Advocacy training in US advanced pediatric dentistry training programs

PURPOSE: This study: (1) assessed pediatric dentistry residency program directors' attitudes toward and involvement in advocacy training; and (2) identified types and extent of advocacy training in U.S. pediatric dentistry programs. METHODS: Between October 2005 and February 2006, all 66 pediatric dentistry residency program directors were invited to complete a 62-item online questionnaire. The survey investigated: (1) directors' attitudes toward advocacy training; (2) nature of advocacy training offered during residency; (3) extent of resident involvement in different settings; and (4) directors' involvement in advocacy. RESULTS: Forty-two program directors responded (64%). Overall, respondents agreed that advocacy by pediatric dentists for children beyond the dental office was important and that residency programs should provide advocacy training. Most programs did not routinely offer advocacy opportunities in nonclinical settings. Over half of programs required community outreach clinic rotations for all residents. One third offered didactic curriculum in the legislative process. Over 50% of program directors reported personal involvement in legislative oral health lobbying within 3 years, but fewer than a third were involved with professional political action committees (PACs). CONCLUSIONS: Advocacy is seen as on important in pediatric dentistry but variation in attitudes of program directors and program offerings exists in US training programs.     

The role of nitric oxide in orthodontic tooth movement in rats

Nitric oxide (NO) is involved in second messenger formation, osteoblast and osteoclast function, and pulpal blood flow. This raises the question of whether or not altered NO production interferes with orthodontic tooth movement (OTM) by influencing the bone remodeling cycle. To investigate the role of NO in OTM, a rat model was established and 48 rats were divided into four study groups of 12 rats each. A 5 mm nickel-titanium closed-coil spring was ligated between the right maxillary incisor and first molar of each rat to deliver an initial force of 60 g. A saline group received subperiosteal injections of normal saline (50 microL/kg), an L-arginine (L-arg) group received L-arginine (NO precursor) injections (200 mg/kg), and a, L-NAME group received N(G)-nitro-L-arginine methyl ester (nitric oxide synthase inhibitor)(10 mg/kg) injections. All injections were given in the upper right first molar mucosa from the first through the 11th day of force application at 48-hour intervals. A control group received no injections. Tooth movement measurements were done at the time of injections. Animals were sacrificed 13 days after appliance insertion and final OTMs were measured at the time of sacrifice. From the third day till the end of the experiment, the L-arg group showed a significant increase in tooth movements, whereas the L-NAME group showed a significant decrease in tooth movements compared to the control and saline group (P < .001). Histopathologic studies revealed that the number of osteoclasts was significantly higher in the L-arg group smears, while the number of osteoclasts in the L-NAME group was significantly lower as compared to the control group (P < .001). Scanning electron microscope analysis showed that the force-induced root resorption in the L-arg group was less than the control group. This study suggests a role for NO in the bone remodeling cycle.     

A new method for the solution of hybrid analog digital beamforming problems

By going to millimeter wave (mmWave) we can use large scale MIMO due to short mmWave wavelength to overcome path loss by using beamforming to focus power of signal to the receiver. System structure of mmWave band is different with conventional MIMO because of large scale MIMO which is leading to use many RF-chains. For this reason Hybrid structure have been proposed for large Scale MIMO. By going to Hybrid structure a new issue has been created with phase shifter constraint. In this paper we propose a novel solution to make a hybrid precoding and combing to reach high spectral efficiency. Our problem includes a maximizing Frobenius norm of multiplying five complex matrices. As constraints, all elements of some matrices must have unit norm, and also the multiplication of some matrices must have a specific Frobenius norm. A novel solution is proposed for the problem, which is gained in two steps. At the first step, we propose a new decomposition usable for kind of complex matrices which could lead to reduce the dimension of the objective function, and eliminating constraints completely and in the second step, we propose an iterated algorithm for the resulting problem. By proposing another novel technique, we show that in each iteration, the optimal problem is equivalent to a quadratic optimal problem with limitations on the vector norm, and as a result, an optimal problem is obtained quickly. Moreover, some other real examples are included to demonstrate the usefulness and effectiveness of the proposed algorithm.     

Immunological role of CD4<Superscript>+</Superscript>CD28<Superscript>null</Superscript> T lymphocytes,natural killer cells,and interferon-gamma in pediatric patients with sickle cell disease: relation to disease severity and response to therapy

Sickle cell disease (SCD) is associated with alterations in immune phenotypes. CD4⁺CD28^null T lymphocytes have pro-inflammatory functions and are linked to vascular diseases. To assess the percentage of CD4⁺CD28^null T lymphocytes, natural killer cells (NK), and IFN-gamma levels, we compared 40 children and adolescents with SCD with 40 healthy controls and evaluated their relation to disease severity and response to therapy. Patients with SCD steady state were studied, focusing on history of frequent vaso-occlusive crisis, hydroxyurea therapy, and IFN-gamma levels. Analysis of CD4⁺CD28^null T lymphocytes and NK cells was done by flow cytometry. Liver and cardiac iron overload were assessed. CD4⁺CD28^null T lymphocytes, NK cells, and IFN-gamma levels were significantly higher in patients than controls. Patients with history of frequent vaso-occlusive crisis and those with vascular complications had higher percentage of CD4⁺CD28^null T lymphocytes and IFN-gamma while levels were significantly lower among hydroxyurea-treated patients. CD4⁺CD28^null T lymphocytes were positively correlated to transfusional iron input while these cells and IFN-gamma were negatively correlated to cardiac T2* and duration of hydroxyurea therapy. NK cells were correlated to HbS and indirect bilirubin. Increased expression of CD4⁺CD28^null T lymphocytes highlights their role in immune dysfunction and pathophysiology of SCD complications.     

Spatial and statistical analyses of the relations between vegetation cover and incidence of cutaneous leishmaniasis in an endemic province,northeast of Iran

Objective

To investigate the relations between the vegetation cover and occurrence of cutaneous leishmaniasis (CL) in Golestan province during 2010-2012.

Methods

Data of monthly CL incidence and remote sensing normalized difference vegetation index (NDVI) of moderate resolution imaging spectroradiometer sensor were used in the study. Pearson''s correlation analysis was conducted to examine the type and strength of relationships between the spatially averaged NDVI variables (i.e. minimum, maximum and mean NDVI values) and CL incidence in township level. Spearman rank correlation was carried out to explain associations between the monthly CL incidence and NDVI variables at 0, 1, 2, 3 and 4 months lagged periods. Locations of CL cases at village level were geocoded and compared with frequency of CL cases in each NDVI-derived vegetation categories.

Results

Pearson''s analysis revealed significant associations between the NDVI variables and CL incidence at the township level (P<0.05). Results of Spearman analysis indicated that the highest correlations between NDVI variables and monthly CL incidence were established when the NDVI time-series lagged the CL incidence series NDVI variables. Purely spatial analysis demonstrated that despite majority of cases occurred at partially-vegetated areas, the possibility of CL occurrence was higher in bare soil areas by taking into account area of each vegetation zones.

Conclusions

lack or low vegetation cover is a major determinant of CL frequencies in Golestan province. The decrease of the mean vegetation density in townships is accompanied by increase of CL occurrence and vice versa.