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141.
Production of corn gluten meal (CGM), a high‐protein coproduct from wet milling of corn, is increasing as production of fuel ethanol from corn increases. Unpleasant taste and odor have limited the use of CGM in human food. Adjustment of pH and extraction with water have been reported to reduce the off‐flavor of CGM but the improvement is not enough for substantial addition of CGM to the human diet. More study of CGM is needed. In this study, volatile compounds released under different conditions of pH, water extraction, and temperature were identified and compared using solid‐phase microextraction‐gas chromatography‐mass spectrometry (SPME‐GC‐MS). The water‐extractable portion, which improves the taste of CGM by its absence, was dried and analyzed by SPME‐GC‐MS. In addition, materials extractable from CGM with methylene chloride were identified by gas chromatography‐mass spectrometry (GC‐MS). Further, the spontaneous generation of a CGM‐like odor accompanied by a change in physical appearance of the CGM sample was described. Flavors and odors known to be associated with the identified CGM compounds were listed. Some possible origins of the volatiles, from degradation of corn constituents or as fermentation products of the corn steeping process, were noted.  相似文献   
142.
Herbicide-resistant weed biotypes are an increasing problem in agriculture, with reports of resistance to almost every herbicide class at some place in the world, and the total number of resistant biotypes at over 250. Agricultural Research Service (ARS) scientists have been key players in this area since the first substantiated occurrence of these resistant biotypes in the 1970s. The most significant of their contributions is the complete unraveling of the mechanism of triazine resistance by Arntzen and colleagues, then with ARS at the University of Illinois. These studies established a high benchmark for research in this area and are a model for all studies in this area. Other ARS scientists have investigated a large number of weed biotypes with resistance to a wide range of herbicide classes and mechanisms of resistance. Collectively, these studies have been used to generate herbicide resistance-management schemes for growers, based upon the herbicide site and the potential for resistance development.  相似文献   
143.
144.
The herbicidal action of acifluorfen {5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid} was studied with greened and expanded discs from cotyledons of cucumber (Cucumis sativus L.). Discs were floated on various treatment solutions for 20 hr in darkness before exposure to 400 μE m?2 sec?1 of white light. Herbicide damage, as measured by electrolyte leakage, began in the light after a 1- to 2-hr lag period. Cytochemical methods at the ultrastructural level indicated that acifluorfen caused marked increases in production of superoxide radical and hydrogen peroxide in the mitochondrion, but not in the plastid. The mitochondrial inhibitors antimycin A, rotenone, CCCP, and DNP antagonized the action of acifluorfen, lengthening the lag period and reducing the rate of electrolyte leakage. Ethanol, α-tocopherol, N-[2-(2-oxo-1-imidazolidinyl)ethyl]-N′-phenylurea, and copper-penicillin also lengthened the lag phase and slowed the rate of damage, indicating that acifluorfen damage involves toxic oxygen species. PS II-inhibiting levels of DCMU, atrazine, or bentazon did not affect acifluorfen-induced ion leakage. Yellow tissue produced by treatment with tentoxin was supersensitive to acifluorfen, but white tissue produced by treatment with norflurazon was relatively insensitive. These data indicate that, after an initial carotenoid-acifluorfen interaction, the mitochondrion is involved in production of toxic oxygen species and that this process is closely tied to the mechanism of action of this herbicide.  相似文献   
145.
Several volatile monoterpenes, which are among the major constituents of several easily obtainable essential oils, were phytotoxic in the gaseous phase to emerged potato tuber sprouts. Analyses of the more phytotoxic monoterpenes were conducted using a continuous-flow system in which the compounds were released as volatiles into the headspace surrounding the tubers. Several of these compounds, which have low mammalian toxicities and are currently used in large amounts as flavorings, over-the-counter medications and perfumes, effectively inhibited sprouting and fungal growth at relatively low molar concentrations.  相似文献   
146.
Nuclear polyhedrosis virus (NPV) and Bacillus thuringiensis (Bt) are the most commonly used biopesticides for the control of Helicoverpa spp. larvae on cotton crops in Australia. The performance of NPV and Bt against Helicoverpa spp. larvae on cotton crops, is inconsistent and at times totally unsatisfactory against high densities of Helicoverpa spp. larvae. We determined the effect of mixing petroleum spray oils, containing ultra-violet light absorbing compounds, with NPV and Bt for efficacy against Helicoverpa spp. larvae, levels of cotton plant damage, and persistence of efficacy. The study showed that the efficacy and persistence of NPV and Bt were increased when mixed with petroleum spray oil (PSO?–?Canopy®) at the rate of 2% (v/v). In the field experiments, mixing NPV with 1 and 2% (v/v) PSO, increased Helicoverpa spp. mortality from 25.9 to 31.5 and 44.8%, respectively. Similarly, the mortality caused by Bt, when mixed with 1 and 2% (v/v) PSO, was increased from 31.5 to 36.0 and 48.2%, respectively. In addition, 1 and 2% PSO mixtures with NPV increased persistence of efficacy from 1.1 to 1.6 and 2.5 days, respectively, whilst persistence of Bt was increased from 1.5 to 1.8 and 2.6 days, respectively. In another study using potted cotton plants, in which the plants were left outdoors throughout the study, the average NPV induced mortality of first instar Helicoverpa larvae was increased from 20.9% to 35.9 and 43.4% by 1 and 2% (v/v) PSO, respectively. Persistence of NPV efficacy was enhanced by 2 and 3.1 times by 1 and 2% (v/v) PSO, respectively. Similarly, Bt induced mortality of Helicoverpa larvae was increased by 1 and 2% PSO from 68.1 to 78.8 and 83.2%, respectively, and the persistence of Bt efficacy was enhanced 1.3?–?2.0 times, respectively. In a mesh house study, young cotton plants, treated with a PSO/biopesticide mixture, suffered less leaf damage than cotton plants treated with the biopesticides alone. In conclusion, the results of this study showed synergies from the combined use of UV protected PSO and NPV or Bt, against Helicoverpa spp. larvae on cotton. Such a biopesticide-PSO combinations could be a useful tool for IPM program in cotton.  相似文献   
147.
The variation in the kidding size of Black Bengal and Sirohi breed of goats makes them an interesting genetic material to study the underlying genetic mechanism of prolificacy. Accordingly, we studied the comparative ovarian morphometry including disparity in numbers of antral follicles of different sizes between these two breeds. Further, we evaluated the differential expression of the important candidate genes (viz., BMP15, GDF9 and BMPR1B) known to influence the ovulation rates and the prolificacy. The ovaries of Black Bengal (n = 20) goat were lighter (p < 0.01) in weight and smaller (p < 0.01) in diameter than those of Sirohi (n = 19) goats but possessed more numbers (p < 0.05) of corpus luteum (CL), large and small antral follicles. Quantitative real‐time PCR (RT‐qPCR) analysis revealed differential expression of mRNAs encoding for the BMP15 and GDF9. Small antral follicles of Black Bengal goats expressed 2.78‐fold more (p < 0.05) of BMP 15 than those of Sirohi goat. Expression of BMP15 (p < 0.01) and GDF9 (p < 0.05) mRNAs was more abundant in the small than the large antral follicles of Black Bengal goat. The more numbers of antral follicles per unit of ovarian mass and differential expression of BMP15 and GDF9 may serve as an important clue for higher prolificacy.  相似文献   
148.
The objective of the study was to elucidate mRNA expression of CYP26b1 (cytochrome P450, family 26, subfamily B, polypeptide 1) and signalling molecules ALDH1 (aldehyde dehydrogenase 1), CRABPII (cellular retinoic acid‐binding protein II), RARα (retinoic acid receptor alpha) and STRA8 (stimulated by retinoic acid gene 8) in dog testis from different post‐natal developmental ages. Testicular tissue samples were collected from medium‐sized mixed breed dogs at different ages such as young (<4 months; N = 4), peripubertal (4–8 months; N = 3) and adult (>8 months; N = 4) were used to evaluate relative mRNA expression. Genes of RA‐degrading enzyme CYP26b1, ALDH1 involved in RA synthesis and genes of carrier protein CRABPII involved in RA metabolism were turned on during the post‐natal testicular development in dogs. Their expression pattern differs at different developmental ages (p < 0.05), and the levels of mRNA expression were compensated towards a normal developmental response for the sexual maturity and continuous spermatogenesis. The mRNA expression of RARα, one of the RA receptors participates in RA signalling in connection to spermatogenesis, was recorded in young and adult stages at varying degree. STRA8 is one of the responsive genes with regard to meiosis, and this functional gene product was expressed in all ages with the changing level (p < 0.01). In summary, the expression pattern of RA signalling molecules differed from young to adult ages, and it is expected that these changes are to compensate towards a normal developmental response for the sexual maturity and continuous spermatogenesis.  相似文献   
149.
Exposure of male hamsters to short daily photoperiods (1 hour of light and 23 hours of darkness daily for 9 weeks led to total involution of the testes and accessory sex organs (seminal vesicles and coagulating glands). Pituitary levels of immunoreactive prolaction also decreased by about 60 percent after dark exposure. The inhibitory effects of darkness on the reproductive organs were prevented either by pinealectomy or by the subcutaneous implantation of a melatonin-beeswax pellet into the animals each week. Both pinealectomy and melatonin treatment also returned pituitary levels of prolactin toward normal. The results suggest that melatonin is not the pineal antigonadotrophic factor in the male golden hamster.  相似文献   
150.
Cultures of the insect cell line derived by Grace from Antheraea eucalypti Scott [Austrocaligula eucalypti (Scott)] were successfully adapted to medium supplemented with fetal bovine serum, whole-egg ultrafiltrate, and bovine plasma albumin instead of insect hemolymph. Cells, now in their 37th passage, have a population doubling time of 2.5 days; those of unadapted cultures, 4.2 days.  相似文献   
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