Análisis estadístico de los resultados de una investigación de los efectos de la influencia de la contaminación atmosférica sobre indicadores biológicos en escolares de sexo masculino

Con el objeto de buscar indicadores biológicos humanos de los efectos de la contaminación atmosférica se ha ejecutado un proyecto analítico exploratorio con poblaciones escolares en el centro de la ciudad de Santiago y en la comuna rural de María Pinto (Región Metropolitana). Se trabajó con 114 voluntarios escolares varones entre 10 y 14 años en el Instituto Nacional en Santiago y con un grupo de conrtol, similar, de 51 escolares en María Pinto. En sangre venosa y saliva obtenidas de estos voluntarios se hicieron determinaciones de variables inmunológicas, hematológicas y bioquímicas y medición de la actividad fagocítica del macrófago de sangre periférica. Se hicieron igualmente determinaciones antropométricas. Se determinó también factores de contaminación atmosférica por partículas en ambos lugares: se comprobó que la calidad de aire es significativamente diferente en ellos. Se resumen los resultados globales del proyecto y su análisis estadístico: se discuten tres metodologías alternativas que permitirían tomar en cuenta diferencias de estado nutricional entre ambas poblaciones que pudieran afectar los niveles de respuesta en las variables principales. Las concentraciones de imnunoglobulinas y los factores de complementos C3 y C4 no se muestran como indicadores biológicos efectivos de la contaminación por partículas en la atmósfera. Subsiste la posibilidad de que las variables: capacidad antioxidante del plasma, metahemoglobina, hematocrito, concentración de Fe en materia seca de sangre y otras puedan servir como tales indicadores. Las variaciones conjuntas del índice de fagocitosis y del % de killing evidencian un significativo stress oxidativo

Universality of Electron Mobility in LaAlO3_3/SrTiO3_3 and bulk SrTiO3_3

Metallic LaAlO$_3$/SrTiO$_3$ (LAO/STO) interfaces attract enormous attention, but the relationship between the electron mobility and the sheet electron density, $n_s$, is poorly understood. Here we derive a simple expression for the three-dimensional electron density near the interface, $n_{3D}$, as a function of $n_s$ and find that the mobility for LAO/STO-based interfaces depends on $n_{3D}$ in the same way as it does for bulk doped STO. It is known that undoped bulk STO is strongly compensated with $N \simeq 5 \times 10^{18}~\rm{cm^{-3}}$ background donors and acceptors. In intentionally doped bulk STO with a concentration of electrons $n_{3D} < N$ background impurities determine the electron scattering. Thus, when $n_{3D} < N$ it is natural to see in LAO/STO the same mobility as in the bulk. On the other hand, in the bulk samples with $n_{3D} > N$ the mobility collapses because scattering happens on $n_{3D}$ intentionally introduced donors. For LAO/STO the polar catastrophe which provides electrons is not supposed to provide equal number of random donors and thus the mobility should be larger. The fact that the mobility is still the same implies that for the LAO/STO the polar catastrophe model should be revisited.Comment: 4 pages and 1 figur

Registration of a Validated Mechanical Atlas of Middle Ear for Surgical Simulation

International audienceThis paper is centered on the development of a new train- ing and rehearsal simulation system for middle ear surgery. First, we have developed and validated a mechanical atlas based on finite element method of the human middle ear. The atlas is based on a microMRI. Its mechanical behavior computed in real-time has been successfully val- idated. In addition, we propose a method for the registration of the mechanical atlas on patient imagery. The simulation can be used for a rehearsal surgery with the geometrical anatomy of a given patient and with mechanical data that are validated. Moreover, this process does not necessitate a complete re-built of the model

Plasma plume effects on the conductivity of amorphous-LaAlO₃/SrTiO₃ interfaces grown by pulsed laser deposition in O₂ and Ar

Amorphous LaAlO3/SrTiO3 interfaces exhibit metallic conductivity similarto those found for the extensively studied crystalline-LaAlO3/SrTiO3 interfaces. Here, we investigate the conductivity of the amorphous-LaAlO3/SrTiO3 interfaces grown in different pressures of O2 and Ar background gases. During the deposition, the LaAlO3 ablation plume is also studied, in situ, by fast photography and space-resolved optical emission spectroscopy. An interesting correlation between interfacial conductivity and kinetic energy of the Al atoms in the plume is observed: to assure conducting interfaces of amorphous-LaAlO3/SrTiO3, the kinetic energy of Al should be higher than 1 eV. Our findings add further insights on mechanisms leading to interfacial conductivity in SrTiO3-based oxide heterostructures

Exploring the effects of replicating shape, weight and recoil effects on VR shooting controllers

Commercial Virtual Reality (VR) controllers with realistic force feedback are becoming available, to increase the realism and immersion of first-person shooting (FPS) games in VR. These controllers attempt to mimic not only the shape and weight of real guns but also their recoil effects (linear force feedback parallel to the barrel, when the gun is shot). As these controllers become more popular and affordable, this paper investigates the actual effects that these properties (shape, weight, and especially directional force feedback) have on performance for general VR users (e.g. users with no marksmanship experience), drawing conclusions for both consumers and device manufacturers. We created a prototype replicating the properties exploited by commercial VR controllers (i.e. shape, weight and adjustable force feedback) and used it to assess the effect of these parameters in user performance, across a series of user studies. We first analysed the benefits on user performance of adding weight and shape vs a conventional controller (e.g. Vive controller). We then explore the implications of adding linear force feedback (LFF), as well as replicating the shape and weight. Our studies show negligible effects on the immediate shooting performance with some improvements in subjective appreciation, which are already present with low levels of LFF. While higher levels of LFF do not increase subjective appreciations any further, they lead users to reach their maximum distance skillset more quickly. This indicates that while adding low levels of LFF can be enough to influence user’s immersion/engagement for gaming contexts, controllers with higher levels of LFF might be better suited for training environments and/or when dealing with particularly demanding aiming tasks

Ambulance services in Copenhagen, Odense and Ringkøbing County. Results from the spot test conducted by the Ministry of Health and the County Councils Association in 1990. 2. Treatment by ambulance staff, medical support and pattern of diagnoses

In this investigation, the results from a spot test investigation comprising 3182 emergency ambulance services (AU) from three geographical regions with different degrees of urbanization are presented: The Danish capital (Municipality of Copenhagen), a large provincial town (Odense) and a rural district with smaller towns (the County of Ringkøbing). The conditions of the patients were assessed by the ambulance staff: 7-12% of the patients transported had visible haemorrhage, 5-8% were unconscious, 4-7% were cyanotic, 2-3% had seizures and 1-2% had pareses. The serious cases tended to be most frequent in the least urbanized regions. Registration of the therapeutic efforts by the ambulance staff prior to and during transport revealed that 15-33% of the patients did not receive any treatment. The commonest forms of treatment consisted of oxygen treatment (13-18%), treatment for shock (8-12%), Nato position (4-16%) and stopping of haemorrhage (7-12%). No differences were observed between the three geographic regions except that fewer patients in the capital received treatment. In cases of emergency ambulance services employing signals, medical support was available in 22% of the cases in Copenhagen, mainly by means of medically staffed ambulances. In the County of Ringkøbing, doctors, usually the doctor-on-call, participated in 27% of these services while medical support was only available in 2% of the cases in Odense. Registration of the diagnoses by the hospitals which received the patients revealed that the commonest group of diagnoses were injuries (36-44%) and cardiovascular disease (14-21%).(ABSTRACT TRUNCATED AT 250 WORDS)</p

Ambulance services in Copenhagen, Odense and Ringkøbing County. Results of the spot test conducted by the Ministry of Health and the County Councils Association in 1990. 1. Epidemiological data

In 1990, The Danish Ministry of Health and the County Council Association undertook a spot test investigation of the activities in connection with 3,182 emergency ambulance services (AU) in the Municipality of Copenhagen (a city), the Odense district (a large provincial town) and the County of Ringkøbing (a mixed rural and urban region). The investigation included data collected by the ambulance staff before hospitalization and the diagnoses on discharge from casualty and hospital departments. The frequency of AU per 1,000 population was found to be 101 annually in Copenhagen, 44 in Odense and 19 in the County of Ringkøbing. More than 10% of the services in all three regions did not result in transport of the patient to hospital treatment. The average age of the patients was 52 years in Copenhagen compared with 44 years in the other two regions. The age-specific frequency of AU for patients aged 0-4 year-old was nine times as great in Copenhagen than in Odense and the County of Ringkøbing and, where patients aged more than 80 years were concerned, the frequency was 4-10 times as great. In all three regions, the activities of ambulance services were most numerous between 6-16 hours and lowest during the period 0-6 hours. Services to patients' homes constituted 44-46% and to traffic regions 32-40%. Services on account of illness constituted 41-45% and, on account of accidents, 27-35%. In cases of rapid emergency transport (using signals), 78% of the ambulances had reached the patient within five minutes in Copenhagen as compared with 44% in Odense and the County of Ringkøbing.(ABSTRACT TRUNCATED AT 250 WORDS)</p

Ambulance services in Copenhagen, Odense and Ringkøbing County. Results from the spot test conducted by the Ministry of Health and the County Councils Association in 1990. 2. Treatment by ambulance staff, medical support and pattern of diagnoses

In this investigation, the results from a spot test investigation comprising 3182 emergency ambulance services (AU) from three geographical regions with different degrees of urbanization are presented: The Danish capital (Municipality of Copenhagen), a large provincial town (Odense) and a rural district with smaller towns (the County of Ringkøbing). The conditions of the patients were assessed by the ambulance staff: 7-12% of the patients transported had visible haemorrhage, 5-8% were unconscious, 4-7% were cyanotic, 2-3% had seizures and 1-2% had pareses. The serious cases tended to be most frequent in the least urbanized regions. Registration of the therapeutic efforts by the ambulance staff prior to and during transport revealed that 15-33% of the patients did not receive any treatment. The commonest forms of treatment consisted of oxygen treatment (13-18%), treatment for shock (8-12%), Nato position (4-16%) and stopping of haemorrhage (7-12%). No differences were observed between the three geographic regions except that fewer patients in the capital received treatment. In cases of emergency ambulance services employing signals, medical support was available in 22% of the cases in Copenhagen, mainly by means of medically staffed ambulances. In the County of Ringkøbing, doctors, usually the doctor-on-call, participated in 27% of these services while medical support was only available in 2% of the cases in Odense. Registration of the diagnoses by the hospitals which received the patients revealed that the commonest group of diagnoses were injuries (36-44%) and cardiovascular disease (14-21%).(ABSTRACT TRUNCATED AT 250 WORDS)</p