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301.
Two experiments were undertaken to evaluate the effect on milk and cheese fatty acid composition of feeding different fresh forages to dairy sheep both in winter (experiment 1, growing stage of the forages, early lactating ewes) and in spring (experiment 2, reproduction stage of the forages, midlactating ewes). Four forage species were compared: annual ryegrass (RY, Lolium rigidum Gaudin), sulla (SU, Hedysarum coronarium L.), burr medic (BM, Medicago polymorpha L.), and a daisy forb (CH, Chrysanthemum coronarium L.). The forages were cut twice daily and offered ad libitum to 4 replicate groups of Sarda dairy sheep (groups RY, SU, BM, and CH). The CH forage was particularly rich in linoleic acid in both periods, whereas BM and SU forages were rich in linolenic acid in winter and spring, respectively. Milk fatty acid composition was affected by the forage in both experiments. Milk conjugated linoleic acid and vaccenic acid contents were higher in CH and BM groups (winter) and CH group (spring) than in the other groups. No differences were observed when comparing fatty acid profile between milk, 1-d-old cheeses, and 60-d-old cheeses within experimental groups, suggesting that the fatty acid recovery rates during cheese making and ripening were not affected by the feeding regimens. After stepwise discriminant analyses of the pooled data, the milks and cheeses sourced in the different feeding regimens differed among them. Based on these results, we conclude that it is possible to manipulate the fatty acid profile of sheep dairy produce to maximize the content of beneficial fatty acids by the use of appropriate fresh forage-based regimens.  相似文献   
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A simple technique for estimating the camera displacement from point correspondences in eye-in-hand visual servoing is presented. The idea for providing more accurate results than existing methods consists of taking into account that the point correspondences used during the camera motion correspond to stationary spatial points, hence exploiting additional information, This is done by first estimating the object Euclidean structure and then estimating the camera displacement from this estimate.  相似文献   
304.
In cardiovascular variability analysis, the significance of the coupling between two time series is commonly assessed by setting a threshold level in the coherence function. While traditionally used statistical tests consider only the parameters of the adopted estimator, the required zero-coherence level may be affected by some features of the observed series. In this study, three procedures, based on the generation of surrogate series sharing given properties with the original but being structurally uncoupled, were considered: independent identically distributed (IID), Fourier transform (FT), and autoregressive (AR). IID surrogates maintained the distribution of the original series, while FT and AR surrogates preserved the power spectrum. The ability of the three methods to define the threshold for zero coherence was validated and compared by computer simulations reproducing typical cardiovascular interactions. While the IID threshold depended only on record length and design parameters of the coherence estimator, FT and AR thresholds were frequency-dependent with peaks corresponding to the local maxima of the estimated coherence. FT and AR surrogates were able to compensate spurious coherence peaks due to equal-frequency but independent oscillations in the two series. The benefit of frequency-dependent thresholds was evident for short series with narrow-band oscillations. Thus, surrogates preserving the power spectrum of the original series are recommended to avoid false coupling detections in the presence of oscillations occurring at nearby frequencies but produced by different mechanisms, as may frequently happen in cardiovascular and cardiorespiratory regulation.  相似文献   
305.
Two converging, multimethod studies probed the hypothesis that individual differences in Agreeableness are related to patterns of interpersonal conflict. In Study 1, participants (N = 263) evaluated the efficacy of 11 modes of conflict resolution within the context of 5 different interpersonal relationships. Across all relationships, high- and low-agreeable participants rated negotiation and disengagement tactics as better choices that power assertion tactics. However, low-agreeable participants rated power assertion as a better choice than did high-agreeable participants. In Study 2, participants (N = 124) were assigned partners and were asked to resolve jointly 2 social conflict problems. Partners were videotaped, and observers coded behaviors. Participants also completed ratings of perceived conflict, partner perception, and liking of their partner. Agreeableness differences, sex of participant, and type of dyad partner were related to patterns of interpersonal conflict. Results were discussed in terms of personality and social influences during interpersonal conflict.  相似文献   
306.
Inflammatory fibroid polyp (IFP) is a rare lesion of the gastroenteric tract more frequently occurring at the level of the stomach. The etiopathogenesis of IFP as well as the nature of the cells constituting these lesions remain unknown. Abdominal pain and anaemia due to chronic blood loss are the most common presenting features but neither radiology and CT scanning nor endoscopy are capable to achieve any conclusive diagnostic information. Histologic examination of the specimen obtained by endoscopic or surgical excision is considered to be the only way for the definitive exclusion of a neoplastic nature. A case of IFP treated by means of total gastrectomy is presented.  相似文献   
307.
When children do not exhibit certain minimum academic competencies, they are retained in grade. Despite the pervasiveness of this school practice, little is known about the effects of grade retention on children's social development. The present study explored the hypotheses that peer discrimination may be one factor contributing to the negative effects of grade retention reported in the previous literature. Specifically, it was expected that retained children would (a) receive unfavorable peer attributions, (b) be assigned lower social status, (c) be the targets of peer discrimination, and (d) have lower expectations for themselves and for school. Evidence for peer discrimination against retained children was found, but effects were moderated by the age, gender, relative physical size, and retention status of the rater. Contrary to prediction, retained children had higher self-esteem than did nonretained children. These and other findings were discussed in terms of school and peer influence on social development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Li‐ion batteries are omnipresent in consumer electronics and are seen as the most promising technology for electric vehicles. Na‐ion batteries have emerged as viable and cheaper alternatives for stationary applications where Li‐ion batteries are too expensive. However, the larger size of sodium ion compared to lithium makes traditional positive materials for Li‐ion batteries not always suitable for the reversible insertion of sodium ions. Herein, a microwave‐assisted solution synthesis of NaFeF3 perovskite nanoparticles from presynthesized rutile FeF2 colloidal particles, sodium ethoxide, and ammonium fluoride is presented. This NaFeF3 material shows a reversible electrochemical activity of 1Na or 1Li per iron with low polarization and excellent capacity retention after 100 cycles. The unexpected reversible insertion of both sodium and lithium ions, herein studied through ex situ and operando X‐ray diffraction measurements, is attributed to a kinetic stabilization of corner‐shared cubic AxFeF3 (A = Li, Na) frameworks along the cycles involving low volume change without high thermodynamic cost as supported by a polymorphism theoretical analysis.  相似文献   
310.
The identification and the development of a quantification technique of the modes of fracture in fatigue fracture surfaces of a 2618-T6 aluminum alloy were developed during this research. Fatigue tests at room and high temperature (230 °C) were carried out to be able to compare the microscopic fractographic features developed by this material under these testing conditions. The overall observations by scanning electron microscopy (SEM) of the fracture surfaces showed a mixture of transgranular and ductile intergranular fracture. The ductile intergranular fracture contribution appears to be more significant at room temperature than at 230 °C. A quantitative methodology was developed to identify and to measure the contribution of these microscopic fractographic features. The technique consisted of a combination of stereophotogrammetry and image analysis. Stereo-pairs were randomly taken along the crack paths and were then analyzed using the profile module of MeX software. The analysis involved the 3-D surface reconstruction, the trace of primary profile lines in both vertical and horizontal directions within the stereo-pair area, the measurements of the contribution of the modes of fracture in each profile, and finally, the calculation of the average contribution in each stereo-pair. The technique results confirmed a higher contribution of ductile intergranular fracture at room temperature than at 230 °C. Moreover, there was no indication of a direct relationship between this contribution and the strain amplitudes range applied during the fatigue testing.  相似文献   
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