On the Kernel function of the integral equation relating lift and downwash distributions of oscillating wings in supersonic flow

This report treats the Kernel function of the integral equation that relates a known or prescribed downwash distribution to an unknown lift distribution for harmonically oscillating wings in supersonic flow. The treatment is essentially an extension to supersonic flow of the treatment given in NACA report 1234 for subsonic flow. For the supersonic case the Kernel function is derived by use of a suitable form of acoustic doublet potential which employs a cutoff or Heaviside unit function. The Kernel functions are reduced to forms that can be accurately evaluated by considering the functions in two parts: a part in which the singularities are isolated and analytically expressed, and a nonsingular part which can be tabulated

Ejector Noise Suppression with Auxiliary Jet Injection

An experimental program to reduce aircraft jet turbulence noise investigated the interaction of small auxiliary jets with a larger main jet. Significant reductions in the far field jet noise were obtained over a range of auxiliary jet pressures and flow rates when used in conjunction with an acoustically lined ejector. While the concept is similar to that of conventional ejector suppressors that use mechanical mixing devices, the present approach should improve thrust and lead to lower weight and less complex noise suppression systems since no hardware needs to be located in the main jet flow. A variety of auxiliary jet and ejector configurations and operating conditions were studied. The best conditions tested produced peak to peak noise reductions ranging from 11 to 16 dB, depending on measurement angle, for auxiliary jet mass flows that were 6.6% of the main jet flow with ejectors that were 8 times the main jet diameter in length. Much larger reductions in noise were found at the original peak frequencies of the unsuppressed jet over a range of far field measurement angles

On the need for an international effort to capture, share and use crystallization screening data

Development of an ontology for the description of crystallization experiments and results is proposed

Updating Photon-Based Normal Tissue Complication Probability Models for Pneumonitis in Patients With Lung Cancer Treated With Proton Beam Therapy

Purpose: No validated models for predicting the risk of radiation pneumonitis (RP) with proton beam therapy (PBT) currently exist. Our goal was to externally validate and recalibrate multiple established photon-based normal tissue complication probability models for RP in a cohort with locally advanced nonsmall cell lung cancer treated with contemporary doses of chemoradiation using PBT. Methods and Materials: The external validation cohort consisted of 99 consecutive patients with locally advanced nonsmall cell lung cancer treated with chemoradiation using PBT. RP was retrospectively scored at 3 and 6 months posttreatment. We evaluated the performance of the photon Quantitative Analyses of Normal Tissue Effects in the Clinic (QUANTEC) pneumonitis model, the QUANTEC model adjusted for clinical risk factors, and the newer Netherlands updated QUANTEC model. A closed testing procedure was performed to test the need for model updating, either by recalibration-in-the-large (re-estimation of intercept), recalibration (re-estimation of intercept/slope), or model revision (re-estimation of all coefficients). Results: There were 21 events (21%) of ≥grade 2 RP. The closed testing procedure on the PBT data set did not detect major deviations between the models and the data and recommended adjustment of the intercept only for the photon-based Netherlands updated QUANTEC model (intercept update: –1.2). However, an update of the slope and revision of the model coefficients were not recommended by the closed testing procedure, as the deviations were not significant within the power of the data. Conclusions: The similarity between the dose-response relationship for PBT and photons for normal tissue complications has been an assumption until now. We demonstrate that the preexisting, widely used photon based models fit our PBT data well with minor modifications. These now-validated and updated normal tissue complication probability models can aid in individualizing selection of the most optimal treatment technique for a particular patient

Changes in use of herbs and dietary supplements (HDS) among clinicians enrolled in an online curriculum

<p>Abstract</p> <p>Background</p> <p>Little is known about clinicians' use of herbs and dietary supplements (HDS), how their personal HDS use changes with time and training, and how changes in their personal use affect their confidence or communication with patients about HDS.</p> <p>Methods</p> <p>We conducted a prospective cohort study of clinicians before and after an on-line curriculum about HDS in winter-spring, 2005.</p> <p>Results</p> <p>Of the 569 clinicians who completed surveys both at baseline and after the course, 25% were male and the average age was 42 years old; 88% used HDS before and after the course. The average number of supplements used fell slightly from 6.2 at baseline to 5.8 after the course (P < 0.01). The most commonly used supplements at baseline were: multivitamins (65%), calcium (42%), B vitamins (34%), vitamin C (34%), green tea (27%), fish oil (27%) and vitamin E (25%). Use of fish oil increased to 30% after the course (P = 0.01). Use of supplements traditionally used to treat colds decreased: vitamin C (34% to 27%), zinc (13% to 10%), and echinacea (7% to 5%, P < 0.05 for all three). Changes in personal HDS use were not associated with significant changes in confidence or communication with patients.</p> <p>Conclusion</p> <p>Many clinicians use HDS personally; use changes seasonally and to a small extent with professional education. Professional use of HDS is dynamic and seasonal. Additional research is needed to understand the impact of personal use on professional attitudes and behavior in populations with lower baseline uses of HDS.</p

Identification of the Rostral Migratory Stream in the Canine and Feline Brain

In the adult rodent brain, neural progenitor cells migrate from the subventricular zone of the lateral ventricle towards the olfactory bulb in a track known as the rostral migratory stream (RMS). To facilitate the study of neural progenitor cells and stem cell therapy in large animal models of CNS disease, we now report the location and characteristics of the normal canine and feline RMS. The RMS was found in Nissl-stained sagittal sections of adult canine and feline brains as a prominent, dense, continuous cellular track beginning at the base of the anterior horn of the lateral ventricle, curving around the head of the caudate nucleus and continuing laterally and ventrally to the olfactory peduncle before entering the olfactory tract and bulb. To determine if cells in the RMS were proliferating, the thymidine analog 5-bromo-2-deoxyuridine (BrdU) was administered and detected by immunostaining. BrdU-immunoreactive cells were present throughout this track. The RMS was also immunoreactive for markers of proliferating cells, progenitor cells and immature neurons (Ki-67 and doublecortin), but not for NeuN, a marker of mature neurons. Luxol fast blue and CNPase staining indicated that myelin is closely apposed to the RMS along much of its length and may provide guidance cues for the migrating cells. Identification and characterization of the RMS in canine and feline brain will facilitate studies of neural progenitor cell biology and migration in large animal models of neurologic disease

Perceived efficacy of herbal remedies by users accessing primary healthcare in Trinidad

BACKGROUND: The increasing global popularity of herbal remedies requires further investigation to determine the probable factors driving this burgeoning phenomenon. We propose that the users' perception of efficacy is an important factor and assessed the perceived efficacy of herbal remedies by users accessing primary health facilities throughout Trinidad. Additionally, we determined how these users rated herbal remedies compared to conventional allopathic medicines as being less, equally or more efficacious. METHODS: A descriptive cross-sectional study was undertaken at 16 randomly selected primary healthcare facilities throughout Trinidad during June-August 2005. A de novo, pilot-tested questionnaire was interviewer-administered to confirmed herbal users (previous or current). Stepwise multiple regression analysis was done to determine the influence of predictor variables on perceived efficacy and comparative efficacy with conventional medicines. RESULTS: 265 herbal users entered the study and cited over 100 herbs for the promotion of health/wellness and the management of specific health concerns. Garlic was the most popular herb (in 48.3% of the sample) and was used for the common cold, cough, fever, as 'blood cleansers' and carminatives. It was also used in 20% of hypertension patients. 230 users (86.8%) indicated that herbs were efficacious and perceived that they had equal or greater efficacy than conventional allopathic medicines. Gender, ethnicity, income and years of formal education did not influence patients' perception of herb efficacy; however, age did (p = 0.036). Concomitant use of herbs and allopathic medicines was relatively high at 30%; and most users did not inform their attending physician. CONCLUSION: Most users perceived that herbs were efficacious, and in some instances, more efficacious than conventional medicines. We suggest that this perception may be a major contributing factor influencing the sustained and increasing popularity of herbs. Evidence-based research in the form of randomized controlled clinical trials should direct the proper use of herbs to validate (or otherwise) efficacy and determine safety. In the Caribbean, most indigenous herbs are not well investigated and this points to the urgent need for biomedical investigations to assess the safety profile and efficacy of our popular medicinal herbs