periodic. The approach used is presented in the next section of this paper that describes the GE90 engine, the turbomachinery solver, the combustor solver and the coupling strategy. The results section then briefly discusses the simulations and the coupling of the combustor with the turbine in further detail. The solution timings of the parallel solvers are discussed next. At the end of the paper is a discussion on the major conclusions and future work.

To compare the insertion time and incidence of catheter damage between skin puncture (SP) and no skin puncture (NP) techniques prior to arterial catheter insertion in patients undergoing neurosurgery.Patients undergoing surgery for intracranial tumours or cervical spine lesions were randomized to receive either SP or NP prior to arterial catheter insertion. The total insertion time, number of passes made, number of catheters used, method of insertion (direct or transfixation) and whether catheter was inserted with patients awake or anesthetised were recorded. After removal, catheters were examined microscopically for damage.Eighty-two patients, 36 in SP group and 46 in NP group were recruited. Microscopic damage was seen in 36.5% of catheters and there was no difference between the two groups. The mean/median insertion time were 180/62 sec and 205/77 sec for SP and NP respectively (P:NS). The insertion time was shorter for the direct than for the transfixation technique with median of 42 vs 174 sec (P = 0.001).There are no differences in insertion time or catheter damage between skin puncture and no skin puncture techniques prior to arterial catheter insertion. The practice of skin puncture may be abandoned resulting in decreased risk of needlestick injury.

The ECJ reiterates its support for the comparative advertiser by indicating that common sense is needed to comply with the Misleading Advertising and Comparative Advertising Directive (Directive 97/55).

In modeling turbulent reactive flows, Probability Density Function (PDF) methods have an advantage over the more traditional moment closure schemes in that the PDF formulation treats the chemical reaction source terms exactly, while moment closure methods are required to model the mean reaction rate. The common model used is the laminar chemistry approximation, where the effects of turbulence on the reaction are assumed negligible. For flows with low turbulence levels and fast chemistry, the difference between the two methods can be expected to be small. However for flows with finite rate chemistry and high turbulence levels, significant errors can be expected in the moment closure method. In this paper, the ability of the PDF method and the moment closure scheme to accurately model a turbulent reacting flow is tested. To accomplish this, both schemes were used to model a CO/H2/N2- air piloted diffusion flame near extinction. Identical thermochemistry, turbulence models, initial conditions and boundary conditions are employed to ensure a consistent comparison can be made. The results of the two methods are compared to experimental data as well as to each other. The comparison reveals that the PDF method provides good agreement with the experimental data, while the moment closure scheme incorrectly shows a broad, laminar-like flame structure.

A small amplitude non-contact atomic force microscope/scanning tunnelling microscope (nc-AFM/STM) is used to study dissipative interactions at atomic resolution on Cu(100) and Si(111) surfaces. For Cu(100) atomic resolution images of phase contrast are obtained, showing energy dissipation as high as 100 meV/cycle at each atomic site during constant tunnel current scans. In contrast, the Si(111) 7×7 surface usually did not exhibit significant phase contrast during normal STM operating conditions. However, when the driving oscillation frequency was set to a sub-harmonic of the lever resonant frequency, atomic contrast in phase could be readily observed. We believe this harmonic coupling is due to the nonlinearity of the tip-sample interaction, and at these frequencies part of the energy is dissipated via the lever Q.

Four patients reporting symptoms of torsional diplopia following retinal detachment repair were seen. One patient most likely had a pre-existing, partially compensated superior oblique palsy as the cause of her vertical deviation and excyciotorsion. A second was found to have the superior oblique tendon adherent anteriorly to the encircling band and buckle just behind the superior rectus insertion, resulting in incyclotorsion. Release of these restrictions reduced the torsion to a small, asymptomatic degree. The third and fourth patients had excyciotorsion for unexplained reasons. Removing the scleral exoplant and Harada-Ito type surgery on the superior oblique tendon did not relieve the symptoms and only minimally reduced the excyciotorsion in one patient. A second procedure, with advancement of the anterior portion of the superior oblique tendon, successfully eliminated cyclotorsional symptoms.