Masticatory muscle reaction in simulated low-velocity rear-end impacts

AIMS: To evaluate the electromyographic (EMG) activity of masseter and temporalis muscles in relation to impact awareness, gender, impact magnitude, and kinematics of head movement in simulated low-velocity rear-end impacts. METHODS: Twenty-nine individuals (17 men and 12 women) were subjected in random order to 3 rear-end impacts: 2 unexpected impacts (chair accelerations of 4.5 m/s2 and 10.1 m/s2) and 1 expected impact (chair acceleration of 10.1 m/s2). The EMG activity of the deep and superficial masseter muscle was recorded bilaterally. EMG activity was also recorded for the left anterior temporalis muscle. Angular acceleration and angular displacement of the head were also recorded. The temporal relationship between onset of the masticatory muscle activity and maximum peak of the kinematics of head movement was determined. RESULTS: The magnitude of normalized masticatory EMG activity ranged from 1.4 to 1.8 times higher (P < .05) for fast unexpected impacts compared to slow unexpected impacts in all masticatory muscles. The magnitude of normalized anterior temporalis EMG peak response ranged from 1.8 to 2.5 times higher (P < .05) in female subjects than in male subjects for all impacts. No significant differences were identified for impact awareness in the magnitude of normalized EMG activity for any masticatory muscle. No significant differences were identified with respect to timing of masticatory muscle response (P > .05). CONCLUSION: EMG activity increased with increased impact magnitude. Temporal and amplitude awareness of a simulated impact did not produce a difference in the masticatory muscle response. Gender differences were identified in the anterior temporalis muscle response. The onset of the masticatory muscle response occurred after peak angular acceleration of the head but prior to peak angular displacement of the head.     

Distance from Typical Scan Path When Viewing Complex Stimuli in Children with Autism Spectrum Disorder and its Association with Behavior

Journal of Autism and Developmental Disorders - Eye-tracking is often used to study attention in children with autism spectrum disorder (ASD). Previous research has identified multiple atypical...     

Locus of control moderates the relationship between headache pain and depression

The aim of the current study was to triangulate qualitative and quantitative data in order to examine in greater detail the relationship between self-reported headache pain severity, depression and coping styles. Psychosocial scales, headache characteristic scales and in-depth interviews were administered to 71 adults with the diagnosis of primary headache. Regression analyses with the scales showed that greater self-reported headache pain severity was associated with higher levels of depression. A high internal locus of control weakened the relationship between the headache severity and depression variables. The qualitative data supported the relationship between pain severity and internal locus of control and, in addition, revealed that perceived efficacy of pharmacologic intervention might be a related factor. The results suggested that stronger coping skills might reduce depression among headache sufferers.     

The salivary microbiota as a diagnostic indicator of oral cancer: A descriptive,non-randomized study of cancer-free and oral squamous cell carcinoma subjects

Background  

The purpose of the present investigation was to determine if the salivary counts of 40 common oral bacteria in subjects with an oral squamous cell carcinoma (OSCC) lesion would differ from those found in cancer-free (OSCC-free) controls.     

Multicenter retrospective development and validation of a clinical prediction rule for nosocomial invasive candidiasis in the intensive care setting

The study presented here was performed in order to create a rule that identifies subjects at high risk for invasive candidiasis in the intensive care setting. Retrospective review and statistical modelling were carried out on 2,890 patients who stayed at least 4 days in nine hospitals in the USA and Brazil; the overall incidence of invasive candidiasis in this group was 3% (88 cases). The best performing rule was as follows: Any systemic antibiotic (days 1–3) OR presence of a central venous catheter (days 1–3) AND at least TWO of the following—total parenteral nutrition (days 1–3), any dialysis (days 1–3), any major surgery (days −7–0), pancreatitis (days −7–0), any use of steroids (days −7–3), or use of other immunosuppressive agents (days −7–0). The rate of invasive candidiasis among patients meeting the rule was 9.9%, capturing 34% of cases in the units, with the following performance: relative risk 4.36, sensitivity 0.34, specificity 0.90, positive predictive value 0.01, and negative predictive value 0.97. The rule may identify patients at high risk of invasive candidiasis. Results of this project were partially presented at Focus on Fungal Infections 14, New Orleans, LA, USA, 2004. Abstract no. 51.