An analytical model for the underwater sound pressure waveforms radiated when an offshore pile is driven.

An analytical model has been developed for the pile vibration and consequent sound pressure and particle velocity radiated underwater when an offshore cylindrical pile is struck by a drop hammer. The model, which is based on the coupled equations of motion for axial and radial vibration of a thin cylindrical shell, yields frequency-dependent phase velocity and attenuation of these vibrations. The amplitude of the pulse of axial and radial displacement that travels down a pile following an axial impact is described in terms of the hammer properties. Solutions are obtained for the radiated sound pressure and particle velocity, using Junger and Feit's Transform Formulation of the Pressure Field of Cylindrical Radiators [(Acoustical Society of America, New York, 1993), p. 216]. The model is applied to published data on radiated noise from offshore driving of a steel pile. The modeled pressure waveforms at 12-m horizontal range and at 9 hydrophone depths correlate significantly with the measured waveforms. The modeled pressures of the initial positive peaks (appropriately low-pass filtered) agree with data to within 1 dB. The initial negative peaks however exceed the data by up to 7 dB, and as hydrophone depth increases, the model negative peaks have a maximum at 7 m, whereas the data have a maximum at 9 m.

Cutaneous T-cell Lymphoma Progression: A Potential Dupilumab Pitfall.

Dupilumab is a monoclonal antibody inhibiting key drivers in the inflammatory signaling cascade. It has been considered a saving grace for many patients suffering from severe atopic dermatitis and has quickly become a widespread treatment option for many inflammatory pathologies. However, recent reports have linked dupilumab with exacerbating symptoms and accelerated disease progression of cutaneous T-cell lymphoma (CTCL). This report presents the case of a 60-year-old African American female who was diagnosed with CTCL three months after her initial treatment with dupilumab for presumed atopic dermatitis. An appreciation of this unique relationship, as well as the morphological differences seen in patient presentation, is important for physicians to better guide timely diagnoses while working to uncover the true relationship between dupilumab and CTCL.

A Cross-Sectional Study Comparing Traumatic Alopecia Among B-Boys and B-Girls to Other Dance Styles and Its Impact on Dance Performance and Health.

INTRODUCTION: Breaking, often mislabeled as breakdancing in the media, is a dance style originating from the Bronx of New York in the early 1970s. A unique condition in this population is a form of alopecia known as "headspin hole," or "breakdancer overuse syndrome" of the scalp. This form of hair loss may show a variety of patterns based on the activities of the dancer. The purpose of this study was to investigate the relationship between alopecia and breaking, the level of concern dancers have regarding hair loss, barriers to medical treatment, and how it affects their dancing. METHODS: This was a cross-sectional study using an online survey. The survey addressed participants' demographics, hair, dancing styles, training, and health history. Questions about the effects of hair loss on the participants were also asked. RESULTS: This study found that there was a significant difference in hair loss among breakers compared to non-breakers. This was not seen after controlling for age and sex. However, the concern for hair loss was significant even after controlling for these variables. Similarly, hair loss was significantly associated with the frequency of headspins. Despite these concerns, breakers were less likely to seek medical attention. CONCLUSIONS: This study showed that there are significant disparities in hair loss between breaking and other dance styles. Hair loss due to breaking has been shown to have significant effects on an individual's concerns, which may be compounded by the fact that this population is less likely to seek out medical care and have significantly greater substance use compared to the other dancers surveyed. Further research is necessary to investigate interventions to prevent and treat hair loss in this population and the means to decrease the gap in health care in the dance population.

In vivo bioluminescence imaging for early detection and monitoring of disease progression in a murine model of neuroblastoma.

BACKGROUND: We evaluated the potential of bioluminescence imaging (BLI) for early tumor detection, demonstrating occult sites of disseminated disease and assessing disease progression in a murine model of neuroblastoma. METHODS: Neuroblastoma cells engineered to express the enzyme firefly luciferase were used to establish localized tumors and disseminated disease in SCID mice. Bioluminescent signal intensity was measured at serial time points, and compared with traditional methods of evaluating tumor growth. RESULTS: Bioluminescence imaging detected subcutaneous and retroperitoneal tumors weeks before they were palpable or appreciable by ultrasound. Bioluminescent signal intensity at both sites then paralleled tumor growth. After intravenous administration of tumor cells, BLI revealed disseminated disease in the liver, lungs, and bone marrow, again weeks before any gross disease was present. The presence of tumor within these sites at early time points was confirmed by reverse transcriptase-polymerase chain reaction. Finally, BLI permitted a real-time, noninvasive, quantitative method for following response to therapy in a model of minimal residual disease. CONCLUSION: Bioluminescence imaging detects tumor much earlier than traditional methods. In addition, it can detect, quantify, and follow micrometastasis in real-time during disease progression. This methodology is extremely valuable for studying tumor tissue tropism, mechanisms of metastasis, and response to therapy in murine tumor models.