In October 2016, we conducted an aerial survey to obtain geo-referenced imagery that sampled greater sea surface area and improved estimations for debris larger than 0.5 m.
Hasta ahí, todo lo que has descrito previamente, forma parte de la introducción del texto (veo que has llegado lejos), donde se analiza la situación y se mencionan estudios previos, vamos, que estás tirando piedras al vacío como has venido haciendo hasta ahora..
De hecho es para partirse porque los estudios previos (a los que citas) son del 2014 y ahora vienes con eso de que un objeto se contaría varias veces en este que es de 2016.. pues si.. oye.. en 2 años puede que se cuente varias veces
les dan a las tripulaciones un curso online y un taller formativo y luego te dicen que la estimacion de falso positivos es baja y de falsos negativos es alta, porque los observadores tienen una actitud conservadora... me parto
¿Por que no lo lees entero? ¿Citas lo que te da la gana para sacarlo fuera del contexto?
While towing the trawl, the most experienced sailor aboard the vessel estimated the sea state (Beaufort scale) by measuring wind speeds and observing wave heights. This data was recorded in the standard datasheets provided, alongside the date, duration, as well as initial and final coordinates of each tow. The location and length of all net tows were confirmed during the post-processing phase by inspecting the position data from GPS trackers installed on all participating vessels. Most sampling stations encompassed a single net tow (n = 350 sampling stations) using a Manta trawl (0.5 mm square mesh, 90 cm × 15 cm mouth), which is one of the standard devices for quantifying plastic pollution levels. With the largest participating vessel (RV Ocean Starr), we simultaneously towed two Manta trawls, alongside two large Neuston trawls (1.5 cm square mesh, 6 m × 1.5 m mouth, of which 0.5 m above the water line; thereafter called ‘Mega trawls’) at every sampling location (n = 76 stations). After each Manta net tow, the net was rinsed from the outside with seawater, and its single-use cod-end removed, closed with staples and placed in an individual zip-lock bag. After each Mega trawl tow, the net was also rinsed from the outside with seawater and its large cod-end opened in a box filled with seawater. All buoyant plastics were then removed, wrapped in aluminium and placed in labelled plastic bags. The whole content captured by the Manta trawls was stored, while the organisms captured by the Mega trawls (mostly alive) were released back into the ocean. All samples were stored in a fridge or freezer while at-sea, and in a FedEx cool box (2–8 °C) or reefer (−2 °C) while being shipped to the laboratory. Even though we were careful when handling samples, some debris items may have been broken during transportation, leading to some bias in our debris size distribution.
Es para eso para lo que fueron entrenados....
y luego te dicen que la estimacion de falso positivos es baja y de falsos negativos es alta, porque los observadores tienen una actitud conservadora... me parto
Un poco antes, mencionan esto:
Even though we surveyed floating debris using trained observers and three types of sensor (Lidar, SWIR imager, and RGB camera), here we only analyse information coming from the geo-referenced mosaics produced by a RGB camera (CS-4800i) that generally took photographs every second during surveying time (frame size = ~360 m across track, ~240 m along track, ~0.1 m resolution).
Justo después mencionan esto:
As such, many features that could be debris, but resembled other natural features, such as sun glint and breaking wave, were not logged into our ocean plastic dataset. Once this work was finalised, we ran an experimental algorithm capable of detecting potential debris in all our RGB mosaics as a quality control step. To avoid any false positives, all features detected by the algorithm were also visually inspected by an observer and only those visually identified as debris were logged in our QGIS database. For every sighting, we recorded position (latitude, longitude), length (widest dimension of the object), width, and object type: (1) ‘bundled net’ – a group of fishing nets bundled tightly together; they are commonly colourful and of a rounded shape; (2) ‘loose net’ – a single fishing net; they were generally quite translucent and rectangular in shape; (3) ‘container’ – rectangular and bright objects, such as fishing crates and drums; (4) ‘rope’ – long cylindrical objects around 15 cm thick; (5) ‘buoy/lid’, rounded bright objects that could be either a large lid or a buoy; (6) ‘unknown’ – objects that are clearly debris but whose object type was not identified, they were mostly irregular-shaped items resembling plastic fragments; and (7) Other – only one object was successfully identified but did not belong to any category above: a life ring. We recorded 1,595 debris items (403 and 1,192 in flights 1 and 2 respectively); 626 were 10–50 cm and 969 were >50 cm in length. Most of them were classified as ‘unknown’ (78% for 10–50 cm, 32% for >50 cm), followed by ‘buoy or lid’ (20%) and ‘bundled net’ (1%) for 10–50 cm debris, and by ‘bundled net’ (29%), ‘container’ (18%), ‘buoy or lid’ (9%), ‘rope’ (6%), and ‘lose net’ (4%) for >50 cm debris. To calculate ocean plastic concentrations, we grouped the geo-referenced images into 31 ~10 km2 mosaics.
luego cuando ya llegas al tema de la descripción de los coeficientes, el viento, las corrientes etc, vamos el tema de las formulas, cogen publicaciones y modelos del 2002-2004 existiendo modelos mas actuales de 2016, porque les conviene mas, en fin, una seriedad y un rigor...
Bla bla bla formulas bla bla bla modelos .. ah mira!! son viejos!! jajajaja! ya lo tienen todo mal jajajaja...As we analysed the accumulation of model particles in the GPGP region, we noticed significant seasonal and inter-annual variations of the GPGP position. The modelled GPGP dimensions was relatively consistent throughout our 12 years of analysis, but the relative position of this accumulation zone varied with years and seasons. We first decided to test our model for seasonal variation by comparing our microplastic concentrations (measured in July – September 2015) against modelled concentrations averages for the July–September periods of 2000 to 2012. This comparison yielded poorer results (R2 = 0.46 to 0.21, depending on forcing scenario) than with the 12 years average solution (R2 = 0.52) as the July–September GPGP position varied substantially among years.
As such, to account for inter-annual variation, we compared latitudinal and longitudinal position of the GPGP against these two climate indexes: ENSO and PDO. We found that 2002 and 2004 were similar to the conditions experienced during our multi-vessel expedition. Thus, we compared our measurements against particle visit averages for July–September of 2002 and 2004 combined. This second attempt exhibited better results (R2 = 0.58 to 0.41, depending on forcing scenario), suggesting that climatic events such as ENSO or PDO influence the average position of the GPGP. Therefore, we decided to use the July–September average for 2002 and 2004, which better accounts for inter-annual variations in the GPGP position.
leete de nuevo el articulo, y veras que este simple cientifico, que solo ha ganado el premio novel de medicina
Me parece muy bien, seguro que ha aportado muchísimo a la humanidad y no he dudado en ningún momento de sus conocimientos o de su premio nobel. Dicho esto, que le da más importancia a este tío que a los que los que han escrito o los que han revisado del estudio que estamos discutiendo? Porque si vamos con esas... Barack Obama ganó el premio nobel de la paz.. y pacifico no fue
Quiero decir, a estas alturas, justifiquemos las cosas con datos.
se queja de que las revistas nature,science, y dell estan mas pendientes de conseguir suscriptores (obvio es de lo que viven) y por tanto publican estudios de los temas que estan de moda, aunque no sean buenos,
No se si lo sabes, pero así es como se fundan estos estudios y en general el cómo se reciben fondos. La mayoría de revistas científicas de rigor funcionan con suscripciones.. incluso en universidades como el MIT tienes que pagar por leer artículos científicos de ese nivel.
como creo que es el caso.
Ja.
CREO que este estudio es una ***** porque me ha dado una corazonada o porque no acabo de creerme que haya plastico en el océano y que no salga en Google Maps. CREO que en base a eso, puedo hacer comentarios sobre el nivel intelectual de otros y darmelas de guay con las fake news. Pero ojo, que CREO que si eh..Lamentable lo tuyo...
y tambien dice que este tipo de revistas, no publican estudios que desmientan o desbaraten estudios publicados.
Si, y han publicado artículos que luego se ha demostrado no son correctos o no validos y se han tenido que retractar o retirar ciertos artículos. De hecho, recuerdas el tio que dijo que las vacunas causan autismo? Su estudio fue publicado en The Lancet, una revista medica bastante prestigiosa.. ¿y? ¿que me quieres decir con eso? Que son fake news porque ciertas revistas en casos que se pueden contar con los dedos de las manos se han equivocado? Por esa regla de tres, vamos a descargar cualquier puto estudio que se haya hecho hasta ahora porque cuando salió fueron fake news.
Es que este argumento es muy triste y lo más triste es que lo sigues utilizando....
sinceramente creo que no, al contrario creo que soy el único que se ha leído el estudio por lo que veo.
Si... se ve que eres el que se ha leido solo lo que le ha dado la gana xD. Enhorabuena =)
Saludos
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