Sleep Endoscopy in the Evaluation of Pediatric Obstructive Sleep Apnea

Pediatric obstructive sleep apnea (OSA) is not always resolved or improved with adenotonsillectomy. Persistent or complex cases of pediatric OSA may be due to sites of obstruction in the airway other than the tonsils and adenoids. Identifying these areas in the past has been problematic, and therefore, therapy for OSA in children who have failed adenotonsillectomy has often been unsatisfactory. Sleep endoscopy is a technique that can enable the surgeon to determine the level of obstruction in a sleeping child with OSA. With this knowledge, site-specific surgical therapy for persistent and complex pediatric OSA may be possible

Excitation spectra for Andreev billiards of box and disk geometries

We study Andreev billiards of box and disk geometries by matching the wave functions at the interface of the normal and the superconducting region using the exact solutions of the Bogoliubov-de Gennes equation. The mismatch in the Fermi wave numbers and the effective masses of the normal system and the superconductor, as well as the tunnel barrier at the interface are taken into account. A Weyl formula (for the smooth part of the counting function of the energy levels) is derived. The exact quantum mechanical calculations show equally spaced singularities in the density of states. Based on the Bohr-Sommerfeld quantization rule a semiclassical theory is proposed to understand these singularities. For disk geometries two kinds of states can be distinguished: states either contribute through whispering gallery modes or are Andreev states strongly coupled to the superconductor. Controlled by two relevant material, parameters, three kinds of energy spectra exist in disk geometry. The first is dominated by Andreev reflections, the second, by normal reflections in an annular disk geometry. In the third case the coherence length is much larger than the radius of the superconducting region, and the spectrum is identical to that of a full disk geometry

Nonthermal broadening in the conductance of double quantum dot structures

We study the transport properties of a double quantum dot (DQD) molecule at zero and at finite temperature. The properties of the zero-temperature conductance depend on whether the level attraction between the symmetric and antisymmetric states of the DQD, produced by the coupling to the leads, exceeds or not the interdot tunneling. For finite temperature, we find a remarkable nonthermal broadening effect of the conductance resonance when the energy levels of the individual dots are detuned

Fine-tuning the functional properties of carbon nanotubes via the interconversion of encapsulated molecules

Tweaking the properties of carbon nanotubes is a prerequisite for their practical applications. Here we demonstrate fine-tuning the electronic properties of single-wall carbon nanotubes via filling with ferrocene molecules. The evolution of the bonding and charge transfer within the tube is demonstrated via chemical reaction of the ferrocene filler ending up as secondary inner tube. The charge transfer nature is interpreted well within density functional theory. This work gives the first direct observation of a fine-tuned continuous amphoteric doping of single-wall carbon nanotubes

SPORTS, EXERCISE ONLINE? THE OPINION OF SPORT MAJORS ON THE NON-ATTENDANCE TUITION

Aim of the study: The aim of our research is to map out the new aspect of life, in one section of higher education, created by the epidemiological situation, to get to know the methodics used by the teachers of the two sport science institutes (ESI, STI) in our faculty, and get to know our student's opinion on the topic. Methods: We worked with our own questionnaire, which includes the following groups of questions: demographic data, questions about the students' availability of tools, students' opinions about the requirements, communication with the instructor, the completion of the courses, changes in their own learning habits and their physical and practical preparation capabilities. The members of sample was studied at the Eötvös Loránd University PPK in Szombathely and Budapest by students majoring in sport field. Results: No difficulties were reported by our students, 90% had adequate tools. Their workload was much higher than in previous periods, which was reflected in a strong increase in time spent with studying (p <0.01). The lessons, tasks and dissertations carried out in the online learning space were a bigger challenge for the lecturers, based on the opinion of our students, the education did not seem more exciting or creative (2.8 on a 6-point scale). Opinions about the educational platforms used were evenly distributed, they did not find it difficult to navigate between the different surfaces (3.66 on a scale of 6.).Conclusion: The virtue of problem solving could be practiced in recent times. It is advisable to incorporate the experience of the recent period into the solutions of the important tasks aheadAim of the study: The aim of our research is to map out the new aspect of life, in one section of higher education, created by the epidemiological situation, to get to know the methodics used by the teachers of the two sport science institutes (ESI, STI) in our faculty, and get to know our student's opinion on the topic. Methods: We worked with our own questionnaire, which includes the following groups of questions: demographic data, questions about the students' availability of tools, students' opinions about the requirements, communication with the instructor, the completion of the courses, changes in their own learning habits and their physical and practical preparation capabilities. The members of sample was studied at the Eötvös Loránd University PPK in Szombathely and Budapest by students majoring in sport field. Results: No difficulties were reported by our students, 90% had adequate tools. Their workload was much higher than in previous periods, which was reflected in a strong increase in time spent with studying (p <0.01). The lessons, tasks and dissertations carried out in the online learning space were a bigger challenge for the lecturers, based on the opinion of our students, the education did not seem more exciting or creative (2.8 on a 6-point scale). Opinions about the educational platforms used were evenly distributed, they did not find it difficult to navigate between the different surfaces (3.66 on a scale of 6.).Conclusion: The virtue of problem solving could be practiced in recent times. It is advisable to incorporate the experience of the recent period into the solutions of the important tasks ahea

Markov-chain-inspired search for MH370

Markov-chain models are constructed for the probabilistic description of the drift of marine debris from Malaysian Airlines flight MH370. En route from Kuala Lumpur to Beijing, the MH370 mysteriously disappeared in the southeastern Indian Ocean on 8 March 2014, somewhere along the arc of the 7th ping ring around the Inmarsat-3F1 satellite position when the airplane lost contact. The models are obtained by discretizing the motion of undrogued satellite-tracked surface drifting buoys from the global historical data bank. A spectral analysis, Bayesian estimation, and the computation of most probable paths between the Inmarsat arc and confirmed airplane debris beaching sites are shown to constrain the crash site, near 25$^{\circ}$S on the Inmarsat arc.Comment: Submitted to Chao

Doped carbon nanotubes as a model system of biased graphene

Albeit difficult to access experimentally, the density of states (DOS) is a key parameter in solid state systems which governs several important phenomena including transport, magnetism, thermal, and thermoelectric properties. We study DOS in an ensemble of potassium intercalated single-wall carbon nanotubes (SWCNT) and show using electron spin resonance spectroscopy that a sizeable number of electron states are present, which gives rise to a Fermi-liquid behavior in this material. A comparison between theoretical and the experimental DOS indicates that it does not display significant correlation effects, even though the pristine nanotube material shows a Luttinger-liquid behavior. We argue that the carbon nanotube ensemble essentially maps out the whole Brillouin zone of graphene thus it acts as a model system of biased graphene

Transition paths of marine debris and the stability of the garbage patches

We used transition path theory (TPT) to infer "reactive" pathways of floating marine debris trajectories. The TPT analysis was applied on a pollution-aware time-homogeneous Markov chain model constructed from trajectories produced by satellite-tracked undrogued buoys from the NOAA Global Drifter Program. The latter involved coping with the openness of the system in physical space, which further required an adaptation of the standard TPT setting. Directly connecting pollution sources along coastlines with garbage patches of varied strengths, the unveiled reactive pollution routes represent alternative targets for ocean cleanup efforts. Among our specific findings we highlight: constraining a highly probable pollution source for the Great Pacific Garbage Patch; characterizing the weakness of the Indian Ocean gyre as a trap for plastic waste; and unveiling a tendency of the subtropical gyres to export garbage toward the coastlines rather than to other gyres in the event of anomalously intense winds.Comment: Submitted to Chao

Electron spin resonance signal of Luttinger liquids and single-wall carbon nanotubes

A comprehensive theory of electron spin resonance (ESR) for a Luttinger liquid (LL) state of correlated metals is presented. The ESR measurables such as the signal intensity and the line-width are calculated in the framework of Luttinger liquid theory with broken spin rotational symmetry as a function of magnetic field and temperature. We obtain a significant temperature dependent homogeneous line-broadening which is related to the spin symmetry breaking and the electron-electron interaction. The result crosses over smoothly to the ESR of itinerant electrons in the non-interacting limit. These findings explain the absence of the long-sought ESR signal of itinerant electrons in single-wall carbon nanotubes when considering realistic experimental conditions.Comment: 5 pages, 1 figur