ABSTRACT
Ocean color is the result of absorption and scattering, as light interacts with the water and the optically active constituents. The measurement of ocean color changes enables monitoring of these constituents (dissolved or particulate materials). The main objective of this research is to use digital images to estimate the light attenuation coefficient (Kd), the Secchi disk depth (ZSD), and the chlorophyll a (Chla) concentration and to optically classify plots of seawater using the criteria proposed by Jerlov and Forel using digital images captured at the ocean surface. The database used in this study was obtained from seven oceanographic cruises performed in oceanic and coastal areas. Three approaches were developed for each parameter: a general approach that can be applied under any optical condition, one for oceanic conditions, and another for coastal conditions. The results of the coastal approach showed higher correlations between the modeled and validation data, with rp values of 0.80 for Kd, 0.90 for ZSD, 0.85 for Chla, 0.73 for Jerlov, and 0.95 for Forel-Ule. The oceanic approach failed to detect significant changes in a digital photograph. The most precise results were obtained when images were captured at 45° (n = 22; Fr cal=11.02>Fr crit=5.99). Therefore, to ensure precise results, the angle of photography is key. This methodology can be used in citizen science programs to estimate ZSD, Kd, and the Jerlov scale.
ABSTRACT
Resumen La microangiopatía trombótica asociada a cáncer (MTAC) comprende la presencia de anemia hemolítica microangiopática, trombocitopenia y lesión isquémica de órganos en pacientes con neoplasia de origen conocido o desconocido. Su diagnóstico es desafiante pues suele ser confundido con la púrpura trombocitopénica trombótica, que es la causa más frecuente de microangiopatía trombótica en pacientes sanos. La MTAC puede ser manifestación de la neoplasia en sí misma o manifestación de complicación de la quimioterapia, por lo que tiene un pronóstico pobre. A continuación se presenta el caso de una paciente que desarrolló MTAC en el contexto de cáncer metastásico de origen primario desconocido.
Abstract Cancer-associated thrombotic microangiopathy (CATM) consists of microangiopathic haemolytic anaemia, thrombocytopenia, and ischaemic end organ-damage in patients with a known or unknown primary malignancy. Its diagnosis is challenging, as it is sometimes confused with thrombotic thrombocytopenic purpura, which is the most common cause of thrombotic microangiopathy in healthy patients. CATM can be a manifestation of the malignancy itself or a chemotherapy-related complication, with these patients having a poor prognosis. A case is presented of a patient who developed CATM in the context of metastatic cancer with an unknown primary site.
