5 research outputs found
Assessing uncertainties in estimating surface energy fluxes from remote sensing over natural grasslands in Brazil
Evapotranspiration (ET) is one of the main fluxes in the global water cycle. As the Brazilian Pampa biome carries a rich biodiversity, accurate information on the ET dynamics is essential to support its proper monitoring and establish conservation strategies. In this context, we assessed an operational methodology based on the Simplified Surface Energy Balance Index (S-SEBI) model to estimate energy fluxes over the natural grasslands of the Pampa between 2014 and 2019. The S-SEBI is an ET model that requires a minimum of meteorological inputs and has demonstrated reasonable accuracy worldwide. Therefore, we investigated the model performance considering radiation data from both ERA5 reanalysis and Eddy Covariance measurements from a flux tower. Furthermore, comparisons from satellite-based estimates with in situ measurements were performed with and without energy balance closure (EBC). Results indicated that the meteorological inputs have low sensitivity on daily ET estimates from the S-SEBI model. In contrast, the instantaneous energy balance components are more affected. The strong seasonality impacts the evaporative fraction, which is more evident in late summer and autumn and may compromise the performance of the model in the biome. The effects in the daily ET are lower when in situ data without EBC are considered as ground truth. However, they are less correlated with the remote sensing-based estimates. These insights are useful to monitor water and energy fluxes from local to regional scale and provide the opportunity to capture ET trends over the natural grasslands of the Pampa
Meloxicam associado ou não ao tramadol no controle da dor após ovário-histerectomia videoassistida em cadelas
Brown seaweed meal to nile tilapia fingerlings
This work evaluated the effects of increasing
levels of the brown seaweed Ascophyllum
nodosum meal (BSM) in the feed given to Nile tilapia
Oreochromis niloticus fingerlings. The completely
randomized design experiment lasted 42 days.
Nile tilapia fingerlings (n=75) with an average age
of 30 days and average weight of 0.43 ± 0.02 g
were assigned to 25 plastic tanks and submitted
to five treatments in five repetitions. The treatments
were increasing levels of BSM (5, 10, 15, and 20
g kg -1 of feed) and a control feed (no BSM). Each
experimental unit was made up of a 36 L plastic
tank with three fingerlings. The parameters studied
were final average weight, percentage of weight
gain, apparent feed conversion ratio, total length
and carcass yield with and without head. The final
average weight, percentage of weight gain, and
total length were not affected by the treatments
(p>0.05). The apparent feed conversion ratio
improved linearly (p<0.01) and carcass yield
increased linearly (p<0.01) as the BSM in feeds
increased. BSM is an additive with potential use in
Nile tilapia feed at the level of 20 g kg -1 because it
does not result in growth loss and improves the
feed conversion ratio and carcass yield in Nile
tilapia during the fingerling period.Este trabalho avaliou os efeitos de níveis
crescentes da farinha de alga marrom Ascophyllum
nodosum (FAM) nas rações para alevinos de
tilápia do Nilo Oreochromis niloticus. O experi-
mento, com delineamento inteiramente casua-
lizado, durou 42 dias. Foram utilizados alevinos de
tilápia do Nilo (n= 75) com idade média de 30 dias
e peso médio de 0,43 ± 0,02 g, distribuídos em 25
tanques plásticos submetidos à cinco tratamentos
e cinco repetições. Os tratamentos foram níveis
crescentes de farinha de alga marrom (5, 10, 15
e 20 g kg -1 de ração) e uma ração controle (sem
FAM). Cada unidade experimental foi composta
por um tanque plástico de 36 L com três alevinos.
Foram estudados os parâmetros médios de peso
final, percentagem de ganho de peso, taxa de
conversão alimentar aparente, comprimento total
e rendimento de carcaça, com e sem cabeça. As
médias de peso final, percentagem de ganho de
peso e comprimento total não foram influenciadas
pelos tratamentos (p>0,05). Os valores da taxa de
conversão alimentar aparente melhoraram
linearmente (p<0,01) e os valores de rendimento
de carcaça aumentaram linearmente (p<0,01) à
medida que se aumentaram os níveis de FAM nas
rações. A farinha de alga marrom é um aditivo com
potencial utilização em rações de tilápia do Nilo no
nível de 20 g kg -1 , pois não diminui o crescimento
e promove melhora da taxa de conversão alimen-
tar e do rendimento de carcaça de alevinos de
tilápia do Nilo
Assessing uncertainties in estimating surface energy fluxes from remote sensing over natural grasslands in Brazil
Evapotranspiration (ET) is one of the main fluxes in the global water cycle. As the Brazilian Pampa biome carries a rich biodiversity, accurate information on the ET dynamics is essential to support its proper monitoring and establish conservation strategies. In this context, we assessed an operational methodology based on the Simplified Surface Energy Balance Index (S-SEBI) model to estimate energy fluxes over the natural grasslands of the Pampa between 2014 and 2019. The S-SEBI is an ET model that requires a minimum of meteorological inputs and has demonstrated reasonable accuracy worldwide. Therefore, we investigated the model performance considering radiation data from both ERA5 reanalysis and Eddy Covariance measurements from a flux tower. Furthermore, comparisons from satellite-based estimates with in situ measurements were performed with and without energy balance closure (EBC). Results indicated that the meteorological inputs have low sensitivity on daily ET estimates from the S-SEBI model. In contrast, the instantaneous energy balance components are more affected. The strong seasonality impacts the evaporative fraction, which is more evident in late summer and autumn and may compromise the performance of the model in the biome. The effects in the daily ET are lower when in situ data without EBC are considered as ground truth. However, they are less correlated with the remote sensing-based estimates. These insights are useful to monitor water and energy fluxes from local to regional scale and provide the opportunity to capture ET trends over the natural grasslands of the Pampa