Predicting postoperative gait in cerebral palsy.

In this work, postoperative lower limb kinematics are predicted with respect to preoperative kinematics, physical examination and surgery data. Data of 115 children with cerebral palsy that have undergone single-event multilevel surgery were considered. Preoperative data dimension was reduced utilizing principal component analysis. Then, multiple linear regressions with 80% confidence intervals were performed between postoperative kinematics and bilateral preoperative kinematics, 36 physical examination variables and combinations of 9 different surgical procedures. The mean prediction errors on test vary from 4° (pelvic obliquity and hip adduction) to 10° (hip rotation and foot progression), depending on the kinematic angle. The unilateral mean sizes of the confidence intervals vary from 5° to 15°. Frontal plane angles are predicted with the lowest errors, however the same performance is achieved when considering the postoperative average signals. Sagittal plane angles are better predicted than transverse plane angles, with statistical differences with respect to the average postoperative kinematics for both plane's angles except for ankle dorsiflexion. The mean prediction errors are smaller than the variability of gait parameters in cerebral palsy. The performance of the system is independent of the preoperative state severity of the patient. Even if the system is not yet accurate enough to define a surgery plan, it shows an unbiased estimation of the most likely outcome, which can be useful for both the clinician and the patient. More patients' data are necessary for improving the precision of the model in order to predict the kinematic outcome of a large number of possible surgeries and gait patterns.

A multi-site analysis of the association between black carbon concentrations and vehicular idling, traffic, background pollution, and meteorology during school dismissals.

A study was performed to assess the relationship between black carbon (BC), passing traffic, and vehicular idling outside New York City (NYC) schools during student dismissal. Monitoring was performed at three school sites in East Harlem, the Bronx, and Brooklyn for 1month per year over a two-year period from November 2006-October 2008. Monitoring at each site was conducted before and after the Asthma Free School Zone (AFSZ) asthma reduction education program was administered. Real-time equipment with a one-minute averaging interval was used to obtain the BC data, while volume counts of idling and passing school busses, trucks, and automobiles were collected each minute by study staff. These data were matched to ambient PM(2.5) and meteorology data obtained from the New York State Department of Environmental Conservation. A generalized additive model (GAM) model was run to examine the relationship between BC concentration and each variable while accounting for site-to-site differences. F-tests were employed to assess the significance of each of the predictor variables. The model results suggested that variability in ambient PM(2.5) concentration contributed 24% of the variability in transformed BC concentration, while variability in the number of idling busses and trucks on the street during dismissal contributed 20% of the variability in transformed BC concentration. The results of this study suggest that a combination of urban scale and local traffic control approaches in combination with cessation of school bus idling will produce improved local BC concentration outside schools.

[Human immunodeficiency virus infection in an emergency department]. / Infección por virus de la inmunodeficiencia humana en un servicio de Urgencias.

Unlabeled serum samples from patients attended at the Emergency Department of our Hospital were collected for a 10-week period to measure the presence of anti-HIV antibodies and assess the prevalence of the infection in this population. Both suspected (with warning mark on samples) and non-suspected patients of having the infection were included. Concurrently, health care personnel in the Emergency Department were asked to complete a questionnaire on issues concerning the knowledge of this infection and the precautions to adopt. The compliance of these measures was verified. Only 3 from the 2,293 samples from nonsuspected patients were positive (0.13%). The 79 samples from suspected patients corresponded to 44 persons with previously known infection and 35 persons engaging in high-risk behaviours; from the latter group 11 were ultimately positive. Although health care personnel was aware of precautions, they only adopted them with suspected patients but incorrectly. Thus, there was inconsistency between the perceived risk by health care personnel and the precautions adopted. While the prevalence of HIV infection is still low in the attended population at the Emergency Department, efforts must be made to decrease accidental exposures, as an increase in its prevalence is to be expected.