46 research outputs found
Confiabilidade da Avaliação da Orientação e Posição de Repouso da Escápula de Indivíduos Saudáveis e Sedentários com o Sistema Eletromagnético de Aquisição de Dados
Electromagnetic systems for motion analysis are claimed as a precise technique for tracking position and orientation of human body segments. To date, reliability electromagnetic tracking was described only for the dynamic assessment of the scapula motion, and no reliability studies on its resting posture or positioning were found. The aim of this study was to analyze intra- and inter-session reliabilities and absolute errors of the scapular orientation and position at habitual resting posture in healthy individuals. Twenty-two shoulder symptom-free individuals non participants in professional or recreational sports activities involving upper extremities were volunteers in this study. The equipment used was 3SPACE Liberty system (Polhemus Inc.). The same examiner collected the kinematic data from subjects in two different sessions, with an interval from seven to ten days. Intraclass Correlation Coefficient (ICC2,1 and ICC2, k) and Standard Error of Measurement (SEM) were calculated. Inter-session reliability ranged from good to excellent (ICC from 0.66 to 0.96) and intra-session reliability was excellent (ICC ≥ 0.97). SEM values found for linear distances were smaller than 0.02 cm and scapular rotations ranged from 0.72° to 5.48°. Results of this study demonstrated that electromagnetic data acquisition of scapula habitual posture is a reliable tool for defining scapular position and orientation in sedentary shoulder symptom-free individuals.Sistemas eletromagnéticos para análise de movimento são conhecidos como precisos para registrar a posição e orientação dos segmentos do corpo humano. Até o momento, a confiabilidade do registro eletromagnético foi descrita apenas para a dinâmica da escápula, não sendo encontrados estudos de confiabilidade da posição de repouso ou postura da mesma. O objetivo deste estudo foi a análise da confiabilidade intra- e inter-sessão e erros absolutos do registro eletromagnético da posição e orientação da escápula na postura habitual de repouso de indivíduos saudáveis. Foram voluntários no estudo 22 indivíduos sem sintomas no complexo articular do ombro e não-praticantes amadores ou profissionais de esporte e atividade física envolvendo os membros superiores. O equipamento utilizado foi o sistema 3SPACE Liberty (Polhemus Inc.). Um mesmo avaliador coletou os dados cinemáticos em duas sessões diferentes com um intervalo de sete a dez dias. O Coeficiente de Correlação Intraclasse (ICC2,1 e ICC2,k) e o Erro Padrão de Medida (EPM) foram calculados. A confiabilidade inter-sessão variou entre boa a excelente (ICC de 0,66 a 0,96) e a confiabilidade intra-sessão foi sempre excelente (ICC ≥ 0,97). Os valores de EPM encontrados para as distâncias lineares foram menores que 0,02 cm e para as rotações da escápula relativa ao tórax variaram entre 0,72 º e 5,48 º. Os resultados deste estudo demonstraram que o registro eletromagnético da posição habitual de repouso da escápula é confiável para determinar a posição e a orientação da mesma em um população sedentária e sem sintomas no complexo articular do ombro.University of São Paulo School of Medicine of Ribeirão Preto Department of PhysiotherapyFederal University of São Paulo Department of Human Movement ScienceUniversity of Washington Division of Physical Therapy School of MedicineUNIFESP, Department of Human Movement ScienceSciEL
Limitations and Improvements of the Intelligent Driver Model (IDM)
This contribution analyzes the widely used and well-known "intelligent driver
model" (briefly IDM), which is a second order car-following model governed by a
system of ordinary differential equations. Although this model was intensively
studied in recent years for properly capturing traffic phenomena and driver
braking behavior, a rigorous study of the well-posedness of solutions has, to
our knowledge, never been performed. First it is shown that, for a specific
class of initial data, the vehicles' velocities become negative or even diverge
to in finite time, both undesirable properties for a car-following
model. Various modifications of the IDM are then proposed in order to avoid
such ill-posedness. The theoretical remediation of the model, rather than post
facto by ad-hoc modification of code implementations, allows a more sound
numerical implementation and preservation of the model features. Indeed, to
avoid inconsistencies and ensure dynamics close to the one of the original
model, one may need to inspect and clean large input data, which may result
practically impossible for large-scale simulations. Although well-posedness
issues occur only for specific initial data, this may happen frequently when
different traffic scenarios are analyzed, and especially in presence of
lane-changing, on ramps and other network components as it is the case for most
commonly used micro-simulators. On the other side, it is shown that
well-posedness can be guaranteed by straight-forward improvements, such as
those obtained by slightly changing the acceleration to prevent the velocity
from becoming negative.Comment: 29 pages, 23 Figure
Seminaphthofluorescein-Based Fluorescent Probes for Imaging Nitric Oxide in Live Cells
Fluorescent turn-on probes for nitric oxide based on seminaphthofluorescein scaffolds were prepared and spectroscopically characterized. The Cu(II) complexes of these fluorescent probes react with NO under anaerobic conditions to yield a 20–45-fold increase in integrated emission. The seminaphthofluorescein-based probes emit at longer wavelengths than the parent FL1 and FL2 fluorescein-based generations of NO probes, maintaining emission maxima between 550 and 625 nm. The emission profiles depend on the excitation wavelength; maximum fluorescence turn-on is achieved at excitations between 535 and 575 nm. The probes are highly selective for NO over other biologically relevant reactive nitrogen and oxygen species including NO3–, NO2–, HNO, ONOO–, NO2, OCl–, and H2O2. The seminaphthofluorescein-based probes can be used to visualize endogenously produced NO in live cells, as demonstrated using Raw 264.7 macrophages.National Science Foundation (U.S.) (CHE-0611944)National Institutes of Health (U.S.) (K99GM092970
Rationale and design of an independent randomised controlled trial evaluating the effectiveness of aripiprazole or haloperidol in combination with clozapine for treatment-resistant schizophrenia
<p>Abstract</p> <p>Background</p> <p>One third to two thirds of people with schizophrenia have persistent psychotic symptoms despite clozapine treatment. Under real-world circumstances, the need to provide effective therapeutic interventions to patients who do not have an optimal response to clozapine has been cited as the most common reason for simultaneously prescribing a second antipsychotic drug in combination treatment strategies. In a clinical area where the pressing need of providing therapeutic answers has progressively increased the occurrence of antipsychotic polypharmacy, despite the lack of robust evidence of its efficacy, we sought to implement a pre-planned protocol where two alternative therapeutic answers are systematically provided and evaluated within the context of a pragmatic, multicentre, independent randomised study.</p> <p>Methods/Design</p> <p>The principal clinical question to be answered by the present project is the relative efficacy and tolerability of combination treatment with clozapine plus aripiprazole compared with combination treatment with clozapine plus haloperidol in patients with an incomplete response to treatment with clozapine over an appropriate period of time. This project is a prospective, multicentre, randomized, parallel-group, superiority trial that follow patients over a period of 12 months. Withdrawal from allocated treatment within 3 months is the primary outcome.</p> <p>Discussion</p> <p>The implementation of the protocol presented here shows that it is possible to create a network of community psychiatric services that accept the idea of using their everyday clinical practice to produce randomised knowledge. The employed pragmatic attitude allowed to randomly allocate more than 100 individuals, which means that this study is the largest antipsychotic combination trial conducted so far in Western countries. We expect that the current project, by generating evidence on whether it is clinically useful to combine clozapine with aripiprazole rather than with haloperidol, provides physicians with a solid evidence base to be directly applied in the routine care of patients with schizophrenia.</p> <p>Trial Registration</p> <p><b>Clincaltrials.gov Identifier</b>: NCT00395915</p