Classifying hyperspectral airborne imagery for vegetation survey along coastlines

This paper studies the potential of airborne hyperspectral imagery for classifying vegetation along the Belgian coastlines. Here, the aim is to build vegetation maps using automatic classification. Besides a general linear multiclass classifier (Linear Discriminant Analysis), several strategies for combining binary classifiers are proposed: one based on a hierarchical decision tree, one based on the Hamming distance between the codewords obtained by binary classifiers and one based on the coupling of posterior probabilities. In addition, a new procedure is proposed for spatial classification smoothing. This procedure takes into account spatial information by letting the decision for classification of a pixel depend on the classification probabilities of neighboring pixels. This is shown to render smoother classification images

Hyperspectral data for coral reef monitoring. A case study: Fordate, Tanimbar, Indonesia

Coral reefs are endangered world-wide by devastating fishing methods (overfishing, dynamite and cyanide fishery), pollution, tourism, environmental changes and bleaching. The aim of this project is to monitor coral reefs and associated ecosystems (mangroves, sea-grass beds) by integrating different remote sensing data with spectral libraries and field measurements. The study area is Fordate, a small island to the northeast of Tanimbar, Indonesia. The monitoring system under development will enable not only the mapping of the coral reefs but also the localisation of those parts of the reefs that are most affected by degradation. A first test with hyperspectral data from the CHRIS/PROBA sensor shows promising results for the discrimination of different bottom-types on the Pulau Nukaha patch reef east of Fordate. Further field sampling and spectral measurements are needed to validate this preliminary classification

Evaluation of renal perfusion in hyperthyroid cats before and after radioiodine treatment

Background: Hyperthyroidism and chronic kidney disease (CKD) are common in elderly cats. Consequently, both diseases often occur concurrently. Furthermore, renal function is affected by thyroid status. Because changes in renal perfusion play an important role in functional renal changes in hyperthyroid cats, investigation of renal perfusion may provide novel insights. Objectives: To evaluate renal perfusion in hyperthyroid cats with contrast-enhanced ultrasound (CEUS). Animals: A total of 42 hyperthyroid cats was included and evaluated before and 1 month after radioiodine treatment. Methods: Prospective intrasubject clinical trial of contrast-enhanced ultrasound using a commercial contrast agent (SonoVue) to evaluate renal perfusion. Time-intensity curves were created, and perfusion parameters were calculated by off-line software. A linear mixed model was used to examine differences between pre-and post-treatment perfusion parameters. Results: An increase in several time-related perfusion parameters was observed after radioiodine treatment, indicating a decreased blood velocity upon resolution of the hyperthyroid state. Furthermore, a small post-treatment decrease in peak enhancement was present in the renal medulla, suggesting a lower medullary blood volume. Conclusions and Clinical Importance: Contrast-enhanced ultrasound indicated a higher cortical and medullary blood velocity and higher medullary blood volume in hyperthyroid cats before radioactive treatment in comparison with 1-month post-treatment control

Changing nationwide trends in endoscopic, medical and surgical admissions for inflammatory bowel disease: 2003-2013.

Background and study aims: In the last decade, there have been major advances in inflammatory bowel disease (IBD) management but their impact on hospital admissions requires evaluation. We aim to investigate nationwide trends in IBD surgical/medical elective and emergency admissions, including endoscopy and cytokine inhibitor infusions, between 2003 and 2013. Patients and methods: We used Hospital Episode Statistics and population data from the UK Office for National Statistics. Results: Age-sex standardised admission rates increased from 76.5 to 202.9/100 000 (p<0.001) and from 69.5 to 149.5/100 000 (p<0.001) for Crohn's disease (CD) and ulcerative colitis (UC) between 2003-2004 and 2012-2013, respectively. Mean length of stay (days) fell significantly for elective (from 2.6 to 0.7 and from 2.0 to 0.7 for CD and UC, respectively) and emergency admissions (from 9.2 to 6.8 and from 10.8 to 7.6 for CD and UC, respectively). Elective lower gastrointestinal (GI) endoscopy rates decreased from 6.3% to 3.7% (p<0.001) and from 18.4% to 17.6% (p=0.002) for CD and UC, respectively. Elective major abdominal surgery rates decreased from 2.8% to 1.0% (p<0.001) and from 4.9 to 2.4 (p=0.010) for CD and UC, respectively, with emergency rates also decreasing significantly for CD. Between 2006-2007 and 2012-2013, elective admission rates for cytokine-inhibitor infusions increased from 11.1 to 57.2/100 000 and from 1.4 to 12.1/100 000 for CD and UC, respectively. Conclusions: Rising IBD hospital admission rates in the past decade have been driven by an increase in the incidence and prevalence of IBD. Lower GI endoscopy and surgery rates have fallen, while cytokine inhibitor infusion rates have risen. There has been a concurrent shift from emergency care to shorter elective hospital stays. These trends indicate a move towards more elective medical management and may reflect improvements in disease control

Square patterns in Rayleigh-Benard convection with rotation about a vertical axis

We present experimental results for Rayleigh-Benard convection with rotation about a vertical axis at dimensionless rotation rates in the range 0 to 250 and upto 20% above the onset. Critical Rayleigh numbers and wavenumbers agree with predictions of linear stability analysis. For rotation rates greater than 70 and close to onset, the patterns are cellular with local four-fold coordination and differ from the theoretically expected Kuppers-Lortz unstable state. Stable as well as intermittent defect-free square lattices exist over certain parameter ranges. Over other ranges defects dynamically disrupt the lattice but cellular flow and local four-fold coordination is maintained.Comment: ReVTeX, 4 pages, 7 eps figures include