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1.
Phycobiliproteins, light-harvesting pigments found in cyanobacteria and in some eukaryotic algae, have numerous commercial applications in food, cosmetic, and pharmaceutical industries. Colorant production from cyanobacteria offers advantages over their production from higher plants, as cyanobacteria have fast growth rate and high photosynthetic efficiency and require less space. In this study, three cyanobacteria strains were studied for phycobiliprotein production and the influence of sodium nitrate, potassium nitrate and ammonium chloride on the growth and phycobiliprotein composition of the strains were evaluated. In the batch culture period of 12 days, Phormidium sp. and Pseudoscillatoria sp. were able to utilize all tested nitrogen sources; however, ammonium chloride was the best nitrogen source for both strains to achieve maximum growth rate μ?=?0.284?±?0.03 and μ?=?0.274?±?0.13 day?1, chlorophyll a 16.2?±? 0.5 and 12.2?±? 0.2 mg L?1, and phycobiliprotein contents 19.38?±?0.09 and 19.99?±?0.14% of dry weight, whereas, for Arthrospira platensis, the highest growth rate of μ?=?0.304?±?0.0 day?1, chlorophyll a 19.1?±?0.5 mg L?1, and phycobiliprotein content of 22.27?±?0.21% of dry weight were achieved with sodium nitrate. The phycocyanin from the lyophilized cyanobacterial biomass was extracted using calcium chloride and food grade purity (A620/A280 ratio >?0.7) was achieved. Furthermore, phycocyanin was purified using two-step chromatographic method and the analytical grade purity (A620/A280 ratio >?4) was attained. SDS-PAGE demonstrated the purity and presence of two bands corresponding to α- and β-subunits of the C-phycocyanin. The results showed that Phormidium sp. and Pseudoscillatoria sp. could be good candidates for phycocyanin production.  相似文献   

2.
The rose aphid, Macrosiphum rosae (L.), is one of the most important pests on rose plants (Rosa spp.) with a worldwide distribution. As resistance indices, the development, survivorship, and reproduction of this aphid were evaluated on 10 rose cultivars, including Bella Vita, Cool Water, Dolce Vita, Maroussia, Orange Juice, Pinkpromise, Roulette, Tea, Valentine, and Persian Yellow in laboratory at 25?±?1°C, 65?±?5% relative humidity, and photoperiod of 16:8 (L/D)?h. Rose aphid successfully survived on all 10 rose cultivars, although mortality rate was higher on Tea and Bella Vita. The number of offspring per female differed significantly among the tested rose cultivars, and ranged from 9.2 on Tea to 38.7 nymphs on Orange Juice. Population growth parameters were significantly affected by rose cultivars. The longest mean generation time (T) was observed on Bella Vita (14.8 days) and Tea (14.7 days) and the shortest on Orange Juice (10.0 days). The net reproductive rate (R 0 ) ranged from 6.9 on Tea to 33.2 nymphs on Orange Juice cultivar. Correspondingly, the highest value of intrinsic rate of increase (r m ) was observed on Orange Juice (0.348 day?1) and lower values on Tea (0.131 day?1) followed by Bella Vita (0.154 day?1). Cluster analysis of all the measured parameters of rose aphid on different rose cultivars revealed that Tea and Bella Vita were relatively resistant to M. rosae. These findings could be useful in developing an integrated pest management (IPM) program for this aphid in urbanized areas and commercial rose potting.  相似文献   

3.
The aim of present study was to elucidate the association of CTLA4 +49 A/G and HLA-DRB1*/DQB1* gene polymorphism in south Indian T1DM patients. The patients and controls (n?=?196 each) were enrolled for CTLA4 and HLA-DRB1*/DQB1* genotyping by RFLP/PCR-SSP methods. The increased frequencies of CTLA4 ‘AG’ (OR?=?1.99; p?=?0.001), ‘GG’ (OR?=?3.94; p?=?0.001) genotypes, and ‘G’ allele (OR?=?2.42; p?=?9.26?×?10?8) were observed in patients. Reduced frequencies of ‘AA’ (OR?=?0.35; p?=?7.19?×?10?7) and ‘A’ (OR?=?0.41; p?=?9.26?×?10?8) in patients revealed protective association. Among HLA-DRB1*/DQB1* alleles, DRB1*04 (OR?=?3.29; p?=?1.0?×?10?5), DRB1*03 (OR?=?2.81; p?=?1.9?×?10?6), DQB1*02:01 (OR?=?2.93; p?=?1.65?×?10?5), DQB1*02:02 (OR?=?3.38; p?=?0.0003), and DQB1*03:02 (OR?=?7.72; p?=?0.0003) were in susceptible association. Decreased frequencies of alleles, DRB1*15 (OR?=?0.32; p?=?2.55?×?10?7), DRB1*10 (OR?=?0.45; p?=?0.002), DQB1*06:01 (OR?=?0.43; p?=?0.0001), and DQB1*05:02 (OR?=?0.28; p?=?2.1?×?10?4) in patients were suggested protective association. The combination of DRB1*03+AG (OR?=?5.21; p?=?1.4?×?10?6), DRB1*04+AG (OR?=?2.14; p?=?0.053), DRB1*04+GG (OR?=?5.21; p?=?0.036), DQB1*02:01+AG (OR?=?4.44; p?=?3.6?×?10?5), DQB1*02:02+AG (OR?=?20.9; p?=?9.5?×?10?4), and DQB1*02:02+GG (OR?=?4.06; p?=?0.036) revealed susceptible association. However, the combination of DRB1*10+AA (OR?=?0.35; p?=?0.003), DRB1*15+AA (OR?=?0.22; p?=?5.3?×?10?7), DQB1*05:01+AA (OR?=?0.45; p?=?0.007), DQB1*05:02+AA (OR?=?0.17; p?=?1.7?×?10?4), DQB1*06:01+AA (OR?=?0.40; p?=?0.002), and DQB1*06:02+AG (OR?=?0.34; p?=?0.001) showed decreased frequency in patients, suggesting protective association. In conclusion, CTLA4/HLA-DR/DQ genotypic combinations revealed strong susceptible/protective association toward T1DM in south India. A female preponderance in disease associations was also documented.  相似文献   

4.
The biodegradation of furfuryl alcohol (FA) in shake flask experiments using a pure culture of Pseudomonas putida (MTCC 1194) and Pseudomonas aeruginosa (MTCC 1034) was studied at 30 °C and pH 7.0. Experiments were performed at different FA concentrations ranging from 50 to 500 mg/l. Before carrying out the biodegradation studies, the bacterial strains were acclimatized to the concentration of 500 mg/l of FA by gradually raising 100 mg/l of FA in each step. The well acclimatized culture of P. putida and P. aeruginosa degraded about 80 and 66% of 50 mg/l FA, respectively. At higher concentration of FA, the percentage of FA degradation decreased. The purpose of this study was to determine the kinetics of biodegradation of FA by measuring biomass growth rates and concentration of FA as a function of time. Substrate inhibition was calculated from experimental growth parameters using the Haldane equation. Data for P. putida were determined as µ max ?=?0.23 h?1, K s ?=?23.93 mg/l and K i ?=?217.1 mg/l and for P. aeruginosa were determined as µ max ?=?0.13 h?1, K s ?=?21.3 mg/l and K i ?=?284.9 mg/l. The experimental data were fitted in Haldane, Aiba and Edwards inhibition models.  相似文献   

5.
The purpose of this study was to evaluate the performance of Neoseiulus californicus (McGregor) for the control of Tetranychus urticae Koch in commercial strawberry fields, under greenhouse conditions, in association or not with the use of acaricides. The N. californicus strain used in this study was tolerant or resistant to several pesticides. Three experiments were carried out in the State of São Paulo, Brazil. For the first experiment, the initial infestation of T. urticae was 87.1 active stages per leaflet. Two applications of propargite were made on the first and the 14th day of the experiment. Approximately 2 h after each propargite application, N. californicus was released at a rate of 3.0 and 1.9 adult mites per plant, respectively, for each application. The population of T. urticae decreased from 87.1 to 2.8 mites per leaflet in the first three weeks. After this period, the population of T. urticae was maintained at low levels (≤1.5 mites/leaflet) until the end of the experiment (10th week). Propargite and dimethoate sprayed on the strawberry field did not affect significantly the population of this predaceous mite. For the second experiment, the infestation of T. urticae was 29.1 mites per leaflet, when the acaricide chorfenapyr was applied on the strawberry field. The release of N. californicus (2 mites per plant) was made 2 weeks after spraying the acaricide. The population of T. urticae was maintained at low levels (≤2.8 mites/leaflet) for 8 weeks (evaluation period). The T. urticae infestations in plots with N. californicus were significantly lower than in non-release plots, for the experiments 1 and 2. In the third experiment, the initial infestation of T. urticae was 40.5 mites per leaflet (55.5 active stages/leaflet on release plants; 25.5 active stages/leaflet on non-release plants). Three releases of N. californicus (average rate of 3.0 adult mites/plant), without any acaricide application, were not sufficient to reduce significantly the T. urticae population in release plots (release plants + non-release plants) in 6 weeks from the first release, however, the spider mite population decreased from 55.5 to 7.8 active stages per leaflet on release plants, during this period. Interplant dispersal of N. californicus was low in this strawberry field with high infestation of T. urticae. The studies indicate the viability of the use of this strain of N. californicus for the control of T. urticae in strawberry fields under greenhouse conditions, especially in association with selective acaricides.  相似文献   

6.
Greenhouse experiments were conducted on various crops (cucumber, tomato, eggplant, green bean) to ascertain the effects of Break-thru® (polyether-polymethylsiloxane-copolymer, a silicone surfactant) and an oil emulsion, on Beauveria bassiana (Balsamo) Vuillemin (Bb) applications for the control of the two spotted spider mite, Tetranychus urticae Koch. The objectives were to compare a) the efficacy of Bb control when applied in aqueous Break-thru® or an oil emulsion; b) the effects of various concentrations of Bb conidia, as affected by each surfactant; and c) the effects of Break-thru® on the activity of the fungus. Conidia were suspended either in an aqueous Break-thru® or an emulsifiable formulation at different conidial concentrations (1.05 × 106, 2.1 × 106 and 4.2 × 106 conidia ml?1) and sprayed onto leaves 2 weeks after artificial pest inoculation. Two sprays were performed, with an interval of one week from one spray to another, and T. urticae population counts (both motile and egg stages) were made on plant leaves 7 days after each spray. Bb conidia in Break-thru® were more efficacious than conidia in emulsifiable formulation. With the highest rate of conidia (4.2 × 106 conidia ml?1), mortality of adult mites ranged from 60 ± 4.2 (mean ± SE) to 85.7 ± 4.3% in the Break-thru® suspension and 39.4 ± 7 to 61.3 ± 6% in the oil emulsion. Leaf damage index was also substantially reduced from 70% in the unsprayed control to 40% by the application of Bb conidia at the highest rate with Break-thru®. Break-thru® can be combined with Bb in the integrated management of T. urticae and Isolate R444 is a promising candidate for the control of the pest.  相似文献   

7.
Cement plants account for significant emissions of CO2 and other pollutants into the atmosphere. As a means for its mitigation, we tested the effect of a cement industry-based flue gas simulation (FGS — 18% CO2, 9% O2, 300 ppm NO2, 140 ppm SO2) on the green alga, Chlorella sorokiniana. Culture pH, cell density, cell viability and productivity, specific growth rates, photosynthetic performance, and biochemical composition were monitored. The treatments consisted of different FGS volumes (0.1, 0.3, 0.8, 1.5, 6, and 48 L day?1) that were applied in a series of laboratory-scale semi-continuous batch cultures under controlled conditions. Controls were exposed to 18% CO2 enriched air. Cell density showed that C. sorokiniana was able to grow in all treatments, but compared to the controls, low pH (~ 5.0) caused by 48 L FGS day?1 led to 27% decrease in specific growth rate. Increasing FGS exposure decreased maximum and operational quantum yields obtained by pulse amplitude modulated fluorometry, while photochemical quenching remained constant (~ 0.93). The α and rETR max parameters calculated from rapid light curves decreased with increasing FGS exposure. Total proteins and carbohydrates (per cell basis) increased after 6 and 48 L FGS day?1, which can be advantageous for biotechnological applications, but cell productivity (cells L?1 day?1) decreased. Despite the effects in physiology, C. sorokiniana could withstand a pH range of 6.0–5.0 imposed by 48 L FGS day?1. Overall, C. sorokiniana can be considered a robust species in flue gas bioremediation.  相似文献   

8.
An annular internally illuminated photobioreatcor (IIPBR) configuration based on the airlift/bubble column principles was developed and validated at an 18 l prototype scale using Scenedemus sp. and Nannochloropsis salina in batch and semi-continuous modes, at constant light supply and constant gas-to-culture volume ratio, but at varying CO2-to-air ratios. Highest biomass production was recorded at CO2-to-air ratio of 4% with Scenedesmus sp. and at 1% with Nannochloropsis salina. The energetic performance of this IIPBR was quantified in terms of biomass productivity per unit energy input, P/E (g W?1 day?1), considering energy input for illumination and for pneumatic mixing and circulation. Under optimal conditions, the IIPBR evaluated in this study achieved P/E of 1.42 g W?1 day?1 for Scenedesmus sp. and P/E of 0.34 g W?1 day?1 for Nannochloropsis salina. These P/E values are better than those estimated for airlift and bubble column photobioreactor configurations reported in the literature.  相似文献   

9.
The two-spotted spider mite Tetranychus urticae is an important pest of strawberry crops in Brazil and many other countries. Focus for biocontrol studies involving entomopathogenic fungi has been on three species from the genus Metarhizium: M. anisopliae sensu stricto (s.s.), M. brunneum and M. robertsii. Also, the species Beauveria bassiana has been studied for spider mite control and one isolate (ESALQPL63) is commercially available in Brazil. New and undescribed Metarhizium species have been found recently in Brazil and provide a pool of isolates with potential for biocontrol in Brazil and probably also elsewhere. The mortality of adult females of T. urticae when exposed to four new Brazilian species of Metarhizium was compared to the mortality when exposed to M. anisopliae s.s., M. brunneum, M. pingshaense, M. robertsii and Beauveria bassiana ESALQPL63. Fungal suspensions were sprayed onto mites at 107 conidia/mL with 0.05% Tween 80 in laboratory bio-assays. We measured total mortality and percentage sporulating cadavers 10 days after exposure and calculated median lethal time (LT50). The lowest LT50 (4.0 ± 0.17) was observed for mites treated with Metarhizium sp. Indet. 1 (ESALQ1638), which also performed well with respect to mortality after 10 days and capacity to sporulate from cadavers. Among the other little studied species tested, M. pingshaense (ESALQ3069 and ESALQ3222) and Metarhizium Indet. 2 (ESALQ1476) performed well and were comparable to B. bassiana (ESALQPL63). The new Metarhizium isolates and species thus showed potential for biological control.  相似文献   

10.
The study tested the effect of the chitin metabolic effectors, teflubenzuron, diflubenzuron, and calcofluor, and a combination of a chitinase and soybean trypsin inhibitor (STI) on the population growth of eight species of stored product mites under laboratory conditions. The compounds were incorporated into the diets of the mites in concentrations ranging from 0.01 to 50 mg g?1. The final populations of mites were observed after 21 days of growth in controlled conditions. Diflubenzuron and calcofluor suppressed the growth of all the tested species more effectively than the other compounds. The doses required to suppress the mite populations to 50% (rc50) in comparison to the control ranged from 0.29 to 12.68 mg g?1 for diflubenzuron and from 1.75 to 37.7 mg g?1 for calcofluor, depending on the mite species. When tested at the highest concentration (10 mg g?1), teflubenzuron also suppressed all of the tested mite species in comparison to the control. The addition of chitinase/STI into the diet influenced population growth in several ways. When the highest concentration of chitinase in a cocktail of chitinase and STI (12.5 mg g?1 of diet) was compared to the control, populations of Acarus siro, Aleuroglyphus ovatus and Aëroglyphus robustus decreased significantly, whereas populations of Tyroborus lini and Sancassania rodionovi increased significantly. The sensitivity of species to the tested compounds differed among species. The most tolerant species was S. rodionovi, the most sensitive was A. ovatus. The results confirmed that calcofluor and diflubenzuron have a toxic effect on stored product mites.  相似文献   

11.
The filamentous Cyanobacterium Arthrospira is commercially produced and is a functional, high-value, health food. We identified 5 low temperature and low light intensity tolerant strains of Arthrospira sp. (GMPA1, GMPA7, GMPB1, GMPC1, and GMPC3) using ethyl methanesulfonate mutagenesis and low temperature screening. The 5 Arthrospira strains grew rapidly below 14?°C, 43.75 μmol photons m?2 s?1 and performed breed conservation at 2.5?°C, 8.75 μmol photons m?2 s?1. We used morphological identification and molecular genetic analysis to identify GMPA1, GMPA7, GMPB1 and GMPC1 as Arthrospira platensis, while GMPC3 was identified as Arthrospira maxima. Growth at different culture temperatures was determined at regular intervals using dry biomass. At 16?°C and 43.75 μmol photons m?2 s?1, the maximum dry biomass production and the mean dry biomass productivity of GMPA1, GMPB1, and GMPC1 were 2057?±?80 mg l?1, 68.7?±?2.5 mg l?1 day?1, 1839?±?44 mg l?1, 60.6?±?1.8 mg l?1 day?1, and 2113?±?64 mg l?1, 77.7?±?2.5 mg l?1 day?1 respectively. GMPB1 was chosen for additional low temperature tolerance studies and growth temperature preference. In winter, GMPB1 grew well at mean temperatures <10?°C, achieving 3258 mg dry biomass from a starting 68 mg. In summer, GMPB1 grew rapidly at mean temperatures more than 28?°C, achieving 1140 mg l?1 dry biomass from a starting 240 mg. Phytonutrient analysis of GMPB1 showed high levels of C-phycocyanin and carotenoids. Arthrospira metabolism relates to terpenoids, and the methyl-d-erythritol 4-phosphate pathway is the only terpenoid biosynthetic pathway in Cyanobacteria. The 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) gene from GMPB1 was cloned and phylogenetic analysis showed that GMPB1 is closest to the Cyanobacterium Oscillatoria nigro-viridis PCC711. Low temperature tolerant Arthrospira strains could broaden the areas suitable for cultivation, extend the seasonal cultivation time, and lower production costs.  相似文献   

12.
Sublethal concentrations of chemical insecticides may cause changes in some behavioral characteristics of natural enemies such as functional responses. The residual effect of three synthetic insecticides including deltamethrin, fenvalerate and azadirachtin were studied on functional response of Habrobracon hebetor Say to Ephestia kuehniella Zeller larvae. Seven host densities (2, 4, 8, 16, 32, 64 and 96) were used during a 24 h period. The resulting data were appropriately fit to Type II functional response models in all treatments: (1) control (0.0916 h?1; and T h  = 0.2011 h); (2) deltamethrin (a = 0.0839 h?1; and T h  = 0.3560 h); (3) fenvalerate (a = 0.0808 h?1 and T h  = 0.3623 h); and (4) azadirachtin (a = 0.0900 h?1 and T h  = 0.2042 h). Maximum theoretical parasitism rate (T/T h ) was 119.34 estimated for control wasps. There was no significant difference between the values of attack rates (a and a + D a ) in all treatments while the handling time was statistically affected in female wasps treated with fenvalerate. Our findings will be useful in safe application of these insecticides in pest management programmes.  相似文献   

13.
A number of business opportunities may arise from microalgae and wastewater treatment becoming an integrated system, as biofuels and high-added value products could be obtained simultaneously. This study, performed under controlled and non-controlled conditions, aimed at cultivating Chlorococcum sp. using a digestate from pig manure as culture medium and assessing its growth and biochemical composition for further applications. Under controlled conditions, cultures of Chlorococcum sp. were established testing various digestate dilutions (v/v). It was found that all tested dilutions (up to 8% v/v) promoted a higher biomass density, compared to the control culture in modified Bold’s Basal Medium (modified BBM). Under non-controlled conditions, it was found that the biomass productivity using the digestate diluted 5.6% v/v (23.4 mg L?1 day?1) was statistically similar to the one obtained using modified BBM (26.4 mg L?1 day?1). The volatile fatty acids contained in the digestate might have allowed mixotrophic growth for Chlorococcum sp. The intracellular lipid content in Chlorococcum sp. remained constant throughout the experiments in both, treatment and control cultures, while carbohydrates increased from 20 to 45% of the cell dry weight in the treatment and from 20 to 42% in the control one. It was concluded that conditions of nitrogen starvation and fluctuating irradiance and temperature benefit carbohydrate accumulation in this strain, since intracellular carbohydrate content increased nearly two-fold during this period. Additionally, the obtained biomass has the potential to be used as feedstock for bioethanol production. This system can meet the concept of a microalgae-based biorefinery, in which biofuels and high-added value products are produced from microalgae and wastewater.  相似文献   

14.
Inheritance pattern of wood traits viz. specific gravity, fibre dimensions and fibre-derived biometrical indices and their interactions among themselves and with that of growth are reported in Hevea brasiliensis. Girth (h2 =???0.02?±?0.44 to h2 =?0.35?±?0.24) showed moderate genetic control. Among wood traits, specific gravity (h2?=?0.15?±?0.31 to h2 =?0.33?±?0.28) was found to be under moderate genetic control. Fibre traits viz., fibre length (h2 =???0.26?±?0.30 to h2 =?0.50?±?0.34), fibre diameter (h2 =?0.19?±?0.49 to h2 =?0.70?±?0.11), fibre lumen diameter (h2 =???0.18?±?0.35 to h2 =?0.56?±?0.47) and fibre wall thickness (h2 =???5.17?±?5.26 to h2 =?0.50?±?0.50) were under moderate to strong genetic control. Among fibre-derived indices, flexibility coefficient (h2 =?0.48?±?0.21 to h2 =?0.89?±?0.29) showed moderate to very strong genetic control. The Runkel ratio (h2 =???0.40?±?0.27 to h2 =?0.42?±?0.29) and slenderness ratio (h2 =???0.36?±?0.29 to h2 =?0.43?±?0.28) showed moderate genetic control. Girth showed very strong positive genetic correlation with fibre wall thickness and strong positive correlation with fibre width indicating scope of indirect selection potential for these traits. Wood specific gravity was not correlated with either girth or fibre traits. Hence, it would be possible to concomitantly improve growth and fibre traits without adversely affecting wood specific gravity. Moderate to very high estimates of heritability for fibre traits, girth and specific gravity indicated that considerable genetic gain can be realised for these traits. Implications of the above findings in genetic improvement of wood in Hevea are discussed.  相似文献   

15.
A complete protocol for the in vitro induction of Eclipta alba tetraploids has been optimized to enhance the wedelolactone content, an anti-cancerous compound. The effects of different concentrations of colchicine (0, 0.01, 0.05, 0.1, 0.2 and 0.3%; w/v) along with treatment durations (12, 24, 36 and 48 h) were investigated on shoot tip (ST) and nodal segment (NS). The treated explants were then incubated on Murashige and Skoog (MS) medium having 1.5 mg L?1 N6-benzylaminopurine and 0.5 mg L?1 α-napthalene acetic acid for shoot regeneration and afterward root was induced on 1.0 mg L?1 indole-3-acetic acid enriched ½MS medium. The tetraploids of E. alba were proficiently induced by the treatment of 0.1% colchicine for 24 h. The highest tetraploid induction efficiency was obtained from ST (30.56%) in comparison to the NS (22.22%). Analysis by spectrophotometry and flow cytometry showed that colchicine treated plants contained higher quantity of DNA than diploid plants. Cytological studies demonstrated doubled the chromosome number in tetraploids (2n?=?4x?=?44) than diploids (2n?=?2x?=?22). The ploidy level enhancement lead to alteration of other traits, like increased plant height, stem diameter, leaf size, stomatal size and chlorophyll content. As determined through high performance thin-layer chromatography, the ultimate achievement of this technique is the higher accumulation of wedelolactone in tetraploid plants (300.32 µg g?1 dry weight) in evaluation to in vitro diploid (131.31 µg g?1 dry weight) and in vivo diploid mother plants (93.26 µg g?1 dry weight), thus improving the pharmaceutical value of E. alba.  相似文献   

16.
Biological control agents can be used as a complementary control measure that can be combined with resistant host plants to control pests. In this study, the effects of different canola cultivars (Karaj-1, Karaj-2, Karaj-3, Licord, Okapi, Opera, RGS003, Sarigol, Talaye and Zarfam) on the performance and life table parameters of the cabbage aphid, Brevicoryne brassicae, and its parasitoid, Diaeretiella rapae, were determined under laboratory conditions. Total fecundity of the cabbage aphid differed with cultivar, with the highest value (59.41 nymphs per female) of this parameter observed on Opera and the lowest (1.67) observed on RGS003. The highest and lowest intrinsic rates of increase (r) of the cabbage aphid were observed on Opera (0.331 day?1) and RGS003 (? 0.242 day?1) cultivars, respectively, suggesting these to be the most susceptible and most resistant cultivars to this pest. However, because the aphid did not settle and feed well on RGS003, it was not possible to determine demographic parameters for its parasitoid. Consequently, the Okapi cultivar, which was the most resistant cultivar to the cabbage aphid after RGS003, was used in this study to assess the parasitoid wasp. The parasitoid’s intrinsic rate of increase (r) varied from 0.426 day?1 on the susceptible cultivar (Opera) to 0.341 day?1 on the resistant canola cultivar Okapi. Aphid performance decreased 93% on the resistant canola cultivar, while parasitoid performance decreased only 20% on the resistant cultivar compared to more susceptible cultivar.  相似文献   

17.
Lumostatic operation was applied for efficient astaxanthin production in autotrophic Haematococcus lacustris cultures using 0.4-L bubble column photobioreactors. The lumostatic operation in this study was performed with three different specific light uptake rates (q e) based on cell concentration, cell projection area, and fresh weight as one-, two- and three-dimensional characteristics values, respectively. The q e value from the cell concentration (q e1D) obtained was 13.5 × 10?8 μE cell?1 s?1, and the maximum astaxanthin concentration was increased to 150 % compared to that of a control with constant light intensity. The other optimum q e values by cell projection area (q e2D) and fresh weight (q e3D) were determined to be 195 μE m?2 s?1 and 10.5 μE g?1 s?1 for astaxanthin production, respectively. The maximum astaxanthin production from the lumostatic cultures using the parameters controlled by cell projection area (2D) and fresh weight (3D) also increased by 36 and 22 % over that of the controls, respectively. When comparing the optimal q e values among the three different types, the lumostatic cultures using q e based on fresh weight showed the highest astaxanthin productivity (22.8 mg L?1 day?1), which was a higher level than previously reported. The lumostatic operations reported here demonstrated that more efficient and effective astaxanthin production was obtained by H. lacustris than providing a constant light intensity, regardless of which parameter is used to calculate the specific light uptake rate.  相似文献   

18.
In this study, an alga-based simultaneous process of treating swine wastewater (SWW) and producing biodiesel was explored. Chlorella vulgaris (UTEX-265) was employed as a model species, and a SWW-based medium was prepared by dilution with tap water. Chlorella vulgaris grew well in the SWW-based medium, and at optimum dilution ratios, it exceeded the conventional culture medium in terms of biomass concentration and productivity. In eightfold diluted SWW, which supported the maximum growth, biomass productivity was 0.247 g L?1 day?1, while the productivity was merely 0.165 g L?1 day?1 in standard tris-acetate-phosphorous (TAP) algal medium. In addition, fatty acid methyl ester (FAME) productivity was greater in the SWW-based medium (0.067 versus 0.058 g L?1 day?1). This enhanced productivity resulted in more than 95 % removal of both nitrogen and phosphorous. All these show that C. vulgaris cultivation is indeed possible in a nutrient-rich wastewater with appropriate dilution, and in so doing, the wastewater can effectively be treated.  相似文献   

19.
The purpose of this study was to investigate the short-term effects of maize (Zea mays)-fallow rotation, residue management, and soil water on carbon mineralization in a tropical cropping system in Ghana. After 15 months of the trial, maize–legume rotation treatments had significantly (P?C 0 (μg CO2–C g?1) than maize–elephant grass (Pennisetum purpureum) rotations. The C 0 for maize–grass rotation treatments was significantly related to the biomass input (r?=?0.95; P?=?0.05), but that for the maize–legume rotation was not. The soil carbon mineralization rate constant, k (per day), was also significantly related to the rotation treatments (P?k values for maize–grass and maize–legume rotation treatments were 0.025 and 0.036 day?1 respectively. The initial carbon mineralization rate, m 0 (μg CO2–C g?1 day ?1), was significantly (P?θ. The m 0 ranged from 3.88 to 18.67 and from 2.30 to 15.35 μg CO2–C g?1 day?1 for maize–legume and maize–grass rotation treatments, respectively, when the soil water varied from 28% to 95% field capacity (FC). A simple soil water content (θ)-based factor, f w, formulated as: \(f_{\text{w}} = \left[ {\frac{{\theta - \theta _{\text{d}} }}{{\theta _{{\text{FC}}} - \theta _{\text{d}} }}} \right]\), where θ d and θ FC were the air-dry and field capacity soil water content, respectively, adequately described the variation of the m 0 with respect to soil water (R 2?=?0.91; RMSE?=?1.6). Such a simple relationship could be useful for SOC modeling under variable soil water conditions.  相似文献   

20.

Background

Pancreatic cancer (PC) has poorer prognosis and higher surgical invasiveness than many other cancers, with associated psychiatric symptoms including depression and anxiety. Perioperative depression has not been investigated in PC patients regarding surgical stress and relevant interventions.

Methods

We evaluated chronological depressive changes and subjective physical symptoms in surgically treated PC patients preoperatively and at 3 and 6 months postoperatively.Enrolled patients undergoing pancreatic tumor surgery completed questionnaires based on the Self-Rating Depression Scale (SDS) and Functional Assessment of Cancer Therapy for Patients with Hepatobiliary Cancer (FACT-Hep) preoperatively, and at 3 and 6 months postoperatively. Responses were analyzed with JMP® Pro using one-way and two-way ANOVA, Spearman’s rank correlation coefficient, and multiple regression analysis.

Results

Malignancy was diagnosed in 73 of 101 patients postoperatively; SDS score was significantly higher in these patients than in those with benign tumors at all timepoints: malignant/benign, 41.8/37.9 preoperatively (p?=?0.004); 43.5/37.8 3 months postoperatively (p?=?0.006); and 42.9/37.7 6 months postoperatively (p?=?0.020). SDS scores were significantly higher in patients <?65 years old with malignancy at 3 months than at 6 months postoperatively (44.6/42.5, p?=?0.046) and in patients with malignancy who underwent pancreaticoduodenectomy at 3 months postoperatively than preoperatively (43.4/41.1; p?=?0.028). SDS scores moderately correlated with 8 physical symptom-related FACT-Hep items 3 months postoperatively (p?<?0.05), showing low-to-moderate correlation with 16 physical symptom-related FACT-Hep items at 6 months postoperatively (p?<?0.05). Multiple regression analysis of FACT-Hep symptoms significantly correlated with SDS scores revealed the following significant variables: “lack of energy” (p?<?0.000) and “pain” (p?=?0.018) preoperatively (R2?=?0.43); “able to perform usual activities” (p?=?0.031) and “lack of energy” (p?<?0.000) at 3 months postoperatively (R2?=?0.51); and “stomach swelling or cramps” (p?=?0.034) and “bowel control” (p?=?0.049) at 6 months postoperatively (R2?=?0.52).

Conclusions

PC patients experience persistently high levels of depression preoperatively through 6 months postoperatively, with associated subjective symptoms including pain and gastrointestinal symptoms.

Trial registration

UMIN Clinical Trials Registry 000009592, Registered 20 December 2012.
  相似文献   

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