64 research outputs found
MEASURING THE WAVE DISSIPATION PRODUCED BY A SWIMMING-LINE SEPARATION ROPE
Hydrodynamic drag (D) seems to be one of the major determinants of swimming performance. D is usually divided into pressure, friction and wave drag (Dw). Meanwhile, Dw can be due to two distinct phenomena: (i) wave production (Dwwp) and (ii) transfer of negative wave momentum (Dwtm). Dwwp refers to the energy dissipated from the kinetic energy of the swimmer and used to generate waves, and Dwtm refers to the drag effect (reduction of forward kinetic energy of the swimmer) attributed to the impact of waves produced by others, or produced by the swimmer itself and rebounded at a swimming pool wall. In order to define the competition lane of each swimmer, the competition swimming pools dispose of swimming-line separation ropes (S-LSR). In the meantime, the manufacturers of this S-LSR claim that they have the ability to absorb waving energy, and thus to dissipate waves avoiding Dw tm, and other perturbing wave effects. The purpose of this research was to characterize the swimmer’s wave production, and to measure the effect upon the wave energy dissipation of a common S-LSR (Fig.1)
Measurements of Proton, Helium and Muon Spectra at Small Atmospheric Depths with the BESS Spectrometer
The cosmic-ray proton, helium, and muon spectra at small atmospheric depths
of 4.5 -- 28 g/cm^2 were precisely measured during the slow descending period
of the BESS-2001 balloon flight. The variation of atmospheric secondary
particle fluxes as a function of atmospheric depth provides fundamental
information to study hadronic interactions of the primary cosmic rays with the
atmosphere.Comment: 21 pages, 11 figures, 4 table
Genome-wide association study identifies multiple susceptibility loci for craniofacial microsomia
Craniofacial microsomia (CFM) is a rare congenital anomaly that involves immature derivatives from the first and second pharyngeal arches. The genetic pathogenesis of CFM is still unclear. Here we interrogate 0.9 million genetic variants in 939 CFM cases and 2,012 controls from China. After genotyping of an additional 443 cases and 1,669 controls, we identify 8 significantly associated loci with the most significant SNP rs13089920 (logistic regression P 1�4 2.15 � 10 � 120) and 5 suggestive loci. The above 13 associated loci, harboured by candidates of ROBO1, GATA3, GBX2, FGF3, NRP2, EDNRB, SHROOM3, SEMA7A, PLCD3, KLF12 and EPAS1, are found to be enriched for genes involved in neural crest cell (NCC) development and vasculogenesis. We then perform whole-genome sequencing on 21 samples from the case cohort, and identify several novel loss-of-function mutations within the associated loci. Our results provide new insights into genetic background of craniofacial microsomia
L'analyse des courbes de débit/temps, pression/temps et volume/temps en ventilation contrôlée à pression constante. Observations cliniques
Paukenerguss beim allergischen Kind – primär konservativ behandeln oder ist eine operative Sanierung erforderlich?
Der chronische Paukenerguss ist eine der häufigsten Erkrankungen im Kindesalter und hat direkte Konsequenzen für den Spracherwerb und die weitere kognitive Entwicklung eines Kindes. Für die Entstehung des Paukenergusses ist zumeist eine anhaltende Tubenventilationsstörung verantwortlich. Lokale inflammatorische Reize, die tubare Insuffizienz und der daraus resultierende tympanale Unterdruck bedingen einen zunächst serösen Erguss, der bei länger bestehenden Prozessen zunehmend mukös wird. Obwohl die derzeit in Überarbeitung befindliche deutsche Leitlinie klare Empfehlungen für konservative und chirurgische Therapie ausspricht, ist die Datenbasis für diese Empfehlungen nicht optimal, da die Patienten nicht nach klinisch relevanter Allergie stratifiziert wurden. Deswegen sind konklusive Empfehlungen für diese Patienten schwierig
Work of breathing during pressure support ventilation and proportional assist ventilation
Two-level non-invasive positive pressure ventilation in the initial treatment of acute respiratory failure in an emergency department.
There are few data on the use of two-level non-invasive positive pressure ventilation (two-level nIPPV) in the initial treatment of severe acute respiratory failure in emergency departments (ED). In a prospective, non-randomized, pilot study, we assessed (1) the feasability of this method in an ED, (2) its effect on clinical and laboratory data, and (3) its effect on the need of intubation and the final outcome of patients. During a 1-year period all eligible patients admitted for acute respiratory failure, with absence of improvement after periods of specific classic treatments, were included in the study. Each patient received a specific classic treatment and two-level nIPPV with a two-level positive pressure ventilator through a face mask. We recorded parameters on admission, after 15 and 45 minutes of nIPPV and at the end of nIPPV. Sixty-two patients were included: 29 with acute pulmonary oedema (APO), 16 with acute exacerbation of chronic obstructive pulmonary disease (COPD), four with asthma, and 13 with various diseases. In the APO-group, we observed a statistically significant improvement of respiratory and pulse rates, diastolic blood pressure, pH, PaCO2 and SaO2. In acute exacerbation of COPD, we observed only a statistical improvement of respiratory and pulse rates without any significant change of PaCO2 and pH. In the two other groups, there was a clinical, gasometric and haemodynamic improvement in all patients. Four patients were intubated and 10 died, but none in the ED or in the first 24 hours after hospital admission. We were able to institute two-level nIPPV for severe acute respiratory failure in an ED without complications. Its addition to the rest of classic specific treatment seems to bring about a rapid improvement of various clinical and laboratory parameters in most patients. We found no deleterious effect of nIPPV when implemented for short periods of time in the emergency department setting
- …