35 research outputs found
The influence of the Tübingen soft palate plate and early cleft closure on the nasopharyngeal airway for the management of airway obstruction in an infant with Pierre Robin sequence: A case report
AbstractINTRODUCTIONA Tübingen palate plate and early cleft closure for successful airway management is described in a newborn with Pierre Robin sequence.PRESENTATION OF CASEA three-day-old newborn with an acute airway obstruction underwent primary treatment with a Tübingen soft palate plate.DISCUSSIONAfter stabilization of the airway, the cleft soft palate was closed after three months.CONCLUSIONThe Tübingen soft palate plate proved to be a very satisfactory treatment for the infant
The Atacama Large Aperture Submillimetre Telescope (AtLAST)
The coldest and densest structures of gas and dust in the Universe have
unique spectral signatures across the (sub-)millimetre bands (~GHz). The current generation of single dish facilities has given a
glimpse of the potential for discovery, while sub-mm interferometers have
presented a high resolution view into the finer details of known targets or in
small-area deep fields. However, significant advances in our understanding of
such cold and dense structures are now hampered by the limited sensitivity and
angular resolution of our sub-mm view of the Universe at larger scales.
In this context, we present the case for a new transformational astronomical
facility in the 2030s, the Atacama Large Aperture Submillimetre Telescope
(AtLAST). AtLAST is a concept for a 50-m-class single dish telescope, with a
high throughput provided by a 2~deg - diameter Field of View, located on a
high, dry site in the Atacama with good atmospheric transmission up to ~THz, and fully powered by renewable energy.
We envision AtLAST as a facility operated by an international partnership
with a suite of instruments to deliver the transformative science that cannot
be achieved with current or in-construction observatories. As an 50m-diameter
telescope with a full complement of advanced instrumentation, including highly
multiplexed high-resolution spectrometers, continuum cameras and integral field
units, AtLAST will have mapping speeds hundreds of times greater than current
or planned large aperture ( 12m) facilities. By reaching confusion limits
below L in the distant Universe, resolving low-mass protostellar cores at
the distance of the Galactic Centre, and directly mapping both the cold and the
hot (the Sunyaev-Zeldovich effect) circumgalactic medium of galaxies, AtLAST
will enable a fundamentally new understanding of the sub-mm Universe.Comment: 20 pages, 5 figures, to be submitted to SPIE Astronomical telescopes
& Instruments 2020, Ground-based and Airborne Telescopes VIII (conference
11445, abstract 290
The Qitai Radio Telescope
This study presents a general outline of the Qitai radio telescope (QTT)
project. Qitai, the site of the telescope, is a county of Xinjiang Uygur
Autonomous Region of China, located in the east Tianshan Mountains at an
elevation of about 1800 m. The QTT is a fully steerable, Gregorian type
telescope with a standard parabolic main reflector of 110 m diameter. The QTT
has adopted an um-brella support, homology-symmetric lightweight design. The
main reflector is active so that the deformation caused by gravity can be
corrected. The structural design aims to ultimately allow high-sensitivity
observations from 150 MHz up to 115 GHz. To satisfy the requirements for early
scientific goals, the QTT will be equipped with ultra-wideband receivers and
large field-of-view mul-ti-beam receivers. A multi-function signal-processing
system based on RFSoC and GPU processor chips will be developed. These will
enable the QTT to operate in pulsar, spectral line, continuum and Very Long
Baseline Interferometer (VLBI) observing modes. Electromagnetic compatibility
(EMC) and radio frequency interference (RFI) control techniques are adopted
throughout the system design. The QTT will form a world-class observational
platform for the detection of low-frequency (nanoHertz) gravitational waves
through pulsar timing array (PTA) techniques, pulsar surveys, the discovery of
binary black-hole systems, and exploring dark matter and the origin of life in
the universe.Comment: 12 pages, 11 figures, accepted for publication in Science China
Physics, Mechanics & Astronom
Quasi-spherical ice in convective clouds
Homogeneous freezing of supercooled droplets occurs in convective systems in low and midlatitudes. This droplet-freezing process leads to the formation of a large amount of small ice particles, so-called frozen droplets, that are transported to the upper parts of anvil outflows, where they can influence the cloud radiative properties. However, the detailed microphysics and, thus, the scattering properties of these small ice particles are highly uncertain. Here, the link between the microphysical and optical properties of frozen droplets is investigated in cloud chamber experiments, where the frozen droplets were formed, grown, and sublimated under controlled conditions. It was found that frozen droplets developed a high degree of small-scale complexity after their initial formation and subsequent growth. During sublimation, the small-scale complexity disappeared, releasing a smooth and near-spherical ice particle. Angular light scattering and depolarization measurements confirmed that these sublimating frozen droplets scattered light similar to spherical particles: that is, they had angular light-scattering properties similar to water droplets. The knowledge gained from this laboratory study was applied to two case studies of aircraft measurements in midlatitude and tropical convective systems. The in situ aircraft measurements confirmed that the microphysics of frozen droplets is dependent on the humidity conditions they are exposed to (growth or sublimation). The existence of optically spherical frozen droplets can be important for the radiative properties of detraining convective outflows.Peer reviewe
Stratospheric aerosol - Observations, processes, and impact on climate
Interest in stratospheric aerosol and its role in climate have increased over the last decade due to the observed increase in stratospheric aerosol since 2000 and the potential for changes in the sulfur cycle induced by climate change. This review provides an overview about the advances in stratospheric aerosol research since the last comprehensive assessment of stratospheric aerosol was published in 2006. A crucial development since 2006 is the substantial improvement in the agreement between in situ and space-based inferences of stratospheric aerosol properties during volcanically quiescent periods. Furthermore, new measurement systems and techniques, both in situ and space based, have been developed for measuring physical aerosol properties with greater accuracy and for characterizing aerosol composition. However, these changes induce challenges to constructing a long-term stratospheric aerosol climatology. Currently, changes in stratospheric aerosol levels less than 20% cannot be confidently quantified. The volcanic signals tend to mask any nonvolcanically driven change, making them difficult to understand. While the role of carbonyl sulfide as a substantial and relatively constant source of stratospheric sulfur has been confirmed by new observations and model simulations, large uncertainties remain with respect to the contribution from anthropogenic sulfur dioxide emissions. New evidence has been provided that stratospheric aerosol can also contain small amounts of nonsulfate matter such as black carbon and organics. Chemistry-climate models have substantially increased in quantity and sophistication. In many models the implementation of stratospheric aerosol processes is coupled to radiation and/or stratospheric chemistry modules to account for relevant feedback processes
Data from: Killing and replacing queen-laid eggs: low cost of worker policing in the honeybee
Worker honeybees, Apis mellifera, police each other’s reproduction by killing worker-laid eggs. Previous experiments demonstrated that worker policing is effective, killing most (∼98%) worker-laid eggs. However, many queen-laid eggs were also killed (∼50%) suggesting that effective policing may have high costs. In these previous experiments, eggs were transferred using forceps into test cells, mostly into unrelated discriminator colonies. We measured both the survival of unmanipulated queen-laid eggs and the proportion of removal errors that were rectified by the queen laying a new egg. Across 2 days of the 3-day egg stage, only 9.6% of the queen-laid eggs in drone cells and 4.1% in worker cells were removed in error. When queen-laid eggs were removed from cells, 85% from drone cells and 61% from worker cells were replaced within 3 days. Worker policing in the honeybee has a high benefit to policing workers because workers are more related to the queen’s sons (brothers, r = 0.25) than sister workers’ sons (0.15). This study shows that worker policing also has a low cost in terms of the killing of queen-laid eggs, as only a small proportion of queen-laid eggs are killed, most of which are rapidly replaced
Central Giant Cell Granuloma Resistant to Calcitonin Nasal Spray: A Case Report
Purpose: We describe successful treatment of a recurrent central giant cell granuloma (CGCG). This is a rare benign intraosseous lesion that occurs before age 30 and can quickly recur as a painless lesion of the mandible. Because of its aggressive growth and tendency to progress as well as its morphological similarity to a giant cell tumour, it justifies radical surgery. Patients and methods: A female patient aged 18 years presented with a CGCG lesion in the mandible that recurred despite standard treatment with calcitonin nasal spray after enucleation of the initial lesion. Results: The recurrence in the mandible required radical surgery and reconstruction with a microvascular iliac bone flap; there was no injury to cranial nerves and facial appearance was normal. Conclusion: Radical surgical treatment of CGCG recurrence is the best option when calcitonin nasal spray fails to prevent recurrence