575 research outputs found
The period bouncer system SDSS J105754.25+275947.5: first radial velocity study
We report the first radial velocity spectroscopic study of the eclipsing
period bouncer SDSS J105754.25+275947.5. Together with eclipse light curve
modeling, we redetermined the system parameters and studied the accretion disk
structure. We confirm that the system contains a white dwarf with
and an effective temperature of 11,500(400)K.
The mass of the secondary is with an effective
temperature of T=2,100K or below. The system inclination is .
The data is in good agreement with our determination of = 33(4) km
s. We estimate the mass transfer rate as 1.9(2). Based on an analysis of the SDSS and OSIRIS spectra,
we conclude that the optical continuum is formed predominantly by the radiation
from the white dwarf. The contribution of the accretion disk is low and
originates from the outer part of the disk. The Balmer emission lines are
formed in a plasma with = 12.7 [cm] and a kinetic
temperature of T10,000K. The size of the disk, where the emission lines
are formed, expands up to . The inner part of
the emission line forming region goes down to . The Doppler tomography and trailed spectra show the presence
of a hot spot and a clumpy structure in the disk, with variable intensity along
the disk position angle. There is an extended region at the side opposite the
hot spot with two bright clumps caused more probably by non-Keplerian motion
there.Comment: 8 pages, 9 figures, accepted for publication in MNRA
Overbite as an Etiological Factor of TMJ Disorders. Clinical and Electromyographic Exploration
INTRODUCTION: The intermaxillar relationship in overbite is one of the etiological factors of TMJ disorders (Pulinger, Sellingman and Gorbeirn, 1993). Nevertheless, it does not always cause malfunction. Sometimes the compensating mechanisms of the individual prevent the occurrence of symptoms and it only appears when parafunctional habit overloads the stomatognathic apparatus.
OBJECTIVE: The aim of this study was to escamine neuromuscular behaviour in patients with such occlusal alteration.
MATERIAL AND METHODS: We present two cases with overbite: one bruxist with malfunction and one nonbruxist without symptoms of malfunction. An occlusal analysis and clinical, kinesiographic and
electromyographic exploration was performed in both patients. For the analysis we used a Dentatus A.R.L. articulator,
Myotronics electromyograph and K6 kinesiograph.
RESULTS AND CONCLUSIONS: The results of the exploration were compared with those of a healthy individual with normal occlusion, used as a reference. Lateral movements were restricted and with a mainly vertical component. In both cases there was an increase in electromyographic activity during normal mastication and swallowing, and in maximum force bite there was the same response between
anterior temporalis and masseter muscles. The study demonstrated that the mandibular movements in both patients were very similar, and determined by the occlusal factor, in comparison to normal individuals. Nevertheless, the electromyographic exploration shows
a different neuromuscular response by the patient adapted to this occlusal problem and the dysfunctional patient
Global noise studies for CMS Tracker upgrade
7 páginas, 6 figuras.-- Trabajo presentado al "Topical Workshop on Electronics for Particle Physics 2010 (TWEPP-10)" celebrado en Alemania.-- Open Access.-- et al.The characterization of the noise emissions of DC-DC converters at system level is critical to optimize the design of the detector and define rules for the integration strategy. This paper presents the impedance effects on the noise emissions of DC-DC converters at system level. Conducted and radiated noise emissions at the input and at the output from DC-DC converters have been simulated for different types of power network and FEE impedances. System aspects as granularity, stray capacitances of the system and different working conditions of the DC-DC converters are presented too. This study has been carried out using simulation models of noise emissions of DC-DC converters in the real scenario. The results of these studies show important recommendations and criteria to be applied to integrate the DC-DC converters and decrease the system noise level.C.R. wants to thank to US DOE, under contract DE-AC02-76SF00515,
for the support of this work.Peer reviewe
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Cooperative Robot Localization Using Event-Triggered Estimation
It is known that multiple robot systems that need to cooperate to perform certain activities or tasks incur in high energy costs that hinder their autonomous functioning and limit the benefits provided to humans by these kinds of platforms. This work presents a communications-based method for cooperative robot localization. Implementing concepts from event-triggered estimation, used with success in the field of wireless sensor networks but rarely to do robot localization, agents are able to only send measurements to their neighbors when the expected novelty in this information is high. Since all agents know the condition that triggers a measurement to be sent or not, the lack of a measurement is therefore informative and fused into state estimates. In the case agents do not receive either direct nor indirect measurements of all others, the agents employ a covariance intersection fusion rule in order to keep the local covariance error metric bounded. A comprehensive analysis of the proposed algorithm and its estimation performance in a variety of scenarios is performed, and the algorithm is compared to similar cooperative localization approaches. Extensive simulations are performed that illustrate the effectiveness of this method
Recommended from our members
Cooperative Robot Localization Using Event-Triggered Estimation
It is known that multiple robot systems that need to cooperate to perform certain activities or tasks incur in high energy costs that hinder their autonomous functioning and limit the benefits provided to humans by these kinds of platforms. This work presents a communications-based method for cooperative robot localization. Implementing concepts from event-triggered estimation, used with success in the field of wireless sensor networks but rarely to do robot localization, agents are able to only send measurements to their neighbors when the expected novelty in this information is high. Since all agents know the condition that triggers a measurement to be sent or not, the lack of a measurement is therefore informative and fused into state estimates. In the case agents do not receive either direct nor indirect measurements of all others, the agents employ a covariance intersection fusion rule in order to keep the local covariance error metric bounded. A comprehensive analysis of the proposed algorithm and its estimation performance in a variety of scenarios is performed, and the algorithm is compared to similar cooperative localization approaches. Extensive simulations are performed that illustrate the effectiveness of this method
Leishmaniose en Equateur : 4. Infestation naturelle du chien par Leishmania panamensis
Dans deux stations de la plaine côtière d'Equateur, région endémique de leishmaniose à #Leishmania panamensis, 34 chiens ont été contrôlés aux plans clinique, sérologique et parasitologique; des tests d'immunofluorescence indirecte et d'électrosynérèse, des ponctions ganglionnaires, des biopsies de lésions ont été pratiqués. De deux chiens présentant des lésions suspectes, un seul avait des lésions de la truffe et du scrotum infectées par des #Leishmania. La souche isolée a été rapportée à #L. panamensis (complexe #L. guyanensis). L'atteinte leishmanienne était strictement tégumentaire. Dans la zone d'étude, le chien semble un hôte accidentel. (Résumé d'auteur
Knowledge and practices of tour guides in Cuzco on the prevention and treatment of traveler's diarrhea
Objectives: To describe the knowledge and practices among tour guides in Cuzco, Peru regarding prevention and treatment of traveler's diarrhea.
Methods: The main tour guide association in Cuzco organized a mandatory re-certification course for tour guides in February 2004. We invited tour guides attending this course to participate in the study. Those aged 18 to 50 who had worked as a tour guide for at least one year were asked to complete a brief anonymous questionnaire.
Results: A total of 173 questionnaires were returned; 137 met the inclusion criteria and were included in the analysis. The median age was 31 years (interquartile range (IQR): 28-34 years), and 56.7% were male. The median number of foreign languages spoken by subjects included was 1, being English (91.9%) the most common, followed by French (17.9%) and Italian (16.8%). The median time working as a tour guide was 4 years (IQR: 2-8 years). Tour guidance was a full-time job for 47.1% of the subjects, and for 82.4% Inca Trail was the most commonly covered route.
Traveler's diarrhea was considered a food-borne disease by 85.4%, but only 60.6% considered it a water-borne disease. The majority of subjects identified raw salads (84.4%), cold sauces (81.5%) and tap water (81.1%) as risky products whereas hot soups (77 8%) and bread (75.0%) were mainly considered as safe.
Most of the tour guides considered bloody stools (84.8%) and fever (60.6%) as indications to seek medical attention. The medications most frequently recommended by tour guides were oral re-hydration solutions ( 85.1%), trimethoprim-sulphamethoxazole (26.1%) and loperamide (20.1%).
Conclusions: Tour guides have a basic knowledge about traveler's diarrhea. However, more training is necessary to improve management while trekking outside of Cuzco The recommendation to seek pharmacists should be particularly addressed
Short-Term Evaluation of Cellular Fate in an Ovine Bone Formation Model.
The ovine critical-sized defect model provides a robust preclinical model for testing tissue-engineered constructs for use in the treatment of non-union bone fractures and severe trauma. A critical question in cell-based therapies is understanding the optimal therapeutic cell dose. Key to defining the dose and ensuring successful outcomes is understanding the fate of implanted cells, e.g., viability, bio-distribution and exogenous infiltration post-implantation. This study evaluates such parameters in an ovine critical-sized defect model 2 and 7 days post-implantation. The fate of cell dose and behaviour post-implantation when combined with nanomedicine approaches for multi-model tracking and remote control using external magnetic fields is also addressed. Autologous STRO-4 selected mesenchymal stromal cells (MSCs) were labelled with a fluorescent lipophilic dye (CM-Dil), functionalised magnetic nanoparticles (MNPs) and delivered to the site within a naturally derived bone extracellular matrix (ECM) gel. Encapsulated cells were implanted within a critical-sized defect in an ovine medial femoral condyle and exposed to dynamic gradients of external magnetic fields for 1 h per day. Sheep were sacrificed at 2 and 7 days post-initial surgery where ECM was harvested. STRO-4-positive (STRO-4+) stromal cells expressed osteocalcin and survived within the harvested gels at day 2 and day 7 with a 50% loss at day 2 and a further 45% loss at 7 days. CD45-positive leucocytes were also observed in addition to endogenous stromal cells. No elevation in serum C-reactive protein (CRP) or non-haem iron levels was observed following implantation in groups containing MNPs with or without magnetic field gradients. The current study demonstrates how numbers of therapeutic cells reduce substantially after implantation in the repair site. Cell death is accompanied by enhanced leucocyte invasion, but not by inflammatory blood marker levels. Crucially, a proportion of implanted STRO-4+ stromal cells expressed osteocalcin, which is indicative of osteogenic differentiation. Furthermore, MNP labelling did not alter cell number or result in a further deleterious impact on stromal cells following implantation
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