scholarly journals ESTIMATION OF PHOSPHORUS AND NITROGEN RELEASED BY THE BREEDING OF OREOCHROMIS NILOTICUS IN CAGES IN THE TOHO AND TODOUGBA LAGOONS(SOUTHER BENIN) BETWEEN 2017 AND 2020

2021 ◽  
Vol 9 (11) ◽  
pp. 422-430
Author(s):  
Achoh Mardochee Ephraim ◽  
◽  
Agadjihouede Hyppolite ◽  
Gangbe Luc ◽  
Aizonou Romaric ◽  
...  
Keyword(s):  
Organic Matter ◽  
Water Column ◽  
Oreochromis Niloticus ◽  
Nutrient Release ◽  
Laboratory Analysis ◽  
The Other ◽  
Production Data ◽  
Nitrogen Concentrations ◽  
High Production

The present study aim to estimate the ratio of aquaculture in the phosphorus and nitrogen concentrations determined in the Toho - Todougba lagoons. For this purpose, the two lagoons were subdivided into 7 stations for the determination of phosphorus and nitrogen concentrations in the water column. Production data from 2017 to 2019 were collected from the Direction of the Ficheries Production and from the literature. Data for 2020 were collected directly from fish farmers. Annual tilapia production was estimated by year and the amounts of phosphorus and nitrogen released from aquaculture are deduced based on the ratio of Montanhini Neto & Ostrensky (2013). The concentration of each of these nutrients was estimated by station and compared to the concentration determined by laboratory analysis of the water. This methodology shows that the amount of phosphorus and nitrogen released to the environment varies from 0.49 mg/L to 0.18 mg/L for phosphorus and from 1.53 mg/L to 0.58 mg/L for nitrogen. The lowest values are obtained in 2020 and differ significantly from the other years (p <0.05). The quantity of phosphorus discharged is higher at the high production stations (Tonon 0.20 mg/L and Lokohoue 0.11 mg/L). Some of this is stored in the sediment. The nitrogen generated by aquaculture is significantly lower than the average determined in water (p <0.05). However, the concentration determined is still related to the amount of organic matter released due to aquaculture. Although aquaculture is not the only source of nutrient release to water, strategies for aquaculture with less nutrient release should be determined.

scholarly journals Effects of temperature and organic pollution on nutrient cycling in marine sediments

2015 ◽  
Vol 12 (15) ◽  
pp. 4565-4575 ◽  
Author(s):  
C. Sanz-Lázaro ◽  
T. Valdemarsen ◽  
M. Holmer
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Nutrient Cycling ◽  
Water Column ◽  
Temperature Rise ◽  
Nutrient Release ◽  
Organic Pollution ◽  
Coastal Sediments ◽  
Effect Of Temperature ◽  
Climate Change Scenarios

Abstract. Increasing ocean temperature due to climate change is an important anthropogenic driver of ecological change in coastal systems. In these systems sediments play a major role in nutrient cycling. Our ability to predict ecological consequences of climate change is enhanced by simulating real scenarios. Based on predicted climate change scenarios, we tested the effect of temperature and organic pollution on nutrient release from coastal sediments to the water column in a mesocosm experiment. PO43− release rates from sediments followed the same trends as organic matter mineralization rates, increased linearly with temperature and were significantly higher under organic pollution than under nonpolluted conditions. NH4+ release only increased significantly when the temperature rise was above 6 °C, and it was significantly higher in organic polluted compared to nonpolluted sediments. Nutrient release to the water column was only a fraction from the mineralized organic matter, suggesting PO43− retention and NH4+ oxidation in the sediment. Bioturbation and bioirrigation appeared to be key processes responsible for this behavior. Considering that the primary production of most marine basins is N-limited, the excess release of NH4+ at a temperature rise > 6 °C could enhance water column primary productivity, which may lead to the deterioration of the environmental quality. Climate change effects are expected to be accelerated in areas affected by organic pollution.

scholarly journals Effects of global climate change and organic pollution on nutrient cycling in marine sediments

2015 ◽  
Vol 12 (1) ◽  
pp. 21-49
Author(s):  
C. Sanz-Lázaro ◽  
T. Valdemarsen ◽  
M. Holmer
Keyword(s):  
Climate Change ◽  
Organic Matter ◽  
Nutrient Cycling ◽  
Water Column ◽  
Temperature Rise ◽  
Nutrient Release ◽  
Organic Pollution ◽  
Coastal Sediments ◽  
Effect Of Temperature ◽  
Climate Change Scenarios

Abstract. Increasing ocean temperature due to climate change is an important anthropogenic driver of ecological change in coastal systems, where sediments play a major role in nutrient cycling. Our ability to predict ecological consequences of climate change is enhanced by simulating real scenarios especially when the interactions among drivers may not be just additive. Based on predicted climate change scenarios, we tested the effect of temperature and organic pollution on nutrient release from coastal sediments to the water column in a mesocosm experiment. PO43− release rates from sediments followed the same trends as organic matter mineralization rates, and increased linearly with temperature and were significantly higher under organic pollution than under non-polluted conditions. NH4+ release only increased significantly when the temperature rise was above 6 °C, and was significantly higher in organic polluted compared to non-polluted sediments. Nutrient release to the water column was only a fraction from the mineralized organic matter, suggesting PO43− retention and NH4+ oxidation in the sediment. Bioturbation and bioirrigation appeared to be key processes responsible of this behaviour. Considering that the primary production of most marine basins is N-limited, the excess release of NH4+ at temperature rise >6 ° could enhance water column primary productivity, which may lead to the deterioration of the environmental quality. Climate change effects are expected to be accelerated in areas affected by organic pollution.

Determination of the lattice translation across {110} APBs in GaAs

1988 ◽  
Vol 46 ◽  
pp. 600-601
Author(s):  
D.R. Rasmussen ◽  
N.-H. Cho ◽  
C.B. Carter
Keyword(s):  
Grain Boundaries ◽  
Lower Energy ◽  
Antiphase Boundary ◽  
The Other ◽  
Boundary Structure ◽  
Interface Plane ◽  
Inversion Symmetry ◽  
High Angle ◽  
Equilibrium Distance

Domains in GaAs can exist which are related to one another by the inversion symmetry, i.e., the sites of gallium and arsenic in one domain are interchanged in the other domain. The boundary between these two different domains is known as an antiphase boundary [1], In the terminology used to describe grain boundaries, the grains on either side of this boundary can be regarded as being Σ=1-related. For the {110} interface plane, in particular, there are equal numbers of GaGa and As-As anti-site bonds across the interface. The equilibrium distance between two atoms of the same kind crossing the boundary is expected to be different from the length of normal GaAs bonds in the bulk. Therefore, the relative position of each grain on either side of an APB may be translated such that the boundary can have a lower energy situation. This translation does not affect the perfect Σ=1 coincidence site relationship. Such a lattice translation is expected for all high-angle grain boundaries as a way of relaxation of the boundary structure.

Determination of the Burgers vector of a dislocation in a Fe-Mn alloy by weak-beam image in HVEM

1978 ◽  
Vol 36 (1) ◽  
pp. 330-331
Author(s):  
Y. Ishida ◽  
H. Ishida ◽  
K. Kohra ◽  
H. Ichinose
Keyword(s):  
High Order ◽  
Simulation Technique ◽  
The Other ◽  
Image Simulation ◽  
Diffraction Vector ◽  
Burgers Vector ◽  
Weak Beam ◽  
Beam Image ◽  
Edge Component

IntroductionA simple and accurate technique to determine the Burgers vector of a dislocation has become feasible with the advent of HVEM. The conventional image vanishing technique(1) using Bragg conditions with the diffraction vector perpendicular to the Burgers vector suffers from various drawbacks; The dislocation image appears even when the g.b = 0 criterion is satisfied, if the edge component of the dislocation is large. On the other hand, the image disappears for certain high order diffractions even when g.b ≠ 0. Furthermore, the determination of the magnitude of the Burgers vector is not easy with the criterion. Recent image simulation technique is free from the ambiguities but require too many parameters for the computation. The weak-beam “fringe counting” technique investigated in the present study is immune from the problems. Even the magnitude of the Burgers vector is determined from the number of the terminating thickness fringes at the exit of the dislocation in wedge shaped foil surfaces.

Procedures for the Quantitative Determination of Autoprothrombin C

1962 ◽  
Vol 08 (03) ◽  
pp. 434-441 ◽  
Author(s):  
Edmond R Cole ◽  
Ewa Marciniak ◽  
Walter H Seegers
Keyword(s):  
Quantitative Determination ◽  
Plasma Sample ◽  
Quantitative Measure ◽  
The Other ◽  
Clotting Time ◽  
Bovine Plasma ◽  
Autoprothrombin C

SummaryTwo quantitative procedures for autoprothrombin C are described. In one of these purified prothrombin is used as a substrate, and the activity of autoprothrombin C can be measured even if thrombin is in the preparation. In this procedure a reaction mixture is used wherein the thrombin titer which develops in 20 minutes is proportional to the autoprothrombin C in the reaction mixture. A unit is defined as the amount which will generate 70 units of thrombin in the standardized reaction mixture. In the other method thrombin interferes with the result, because a standard bovine plasma sample is recalcified and the clotting time is noted. Autoprothrombin C shortens the clotting time, and the extent of this is a quantitative measure of autoprothrombin C activity.

Determination of Factor XIII Activity and of Factor XIII Inhibitors Using an Ammonium-Sensitive Electrode

1983 ◽  
Vol 50 (02) ◽  
pp. 563-566 ◽  
Author(s):  
P Hellstern ◽  
K Schilz ◽  
G von Blohn ◽  
E Wenzel
Keyword(s):  
Factor Xiii ◽  
Normal Subjects ◽  
The Other ◽  
Activity Measurement ◽  
Factor Xiii Deficiency ◽  
Assay Procedure ◽  
Stabilization Factor ◽  
Release Method ◽  
Sensitive Electrode

SummaryAn assay for rapid factor XIII activity measurement has been developed based on the determination of the ammonium released during fibrin stabilization. Factor XIII was activated by thrombin and calcium. Ammonium was measured by an ammonium-sensitive electrode. It was demonstrated that the assay procedure yields accurate and precise results and that factor XIII-catalyzed fibrin stabilization can be measured kinetically. The amount of ammonium released during the first 90 min of fibrin stabilization was found to be 7.8 ± 0.5 moles per mole fibrinogen, which is in agreement with the findings of other authors. In 15 normal subjects and in 15 patients suffering from diseases with suspected factor XIII deficiency there was a satisfactory correlation between the results obtained by the “ammonium-release-method”, Bohn’s method, and the immunological assay (r1 = 0.65; r2= 0.70; p<0.01). In 3 of 5 patients with paraproteinemias the values of factor XIII activity determined by the ammonium-release method were markedly lower than those estimated by the other methods. It could be shown that inhibitor mechanisms were responsible for these discrepancies.

Reparação óssea no implante dental

2020 ◽  
Vol 12 (45) ◽  
pp. 63-66
Author(s):  
Halim Nagem Filho ◽  
Reinaldo Francisco Maia ◽  
Reinaldo Missaka ◽  
Nasser Hussein Fares
Keyword(s):  
Gene Expression ◽  
Titanium Surface ◽  
Close Contact ◽  
The Other ◽  
Main Function ◽  
Indirect Interaction ◽  
M2 Macrophages ◽  
Activated Macrophages ◽  
M1 Macrophages ◽  
High Production

The osseointegration is the stable and functional union between the bone and a titanium surface. A new bone can be found on the surface of the implant about 1 week after its installation; the bone remodeling begins between 6 and 12 weeks and continues throughout life. After the implant insertion, depending on the energy of the surface, the plasma fluid immediately adheres, in close contact with the surface, promoting the adsorption of proteins and inducing the indirect interaction of the cells with the material. Macrophages are cells found in the tissues and originated from bone marrow monocytes. The M1 macrophages orchestrate the phagocytic phase in the inflammatory region and also produce inflammatory cytokines involved with the chronic inflammation and the cleaning of the wound and damaged tissues from bacteria. On the other hand, alternative-activated macrophages (M2) are activated by IL-10, the immune complex. Its main function consists on regulating negatively the inflammation through the secretion of the immunosuppressant IL-10. The M2 macrophages present involvement with the immunosuppression, besides having a low capacity for presenting antigens and high production of cytokines; these can be further divided into M2a, M2b, and M2c, based on the gene expression profile.

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