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Methods to predict and fill Landsat 7 Scan Line Corrector (SLC)-off data gaps are diverse and their usability is case specific. An appropriate gap-filling method that can be used for seagrass mapping applications has not been proposed previously. This study compared gap-filling methods for filling SLC-off data gaps with images acquired from different dates at similar mean sea-level tide heights, covering the Sungai Pulai estuary area inhabited by seagrass meadows in southern Peninsular Malaysia. To assess the geometric and radiometric fidelity of the recovered pixels, three potential gap-filling methods were examined: (a) geostatistical neighbourhood similar pixel interpolator (GNSPI); (b) weighted linear regression (WLR) algorithm integrated with the Laplacian prior regularization method; and (c) the local linear histogram matching method. These three methods were applied to simulated and original SLC-off images. Statistical measures for the recovered images showed that GNSPI can predict data gaps over the seagrass, non-seagrass/water body, and mudflat site classes with greater accuracy than the other two methods. For optimal performance of the GNSPI algorithm, cloud and shadow in the primary and auxiliary images had to be removed by cloud removal methods prior to filling data gaps. The gap-filled imagery assessed in this study produced reliable seagrass distribution maps and should help with the detection of spatiotemporal changes of seagrasses from multi-temporal Landsat imagery. The proposed gap-filling method can thus improve the usefulness of Landsat 7 ETM+ SLC-off images in seagrass applications. [ABSTRACT FROM AUTHOR]

This review evaluates various methods employed to produce seagrass habitat maps using optical and acoustic remote-sensing (RS) techniques coupled within situsampling to highlight recent advances and to define areas where potential future research should be focused in the application of RS technologies. A critical review of 195 studies revealed that, in the past four decades, advances in the application of RS methods, notably using Landsat imagery, are identified for seagrass detection, assessment of areal coverage, distribution and abundance mapping, and the detection of extent and biomass changes, as illustrated in peer-reviewed literature. Rapid technological and methodological advances have occurred in the acquisition and interpretation of optical and acoustic data for the mapping of seagrass habitats. The methods have been tested to segment, classify, and combine RS data with biological field or ground truth sample data. There is no single technology or approach that is suitable for and capable of measuring all seagrass parameters (presence/absence, cover, species, and biomass) and assessing change. Integration of field, imagery, and mapping approaches is therefore required. Further research is required for continued improvements in understanding of theoretical and methodological aspects of seagrass RS. [ABSTRACT FROM PUBLISHER]

1. The objective of the study was to investigate the effect of dietary karaya saponin on cholesterol deposition in laying hens. 2. A total of 40 Boris Brown hens were randomly assigned at 20 weeks of age to 4 treatment groups and fed on diets supplemented with 0 (control), 25, 50 or 75 mg/kg karaya saponin for an 8-week experimental period. 3. After 8 weeks of dietary supplementation, karaya-saponin-treated groups had significantly lower serum cholesterol (23·0%) and triglycerides but increased high density lipoproteins cholesterol concentration than controls, irrespective of karaya saponin content in the diet. Egg yolk cholesterol and triglycerides were also significantly reduced by dietary karaya saponin. Hepatic cholesterol and triglycerides were significantly reduced by karaya saponin but bile acids concentration in the faeces and liver were significantly increased by karaya saponin. The concentrations of oleic, linoleic and linolenic acids in the yolk were greater in hens receiving karaya saponin than in controls. Karaya saponin significantly increased egg production, feed efficiency and yolk colour compared with controls. Karaya saponin tended to increase egg weight, feed consumption, Haugh units, albumen weight and yolk index. 4. In conclusion, karaya saponin is a potential agent for reducing yolk cholesterol concentration together with an overall increase of production performance and improvement in egg quality. [ABSTRACT FROM AUTHOR]

1. It has been reported that karaya saponin and Rhodobacter capsulatus individually have hypocholesterolaemic activity in laying hens. This study focuses on the effect of adding karaya saponin with R. capsulatus to hen's diet with regard to serum and egg yolk cholesterol and triglycerides. 2. A total of 56 Boris Brown laying hens were divided into 7 groups at 20 weeks of age. Combinations of 25, 50, 75 mg kg-1 karaya saponin and R. capsulatus 200 and 400 mg kg-1 were used as treatment groups. 3. After 8 weeks of supplementation, the effects of all the combinations of karaya saponin and R. capsulatus on serum and egg yolk cholesterol, triglycerides, and high-density lipoprotein (HDL)-cholesterol were greater than either karaya saponin or R. capsulatus alone. The combination of karaya saponin 50 mg kg-1+ R. capsulatus 400 mg kg-1 exhibited the greatest reduction of serum (32⋅5%) and yolk (22⋅5%) cholesterol and the greatest increase of faecal, liver bile acids and yolk fatty acid (oleic, linoleic and linolenic) concentrations. In addition, egg production and yolk colour were significantly improved by the combined use of karaya saponin and R. capsulatus supplementation. 4. Therefore, the dietary supplementation of karaya saponin and R. capsulatus may lead to the production of a low-cholesterol egg, with production performance maintained at a standard level. [ABSTRACT FROM AUTHOR]