The light's in my eyes: optical modeling demonstrates wind is more important than sea surface-reflected sunlight for foraging herons.

Multiple lineages of birds have independently evolved foraging strategies that involve catching aquatic prey by striking at them through the water's surface. Diurnal, visual predators that hunt across the air-water interface encounter several visual challenges, including sun glint, or reflection of sunlight by the water surface. Intense sun glint is common at the air-water interface, and it obscures visual cues from submerged prey. Visually-hunting, cross-media predators must therefore solve the problem of glint to hunt effectively. One obvious solution is to turn away from the sun, which would result in reduction of glint effects. However, turning too far will cast shadows over prey, causing them to flee. Therefore, we hypothesized that foraging herons would orient away from, but not directly opposite to the sun. Our ability to understand how predators achieve a solution to glint is limited by our ability to quantify the amount of glint that free-living predators are actually exposed to under different light conditions. Herons (Ardea spp.) are a good model system for answering questions about cross-media hunting because they are conspicuous, widely distributed, and forage throughout a variety of aquatic habitats, on a variety of submerged prey. To test our hypothesis, we employed radiative transfer modeling of water surface reflectance, drawn from optical oceanography, in a novel context to estimate the visual exposure to glint of free-living, actively foraging herons. We found evidence that Ardea spp. do not use body orientation to compensate for sun glint while foraging and therefore they must have some other, not yet understood, means of compensation, either anatomical or behavioral. Instead of facing away from the sun, herons tended to adjust their position to face into the wind at higher wind speeds. We suggest that radiative transfer modeling is a promising tool for elucidating the ecology and evolution of air-to-water foraging systems.

Influence of carboplatin infusion on osteosarcoma blood flow.

PURPOSE: Herein we report that carboplatin infusion influenced tumor blood flow signal independent of the mechanical decompression induced by the artificial lymphatics system technology that was being evaluated as part of a randomized veterinary clinical trial, treating spontaneously occurring canine appendicular osteosarcoma, a tumor very similar to its human counterpart. METHODS: Blood flow within the central region of the tumor was recorded continuously using laser Doppler flowmetry, a real-time measurement technology. Time-averaged flow values were computed from segments taken from the recordings immediately before starting carboplatin infusion, and during infusion. RESULTS: Carboplatin increased the tumor blood flow signal by an additional 59 +/- 26% (mean +/- SEM; p = 0.06) over the increase induced by the decompression. The increase started within 49 +/- 46 s after the start of infusion, had a response time constant of 19 +/- 21 s and persisted throughout the infusion, ending shortly after infusion ended. CONCLUSION: The rapidity of the flow signal increase suggests that carboplatin may have an autonomic effect on circulation, either local or systemic. The observations identify a new action of this drug and suggest a possible mechanism to exploit therapeutically.

Use of an artificial lymphatic system during carboplatin infusion to improve canine osteosarcoma blood flow and clinical response.

BACKGROUND: The artificial lymphatic system (ALS), a mechanical system designed to reduce increased interstitial fluid pressure in solid tumors and enhance the delivery of chemotherapy, was evaluated within a randomized clinical trial treating spontaneously occurring canine appendicular osteosarcoma (OS), a tumor similar to its human OS counterpart. METHODS: An ALS was investigated for its ability to increase OS blood flow and increase uptake of intravenously administered carboplatin. RESULTS: Blood flow increased by 314% in tumors with active ALS drains versus 126% in control tumors (P < .03). Tumor carboplatin uptake increased by 51% after drain activation (P = .07). Microvascular density (MVD) was measured in tumors after surgical amputation and in corresponding bone regions in a cohort of normal dogs. The OS tumors had equivalent MVD as normal bone, and MVD was higher in the humerus than the femur (P < .03) in both tumor and normal bone. Median survival between the ALS-treated and control cohorts was not different despite increased drug uptake or ALS manipulation. Compared with historic controls, ALS drain insertion into tumors to reduce interstitial fluid pressure did not worsen the prognosis. CONCLUSIONS: The findings in canine spontaneously occurring OS indicate that an ALS may be of value as a chemotherapy adjunct for enhancing the delivery of chemotherapy to tumor interstitium.

The University of California at San Francisco international orthopaedic elective.

International volunteerism helps remedy global inequities in orthopaedic care and provides relief for increasing professional disillusionment experienced by many orthopaedic surgeons in the United States. From 1992 to 1998, 41% of residents from the Department of Orthopaedic Surgery at the University of California, San Francisco volunteered overseas. Approximately one half of those have continued volunteering internationally after residency, including many who led later trips with residents. Based on the success of these trips, the University of California, San Francisco Department of Orthopaedic Surgery established a 1-month elective rotation in Umtata, South Africa in conjunction with Orthopaedics Overseas. Seventy-six percent of residents have chosen this opportunity since the program's inception in 1998. The University of California, San Francisco experience suggests that early exposure to international volunteerism during residency promotes continued participation in volunteer activities after graduation. By providing residents with the opportunity to volunteer overseas, the University of California, San Francisco hopes to enhance resident education, foster a lifelong spirit of volunteerism, and serve as a model for other orthopaedic training programs.