Acurácia da mamografia espectral com contraste para seguimento de tumor residual pós-quimioterapia neoadjuvante em pacientes com câncer de mama: um estudo de viabilidade

Objetivo: avaliar a viabilidade da utilização da mamografia espectral com meio de contraste (CESM) na avaliação do tumor residual em mulheres com câncer de mama submetidas a quimioterapia neoadjuvante. Materiais e métodos: foi avaliada a concordância entre a mensuração do tumor residual na CESM e na mamografia digital (FFDM) com os dados histopatológicos de mulheres submetidas a quimioterapia neoadjuvante entre 2011 e 2013. Após as exclusões, três radiologistas analisaram oito CESMs e FFDMs separadamente. A maior dimensão do tumor residual foi considerada para comparação com os resultados histopatológicos. Concordância e correlação da CESM e FFDM com resultados histopatológicos e a concordância interobservador foram avaliadas. Resultados: a CESM teve sensibilidade, especificidade e valores preditivos positivos e negativos maiores que a FFDM - 83,33%, 100%, 100% e 66% versus 50%, 50%, 50% e 25%, respectivamente. A CESM teve correlação boa e consistente com os achados histopatológicos (coeficiente de correlação = 0,76-0,92; coeficiente de correlação intraclasse = 0,692-0,886). A correlação entre FFDM e os achados histopatológicos não foi estatisticamente significante, com consistência questionável (coeficiente de correlação intraclasse = 0,488-0,598). A concordância entre as dimensões do estudo histopatológico foi mais estreita com a CESM do que com a FFDM. A concordância interobservador foi maior na CESM (0,94) do que na FFDM (0,88). Conclusão: a CESM é viável e pode ser utilizada para avaliação de tumor residual após quimioterapia neoadjuvante. A CESM tem boa correlação e concordância com o estudo histopatológico e excelente concordância interobservador.Objective: to assess the feasibility of contrast-enhanced spectral mammography (CESM) of the breast for assessing the size of residual tumors after neoadjuvant chemotherapy (NAC). Materials and methods: in breast cancer patients who underwent NAC between 2011 and 2013, we evaluated residual tumor measurements obtained with CESM and full-field digital mammography (FFDM). We determined the concordance between the methods, as well as their level of agreement with the pathology. Three radiologists analyzed eight CESM and FFDM measurements separately, considering the size of the residual tumor at its largest diameter and correlating it with that determined in the pathological analysis. Interobserver agreement was also evaluated. Results: the sensitivity, specificity, positive predictive value, and negative predictive value were higher for CESM than for FFDM (83.33%, 100%, 100%, and 66% vs. 50%, 50%, 50%, and 25%, respectively). The CESM measurements showed a strong, consistent correlation with the pathological findings (correlation coefficient = 0.76-0.92; intraclass correlation coefficient = 0.692-0.886). The correlation between the FFDM measurements and the pathological findings was not statistically significant, with questionable consistency (intraclass correlation coefficient = 0.488-0.598). Agreement with the pathological findings was narrower for CESM measurements than for FFDM measurements. Interobserver agreement was higher for CESM than for FFDM (0.94 vs. 0.88). Conclusion: CESM is a feasible means of evaluating residual tumor size after NAC, showing a good correlation and good agreement with pathological findings. For CESM measurements, the interobserver agreement was excellent

A national coastal erosion susceptibility model for Scotland

The upland nature of the Scottish landscape means that much of the social and economic activity has a coastal bias. The importance of the coast is further highlighted by the wide range of ecosystem services that coastal habitats provide. It follows that the threat posed by coastal erosion and flooding has the potential to have a substantial effect on the socioeconomic activity of the whole country. Currently, the knowledge base of coastal erosion is poor and this serves to hinder the current and future management of the coast. To address this knowledge gap, two interrelated models have been developed and are presented here: the Underlying Physical Susceptibility Model (UPSM) and the Coastal Erosion Susceptibility Model (CESM). The UPSM is generated within a GIS at a 50 m2 raster of national coverage, using data relating to ground elevation, rockhead elevation, wave exposure and proximity to the open coast. The CESM moderates the outputs of the UPSM to include the effects of sediment supply and coastal defence data. When validated against locations in Scotland that are currently experiencing coastal erosion, the CESM successfully identifies these areas as having high susceptibility. This allows the UPSM and CESM to be used as tools to identify assets inherently exposed to coastal erosion, areas where coastal erosion may exacerbate coastal flooding, and areas are inherently resilient to erosion, thus allow more efficient and effective management of the Scottish coast

Measurement of the B → D̅ ^((*))D^((*))K branching fractions

We present a measurement of the branching fractions of the 22 decay channels of the B^0 and B+ mesons to D̅ ^((*))D^((*))K, where the D^((*)) and D̅ ^((*)) mesons are fully reconstructed. Summing the 10 neutral modes and the 12 charged modes, the branching fractions are found to be B(B^0→D̅6((*))D^((*))K)=(3.68 ± 0.10 ± 0.24)% and B(B^+→D̅ ^((*))D^((*))K)=(4.05 ± 0.11 ± 0.28)%, where the first uncertainties are statistical and the second systematic. The results are based on 429  fb^(-1) of data containing 471 × 10^6BB̅ pairs collected at the Υ(4S) resonance with the BABAR detector at the SLAC National Accelerator Laboratory

The role of surface roughness, albedo, and Bowen ratio on ecosystem energy balance in the Eastern United States

Land cover and land use influence surface climate through differences in biophysical surface properties, including partitioning of sensible and latent heat (e.g., Bowen ratio), surface roughness, and albedo. Clusters of closely spaced eddy covariance towers (e.g., \u3c10 \u3ekm) over a variety of land cover and land use types provide a unique opportunity to study the local effects of land cover and land use on surface temperature. We assess contributions albedo, energy redistribution due to differences in surface roughness and energy redistribution due to differences in the Bowen ratio using two eddy covariance tower clusters and the coupled (land-atmosphere) Variable-Resolution Community Earth System Model. Results suggest that surface roughness is the dominant biophysical factor contributing to differences in surface temperature between forested and deforested lands. Surface temperature of open land is cooler (−4.8 °C to −0.05 °C) than forest at night and warmer (+0.16 °C to +8.2 °C) during the day at northern and southern tower clusters throughout the year, consistent with modeled calculations. At annual timescales, the biophysical contributions of albedo and Bowen ratio have a negligible impact on surface temperature, however the higher albedo of snow-covered open land compared to forest leads to cooler winter surface temperatures over open lands (−0.4 °C to −0.8 °C). In both the models and observation, the difference in mid-day surface temperature calculated from the sum of the individual biophysical factors is greater than the difference in surface temperature calculated from radiative temperature and potential temperature. Differences in measured and modeled air temperature at the blending height, assumptions about independence of biophysical factors, and model biases in surface energy fluxes may contribute to daytime biases

Global and regional importance of the direct dust-climate feedback.

Feedbacks between the global dust cycle and the climate system might have amplified past climate changes. Yet, it remains unclear what role the dust-climate feedback will play in future anthropogenic climate change. Here, we estimate the direct dust-climate feedback, arising from changes in the dust direct radiative effect (DRE), using a simple theoretical framework that combines constraints on the dust DRE with a series of climate model results. We find that the direct dust-climate feedback is likely in the range of -0.04 to +0.02 Wm -2 K-1, such that it could account for a substantial fraction of the total aerosol feedbacks in the climate system. On a regional scale, the direct dust-climate feedback is enhanced by approximately an order of magnitude close to major source regions. This suggests that it could play an important role in shaping the future climates of Northern Africa, the Sahel, the Mediterranean region, the Middle East, and Central Asia