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21.
Two studies investigated adult age differences in the frequency and emotional consequences of motivational conflicts (i.e., feeling that one wants to or should do something else in a given situation). Study 1 compared younger and older adults. Study 2 included a more age-heterogeneous sample ranging from 20 to 70 years. Data were obtained using diary and experience-sampling methods. Multilevel regression showed that motivational conflict was associated with lower emotional well-being. With age, the frequency of motivational conflict decreased, while emotional well-being increased. Importantly, the age-related decrease in motivational conflicts partly accounted for the age-related increase in emotional well-being. Findings were consistent across studies and robust after the authors controlled for age differences in a number of control variables including time use. The authors conclude that an age-related decrease in motivational conflicts in daily life may be among the factors underlying the positive development of emotional well-being into older adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
22.
Current technological possibilities for implementing multi-service networks include both single technology ATM or IP networks and multi-technology networks such as SONET-based or flat networks. However, regardless of the technology employed, the synthesis problem – to optimally route traffic and divide the network's transmission resources between its virtual links – remains of prime importance.In this paper, we review, compare, and classify the extensive recent literature concerning multi-service network synthesis methods. In order to do this, we propose a typology based on switching and control strategies and a general notation that reflects the layered nature of the network. Technology independent mathematical models describe the various, essentially different, approaches presently found in the literature. 相似文献
23.
Kiernan Michaela; Kraemer Helena C.; Winkleby Marilyn A.; King Abby C.; Taylor C. Barr 《Canadian Metallurgical Quarterly》2001,6(1):35
Identifying subgroups of high-risk individuals can lead to the development of tailored interventions for those subgroups. This study compared two multivariate statistical methods (logistic regression and signal detection) and evaluated their ability to identify subgroups at risk. The methods identified similar risk predictors and had similar predictive accuracy in exploratory and validation samples. However, the 2 methods did not classify individuals into the same subgroups. Within subgroups, logistic regression identified individuals that were homogeneous in outcome but heterogeneous in risk predictors. In contrast, signal detection identified individuals that were homogeneous in both outcome and risk predictors. Because of the ability to identify homogeneous subgroups, signal detection may be more useful than logistic regression for designing distinct tailored interventions for subgroups of high-risk individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
24.
25.
Skeletal muscle is an integral body tissue playing key roles in strength, performance, physical function, and metabolic regulation. It is essential for athletes to ensure that they have optimal amounts of muscle mass to ensure peak performance in their given sport. However, the role of maintaining muscle mass during weight loss and as we age is an emerging concept, having implications in chronic disease prevention, functional capacity, and quality of life. Higher‐protein diets have been shown to: (1) promote gains in muscle mass, especially when paired with resistance training; (2) spare muscle mass loss during caloric restriction; and (3) attenuate the natural loss of muscle mass that accompanies aging. Protein quality is important to the gain and maintenance of muscle mass. Protein quality is a function of protein digestibility, amino acid content, and the resulting amino acid availability to support metabolic function. Whey protein is one of the highest‐quality proteins given its amino acid content (high essential, branched‐chain, and leucine amino acid content) and rapid digestibility. Consumption of whey protein has a robust ability to stimulate muscle protein synthesis. In fact, whey protein has been found to stimulate muscle protein synthesis to a greater degree than other proteins such as casein and soy. This review examines the existing data supporting the role for protein consumption, with an emphasis on whey protein, in the regulation of muscle mass and body composition in response to resistance training, caloric restriction, and aging. 相似文献
26.
Michaela K. Back Sonia Ruggieri Eric Jacobi Jakob von Engelhardt 《International journal of molecular sciences》2021,22(12)
Onset and progression of Alzheimer’s disease (AD) pathophysiology differs between brain regions. The neocortex, for example, is a brain region that is affected very early during AD. NMDA receptors (NMDARs) are involved in mediating amyloid beta (Aβ) toxicity. NMDAR expression, on the other hand, can be affected by Aβ. We tested whether the high vulnerability of neocortical neurons for Aβ-toxicity may result from specific NMDAR expression profiles or from a particular regulation of NMDAR expression by Aβ. Electrophysiological analyses suggested that pyramidal cells of 6-months-old wildtype mice express mostly GluN1/GluN2A NMDARs. While synaptic NMDAR-mediated currents are unaltered in 5xFAD mice, extrasynaptic NMDARs seem to contain GluN1/GluN2A and GluN1/GluN2A/GluN2B. We used conditional GluN1 and GluN2B knockout mice to investigate whether NMDARs contribute to Aβ-toxicity. Spine number was decreased in pyramidal cells of 5xFAD mice and increased in neurons with 3-week virus-mediated Aβ-overexpression. NMDARs were required for both Aβ-mediated changes in spine number and functional synapses. Thus, our study gives novel insights into the Aβ-mediated regulation of NMDAR expression and the role of NMDARs in Aβ pathophysiology in the somatosensory cortex. 相似文献
27.
Lucie Vitejnov Vclav Lika Arvind Kumar Jana Ke
kov Ondej Vy
ítal Jan Brha Jan Bene Yaroslav Kolinko Tereza Blassov Zbynk Tonar Michaela Brychtov Marie Karlíkov Jaroslav Racek Hynek Mírka Petr Hoek Daniel Lysk Milena Krlí
kov 《International journal of molecular sciences》2021,22(9)
In liver surgery, biliary obstruction can lead to secondary biliary cirrhosis, a life-threatening disease with liver transplantation as the only curative treatment option. Mesenchymal stromal cells (MSC) have been shown to improve liver function in both acute and chronic liver disease models. This study evaluated the effect of allogenic MSC transplantation in a large animal model of repeated biliary obstruction followed by partial hepatectomy. MSC transplantation supported the growth of regenerated liver tissue after 14 days (MSC group, n = 10: from 1087 ± 108 (0 h) to 1243 ± 92 mL (14 days); control group, n = 11: from 1080 ± 95 (0 h) to 1100 ± 105 mL (14 days), p = 0.016), with a lower volume fraction of hepatocytes in regenerated liver tissue compared to resected liver tissue (59.5 ± 10.2% vs. 70.2 ± 5.6%, p < 0.05). Volume fraction of connective tissue, blood vessels and bile vessels in regenerated liver tissue, serum levels of liver enzymes (AST, ALT, ALP and GGT) and liver metabolites (albumin, bilirubin, urea and creatinine), as well as plasma levels of IL-6, IL-8, TNF-α and TGF-β, were not affected by MSC transplantation. In our novel, large animal (pig) model of repeated biliary obstruction followed by partial hepatectomy, MSC transplantation promoted growth of liver tissue without any effect on liver function. This study underscores the importance of translating results between small and large animal models as well as the careful translation of results from animal model into human medicine. 相似文献
28.
Miroslava Horynová Michaela Remešová Lenka Klakurková Karel Dvořák Ivana Ročňáková Shaokun Yan Ladislav Čelko Guang-Ling Song 《Journal of the American Ceramic Society》2019,102(1):123-135
Magnesium, as a biodegradable metal, offers great potential for use as a temporary implant material, which dissolves in the course of bone tissue healing. It can sufficiently support the bone and promote the bone healing process. However, the corrosion resistance of magnesium implants must be enhanced before its application in clinical practice. A promising approach of enhancing the corrosion resistance is deposition of bioactive coating, which can reduce the corrosion rate of the implants and promote bone healing. Therefore, a well-designed substrate-coating system allowing a good control of the degradation behavior is highly desirable for tailored implants for specific groups of patients with particular needs. In this contribution, the influence of coating formation conditions on the characteristics of potentiostatically electrodeposited CaP coatings on magnesium substrate was evaluated. Results showed that potential variation led to formation of coatings with the same chemical composition, but very different morphologies. Parameters that mostly influence the coating performance, such as the thickness, uniformity, deposits size, and orientation, varied from produced coating to coating. These characteristics of CaP coatings on magnesium were controlled by coating formation potential, and it was demonstrated that the electrodeposition could be a promising coating technique for production of tailored magnesium-CaP implants. 相似文献
29.
Energy policy scenarios to reach challenging climate protection targets in the German electricity sector until 2050 总被引:1,自引:0,他引:1
Stephan Nagl Michaela Fürsch Moritz Paulus Jan Richter Johannes Trüby Dietmar Lindenberger 《Utilities Policy》2011,19(3):185-192
In this article we demonstrate how challenging greenhouse gas reduction targets of up to 95% until 2050 can be achieved in the German electricity sector. In the analysis, we focus on the main requirements to reach such challenging targets. To account for interdependencies between the electricity market and the rest of the economy, different models were used to account for feedback loops with all other sectors. We include scenarios with different runtimes and retrofit costs for existing nuclear plants to determine the effects of a prolongation of nuclear power plants in Germany. Key findings for the electricity sector include the importance of a European-wide coordinated electricity grid extension and the exploitation of regional comparative cost effects for renewable sites. Due to political restrictions, nuclear energy will not be available in Germany in 2050. However, the nuclear life-time extension has a positive impact on end consumer electricity prices as well as economic growth in the medium term, if retrofit costs do not exceed certain limits. 相似文献
30.
The ongoing integration of Information Technology (IT) into various areas of our lives has led to a plethora of digital products and services. To survive competition in the long run, these offerings not only have to keep up with constant technological developments, but also have to adapt from a business point of view. Managers of these digital businesses have to especially focus on the design and evolution of their business’ revenue mechanisms to ensure the viability of their offerings. The related decisions are not trivial, as managers have to be aware of the relevant contextual factors and have to react quickly to changes in the environment. This paper proposes a viability theory for digital businesses described by 17 propositions that may guide managers in the design of revenue mechanisms and thereby support the evolution as well as the viability of a digital business. 相似文献