Feather Vibration as a Stimulus for Sensing Incipient Separation in Falcon Diving Flight

Based on our preceding studies on the aerodynamics of a falcoperegrinus in diving flight along a vertical dam it is known that even when the body shape of the bird is rather streamlined in V-shape some feathers tips may elevate in certain regions of the body. These regions were identified in wind tunnel tests for typical diving flight conditions as regions of locally separated flow. A life-size model in V-shape of a falcoperegrinus with artificial feathers fixed along the body was studied in a wind tunnel to focus on the fluid-structure interaction of feathers located in this sector. The distal ends of the feathers show flow-induced vibrations at typical flight conditions which grow linear in amplitude with increasing angle of incidence until incipient separation. In light of the proven existence of vibration-sensitive mechanoreceptors in the follicles of secondary feathers in birds it is hypothesized that this linear amplitude response offers the bird to sense the angle of incidence during the diving flight using the vibration magnitude as sensory stimulus. Thus the bird in streamlined shape has still a good measure to control its attitude to be in the narrow window of safe angle of incidence. This might have implications also for other birds or technical applications of airfoil sensors regarding incipient separation detection

Aerodynamics of the Cupped Wings during Peregrine Falcon’s Diving Flight

During a dive peregrine falcons can reach velocities of more than 320 km/h and makes themselves the fastest animals in the world. The aerodynamic mechanisms involved are not fully understood yet and the search for a conclusive answer to this fact motivates the three-dimensional (3-D) flow study. Especially the cupped wing configuration which is a unique feature of the wing shape in falcon peregrine dive is our focus herein. In particular, the flow in the gap between the main body and the cupped wing is studied to understand how this flow interacts with the body and to what extend it affects the integral forces of lift and drag. Characteristic shapes of the wings while divingare studied with regard to their aerodynamics using computational fluid dynamics (CFD). The results of the numerical simulations via ICEM CFD and OpenFOAM show predominant flow structures around the body surface and in the wake of the falcon model such as a pair of body vortices and tip vortices. The drag for the cupped wing profile is reduced in relation to the configuration of opened wings (without cupped-like profile) while lift is increased. The purpose of this study is primarily the basic research of the aerodynamic mechanisms during the falcon’s diving flight. The results could be important for maintaining good maneuverability at high speeds in the aviation sector

El terremoto del último 7 de septiembre : tiembla, todo tiembla

Fil: Folguera, Andrés. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Tectónica Andina; Argentina.Fil: Triep, Enrique. Instituto de Sismología Volponi; Argentina.Fil: González Díaz, Emilio M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil: Ramos, Víctor A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Tectónica Andina; Argentina.Los terremotos no son un fenómeno del pasado y las placas que conforman los niveles móviles más\nsuperficiales de la Tierra están aún en pleno movimiento. Con respecto a la intensidad de los mismos y\nsus desplazamientos asociados, la actividad actual, en especial la deformación permanente asociada\na estos terremotos, se ha mantenido en el mismo orden de magnitud que en los últimos 10 millones de\naños. La frecuencia con la que ocurren estos movimientos está también dentro del mismo orden,\nsiendo quizás la diferencia más significativa el avance de la tecnología y las comunicaciones de este\nmundo global que nos permiten conocer al instante este tipo de eventos en cualquier parte del planeta,\npareciendo de esta forma un fenómeno más periódico en la actualidad

Sensitivity of ICD coding for sepsis in children-a population-based study.

BACKGROUND International Classification of Diseases 10th edition (ICD-10) is widely used to describe the burden of disease. AIM To describe how well ICD-10 coding captures sepsis in children admitted to the hospital with blood culture-proven bacterial or fungal infection and systemic inflammatory response syndrome. METHODS Secondary analysis of a population-based, multicenter, prospective cohort study on children with blood culture-proven sepsis of nine tertiary pediatric hospitals in Switzerland. We compared the agreement of validated study data on sepsis criteria with ICD-10 coding abstraction obtained at the participating hospitals. RESULTS We analyzed 998 hospital admissions of children with blood culture-proven sepsis. The sensitivity of ICD-10 coding abstraction was 60% (95%-CI 57-63) for sepsis; 35% (95%-CI 31-39) for sepsis with organ dysfunction, using an explicit abstraction strategy; and 65% (95%-CI 61-69) using an implicit abstraction strategy. For septic shock, the sensitivity of ICD-10 coding abstraction was 43% (95%-CI 37-50). Agreement of ICD-10 coding abstraction with validated study data varied by the underlying infection type and disease severity (p < 0.05). The estimated national incidence of sepsis, inferred from ICD-10 coding abstraction, was 12.5 per 100,000 children (95%-CI 11.7-13.5) and 21.0 per 100,000 children (95%-CI 19.8-22.2) using validated study data. CONCLUSIONS In this population-based study, we found a poor representation of sepsis and sepsis with organ dysfunction by ICD-10 coding abstraction in children with blood culture-proven sepsis when compared against a prospective validated research dataset. Sepsis estimates in children based on ICD-10 coding may thus severely underestimate the true prevalence of the disease. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s44253-023-00006-1

Sensitivity of ICD coding for sepsis in children-a population-based study

BACKGROUND International Classification of Diseases 10th edition (ICD-10) is widely used to describe the burden of disease. AIM To describe how well ICD-10 coding captures sepsis in children admitted to the hospital with blood culture-proven bacterial or fungal infection and systemic inflammatory response syndrome. METHODS Secondary analysis of a population-based, multicenter, prospective cohort study on children with blood culture-proven sepsis of nine tertiary pediatric hospitals in Switzerland. We compared the agreement of validated study data on sepsis criteria with ICD-10 coding abstraction obtained at the participating hospitals. RESULTS We analyzed 998 hospital admissions of children with blood culture-proven sepsis. The sensitivity of ICD-10 coding abstraction was 60% (95%-CI 57-63) for sepsis; 35% (95%-CI 31-39) for sepsis with organ dysfunction, using an explicit abstraction strategy; and 65% (95%-CI 61-69) using an implicit abstraction strategy. For septic shock, the sensitivity of ICD-10 coding abstraction was 43% (95%-CI 37-50). Agreement of ICD-10 coding abstraction with validated study data varied by the underlying infection type and disease severity (p < 0.05). The estimated national incidence of sepsis, inferred from ICD-10 coding abstraction, was 12.5 per 100,000 children (95%-CI 11.7-13.5) and 21.0 per 100,000 children (95%-CI 19.8-22.2) using validated study data. CONCLUSIONS In this population-based study, we found a poor representation of sepsis and sepsis with organ dysfunction by ICD-10 coding abstraction in children with blood culture-proven sepsis when compared against a prospective validated research dataset. Sepsis estimates in children based on ICD-10 coding may thus severely underestimate the true prevalence of the disease. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s44253-023-00006-1

Feather Vibration as a Stimulus for Sensing Incipient Separation in Falcon Diving Flight

Abstract Based on our preceding studies on the aerodynamics of a falcoperegrinus in diving flight along a vertical dam it is known that even when the body shape of the bird is rather streamlined in V-shape some feathers tips may elevate in certain regions of the body. These regions were identified in wind tunnel tests for typical diving flight conditions as regions of locally separated flow. A life-size model in V-shape of a falcoperegrinus with artificial feathers fixed along the body was studied in a wind tunnel to focus on the fluid-structure interaction of feathers located in this sector. The distal ends of the feathers show flow-induced vibrations at typical flight conditions which grow linear in amplitude with increasing angle of incidence until incipient separation. In light of the proven existence of vibration-sensitive mechanoreceptors in the follicles of secondary feathers in birds it is hypothesized that this linear amplitude response offers the bird to sense the angle of incidence during the diving flight using the vibration magnitude as sensory stimulus. Thus the bird in streamlined shape has still a good measure to control its attitude to be in the narrow window of safe angle of incidence. This might have implications also for other birds or technical applications of airfoil sensors regarding incipient separation detection

Feedback of the Glottal Jet Flow with Supraglottal Wall Oscillations

Within this study the influence of wall oscillations in the supraglottal space on the evolution of the glottal jet is investigated. Special focus is laid on the modification of the jet evolution in space and time when small varicose vibrations are excited externally on the walls of the second constriction (ventricular folds) in the supraglottal space. The experiments are carried out in a water flow channel representing a 3:1 upscaled model of the glottal region. Instead of fixed walls in the second constriction we use silicone membranes with an internal air cushion. Sinusoidal pressure oscillations of various frequencies are excited from outside pressure lines. Flow studies show that the glottal deflection in the supraglottal space is highly sensitive to these weak oscillations, hinting on the non-linear interaction of the oscillatory waves with the shear-layer roll-up of the jet. This is known as modelocking in jet dynamics and is expected to have consequences on the sound spectrum in phonation, too

Changepoint analysis of gestational age and birth weight: proposing a refinement of Diagnosis Related Groups

Background: Although the complexity and length of treatment is connected to the newborn’s maturity and birth weight, most case-mix grouping schemes classify newborns by birth weight alone. The objective of this study was to determine whether the definition of thresholds based on a changepoint analysis of variability of birth weight and gestational age contributes to a more homogenous classification. Methods: This retrospective observational study was conducted at a Tertiary Care Center with Level III Neonatal Intensive Care and included neonate cases from 2016 through 2018. The institutional database of routinely collected health data was used. The design of this cohort study was explorative. The cases were categorized according to WHO gestational age classes and SwissDRG birth weight classes. A changepoint analysis was conducted. Cut-off values were determined. Results: When grouping the cases according to the calculated changepoints, the variability within the groups with regard to case related costs could be reduced. A refined grouping was achieved especially with cases of >2500 g birth weight. An adjusted Grouping Grid for practical purposes was developed. Conclusions: A novel method of classification of newborn cases by changepoint analysis was developed, providing the possibility to assign costs or outcome indicators to grouping mechanisms by gestational age and birth weight combined. © 2019, International Pediatric Research Foundation, Inc