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排序方式: 共有459条查询结果,搜索用时 15 毫秒
111.
Cadmium and lead residue control in a hazard analysis and critical control point (HACCP) environment
Pagan-Rodríguez D O'Keefe M Deyrup C Zervos P Walker H Thaler A 《Journal of agricultural and food chemistry》2007,55(4):1638-1642
In 2003-2004, the U.S. Department of Agriculture Food Safety and Inspection Service (FSIS) conducted an exploratory assessment to determine the occurrence and levels of cadmium and lead in randomly collected samples of kidney, liver, and muscle tissues of mature chickens, boars/stags, dairy cows, and heifers. The data generated in the study were qualitatively compared to data that FSIS gathered in a 1985-1986 study in order to identify trends in the levels of cadmium and lead in meat and poultry products. The exploratory assessment was necessary to verify that Hazard Analysis and Critical Control Point plans and efforts to control exposure to these heavy metals are effective and result in products that meet U.S. export requirements. A comparison of data from the two FSIS studies suggests that the incidence and levels of cadmium and lead in different slaughter classes have remained stable since the first study was conducted in 1985-1986. This study was conducted to fulfill FSIS mandate to ensure that meat, poultry, and egg products entering commerce in the United States are free of adulterants, including elevated levels of environmental contaminants such as cadmium and lead. 相似文献
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113.
The effects of several conditions on the amounts and compositions of aggregates formed in mixtures of whey protein hydrolysate, made with Bacillus licheniformis protease, and whey protein isolate were investigated using response surface methodology. Next, the peptides present in the aggregates were separated from the intact protein and identified with liquid chromatography-mass spectrometry. Increasing both temperature and ionic strength increased the amounts of both intact protein and peptides in the aggregates. There was an optimal amount of added intact WPI that could aggregate with peptides, yielding a maximal amount of aggregated material in which the peptide/protein molar ratio was around 6. Under all conditions applied, the same peptides were observed in the protein-peptide aggregates formed. The dominant peptides were beta-lg AB [f1-45], beta-lg AB [f90-108], and alpha-la [f50-113]. It was hypothesized that peptides could form a kind of glue network that can include beta-lactoglobulin via hydrophobic interactions at the hydrophobic binding sites at the surface of the protein. 相似文献
114.
Reddy V Nathues A Le Corre L Sierks H Li JY Gaskell R McCoy T Beck AW Schröder SE Pieters CM Becker KJ Buratti BJ Denevi B Blewett DT Christensen U Gaffey MJ Gutierrez-Marques P Hicks M Keller HU Maue T Mottola S McFadden LA McSween HY Mittlefehldt D O'Brien DP Raymond C Russell C 《Science (New York, N.Y.)》2012,336(6082):700-704
Multispectral images (0.44 to 0.98 μm) of asteroid (4) Vesta obtained by the Dawn Framing Cameras reveal global color variations that uncover and help understand the north-south hemispherical dichotomy. The signature of deep lithologies excavated during the formation of the Rheasilvia basin on the south pole has been preserved on the surface. Color variations (band depth, spectral slope, and eucrite-diogenite abundance) clearly correlate with distinct compositional units. Vesta displays the greatest variation of geometric albedo (0.10 to 0.67) of any asteroid yet observed. Four distinct color units are recognized that chronicle processes--including impact excavation, mass wasting, and space weathering--that shaped the asteroid's surface. Vesta's color and photometric diversity are indicative of its status as a preserved, differentiated protoplanet. 相似文献
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116.
Fisheries Science - China (herein referred as China’s mainland, and excluding Hong Kong, Macau and Taiwan) is the largest contributor to global seafood production. While China’s marine... 相似文献
117.
Hariharan H Sharma S Chikweto A Matthew V DeAllie C 《Comparative immunology, microbiology and infectious diseases》2009,32(1):21-28
One hundred and twenty five chickens from Grenada, consisting of 77 broilers and 48 layers were examined for carriage of thermophilic campylobacters in their ceca by culture. Seventy nine percent of chickens were positive for campylobacters, with an isolation rate of 93.5% for broilers and 56.3% for layers, the difference being significant. Sixty-four pure cultures comprising 39 Campylobacter coli, 21 Campylobacter jejuni, and 4 Campyilobacter lari isolates were tested for their resistance against 7 antibiotics using the E-test. None of the isolates were resistant to chloramphenicol and gentamicin. Resistance rates to other drugs were: ampicillin, 9.4%; ciprofloxacin, 12.5%; erythromycin, 3.1%; metronidazole, 9.4%, and tetracycline, 50% with MICs of >or=256 microg/mL for tetracycline. There were no significant differences in resistance rates between C. coli and C. jejuni. Multiple resistance to >or=2 drugs was seen in 15.6% of total isolates. All C. lari isolates were resistant to ciprofloxacin, and 3 of 4 isolates had multiple drug resistance. Overall, erythromycin, which is the drug of choice for treatment of Campylobacter infections in humans, is effective in vitro against 97% of chicken isolates in Grenada. 相似文献
118.
Katherine P. O'Neill Harry W. Godwin Jeffrey P. Battigelli 《Soil biology & biochemistry》2010,42(2):145-154
Soil microinvertebrates are closely associated with soil decomposition and nutrient cycles and may be particularly responsive indicators for soil management practices. However, identification of appropriate bioindicator species for many systems has been severely limited by a lack of information on species taxonomy, distribution, and functional role. We evaluated Indicator Species Analysis (ISA) as an objective method for assessing the indicator potential of different taxa without regard to their ecological role or expected management response. Restricting ordination and site classification to significant indicator morphotaxa reduced the dimensionality of the community data matrix by 69% while only slightly decreasing the efficiency of unsupervised classification (from 87.2 to 84.4%); the percentage of total variability explained by first two PCA axes increased following ISA. When these same indicator morphotaxa were used to classify an independent set of samples, the percentage of total variability explained by the first two PCA axes increased from 55.3 to 65.2%; cluster analysis of the test dataset correctly classified 47 out of 50 plots by cover type (94% accuracy). However, restriction of analysis to indicator morphotaxa alone reduced detection of differences between sampling dates relative to the complete dataset. Although care needs to be taken to ensure that the dataset used for indicator selection is fully representative of underlying temporal and spatial variability, ISA appears to overcome many of the limitations associated with parametric and multivariate approaches for identifying indicator morphotaxa and has the potential to greatly reduce the taxonomic expertise and labor costs associated with sorting and identification of soil microarthropods. 相似文献
119.
Manuela S. Kaufmann Christian von Hebel Lutz Weihermüller Michael Baumecker Thomas Döring Kathlin Schweitzer Eleanor Hobley Sara L. Bauke Wulf Amelung Harry Vereecken Jan van der Kruk 《Soil Use and Management》2020,36(1):104-116
Electromagnetic induction (EMI) data are often used to investigate spatial and temporal patterns of soil texture, soil water content and soil salinity. We hypothesized that the EMI methodology might thus also offer potential to detect agricultural legacy effects originating from fertilizer application and irrigation of different fields. Therefore, we performed EMI measurements on two long-term field experiments (LTFE) at Thyrow near Berlin (Germany) that differed in agricultural management with regard to long-term irrigation in combination with mineral (NPK and lime) and organic amendments (straw and farmyard manure). Two different rigid-boom multi-coil EMI instruments were used to measure simultaneously the apparent electrical conductivity (ECa) over nine different depth ranges to study the entire soil profile from topsoil to deep subsoil. Additionally, soil samples were taken from the different treatments to ground-truth the measurements and disentangle the nutrient application or irrigation effects from natural soil heterogeneity. The soil samples indicated a rather homogenous soil and the correlation between soil parameters or states were not significant. However, the treatments showed significant differences in measured ECa values. In general, ECa values were largest on regularly irrigated as well as on mineral and organic fertilized plots, with regular irrigation exhibiting the largest impact on EMI records even though the last application was months before the EMI measurement. Overall, this study reveals that EMI data can support the classical in situ assessment of agricultural management effects within LTFE, while offering new potentials in detecting and understanding legacy effects of agricultural management on spatial soil properties at farm level. 相似文献
120.
Maryam Jorjani Mostafa Sharif Rohani Amin Mirhashemi Rostami Harry Ako Aileen Tan Shau Hwai 《Journal of the World Aquaculture Society》2019,50(4):789-799
The present study aimed to determine the effects of different levels of marigold, Calendula officinalis, powder, 0 (control), 0.5% (M0.5), 1.5% (M1.5), and 2.5% (M2.5), on pigmentation and growth performance of the blue gourami after a 70‐day trial. At the end of the experiment, no significant differences (p > 0.05) were found in fish growth performance and body compositions. Color parameters (L*, a*, and b*) were weekly evaluated by examining a point posterior to the fish operculum. The marigold‐fed fish were darker than the control fish at Weeks 9 and 10. Yellowness intensity of the M2.5 was significantly higher than the other treatments at Week 9. Skin and caudal fin total carotenoids, astaxanthin, canthaxanthin, and β‐carotene contents of the treatment M2.5 were significantly different (p < 0.05) compared to the other treatments. Muscle total carotenoids, astaxanthin, and canthaxanthin contents of the marigold‐treated fish were significantly (p < 0.05) higher than the control group. Muscle β‐carotene contents of the treatments M1.5 and M2.5 were significantly (p < 0.05) higher than the control group. This study shows that marigold powder may be considered an efficient natural carotenoid source for pigmentation in blue gourami. 相似文献