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排序方式: 共有3975条查询结果,搜索用时 31 毫秒
981.
Maria del Mar Rey-Mansilla Carmen G. Sotelo Santiago P. Aubourg Hartmut Rehbein Wiebke Havemeister Bo Jørgensen Michael K. Nielsen 《European Food Research and Technology》2001,213(1):43-47
The formation of dimethylamine and formaldehyde from trimethylamine N-oxide by the enzyme trimethylamine N-oxide demethylase in whole hake during frozen storage was studied. The objective was to check if there were parts of the muscle with a higher production of dimethylamine and formaldehyde, and if the presence of kidney during frozen storage had any significant influence on the production. Three variables were examined through one year storage. The first was anatomical location, considering the red muscle and three zones of white muscle, one located right over the kidneys, the dorsal part over the viscera, and the tail. The second variable was the temperature of storage, -11 °C or -18 °C. Finally, the influence of kidneys during storage, comparing fish with and without kidneys, was also evaluated. No differences were found in dimethylamine and formaldehyde production between fish with and without kidneys stored at -18 °C. However at -11 °C the amounts of dimethylamine and formaldehyde detected in fish without kidneys were, in some cases, higher than in those with kidneys. Kidney removal does not have a statistically significant influence on DMA and FA production in frozen storage hake. Differences in dimethylamine and formaldehyde values among different anatomical locations were found, especially in those stored over one year. It was found that, in general, the white muscle located right over the kidneys produced more dimethylamine than other parts of the fish. 相似文献
982.
Ditte Caroline Raben Søren Bie Bogh Birgit Viskum Kim L. Mikkelsen Erik Hollnagel 《Cognition, Technology & Work》2017,19(4):809-817
In recent years, healthcare has put a growing attention to the investigation of successful processes as a supplement to analyzing and investigating unwanted processes, like adverse events and near misses. This new perspective paves the way for developing methods and tools for investigating and understanding how processes function, and how variability can contribute to both success and failure. In the light of this, we have developed a method applicable for identifying leading indicators for successful outcomes of complex healthcare processes. The method, which is termed leading indicator identification method (LIIM) was inspired from similar methods applied in high-risk industries. To demonstrate the usefulness of the method we have conducted a case study with the aim of identifying leading indicators for blood sampling among patients in a Biomedical Department within a Danish hospital. The method builds on and uses steps from the functional resonance analysis method (FRAM). FRAM was developed to analyze how work is performed on a daily basis, in complex systems and can be used prospectively to monitor, manage and control such systems. The contribution of the work is to present the LIIM along with four leading indicators that are important to consider in the planning, management and monitoring of the blood sampling process. 相似文献
983.
984.
985.
Prediction and validation of residual feed intake and dry matter intake in Danish lactating dairy cows using mid-infrared spectroscopy of milk 总被引:1,自引:0,他引:1
The present study explored the effectiveness of Fourier transform mid-infrared (FT-IR) spectral profiles as a predictor for dry matter intake (DMI) and residual feed intake (RFI). The partial least squares regression method was used to develop the prediction models. The models were validated using different external test sets, one randomly leaving out 20% of the records (validation A), the second randomly leaving out 20% of cows (validation B), and a third (for DMI prediction models) randomly leaving out one cow (validation C). The data included 1,044 records from 140 cows; 97 were Danish Holstein and 43 Danish Jersey. Results showed better accuracies for validation A compared with other validation methods. Milk yield (MY) contributed largely to DMI prediction; MY explained 59% of the variation and the validated model error root mean square error of prediction (RMSEP) was 2.24 kg. The model was improved by adding live weight (LW) as an additional predictor trait, where the accuracy R2 increased from 0.59 to 0.72 and error RMSEP decreased from 2.24 to 1.83 kg. When only the milk FT-IR spectral profile was used in DMI prediction, a lower prediction ability was obtained, with R2 = 0.30 and RMSEP = 2.91 kg. However, once the spectral information was added, along with MY and LW as predictors, model accuracy improved and R2 increased to 0.81 and RMSEP decreased to 1.49 kg. Prediction accuracies of RFI changed throughout lactation. The RFI prediction model for the early-lactation stage was better compared with across lactation or mid- and late-lactation stages, with R2 = 0.46 and RMSEP = 1.70. The most important spectral wavenumbers that contributed to DMI and RFI prediction models included fat, protein, and lactose peaks. Comparable prediction results were obtained when using infrared-predicted fat, protein, and lactose instead of full spectra, indicating that FT-IR spectral data do not add significant new information to improve DMI and RFI prediction models. Therefore, in practice, if full FT-IR spectral data are not stored, it is possible to achieve similar DMI or RFI prediction results based on standard milk control data. For DMI, the milk fat region was responsible for the major variation in milk spectra; for RFI, the major variation in milk spectra was within the milk protein region. 相似文献
986.
National culture has received a substantial amount of interest in the operations management literature. We present the first structured review of articles studying national culture in operations management. Our search returned 51 papers published in ten leading journals between 2000 and 2017. We sort and analyse the papers according to three focus areas of operations management (strategy, execution and improvement). We also analyse the papers according to whether they address the relevance of national culture, the impact of national culture or the actions managers can use to manage or mitigate the effects of national culture. We find that national culture appears as a relevant variable in all focus areas of operations management research but that the direction and strength of its impact remain undetermined. Only a handful of papers address how managers can actively deal with challenges related to national culture. We propose a research agenda and a guiding framework for future research. 相似文献
987.
Theoretical literature suggests that the complex problems many local governments are facing are drivers towards innovation and new types of collaborative governance arrangements. We add nuance to this presumption by exploring how two Norwegian municipalities act when faced with problems related to mineral extraction and tax revenue. The article shows that similar types of problems give rise to significantly different strategies, ranging from collaborative arrangements to authoritative and competitive strategies. In conclusion, the article argues that local governments need to develop a higher innovative preparedness, and that scholars should also be attentive to governance strategies that are not collaborative. 相似文献
988.
Under natural conditions, cows seek isolation and visual cover when calving becomes imminent, but the degree of visual cover necessary to provide an attractive calving site is not known. When calving indoors, preparturient cows are attracted to other cows' birth fluids, and this may influence their isolation seeking. Therefore, we aimed to investigate the effect of degree of visual cover of secluded areas and the location of birth fluids on dairy cows' calving site selection. One hundred twenty-four Danish Holstein cows were moved in groups of 8 to 12 to a group pen with access to 6 areas secluded by a barrier of either 3 m (wide barrier) or 1.5 m (narrow barrier). Sixty cows calved within 14 d of having been moved to the group pen and were included in the study. From 3 h before partition and until the cow and calf were removed from the pen within 3 h after parturition, the location and posture of cows were recorded, along with the location of where their birth fluids were discharged. In addition, location and posture of calves were recorded during and up to 3 h after calving. All data were collected from continuous video recordings. Continuous data for location and behavior were analyzed by mixed models, binary data were analyzed by chi-squared analysis, and location of calving relative to where the cow's own or alien birth fluids were discharged was analyzed using logistic regression models. Ten percent of the cows calved in a secluded area, with no effect of barrier width. However, before calving, cows with access to secluded areas with a wide barrier spent more time in a secluded area (22 vs. 7 min/3 h), and more cows were observed lying there (58 vs. 28%) than cows with access to secluded areas with a narrow barrier. Secluded areas with a wide barrier were used by more cows and calves during the first hour after calving (36 vs. 10%). Among the cows that entered a secluded area after calving, the latency to enter correlated with their calf's latency to enter, suggesting that the 2 sought seclusion together. Seventy-nine percent of the cows calved in proximity (within a 1.25-m radius) to their own or an alien cow's birth fluids. There was no effect of barrier width on the probability of calving in proximity to their own or alien birth fluids. However, the probability of calving in proximity to their own or alien birth fluids was higher than the probability of not doing so. The greater use of secluded areas with a 3-m-wide barrier before and after parturition suggests that these are preferred over areas with a 1.5-m-wide barrier. Only a few cows calved in a secluded area, and more research is needed to explore the environmental and social factors affecting parturient cows' use of designated calving areas. The majority of cows calved close to where their own or alien birth fluids were discharged, suggesting that cows are attracted to these before calving. This may have affected the use of secluded areas as calving sites. 相似文献
989.
The limitations of a pseudo-transient approach for modeling temperature wave propagation in district heating pipes were investigated by comparing numerical predictions with experimental data. The performance of two approaches, namely a pseudo-transient approach implemented in the finite element code ANSYS and a node method, was examined for a low turbulent Reynolds number regime and small velocity fluctuations. Both approaches are found to have limitations in predicting the temperature response time and predicting the peak values of the temperature wave, which is further hampered by the fact that the fluid is represented as an ideal fluid. The approaches failed to adequately predict the temperature wave propagation in the case of rapid inlet temperature changes. The overall conclusion from this case study was that in order to improve the prediction of the transient temperature, attention has to be given to the detailed modeling of the turbulent flow characteristics. 相似文献
990.
J. F. Huertas-Pérez B. Sejerøe-Olsen T. Gokcen F. Sandor H. Schimmel 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2019,36(1):96-108
The production of certified reference materials requires the application of highly accurate methods for characterisation. A gas chromatography-isotope dilution mass spectrometry method, setting ambitious performance criteria, was developed for eight selected pesticides in soybeans. Pressurised liquid extraction was followed by automated gel-permeation chromatography and solid-phase extraction clean-up. Pesticides identification respected a Commission Decision and guidelines of the Directorate General for Health and Food Safety (DG SANTE). Reliable quantification involved stable isotopically labelled analogues as internal standards. Validation, according to ISO/IEC 17,025 and DG SANTE guidelines, assessed linearity, LOD/LOQ, trueness, selectivity, precision, stability and robustness. Mean recoveries ranges (83–109%, relative standard deviations < 3%), repeatability (2.2–4.8%), day-to-day variation (0.6–4.2%) and combined uncertainty (1.2–4.2%) were fit for purpose. The method is highly accurate and suitable for certification of the selected pesticides in soybean matrix reference material.
Chemical compounds studied in this article: Diazinon (PubChem CID: 3017); malathion (PubChem CID: 4004); chlorpyrifos (PubChem CID: 2730); captan (PubChem CID: 8606); endosulfan (PubChem CID: 3224); tebuconazole (PubChem CID: 86,102); iprodione (PubChem CID: 37,517); cypermethrin (PubChem CID: 2912). 相似文献