Sleep patterns alterations, bruxism and DTM in ecstasy users: a controlled study

Users of MDMA (methylenedioxymethamphetamine), a drug popularly known as ecstasy, report feeling tension in the muscles of the face and bruxism in effect of the drug. We compared a group of users of ecstasy (57 people) to a group of non-users (57 persons) in relation to the presence of changes in architecture or sleep disturbances (by polysomnography), signs and symptoms of temporomandibular disorders (TMD evaluated by the RDC - Research Diagnostic Criteria), bite force, pattern and context of use of ecstasy and other psychoactive substances and associate problems (measured by DUSI-R - Drug Use Screening Inventory Revised). Volunteers were people aged 18 to 40 years, of both sexes, with natural dentition and no history of trauma (cervical or facial), hormonal or neurological disorders, or psychoactive substances dependence (except ecstasy in the experimental group) and not were using drugs acting on the central nervous system. The group of ecstasy users had a higher percentage of stage 3 sleep, less time awake, high number of oxygen desaturations, increased number of episodes of periodic legs moviments, the greater presence of snoring and bruxism phasic. No were found clinically significant differences between groups in symptoms of TMD. The ecstasy users also had higher rates of problems with the use of other psychoactive substances, a higher proportion of relationship problems and adjustment to work. Among users of ecstasy users who were also at risk of alcohol, the presence of bruxism was more pronounced. This confirms in part the association between use of ecstasy and bruxism, which is more evident under the influence of drugs and more rare in the period after cessation of use.Os usuários de MDMA (metilenodioximetanfetamina), droga popularmente conhecida como êxtase, relatam sentir tensão na musculatura do rosto e bruxismo sob efeito da droga. Comparamos um grupo de usuários de êxtase (57 pessoas) a um grupo de não usuários (57 pessoas) em relação à presença de alterações na arquitetura ou distúrbios do sono (por meio de exame de polissonografia); sinais e sintomas de Disfunção Temporomandibular (DTM, avaliados pelo RDC - Research Diagnostic Criteria); força de mordida; padrão e contexto de uso de êxtase e de outras substâncias psicoativas e problemas associados (avaliados pelo DUSI–R - Drug Use Screening Inventory revisado). Foram voluntárias pessoas com idade de 18 a 40 anos, de ambos os sexos, com dentição natural, sem história pregressa de traumas (cervicais ou faciais); distúrbios neurológicos ou hormonais; dependência de substâncias psicoativas (exceto êxtase no grupo experimental) e que não estivessem utilizando medicamentos com ação sobre o sistema nervoso central. O grupo de usuários de êxtase apresentou maior porcentagem de estágio 3 do sono; menor tempo em vigília; maior número de dessaturações de oxigênio, maior número de episódios de movimento periódico das pernas, maior presença de ronco e de bruxismo fásico. Não foram detectadas diferenças clinicamente significativas entre os grupos em relação aos sintomas de DTM. Os usuários de êxtase também apresentaram maior índice de problemas em relação ao consumo de outras substâncias psicoativas, maior proporção de problemas de relacionamento e de adaptação ao trabalho. Entre os usuários de êxtase que também eram usuários de risco de álcool, a presença de bruxismo foi mais acentuada. Desta forma, confirma-se parcialmente a associação entre o uso de êxtase e bruxismo, que é mais evidente sob o efeito da droga e mais rara no período após a cessação do uso.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP: 2004/11301-2TEDEBV UNIFESP: Teses e dissertaçõe

Comparison of IMU Measurements of Curling Stone Dynamics with a Numerical Model

Abstract Despite almost a century of research, the question of what causes a curling stone to curl (move perpendicular to its initial direction of motion) has no complete answer. Many hypotheses have been formulated, but none has been able to account quantitatively for the full magnitude of the observed curl. The objective of this research was to equip a curling stone with an inertial measurement unit (IMU) and measure its motion, in order to verify a previously published, numerical model of curling stone dynamics. Low cost, small size, accuracy, ease of programming and operation, wireless data communication, and a data-sampling rate near 1 kHz, were selection criteria and constraints for the instrument package. We used the MicroStrain 3DM-GX4-25 system. This is a MEMS-based IMU with a tri-axial gyroscope and a tri-axial linear accelerometer. It was mounted and interfaced with a Bluetooth transmitter, on a curling stone handle. The data were streamed to a host laptop and displayed graphically in real time. Post-processing of the data included filtering and time-integration in order to obtain linear and angular velocities, and displacements. We have compared our experimental results with trajectory data calculated using a previously published numerical model, based on a thermodynamic approach to ice friction. While the observed longitudinal and angular motions are captured reasonably well by the model (errors of about 5% or less), no curl is predicted by the model

Numerical Simulation of Ice Formation on Helicopter Fuselage

NRC publication: Ye

In-flight icing of UAVs: the influence of flight speed coupled with chord size

The intensive deployment of unmanned aerial vehicles (UAVs) for surveillance and reconnaissance missions during the last couple of decades has revealed their vulnerability to icing conditions. At present, a common icing avoidance strategy is simply not to fly when icing is forecast. Consequently, UAV missions in cold seasons and cold regions can be delayed for days when icing conditions persist. While this approach limits substantially the failure of UAV missions as a result of icing, there is obviously a need to develop all-weather capabilities. A key step in accomplishing this objective is to understand better the influence of a smaller geometry and a lower speed on the ice accretion process, relative to the extensively researched area of in-flight icing for traditional aircraft configurations characterized by high Reynolds number. Our analysis of the influence of Reynolds number on the ice accretion process is performed for the NACA0012 airfoil. Analytical analysis of the integrated mass and energy balance equations along the airfoil surface allows the identification of regimes of rime and glaze formation, as well as the ice accretion extent as a function of static air temperature and liquid water content. For each Reynolds number, a Computational Fluid Dynamics solver computes the airflow field and the distributions of Stanton number and static air pressure along the airfoil surface. Next, a drop trajectory solver computes the distribution of collection efficiency along the airfoil for a given drop size. Finally, a morphogenetic model is used to predict the ice accretion shape and its extent over the entire Reynolds number range under consideration. Our analysis highlights the differences between ice accretions on components of traditional aircraft and UAVs, arising from their differences in cruising speed and airfoil dimensions.Peer reviewed: YesNRC publication: Ye

Progress towards a 3D numerical simulation of ice accretion on a swept wing using the morphogenetic approach

We have developed an original, three-dimensional icing modelling capability, called the \u201cmorphogenetic\u201d approach, based on a discrete formulation and simulation of ice formation physics. Morphogenetic icing modelling improves on existing ice accretion models, in that it is capable of predicting simultaneous rime and glaze ice accretions and ice accretions with variable density and complex geometries. The objective of this paper is to show preliminary results of simulating complex three-dimensional features such as lobster tails and rime feathers forming on a swept wing. The results are encouraging. They show that the morphogenetic approach can predict realistically both the overall size and detailed structure of the ice accretion forming on a swept wing. Under cold ambient conditions, when drops freeze instantly upon impingement, the numerical ice structure has voids, which reduce its density. At warmer air temperatures, when drops do not freeze on impingement, larger cavities form, due to the shadowing process, along with the development of morphological features called lobster tails. Ice feathers also appear. As far as we know, no other numerical model can simulate these complex, three-dimensional ice structures that form on a swept wing.Peer reviewed: YesNRC publication: Ye

Prediction of supercooled droplet impingement on helicopter rotor blades

The objective of this paper is to examine the predictive capability of NRiCe numerical model, applied to ice formation on helicopter rotor blades. The model consists of three components: an airflow solver, a droplet trajectory solver and a morphogenetic ice growth model.Peer reviewed: YesNRC publication: Ye

Prediction of ice formation on helicopter rotor blades

NRC publication: Ye

Discrete particle modeling of 2-D ice accretion and its experimental verification

This paper discusses, illustrates and validates a novel modeling approach capable of predicting two-dimensional ice accretion on airfoils. The external flow field around a NACA 0012 airfoil is computed using a potential approach with a panel code. In addition to calculating droplet trajectories and impingement locations on the airfoil, the model tracks the behaviour and motion of individual fluid elements on the icing surface. While the envelope of possible behaviour and motion of the elements is constrained by the macroscopic environmental and flight conditions, an intrinsic stochastic variability is present in the model, even under constant external conditions.Peer reviewed: YesNRC publication: Ye