Greenhouse Gas Emissions Associated with Nile Tilapia (Oreochromis niloticus) Pond Fertilization in Western Kenya.

In the recent past, fish farming has gained great prominence in Kenya as the country straggles to meet food security. Nile tilapia (Oreochromis niloticus L.) farming has attracted the most demand, with the use of manure to enhance primary productivity in fish ponds being encouraged as a form of increasing productivity and returns on investment. The objective of this study was to understand the role of Nile tilapia farming in greenhouse emissions (GHGEs) in the region. Generally, there is paucity of such information originating from sub-Saharan Africa. Here, we report the levels of methane (CH4), carbon dioxide (CO2), and nitrous oxide (N2O) emissions from Nile tilapia fish ponds fertilized with organic and inorganic fertilizers. We also try to establish if there exists any relationship between GHGEs and physicochemical parameters (PCPs). The methane fluxes ranged from 0.001 to 0.043°mg·m-2h-1 in UF ponds, 0.005 to 0.068°mg·m-2h-1 in IF ponds, and 0.001 to 0.375°mg·m-2h-1 in OF ponds. The findings show that the fluxes were significantly different (P < 0.05). Mean fluxes of CO2 did not show significant difference among the treatments (P > 0.05), ranging from -0.180 to 1.40°mg·m-2h-1 in UF ponds, -0.020 to 1.101°mg·m-2h-1 in IF ponds, and -0.049 to 1.746°mg m-2h-1 in OF ponds. N2O mean fluxes were not significantly different (P > 0.05), ranging from -0.628 to 0.326°µgm-2h-1 in UF ponds, -0.049 to 0.187°µgm-2h-1 in IF ponds, and -0.022 to 1.384°µgm-2h-1 in OF ponds. UF had a mean flux of -0.003 ± 0.175°µgm-2h-1, IF had a mean flux of 0.032 ± 0.056°µgm-2h-1 and OF had a mean flux of 0.093 ± 0.324°µgm-2h-1. There was significant difference in the carbon to nitrogen (CN) ratio among the fertilization treatments (P < 0.05), whereas temperature, pH, dissolved oxygen, and conductivity showed no significant difference among the fertilization treatments (P > 0.05). The study observed that fertilization of Nile tilapia ponds significantly increases the release of CH4 emission and the CN ratio. Temperature, conductivity, and CN positively correlated with CH4, CO2, and N2O emissions. Dissolved oxygen showed a negative correlation with CH4 and CO2 emissions while negatively correlated with N2O emissions. The study identified the use of OF as a potential form of fish farming that promotes the emission of GHGEs and calls for adoption of sustainable technologies for the management of organic and inorganic fertilizers before their use in pond fertilization.

MALDI imaging mass spectrometry reveals multiple clinically relevant masses in colorectal cancer using large-scale tissue microarrays.

For identification of clinically relevant masses to predict status, grade, relapse and prognosis of colorectal cancer, we applied Matrix-assisted laser desorption ionization (MALDI) imaging mass spectrometry (IMS) to a tissue micro array containing formalin-fixed and paraffin-embedded tissue samples from 349 patients. Analysis of our MALDI-IMS data revealed 27 different m/z signals associated with epithelial structures. Comparison of these signals showed significant association with status, grade and Ki-67 labeling index. Fifteen out of 27 IMS signals revealed a significant association with survival. For seven signals (m/z 654, 776, 788, 904, 944, 975 and 1013) the absence and for eight signals (m/z 643, 678, 836, 886, 898, 1095, 1459 and 1477) the presence were associated with decreased life expectancy, including five masses (m/z 788, 836, 904, 944 and 1013) that provided prognostic information independently from the established prognosticators pT and pN. Combination of these five masses resulted in a three-step classifier that provided prognostic information superior to univariate analysis. In addition, a total of 19 masses were associated with tumor stage, grade, metastasis and cell proliferation. Our data demonstrate the suitability of combining IMS and large-scale tissue micro arrays to simultaneously identify and validate clinically useful molecular marker. Copyright © 2017 John Wiley & Sons, Ltd.