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981.
When wet processed coffee beans are dried, the resulting decrease in the water potential induces various metabolic responses. This study was aimed at elucidating the impact of these reactions on the composition of sugars, representing potential aroma precursors. Wet processed green coffees were dried under defined conditions, and the relevant sugars were analysed. Special emphasis was put on the influence of the drying regime, i.e. continuous dryings and such interrupted by pauses in order to mimic sun dryings. 相似文献
982.
Peter Steffen Westhoff Dirk Castelluccia Claude 《Dependable and Secure Computing, IEEE Transactions on》2010,7(1):20-34
We present an overview of end-to-end encryption solutions for convergecast traffic in wireless sensor networks that support in-network processing at forwarding intermediate nodes. Other than hop-by-hop based encryption approaches, aggregator nodes can perform in-network processing on encrypted data. Since it is not required to decrypt the incoming ciphers before aggregating, substantial advantages are 1) neither keys nor plaintext is available at aggregating nodes, 2) the overall energy consumption of the backbone can be reduced, 3) the system is more flexible with respect to changing routes, and finally 4) the overall system security increases. We provide a qualitative comparison of available approaches, point out their strengths, respectively weaknesses, and investigate opportunities for further research. 相似文献
983.
Ingo Alig Sascha Tadjbach Peter Krüger Harald Oehler Dirk Lellinger 《Progress in Organic Coatings》2009,64(2-3):112-119
Scanning acoustic microscopy (SAM) has been applied to different commercial coating systems on steel substrates in order to evaluate the potential of the method for fast non-destructive testing during material development: the focus was on defect detection after and during accelerated weathering and corrosion tests. The possibility of detecting hidden defects (e.g., blisters) in an early stage of weathering or corrosion tests has been evaluated for different commercial coating systems. Using different scanning modes 2K polyurethane systems (solvent- and water-borne) have been examined by SAM. Debonding at the polymer/substrate interface and the interface between base coat and top coat has been studied in samples after simulated weathering. The time dependence of “blister nucleation and growth” has been studied during a salt spray test. Furthermore, the surface topography has been investigated for UV-cured acrylic systems with and without antioxidants after simulated weathering. 相似文献
984.
M. Giesen T. Welß E. S. zur Wiesche† V. Scheunemann† S. Gruedl Y. Oezkabakcioglu E. Poppe† Dirk Petersohn 《International journal of cosmetic science》2009,31(2):154-155
IFSCC Magazine, 11 (2008) (1) 37–42 Ubiquinones are the most widespread and therefore best investigated bioquinones. Due to their hydrophobic isoprenoid side chain, ubiquinones can be solubilized in organic solvents or lipids but are insoluble in water. Using a specific emulsifier system it has been possible to deliver positive effects to biological systems also from aqueous formulations. Ubiquinone‐50, also referred to as coenzyme Q10, is well known in cosmetic science and especially in skin care because of its antioxidant activity. It is found in the membranes of peroxisomes, lysosomes, vesicles, the endoplasmic reticulum and notably in the inner membrane of the mitochondrion, where it is an important part of the electron transport chain. Using coenzyme Q10 in the proposed emulsifier system we could show that the molecule not only has relevance as an anti‐aging bioactive in skin care but also has positive effects on the human hair follicle. The hair follicle is a complex mini organ and synthesis of hair keratin, the major component of hair fibers, is an essential prerequisite for the growth of strong and healthy hair. But like all biological systems the hair follicle, the biologically active part of the hair, also undergoes an aging process associated among other things with a decline in certain hair keratins. Due to this age‐related shift in basic structural proteins of the hair shaft, mature hair often becomes fragile and difficult to manage. Therefore it is a challenge for cosmetic science to provide bioactives to fight age‐related changes and maintain a youthful appearance of hair. Using cultivated hair follicle keratinocytes we identified coenzyme Q10 as a potent bioactive that stimulates the gene expression of different hair keratins, especially those which are reduced during aging processes in hair follicles. These results led us to investigate a shampoo and a tonic formulation enriched with coenzyme Q10 in a placebo‐controlled panel study. In a left/right comparison a group of healthy volunteers older than 40 years of age applied the formulations daily for 4 days. Throughout the test period the gene expression of different hair keratins from plucked hair follicles was determined using quantitative polymerase chain reaction techniques. Subsequent statistical analysis revealed an increase in age‐relevant hair keratins in human hair roots treated with coenzyme Q10, thus pointing out the striking benefits of coenzyme Q10 in hair care formulations. We conclude that coenzyme Q10 is an ideal ingredient for hair care formulations, providing anti‐aging properties through activation of specific keratins aligned with the needs of mature hair. 相似文献
985.
Suppressing and faking emotional expressions depletes personal resources and predicts job strain for customer-contact employees. The authors argue that personal control over behavior, in the job and within the national culture, provides compensatory resources that reduce this strain. With a survey study of 196 employees from the United States and France, the authors supported that high job autonomy buffered the relationship of emotion regulation with emotional exhaustion and, to a lesser extent, job dissatisfaction. The relationship of emotion regulation with job dissatisfaction also depended on the emotional culture; the relationship was weaker for French customer-contact employees who were proposed to have more personal control over expressions than U.S. employees. Theoretical and research implications for the emotion regulation literature and practical suggestions for minimizing job strain are proposed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
986.
Predicting customer churn with the purpose of retaining customers is a hot topic in academy as well as in today’s business environment. Targeting the right customers for a specific retention campaign carries a high priority. This study focuses on two aspects in which churn prediction models could be improved by (i) relying on customer information type diversity and (ii) choosing the best performing classification technique. (i) With the upcoming interest in new media (e.g. blogs, emails, ...), client/company interactions are facilitated. Consequently, new types of information are available which generate new opportunities to increase the prediction power of a churn model. This study contributes to the literature by finding evidence that adding emotions expressed in client/company emails increases the predictive performance of an extended RFM churn model. As a substantive contribution, an in-depth study of the impact of the emotionality indicators on churn behavior is done. (ii) This study compares three classification techniques – i.e. Logistic Regression, Support Vector Machines and Random Forests – to distinguish churners from non-churners. This paper shows that Random Forests is a viable opportunity to improve predictive performance compared to Support Vector Machines and Logistic Regression which both exhibit an equal performance. 相似文献
987.
Dirk Zahn Oliver Hochrein Gotthard Seifert Rüdiger Kniep 《Science and Technology of Advanced Materials》2007,8(5):434-441
The investigation of the atomistic mechanisms of processes in complex systems constitutes a major challenge to both theory and experiment. While experimental studies offer a wide variety of insights at the macroscopic scale, the atomistic level of detail often remains elusive. On the other hand, molecular simulation approaches may easily achieve microscopic resolution and hence appear particularly suited for detailed mechanistic analyses. However, the computational effort is typically quite considerable and in many cases special simulation strategies are needed to make simulations possible. This review is dedicated to special approaches for tackling the time/length-scale problem inherent to molecular dynamics simulations. Employing these techniques opened a series of new perspectives. The latter are illustrated with the example of recent simulation studies of the atomistic mechanisms involved in complex processes like crystal nucleation, phase transitions and reactions in solution. Along this line, we discuss the reaction mechanisms for He insertion into C60 fullerenes, nucleation events and domain morphogenesis in pressure-induced phase transitions in solids and ion aggregation from solution. 相似文献
988.
Szameitat Diana P.; Alter Kai; Szameitat André J.; Darwin Chris J.; Wildgruber Dirk; Dietrich Susanne; Sterr Annette 《Canadian Metallurgical Quarterly》2009,9(3):397
Although laughter is important in human social interaction, its role as a communicative signal is poorly understood. Because laughter is expressed in various emotional contexts, the question arises as to whether different emotions are communicated. In the present study, participants had to appraise 4 types of laughter sounds (joy, tickling, taunting, schadenfreude) either by classifying them according to the underlying emotion or by rating them according to different emotional dimensions. The authors found that emotions in laughter (a) can be classified into different emotional categories, and (b) can have distinctive profiles on W. Wundt’s (1905) emotional dimensions. This shows that laughter is a multifaceted social behavior that can adopt various emotional connotations. The findings support the postulated function of laughter in establishing group structure, whereby laughter is used either to include or to exclude individuals from group coherence. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
989.
Ben Van Calster Dirk Timmerman Ian T. Nabney Lil Valentin Antonia C. Testa Caroline Van Holsbeke Ignace Vergote Sabine Van Huffel 《Neural computing & applications》2008,17(5-6):489-500
In this paper, we applied Bayesian multi-layer perceptrons (MLP) using the evidence procedure to predict malignancy of ovarian masses in a large (n = 1,066) multi-centre data set. Automatic relevance determination (ARD) was used to select the most relevant inputs. Fivefold cross-validation (5CV) and repeated 5CV was used to select the optimal combination of input set and number of hidden neurons. Results indicate good performance of the models with area under the receiver operating characteristic curve values of 0.93–0.94 on independent data. Comparison with a linear benchmark model and a previously developed logistic regression model shows that the present problem is very well linearly separable. A resampling analysis further shows that the number of hidden neurons specified in the ARD analyses for input selection may influence model performance. This paper shows that Bayesian MLPs, although not frequently used, are a useful tool for detecting malignant ovarian tumours. 相似文献
990.
van den Berg Matthijs; Timmermans Danielle R. M.; Knol Dirk L.; van Eijk Jacques Th. M.; de Smit Denhard J.; van Vugt John M. G.; van der Wal Gerrit 《Canadian Metallurgical Quarterly》2008,27(4):430
Objective: This study is aimed at enhancing understanding prenatal screening decision making through testing a hypothesized decision model based on decision theory and health behavior theory. Design: We obtained questionnaires from 1,666 pregnant women who were offered prenatal screening for Down's syndrome. Path analysis (using LISREL) resulted in a final model with reasonable model fit, which was verified by split-sample cross-validation. Main outcome measures: These included perceived probability, perceived severity, attitude toward termination, response efficacy, attitude toward prenatal screening, subjective norm, child-related anxiety, and intention to undergo prenatal screening. Results: Attitude toward termination of pregnancy, perceived test efficacy, and subjective norm regarding the desirability of having prenatal screening determined a woman's attitude toward having a prenatal test. Anxiety was influenced by perceived risk and perceived severity of having a child with Down's syndrome, and by subjective norm, but this appeared to be a weak predictor of intention to test. Pregnant women with a positive attitude toward prenatal screening, and who perceived a subjective norm in favor of undergoing prenatal screening, showed a greater intention to have prenatal screening done. Conclusion: These findings suggest that more attention should be paid toward the values and social context of pregnant women during the counseling process. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献