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61.
ABSTRACT

Various physicochemical properties of New Zealand hoki and southern blue whiting (SBW) roes and the biological activities of their extracts were investigated. Protein, moisture, and ash contents in both roes were similar; however, the lipid content of hoki roe was higher (p < 0.05) than SBW roe (11.0 ± 0.9 and 2.5 ± 0.1, respectively). Both fish roe extracts contained active protease inhibitors toward trypsin and papain. Neither of the roe extracts agglutinated erythrocytes, indicating the absence of lectins. Both fish roe extracts at 5 mg/mL concentration exhibited slight inhibitory effects on the proliferation of breast cancer cells, but neither of the roe extracts exhibited RNase or antifungal activity.  相似文献   
62.
This study evaluated the nutritional quality of farmed and wild axillary seabream (Pagellus acarne R., 1827) focusing on amino acid profiles, with regards to possible interactions with wild fish aggregating around the cage facility. Total amino acids (∑AA), essential amino acids (∑EAA), non‐essential amino acids (∑NEAA) and neutral amino acids (∑NAA) in farmed fish were lower than those in the wild individuals (p > .05). Amino acid pattern in cage‐aggregated fish showed a slight decline from the wild populations, but still higher than the farmed fish. Based on the amino acid scores (AAS), lysine and leucine could be underlined as the ‘first limiting amino acids’, but all other AASs were over ‘1’, in accordance with reference amino acid contents of FAO/WHO (>1.00), showing that farmed axillary seabream provides high nutritional quality and can be considered as a favourable protein source. The ratios of ∑EAA/∑AA (44%–46%) and ∑EAA/∑NEAA (79%–86%) exceeded the minimum recommendation of 40% and >60% by FAO/WHO for all three groups. It can be concluded that axillary seabream either farmed, farm‐aggregated or distant wild fish presented high‐quality protein generating a healthy source for human food.  相似文献   
63.
Biochar amendments offer promising potential to improve soil fertility, soil organic carbon (SOC) and crop yields; however, a limited research has explored these benefits of biochar in the arid and semi‐arid regions. This two‐year field study investigated the effects of Acacia tree biomass‐derived biochar, applied at 0 and 10 t ha?1 rates with farmyard manure (FYM) or poultry manure (PM) and mineral phosphorus (P) fertilizer combinations (100 kg P ha‐1), on maize (Zea mays L.) productivity, P use efficiency (PUE) and farm profitability. The application of biochar with organic–inorganic P fertilizers significantly increased soil P and SOC contents than the sole organic or inorganic P fertilizers. Addition of biochar and PM as 100% P source resulted in the highest soil P (104% increase over control) and SOC contents (203% higher than control). However, maize productivity and PUE were significantly higher under balanced P fertilizer (50% organic + 50% mineral fertilizer) with biochar and the increase was 110%, 94% and 170% than 100%‐FYM, 100%‐PM and 100% mineral fertilizer, respectively. Maize productivity and yield correlated significantly positively with soil P and SOC contents These positive effects were possibly due to the ability of biochar to improve soil properties, P availability from organic–inorganic fertilizers and SOC which resulted in higher PUE and maize productivity. Despite the significant positive relationship of PUE with net economic returns, biochar incorporation with PM and mineral fertilizer combination was economically profitable, whereas FYM along biochar was not profitable due to short duration of the field experiments.  相似文献   
64.
Soil salinity imposes an unprecedented risk to the soil fertility and availability of plant nutrients. The present proposal is designed to address the effect of salt stress on photosynthetic apparatus of maize including chlorophyll a fluorescence and how silicon nutrition helps to overcome this issue. In a sand culture experiment, two maize cultivars were sown in small pots with two levels of silicon (0 and 2 mM H2SiO3) and two levels of salinity stress (0 and 60 mM NaCl). Salinity stress reduced dry matter yield and potassium (K) concentration in both maize cultivars and also induced inefficient working of photosynthetic apparatus including photochemical efficiency of photosystem II. Silicon addition alleviated NaCl stress on maize crop by improving the dry matter yield and water use efficiency (WUE). It decreased shoot Na concentration by increasing root and shoot K concentration of maize plants. It enhanced maximum quantum yield of primary photochemistry which leads to smooth electron transport chain. It also significantly enhanced shoot silicon concentration and has a significant positive correlation with WUE. Therefore, silicon-treated maize plants have better chance to survive under salt stress conditions as their photosynthetic apparatus is working far better than non-silicon-treated plants.  相似文献   
65.
Commercial bath sponge population in the Mediterranean has been recently reduced due to diseases and the depletion of natural banks. The commercial supply is far below the demand on the last 10–15 years. In this study, we aimed to investigate the farming performance of Spongia officinalis in the Dardanelles. Sponges collected from the Dardanelles cut into pieces of different weight. They were divided into two groups depending on the wet weight ranging from 50 to 150 g (mean weight 102.6 ± 4.81 g) and from 160 to 360 g (mean weight 235.8 ± 8.56 g). Three rope systems located parallel to each other with 6–7 m inter‐distance were constructed for the cultivation of sponges. At the end of the study, while small‐sized sponges could reach mean wet weight of 120.7 ± 14.8 g, large‐sized sponges reached mean wet weight of 247.6 ± 22.4 g. Growth rates were estimated 5–17% at 21st month. The survival rates were found 82% and 88%.  相似文献   
66.
The effects of several feeding frequencies of two, three and four times per day on Asian sea bass Lates calcarifer growth performance have been tested. Fish were reared under ambient Red Sea water conditions; these fish were fed diets containing 48% crude protein for 45 days. The present study was carried out at the Faculty of Marine Science (Abhor branch). The results show that fish population fed twice daily had significantly better growth with a mean body weight and daily weight increment of 59.04 and 1.31 g, respectively (P<0.05), than the other population fed three or four times daily. No significant differences were observed between fish fed two and three times daily in length gain and daily length increment. Growth in weight and length was increased gradually and no mortality was observed during the experimental period. In all the feeding trials, the body weight increased with an increase in length (R2=0.87 and 0.90). The feed conversion ratio (FCR) was significantly affected by feeding frequencies, with a significantly better FCR value of 2.43 in fish fed twice daily (P<0.05) compared with the other two populations fed three and four times daily. These results led to the conclusion that feeding two times daily would result in better growth and utilization of feed for the Asian sea bass L. calcarifer juvenile.  相似文献   
67.
68.
Precision farming technologies were implemented into a commercial harrow to increase selectivity of weed harrowing in spring cereals. Digital cameras were mounted before and after the harrow measuring crop cover. Crop soil cover (CSC) was computed out of these two images. Eight field experiments were carried out in spring cereals. Mode of harrowing intensity was changed in four experiments by speed, number of passes and tine angle. Each mode was varied in five intensities. In four experiments, only intensity of harrowing was changed. Weed control efficacy (WCE) and CSC were measured immediately after harrowing. Crop recovery was assessed 14 days after harrowing. Modes of intensity were not significantly different. However, intensity had significant effects on WCE and CSC. Cereals recovered from 10% CSC, and selectivity was in the constant range at 10% CSC. Therefore, 10% CSC was the threshold for the decision algorithm. If the actual CSC was below 10% CSC, intensity was increased. If the actual CSC was higher than 10%, intensity was decreased. Image analysis, decision support system and automatic control of harrowing intensity by hydraulic adjustment of tine angle were installed on a controller mounted on the harrow. The new system was tested in an additional field study. Threshold values for CSC were set at 10%, 30% and 60%. Automatic tine angle adjustment precisely realised the three different CSC values with variations of 1.5% to 3%. This development contributes to selective weed control and supports farmers during harrowing.  相似文献   
69.
In order to observe the variation in land use changes, satellite images from the Landsat Thematic Mapper (TM) and the Enhanced Thematic Mapper (ETM) for 1991, 2000, 2005, and 2008 were used to compare the differences between selected water quality parameters, including heavy metal (Cd, Pb, and Zn) content in both water and green mussels or Perna viridis (Linnaeus.) before and after the increase in land use activities beginning from 2006. The samples were collected at 11 points for water and 4 points for green mussels between the Second Link and the Causeway Link at the Johor Strait in 2009 and were analyzed for pH, temperature degrees Celsius), dissolved oxygen, ammoniacal nitrogen, and heavy metal (Cd, Pb, and Zn) content.  相似文献   
70.
Abstract

Nitrogen (N) deficiency is a very common problem of alkaline soils. Incorporation of organic residues with urea could be promising practice for improving soil properties and crop yield. This study was aimed, to evaluate the responses of two maize cultivar (Azam and Jalal) to organic wastes and Urea (sole organic residues i.e. seed cake (SC), poultry manure (PM), press mud (PrM) and mineral nitrogen (urea) and their combinations with urea (25%, 50% or 75%) applied at 150?kg N ha?1 under field conditions. Significant differences were recorded for leaf area index, plant height, number of grains ear?1, 1000 grain weight, biological and grain yield to N sources. Maize cultivar Jalal performed significantly better than Azam for all tested traits. The performance of both cultivars was significantly better when N was applied as either SC/PM with urea at 25:75, SC and PM with urea at 25:25:50, 100% sole urea, SC/PrM with urea at 50:50, or all organic N sources (25%) with urea (75%). Integration of organic wastes with urea gave the higher maize yield however, it was similar to the yield obtained from sole urea but due to allied environmental and health hazards, the sole use of urea could not be encouraged.  相似文献   
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