The Influence of Particle Concentration and Bulk Characteristics on Polarized Oceanographic Lidar Measurements

Oceanographic lidar measurements of the linear depolarization ratio, δ, contain information on the bulk characteristics of marine particles that could improve our ability to study ocean biogeochemistry. However, a scarcity of information on the polarized light-scattering properties of marine particles and the lack of a framework for separating single and multiple scattering effects on δ have hindered the development of polarization-based retrievals of bulk particle properties. To address these knowledge gaps, we made single scattering measurements of δ for several compositionally and morphologically distinct marine particle assemblages. We then used a bio-optical model to explore the influence of multiple scattering and particle characteristics on lidar measurements of δ made during an expedition to sample a mesoscale coccolithophore bloom. Laboratory measurements of linear depolarization revealed a complex dependency on particle shape, size, and composition that were consistent with scattering simulations for idealized nonspherical particles. Model results suggested that the variability in δ measured during the field expedition was driven predominantly by shifts in particle concentration rather than their bulk characteristics. However, model estimates of δ improved when calcite particles were represented by a distinct particle class, highlighting the influence of bulk particle properties on δ. To advance polarized lidar retrievals of bulk particle properties and to constrain the uncertainty in satellite lidar retrievals of particulate backscattering, these results point to the need for future efforts to characterize the variability of particulate depolarization in the ocean and to quantify the sensitivity of operational ocean lidar systems to multiple scattering

Fighting Global Disparities in Cancer Care:A Surgical Oncology View

Cancer is the second leading cause of death globally after cardiovascular disease. Long-term cancer survival has improved in the Western world due to early detection and the use of effective combined treatment modalities, as well as the development of effective immunotherapy and drug-targeted therapy. Surgery is still the mainstay for most solid tumors; however, low- and middle-income countries are facing an increasing lack of primary surgical care for easily treatable conditions, including breast, colon, and head and neck cancers. In this paper, a surgical oncology view is presented to elaborate how the Western surgical oncologist can take part in the 'surgical fight' against global disparities in cancer care, and a plea is made to strive for structural solutions, such as a partnership in surgical oncology training. The pros and cons of the use of eHealth and mHealth technologies and education programs for schools and the community are discussed as these create an opportunity to reach a large portion of the population in these countries, at low cost and with high impact

Rapid climate-driven circulation changes threaten conservation of endangered north atlantic right whales

As climate trends accelerate, ecosystems will be pushed rapidly into new states, reducing the potential efficacy of conservation strategies based on historical patterns. In the Gulf of Maine, climate-driven changes have restructured the ecosystem rapidly over the past decade. Changes in the Atlantic meridional overturning circulation have altered deepwater dynamics, driving warming rates twice as high as the fastest surface rates. This has had implications for the copepod Calanus finmarchicus, a critical food supply for the endangered North Atlantic right whale (Eubalaena glacialis). The oceanographic changes have driven a deviation in the seasonal foraging patterns of E. glacialis upon which conservation strategies depend, making the whales more vulnerable to ship strikes and gear entanglements. The effects of rapid climate-driven changes on a species at risk undermine current management approaches.publishedVersio

Health profiles of 996 melanoma survivors: the M. D. Anderson experience

BACKGROUND: The incidence and survival of melanoma are increasing, but little is known about its long-term health effects in adult survivors. METHODS: A health survey was available from 996 melanoma survivors (577 treated with surgery alone, and 391 with combined treatments). Their medical/physiologic and psychosocial responses were analyzed and compared with those of the survivors from other cancers. RESULTS: The melanoma survivors were 44.8 ± 12.8 years of age at diagnosis (significantly younger than the survivors of other cancers) and 63.7 ± 12.8 years at survey. Melanoma survivors were less likely to report that cancer had affected their health than survivors of other cancers (15.8% vs. 34.9%). The 577 individuals treated with surgery alone reported arthritis/osteoporosis, cataracts, and heart problems most frequently (less often than survivors of other cancers). The 391 individuals who had undergone combined treatments reported circulation problems and kidney problems generally as often as survivors of other cancers. Health problems were not associated with number of decades since diagnosis but with age at diagnosis, treatment modality, and family relationships. CONCLUSION: We present information from a large cohort of long-term survivors of melanoma. As a group, they were less likely to report that cancer had affected their overall health than survivors of other cancers; a number of disease related and psychosocial factors appear to influence their health profiles

Adjuvant bevacizumab in patients with melanoma at high risk of recurrence (AVAST-M): preplanned interim results from a multicentre, open-label, randomised controlled phase 3 study

Background Bevacizumab, a monoclonal antibody that targets VEGF, has shown restricted activity in patients with advanced melanoma. We aimed to assess the role of bevacizumab as adjuvant treatment for patients with resected melanoma at high risk of recurrence. We report results from the preplanned interim analysis. Methods We did a multicentre, open-label, randomised controlled phase 3 trial at 48 centres in the UK between July 18, 2007, and March 29, 2012. Patients aged 16 years or older with American Joint Committee on Cancer stage (AJCC) stage IIB, IIC, and III cutaneous melanoma were randomly allocated (1:1), via a central, computer-based minimisation procedure, to receive intravenous bevacizumab 7·5 mg/kg, every 3 weeks for 1 year, or to observation. Randomisation was stratifi ed by Breslow thickness of the primary tumour, N stage according to AJCC staging criteria, ulceration of the primary tumour, and patient sex. The primary endpoint was overall survival; secondary endpoints included disease-free interval, distant-metastases interval and quality of life. Analysis was by intention-to-treat. This trial is registered as an International Standardised Randomised Controlled Trial, number ISRCTN81261306. Findings 1343 patients were randomised to either the bevacizumab group (n=671) or the observation group (n=672). Median follow-up was 25 months (IQR 16ñ37) in the bevacizumab group and 25 months (17ñ37) in the observation group. At the time of interim analysis, 286 (21%) of 1343 enrolled patients had died: 140 (21%) of 671 patients in the bevacizumab group, and 146 (22%) of 672 patients in the observation group. 134 (96%) of patients in the bevacizumab group died because of melanoma versus 139 (95%) in the observation group. We noted no signifi cant di┎ erence in overall survival between treatment groups (hazard ratio [HR] 0·97, 95% CI 0·78ñ1·22; p=0·76); this fi nding persisted after adjustment for stratifi cation variables (HR 1·03; 95% CI 0·81ñ1·29; p=0·83). Median duration of treatment with bevacizumab was 51 weeks (IQR 21ñ52) and dose intensity was 86% (41ñ96), showing good tolerability. 180 grade 3 or 4 adverse events were recorded in 101 (15%) of 671 patients in the bevacizumab group, and 36 (5%) of 672 patients in the observation group. Bevacizumab resulted in a higher incidence of grade 3 hypertension than did observation (41 [6%] vs one [<1%]). There was an improvement in disease-free interval for patients in the bevacizumab group compared with those in the observation group (HR 0·83, 95% CI 0·70ñ0·98, p=0·03), but no signifi cant di┎ erence between groups for distant-metastasis-free interval (HR 0·88, 95% CI 0·73ñ1·06, p=0·18). No signifi cant di┎ erences were noted between treatment groups in the standardised area under the curve for any of the quality-of-life scales over 36 months. Three adverse drug reactions were regarded as both serious and unexpected: one patient had optic neuritis after the fi rst bevacizumab infusion, a second patient had persistent erectile dysfunction, and a third patient died of a haemopericardium after receiving two bevacizumab infusions and was later identifi ed to have had signifi cant predisposing cardiovascular risk factors. Interpretation Bevacizumab has promising tolerability. Longer follow-up is needed to identify an e┎ect on the primary endpoint of overall survival at 5 years. Funding Cancer Research U