865 resultados para Joint Subsystems Hypothesis


Relevância:

100.00% 100.00%

Publicador:

Resumo:

Gray's Reinforcement Sensitivity Theory (RST) consists of the Behavioural Activation System (BAS) which is the basis of Impulsivity, and Behavioural Inhibition System (BIS) which is the basis of Anxiety. In this study, Impulsivity and Anxiety were used as distal predictors of attitudes to religion in the prediction of three religious dependent variables (Church attendance, Amount of prayer, and Importance of church). We hypothesised that Impulsivity would independently predict a Rewarding attitude to the Church and that Anxiety would independently predict an Anxious attitude to the church, and that these attitudes would be proximal predictors of our dependent variables. Moreover, we predicted that interactions between predictors would be proximal. Using structural equation modelling, data from 400 participants supported the hypotheses. We also tested Eysenck's personality scales of Extraversion and Neuroticism and found a key path of the structural equation model to be non-significant. (C) 2003 Elsevier Ltd. All rights reserved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A joint impact hypothesis on symptom experience is introduced that specifies the role of negative mood and self-focus, which have been considered independently in previous research. Accordingly, negative affect only promotes symptom experience when people simultaneously focus their attention on the self. One correlational study and 4 experiments supported this prediction: Only negative mood combined with self-focus facilitated the experience (see the self-reports in Studies 1, 2a, & 2b) and the accessibility (lexical decisions, Stroop task in Studies 3 & 4) of physical symptoms, whereas neither positive mood nor negative mood without self-focus did. Furthermore, the joint impact of negative mood and self-focused attention on momentary symptom experience remained significant after controlling for the influence of dispositional symptom reporting and neuroticism.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The Appetitive Motivation Scale (Jackson & Smillie, 2004) is a new trait conceptualisation of Gray's (I 970 199 1) Behavioural Activation System. In this experiment we explore relationships that the Appetitive Motivation Scale and other measures of Gray's model have with Approach and Active Avoidance responses. Using a sample of 144 undergraduate students, both Appetitive Motivation and Sensitivity to Reward (from the Sensitivity to Punishment and Sensitivity to Reward Questionnaire, SPSRQ; Torrubia, Avila, Molto, & Ceseras, 2001), were found to be significant predictors of Approach and Active Avoidance response latency. This confirms previous experimental validations of the SPSRQ (e.g., Avila, 2001) and provides the first experimental evidence for the validity of the Appetitive Motivation scale. Consistent with interactive views of Gray's model (e.g., Corr, 2001), high SPSRQ Sensitivity to Punishment diminished the relationship between Sensitivity to Reward and our BAS criteria. Measures of BIS did not however interact in this way with the appetitive motivation scale. A surprising result was the failure for any of Carver and White's (1994) BAS scales to correlate with RST criteria. Implications of these findings and potential future directions are discussed. (C) 2004 Elsevier Ltd. All rights reserved.

Relevância:

80.00% 80.00%

Publicador:

Resumo:

Most panel unit root tests are designed to test the joint null hypothesis of a unit root for each individual series in a panel. After a rejection, it will often be of interest to identify which series can be deemed to be stationary and which series can be deemed nonstationary. Researchers will sometimes carry out this classification on the basis of n individual (univariate) unit root tests based on some ad hoc significance level. In this paper, we demonstrate how to use the false discovery rate (FDR) in evaluating I(1)=I(0) classifications based on individual unit root tests when the size of the cross section (n) and time series (T) dimensions are large. We report results from a simulation experiment and illustrate the methods on two data sets.

Relevância:

40.00% 40.00%

Publicador:

Resumo:

Acknowledgments This work has been undertaken with the support of the A*MIDEX project (n ∘ ANR-11-IDEX-0001-02) funded by the “Investissements d’Avenir” French Government program, managed by the French National Research Agency (ANR). We are grateful to Julian Williams, Editor Badi H. Baltagi and an anonymous referee for helpful comments. We are responsible for any errors.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Osteochondroma of the mandibular condyle has been found in the oral and maxillofacial region rarely. This paper describes a case of osteochondroma of the mandibular condyle in a 20-year-old woman, who was referred to our service with facial asymmetry, prognathic deviation of chin, cross-bite to the contralateral side, changes in condylar morphology, limited mouth opening, and malocclusion. Computed tomography (CT) was performed for better evaluation to the pathological conditions on the temporomandibular joint. Based on the clinical examination, patient history, and complementary exams, the hypothesis of osteochondroma was established. Condylectomy was performed using a preauricular approach with total removal of the lesion. After 3 years of postoperative follow up and orthodontic therapy, the patient is symptom-free, and has normal mouth opening with no deviation in the opening pattern.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This study assessed the effect of the agonist 15d-PGJ(2) administered into the rat temporomandibular joint (TMJ) on nociceptive behavioral and the anti-inflammatory potential of this prostaglandin on TMJ. It was observed that 15-deoxy-(Delta 12,14)-prostaglandin J(2) (15d-PGJ(2)) significantly reduced formalin-induced nociceptive behavior in a dose dependent manner, however injection of 15d-PGJ(2) into the contralateral TMJ failed to reduce such effects. This antinociceptive effect is dependent on peroxisome proliferator-activated receptors-gamma (PPAR-gamma) since pre-treatment with GW9662 (PPAR-gamma receptor antagonist) blocked the antinociceptive effect of 15d-PGJ(2) in the TMJ. In addition, the antinociceptive effect of 15d-PGJ(2) was also blocked by naloxone suggesting the involvement of peripheral opioids in the process. Confirming this hypothesis pre-treatment with kappa, delta, but not mu receptor antagonists significantly reduced the antinociceptive effect of 15d-PGJ(2) in the TMJ. Similarly to opioid agonists, the 15d-PGJ(2) antinociceptive action depends on the nitric oxide (NO)/guanilate cyclase (cGMP)/ATP-sensitive potassium channel blocker(K(ATP)(+)) channel pathway since it was prevented by the pre-treatment with the inhibitors of nitric oxide synthase (NOS; aminoguanidine), cGMP (ODQ), or the K(ATP)(+) (glibenclamide). In addition, 15d-PGJ(2) (100 ng/TMJ) inhibits 5-HT-induced TMJ hypernociception. Besides, TMJ treated with 15d-PGJ(2) showed lower vascular permeability, assessed by Evan`s Blue extravasation, and also lower neutrophil migration induced by carrageenan administration. Taken together, these results demonstrate that 15d-PGJ(2) has a potential peripheral antinociceptive and anti-inflammatory effect in the TMJ via PPAR-gamma activation. The results also suggest that 15d-PGJ(2) induced-peripheral antinociceptive response in the TMJ is mediated by kappa/delta opioid receptors by the activation of the intracellular L-arginine/NO/cGMP/K(ATP)(+) channel pathway. The pharmacological properties of the peripheral administration of 15d-PGJ(2) highlight the potential use of this PPAR-gamma agonist on TMJ inflammatory pain conditions. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The concept of danger signals as important triggers of inflammation and immune activation has passed from fanciful hypothesis to a widely accepted biological process with receptors, signalling cascades and mediators. Products of cell death or cell stress are prime examples of DAMPs. They interact with receptors on the cell surface such as TLRs as well as cytoplasmic proteins such as the NLRs to modulate cellular metabolism and activation. Recently, the identification of the inflammasomes and their role in processing IL-1b and IL18 provided further insights into how DAMPs provoke inflammation. A class of substances that are potent activators of the inflammasome is microcrystals. All three microcrystals associated with joint disease in man : urate, CPP and hydroxyapatite require the NLRP3 inflammasome to process and release IL-1b from leucocytes. This mechanism most probably explain the inflammatory phase of acute crystal arthritis. However, microcrystals can also induce apoptosis, cell death as well as cell activation, depending on the cell type they are in contact with. These different cellular effects could well explain the role crystals can play in degenerative joint diseases, where inflammation is not as prominent. Our understanding of the intracellular pathways linking microcrystals to inflammation and cell activation is currently still very sketchy, and we hope that the detailed analysis of these pathways may lead to better comprehension and treatment of microcrystal induced joint diseases.Disclosures : The author has declared no conflicts of interest.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: Tendon transfers and calcaneal osteotomies are commonly used to treat symptoms related to medial ankle arthrosis in fixed pes cavovarus. However, the relative effect of these osteotomies in terms of lateralizing the ground contact point of the hindfoot and redistributing ankle joint contact stresses are unknown. MATERIALS AND METHODS: Pes cavovarus with fixed hindfoot varus was simulated in eight cadaver specimens. The effect of three types of calcaneal osteotomies on the migration of the center of force and tibiotalar peak pressure at 300 N axial static load (half-body weight) were recorded using pressure sensors. RESULTS: A significant lateral shift of the center of force was observed: 4.9 mm for the laterally closing Z-shaped osteotomy with additional lateralization of the tuberosity, 3.4 mm for the lateral sliding osteotomy of the calcaneal tuberosity, and 2.7 mm for the laterally closing Z-shaped osteotomy (all p < 0.001). A significant peak pressure reduction was recorded: -0.53 MPa for the Z-shaped osteotomy with lateralization, -0.58 MPa for the lateral sliding osteotomy of the calcaneal tuberosity, and -0.41 MPa for the Z-shaped osteotomy (all p < 0.01). CONCLUSION: This cadaver study supports the hypothesis that lateralizing calcaneal osteotomies substantially help to normalize ankle contact stresses in pes cavovarus.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective: To determine the effect of ankle joint mobilization on the H reflex amplitude of thesoleus muscle in people with spasticity. Materials and methods: A quasi-experimental study withcrossover design and simple masking was conducted in 24 randomized subjects to initiate thecontrol or experimental group. Traction and rhythmic oscillation were applied for five minutesto the ankle joint. H wave amplitude changes of Hoffmann reflex (electrical equivalent of themonosynaptic spinal reflex) was assessed, stimulating the tibial nerve at the level of the poplitealfossa and recording in the soleus muscle. In each subject 12 measurements were taken: basalrate, during and after mobilization. Changes in H reflex amplitude were calculated in relationto basal measurement. For each measurement a hypothesis test was performed (Student t test).Results: In groups of patients with brain injury and incomplete spinal cord injury, a significantdifference was found between measurements of both studies, concerning variation in H reflexamplitude during the application of joint mobilization techniques, with a decrease in the experimentalgroup and an increase in the control group. In contrast, no significant differences werefound after mobilization therapy. Patients with complete spinal cord injury showed no significantdifferences in any measurements. Conclusion: We demonstrate the effectiveness of jointmobilization in the decrease of H reflex amplitude in patients with brain injury or incompletespinal cord injury during the mobilization maneuver, but no residual effect after completion ofthe trial. This research showed no evidence regarding excitability reduction in complete spinalcord injury. We suggest that therapeutic interventions to decrease muscle tone based on the jointmobilization should be reconsidered.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

A situation assessment uses reports from sensors to produce hypotheses about a situation at a level of aggregation that is of direct interest to a military commander. A low level of aggregation could mean forming tracks from reports, which is well documented in the tracking literature as track initiation and data association. In this paper there is also discussion on higher level aggregation; assessing the membership of tracks to larger groups. Ideas used in joint tracking and identification are extended, using multi-entity Bayesian networks to model a number of static variables, of which the identity of a target is one. For higher level aggregation a scheme for hypothesis management is required. It is shown how an offline clustering of vehicles can be reduced to an assignment problem.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background. The authors compared the efficacy of bilateral balanced and canine guidance (occlusal) splints in the treatment of temporomandibular joint (TMJ) pain in subjects who experienced joint clicking with a nonoccluding splint in a double-blind, controlled randomized clinical trial.Methods. The authors randomly assigned 57 people with signs of disk displacement and TMJ pain into three groups according to the type of splint: bilateral balanced, canine guidance and nonoccluding. The authors followed the groups for six months using analysis of a visual analog scale (VAS), palpation of the TMJ and masticatory muscles, mandibular movements and joint sounds. They used repeated analysis of variance and a XI test to test the hypothesis.Results. The type of guidance used did not influence the pain reduction; yet both occlusal splints were superior to the nonoccluding splint, on the basis of the VAS. Despite similar outcomes in relation to opening, left; lateral and protrusive movements, TMJ and muscle pain on palpation, subjects who used the occlusal splints had improved clinical outcomes. The frequency of joint noises decreased over time, with no significant differences among groups. Subjects in the groups using the occlusal splints reported more comfort.Conclusion. The type of lateral guidance did not influence the subjects'; improvement: All of the subjects had a general improvement on the VAS, though subjects in the occlusal splint groups had better results that did subjects in the nonoccluding splint group.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

BACKGROUND: Mechanical pain sensitivity is assessed in every patient with pain, either by palpation or by quantitative pressure algometry. Despite widespread use, no studies have formally addressed the usefulness of this practice for the identification of the source of pain. We tested the hypothesis that assessing mechanical pain sensitivity distinguishes damaged from healthy cervical zygapophysial (facet) joints. METHODS: Thirty-three patients with chronic unilateral neck pain were studied. Pressure pain thresholds (PPTs) were assessed bilaterally at all cervical zygapophysial joints. The diagnosis of zygapophysial joint pain was made by selective nerve blocks. Primary analysis was the comparison of the PPT between symptomatic and contralateral asymptomatic joints. The secondary end points were as follows: differences in PPT between affected and asymptomatic joints of the same side of patients with zygapophysial joint pain; differences in PPT at the painful side between patients with and without zygapophysial joint pain; and sensitivity and specificity of PPT for 2 different cutoffs (difference in PPT between affected and contralateral side by 1 and 30 kPa, meaning that the test was considered positive if the difference in PPT between painful and contralateral side was negative by at least 1 and 30 kPa, respectively). The PPT of patients was also compared with the PPT of 12 pain-free subjects. RESULTS: Zygapophysial joint pain was present in 14 patients. In these cases, the difference in mean PPT between affected and contralateral side (primary analysis) was −6.2 kPa (95% confidence interval: −19.5 to 7.2, P = 0.34). In addition, the secondary analyses yielded no statistically significant differences. For the cutoff of 1 kPa, sensitivity and specificity of PPT were 67% and 16%, respectively, resulting in a positive likelihood ratio of 0.79 and a diagnostic confidence of 38%. When the cutoff of 30 kPa was considered, the sensitivity decreased to only 13%, whereas the specificity increased to 95%, resulting in a positive likelihood ratio of 2.53 and a diagnostic confidence of 67%. The PPT was significantly lower in patients than in pain-free subjects (P < 0.001). CONCLUSIONS: Assessing mechanical pain sensitivity is not diagnostic for cervical zygapophysial joint pain. The finding should stimulate further research into a diagnostic tool that is widely used in the clinical examination of patients with pain.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Radiofrequency neurotomy is a recognized treatment for cervical zygapophysial joint pain. In several studies, the method has provided complete pain relief in 60-70% of the patients for approximately 9 months. The validated technique has the disadvantage of procedural times of 2-4 hours because several lesions are performed to take into account the variable nerve course. We tested the hypothesis that ultrasound localization of the nerves would enable us to reduce the number of lesions performed, while reaching the benchmark of at least 80% pain relief in 80% of patients with a median duration of 35 weeks, as achieved by a previous investigation using the standard method.