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321.
A novel self-colored polyethylene terephthalate (PET) was synthesized using a synthesized dye, 4-amino-N-propanoic acid-1,8-naphthalimide. For this purpose, the prepared naphthalimide dye was added upon the polycondensation step and then a self-colored PET was prepared by step-growth polymerization. The characterization of synthesized self-colored PET and naphthalimide dye were carried out using TLC, FTIR, 1HNMR, DSC, UV-visible and Fluorometery. Results indicated that, the novel fluorescent yellow-green PET with appropriate properties was obtained. The glass transition temperature of self-colored PET was 70 °C and it was measured by differential scanning calorimeter, which revealed that addition of dye to the chains of polymer did not affect the context of glass transition of polymer. UV-visible spectrum indicated that, 99 percent of dye was incorporated in polymer chains chemically. Furthermore, the intrinsic viscosity of self-colored PET was 0.556 dl/g and molecular weight of polymer was around 35000 (g/mol) and measured using the viscometer technique.  相似文献   
322.
Breeding for high symbiotic nitrogen (N) fixation (SNF) in common bean (Phaseolus vulgaris L.) is expected to contribute to reduced application of chemical fertilizers in cropping systems involving common bean. The magnitude of variation and the genetic and phenotypic correlation among seed yield, SNF, estimated as the percentage of nitrogen derived from atmosphere, and related traits were studied in a population of 140 F4-derived F5 recombinant inbred lines, developed from a cross between low- and high-SNF bean genotypes ‘Sanilac’ and ‘Mist’, respectively. The experiment was conducted in a total of five location-years in Ontario, Canada, from 2011 to 2013. These location-years were grouped into stress- and optimum moisture test sites, based on the total precipitation during the growing season. In each test site two nitrogen supply management strategies, SNF-dependent and N fertilizer-dependent, were simulated separately in the field by inoculating the seed with a commercial Rhizobium leguminosarum bv. phaseoli and by application of N fertilizers at 100 kg ha?1, respectively. The genetic variation was significant for seed yield, SNF and related traits. The heritability of the traits ranged from 14 to 71% and 4 to 25% in optimum moisture and in stress environments, respectively. No significant correlation between SNF and seed yield indicated that selection for high SNF does not necessarily lead to greater seed yield and that selection for both traits should be performed simultaneously.  相似文献   
323.
The fig tree (Ficus carica L.) is widely cultivated in the Mediterranean region under warm climates. Fig yield is governed by the previous crop load and is strongly dependent on shoot length. Special cultural practices are required to stimulate new vegetative growth that will ensure regular and high productivity. The present study focused on the use of the rest breaking agent hydrogen cyanamide (HC) as Dormex to enhance vegetative growth, which influences the yield. A field trial was held in northern Tunisia (36° 49′ N; 9° 48′ E) on mature fig trees cv. Zidi. In reference to untreated trees as control, two hydrogen cyanamide treatments at 1% and 1.5% HC were considered. Bud break rate, vegetative growth, starch content of shoots, yield, and fruit characteristics were assessed. Results indicated that 1.5% HC significantly increased shoot length, fruit number per shoot, and yield. It advanced bud break by 10 days and fruit ripening by 7 days compared to the control. However, leaf number, leaf area, and starch content seem to be unaffected by hydrogen cyanamide treatments. Regarding fruit quality, a 1.5% HC dose significantly increased dry matter content, while fruit diameter and total soluble solids remain unaffected. In conclusion, hydrogen cyanamide could be used under warm conditions to improve vegetative growth of fig trees cv. Zidi and consequently fig productivity. Application of 1.5% HC 40 days before bud break was the most effective in increasing shoot length and yield.  相似文献   
324.
The effects of photoperiod (12L:12D and 18L:6D) and feeding frequency (three, four and five evenly spaced daily feedings) of 10% biomass per day during light hours on growth and stress response of Persian sturgeon (Acipenser persicus) fingerlings were evaluated. The interaction between photoperiod and feeding frequency was not significant (P>0.05). Faster growth was observed in fish exposed to an 18L:6D photoperiod (P<0.01). The feed conversion efficiency (FCE) was also better with an 18L:6D photoperiod (P<0.05). Fish fed four and five meals per day grew similarly (P>0.05) and faster than when fed only three meals (P<0.01). The FCE with four or five meals per day was better than with three meals (P<0.05). At harvest, the proximate composition was similar in all treatments (P>0.05). Stress indicators (cortisol, glucose and haematocrit) did not differ between photoperiods (P<0.05). The results showed that 0.9–8.0 g Persian sturgeon fingerlings should be reared with an 18L:6D photoperiod and fed four times per day to obtain good growth and FCE.  相似文献   
325.
Abstract

Recent trends in peach orchards have focused on intensification and high density plantings using different Prunus rootstock species with different vigor traits. This investigation aims to study the physiological behavior of different Prunus rootstocks in order to identify the most suitable rootstock under warm Mediterranean conditions. Field agronomic performance and foliar nutrient content of the flat peach cultivar ‘Subirana’ grafted on ten different Prunus rootstocks were studied on calcareous soil typical of the Mediterranean area. Ten rootstocks: ‘ADAGAF 04-03’, ‘AGAF 0301-04’, ‘Garnem’, ‘Krymsk® 1’, ‘Krymsk® 86’, ‘PAC 847’, ‘PADAC 04-01’, ‘PADAC 150’, ‘PM 105 AD’, and ‘Rootpac® 70’, were considered. Vegetative growth, chlorophyll SPAD index, leaf mineral status and deviation from the optimum percentage (DOP) index were determined. Leaf chlorophyll content varied depending on the rootstock. ‘PADAC 04-01’ and ‘ADAGAF 04-03’ showed higher chlorophyll index. The lowest SPAD values were observed for the most dwarfing rootstock ‘Krymsk® 1’, which showed visual chlorosis symptoms, and lower leaf mineral contents compared to the other rootstocks. Peach trees on Prunus rootstocks showed differences in leaf macronutrient and micronutrient content. ‘Rootpac® 70’, ‘ADAGAF 04-03’ and ‘PADAC 04-01’ had better adaptation under warm Tunisian conditions but high ΣDOP index. The most invigorating ‘Garnem’ had the highest imbalanced nutritional status, but continues to perform well under warm conditions. Interesting results were obtained with ‘Rootpac® 70’ showing one of the best balanced nutritional values (average ΣDOP index). However, the most dwarfing rootstock ‘Krymsk® 1’ presented the worst adaptation to the studied warm Mediterranean conditions.  相似文献   
326.
This study aimed to evaluate the soil aggregate stability and selected soil quality indicators in various land uses in a semiarid region in central Iran. Random soil sampling was used to collect soil samples from surface (0–5 cm) and subsurface (5–25 cm) soil layers in rangelands of different condition classes, dry farmland and abandoned land. The aggregate size distribution indices including mean weight diameter (MWD), geometric mean diameter (GMD) and median diameter (D50) of water-stable aggregates in the collected soil samples were measured. Our findings showed that percent of macroaggregates (>0.25 mm) of the surface and subsurface layers in rangelands of different condition classes were significantly higher than dry farmlands and abandoned lands (P < 0.05). Results showed that the trend of changes in soil organic matter was similar to soil aggregate stability in different land uses in both soil layers as follows: rangeland with good condition > rangeland with poor condition > abandoned land > dry farmlands. The structural stability indices (i.e. MWD, GMD and D50) of rangelands with good condition were significantly greater than other land uses (P < 0.05). This highlights the importance of maintaining native rangeland to prevent organic matter loss, structure deterioration and soil erosion.  相似文献   
327.
In order to study the effects of desert dust on yield and yield components of cowpea, two field experiments were conducted in the factorial layout based on randomized complete block design with three replicates in Dezful and Mashhad, Iran in 2015. The experimental treatments were combinations of desert dust in three levels (0, 500 and 1500 µg m?3), numbers of desert dust application (once, twice and thrice) and two types of desert dust. The desert-dust particles were collected during dust storms occurred in Dezful and Zabol, which are the main sources of dust in Iran. The results showed that the biological yield and the grain yield were significantly decreased in both studied sites (Dezful and Mashhad) when the plants exposed to 500 µg m?3 desert dust treatment compared to normal conditions. Total soluble sugar and proline contents in plant leaf tissues increased significantly when they affected by 1500 µg m?3 of desert dust, while the plant height was significantly decreased by increasing the desert-dust concentrations at both sites. Biological yield, grain yield, and 100-seed weight were also significantly affected by the desert dust. Overall, the desert dust has adverse effects on yield of cowpea.  相似文献   
328.
Biogenic amines in low- and reduced-fat dry fermented sausages made with konjac gel (KG) as pork backfat replacer were studied. An increase (P < 0.05) was observed in the microbial count during the fermentation process, reaching levels of over 8 Log cfu/g of total viable microorganisms and lactic acid bacteria. However, no significant differences were observed in the microbiota evolution as a function of the reformulation process (fat and konjac gel content). High levels of physiological amines (spermidine, spermine, and agmatine) were observed in the raw material. From day 2 of the fermentation process an increase (P < 0.05) was observed in tyramine and putrescine, which were the predominant amines at the end of the storage period. The increase in these amines was proportional to the presence of KG and fat reduction. This can also be seen for spermine, with agmatine showing the inverse. The biogenic amine levels in these products reformulated with KG are not considered to pose a health risk to consumers.  相似文献   
329.
Soil erosion and dust storms are the main causes of air pollution in regions where there are dust emitting centers and in their adjacent locations. In recent years, various methods have been considered for stabilizing soil surface against wind erosion. In this study, the effects of two stabilizers (anionic polyacrylamide polymer and vegetable-based mulch) for reducing soil loss at four levels of concentration (0, 15%, 30%, and 60%) on three kinds of soils in western Khuzestan, Iran have been studied. The study was conducted in natural and laboratory-based conditions in four, time intervals (0, 3, 6, and 12 months). Moreover, the study covered the persistence and influence of stabilizers on soil chemical properties. The results showed that wind erosion in no treatment was between of 16.36?kg/m2/hand 26.73?kg/m2/?h. The statistical results showed that there was a significant difference between the no treatment and soils treated with stabilizers. The polymer reduced soil loss by more than 90%. Mulch efficiency reduced in natural conditions after 6?months; however, there were no changes in laboratory conditions. There was no significant difference between polymer efficiency in the laboratory and natural conditions and the polymer was resistant in natural and laboratory conditions. Polymer increased EC, pH, and SAR in the soil after 1 year. Mulch decreased pH and SAR but did not change EC.  相似文献   
330.
Organic acids (OA) and their blends have been shown to positively affect performance and health of broilers. However, the data in the literature are not consistent. This study examined the potential of blended short-chain fatty acids (SCFA) with medium-chain fatty acids (MCFA) as alternatives to antibiotic growth promoters (AGP) on performance, health and welfare of broilers infected with necrotic enteritis (NE). The additives used were: A) a blend of SCFA, MCFA, and a phenolic compound (SMP); B) a blend of free and buffered SCFA with MCFA (SMF); C) a blend of free and buffered SCFA with a high concentration of MCFA (SHM). A total of 1,404 Ross 308 one-day-old male parental chicks were randomly distributed into 78-floor pens with 13 replicates of 18 birds each. Six treatments were the following: T1, unchallenged control (UCC); T2, challenged control (CHC); T3, challenged group plus zinc bacitracin (BAC); T4, challenged group plus additive SMP; T5, challenged group plus additive SMF; T6, challenged group plus additive SHM. Challenged birds were gavaged with Eimeria spp. on d 9 and Clostridium perfringens EHE-NE18 on d 14. Post NE challenge and cumulatively, BWG, FCR, and nutrient digestibility of birds were compromised (P < 0.05) by NE challenge indicating a successful induction of sub-clinical NE. Additive SHM had higher BWG compared to CHC and BAC groups (P = 0.001; d 10 to 24) but not different from SMP and SMF groups (P > 0.05). All the 3 additive groups had lower FCR compared to CHC (P = 0.001; d 0 to 35), and exhibited similar jejunal lesions (d 16) compared to BAC and apparent ileal protein digestibility (d 21) compared to UCC and BAC groups (P > 0.05). Birds in additive SHM group had a higher concentration of serum IgA compared to all groups (P = 0.001) except additive SMF (P > 0.05; d 21). All the additive groups had lower footpad dermatitis and hock burns compared to CHC (P < 0.05). The findings suggest the potential of blended OA as alternatives to BAC to protect broilers from NE indicated by improved FCR, immunity, digestibility, and bird welfare.  相似文献   
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