8,275 research outputs found
Photon counting compressive depth mapping
We demonstrate a compressed sensing, photon counting lidar system based on
the single-pixel camera. Our technique recovers both depth and intensity maps
from a single under-sampled set of incoherent, linear projections of a scene of
interest at ultra-low light levels around 0.5 picowatts. Only two-dimensional
reconstructions are required to image a three-dimensional scene. We demonstrate
intensity imaging and depth mapping at 256 x 256 pixel transverse resolution
with acquisition times as short as 3 seconds. We also show novelty filtering,
reconstructing only the difference between two instances of a scene. Finally,
we acquire 32 x 32 pixel real-time video for three-dimensional object tracking
at 14 frames-per-second.Comment: 16 pages, 8 figure
Radical Hysterectomy with Pelvic Lymphadenectomy: Indications, Technique, and Complications
Radical hysterectomy with pelvic lymphadenectomy remains the treatment of choice for women with Stages IA2 and IB1 carcinoma of the cervix, and selected patients with Stage II endometrial cancer. Improvement in surgical techniqe, administration of prophylactic antibiotics, thromboemolic prophylaxis, and advances in critical care medicine have resulted in lower operative morbidity associated with this procedure. Major urinary tract complications such as ureteral injury or vesico-vaginal fistula are now extremely rare (<1%). Five-year survival rates following this procedure vary according to a number of clinical and histologic variables, and may be as high as 90% in women without lymph node metastases
Point Process Algorithm: A New Bayesian Approach for Planet Signal Extraction with the Terrestrial Planet Finder
The capability of the Terrestrial Planet Finder Interferometer (TPF-I) for
planetary signal extraction, including both detection and spectral
characterization, can be optimized by taking proper account of instrumental
characteristics and astrophysical prior information. We have developed the
Point Process Algorithm (PPA), a Bayesian technique for extracting planetary
signals using the sine-chopped outputs of a dual nulling interferometer. It is
so-called because it represents the system being observed as a set of points in
a suitably-defined state space, thus providing a natural way of incorporating
our prior knowledge of the compact nature of the targets of interest. It can
also incorporate the spatial covariance of the exozodi as prior information
which could help mitigate against false detections. Data at multiple
wavelengths are used simultaneously, taking into account possible spectral
variations of the planetary signals. Input parameters include the RMS
measurement noise and the a priori probability of the presence of a planet. The
output can be represented as an image of the intensity distribution on the sky,
optimized for the detection of point sources. Previous approaches by others to
the problem of planet detection for TPF-I have relied on the potentially
non-robust identification of peaks in a "dirty" image, usually a correlation
map. Tests with synthetic data suggest that the PPA provides greater
sensitivity to faint sources than does the standard approach (correlation map +
CLEAN), and will be a useful tool for optimizing the design of TPF-I.Comment: 17 pages, 6 figures. AJ in press (scheduled for Nov 2006
Evaluation of herbal cannabis characteristics by medical users: a randomized trial
BACKGROUND: Cannabis, in herbal form, is widely used as self-medication by patients with diseases such as HIV/AIDS and multiple sclerosis suffering from symptoms including pain, muscle spasticity, stress and insomnia. Valid clinical studies of herbal cannabis require a product which is acceptable to patients in order to maximize adherence to study protocols. METHODS: We conducted a randomized controlled crossover trial of 4 different herbal cannabis preparations among 8 experienced and authorized cannabis users with chronic pain. Preparations were varied with respect to grind size, THC content and humidity. Subjects received each preparation on a separate day and prepared the drug in their usual way in a dedicated and licensed clinical facility. They were asked to evaluate the products based on appearance (smell, colour, humidity, grind size, ease of preparation and overall appearance) and smoking characteristics (burn rate, hotness, harshness and taste). Five-point Likert scores were assigned to each characteristic. Scores were compared between preparations using ANOVA. RESULTS: Seven subjects completed the study, and the product with highest THC content (12%), highest humidity (14%) and largest grind size (10 mm) was rated highest overall. Significant differences were noted between preparations on overall appearance and colour (p = 0.003). DISCUSSION: While the small size of the study precludes broad conclusions, the study shows that medical cannabis users can appreciate differences in herbal product. A more acceptable cannabis product may increase recruitment and retention in clinical studies of medical cannabis
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