259 research outputs found

    Strong convergence theorems for nonexpansive semigroup in Banach spaces

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    AbstractLet K be a nonempty closed convex subset of a reflexive and strictly convex Banach space E with a uniformly GĂąteaux differentiable norm, and F={T(t):t>0} a nonexpansive self-mappings semigroup of K, and f:K→K a fixed contractive mapping. The strongly convergent theorems of the following implicit and explicit viscosity iterative schemes {xn} are proved.xn=αnf(xn)+(1−αn)T(tn)xn,xn+1=αnf(xn)+(1−αn)T(tn)xn. And the cluster point of {xn} is the unique solution to some co-variational inequality

    Decentralized Robust Tracking Control for Uncertain Robots

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    Optimization of recombinant expression enables discovery of novel cytochrome P450 activity in rice diterpenoid biosynthesis

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    The oxygenation reactions catalyzed by cytochromes P450 (CYPs) play critical roles in plant natural products biosynthesis. At the same time, CYPs are one of most challenging enzymes to functionally characterize due to the difficulty of recombinantly expressing these membrane-associated monooxygenases. In the course of investigating rice diterpenoid biosynthesis we have developed a synthetic biology approach for functional expression of relevant CYPs in Escherichia coli. In certain cases activity was observed for only one of two closely related paralogs although it seems clear that related reactions are required for production of the known diterpenoids. Here we report that optimization of the recombinant expression system enabled characterization of not only these previously recalcitrant CYPs, but also discovery of additional activity relevant to rice diterpenoid biosynthesis. Of particular interest, CYP701A8 was found to catalyze 3ÎČ-hydroxylation of syn-pimaradiene, which is presumably relevant to momilactone biosynthesis, while CYP71Z6 & 7 were found to catalyze multiple reactions, with CYP71Z6 catalyzing the production of 2α,3α-dihydroxy-ent-isokaurene via 2α-hydroxy- ent-isokaurene, and CYP71Z7 catalyzing the production of 3α-hydroxy-ent-cassadien-2- one via 2α-hydroxy-ent-cassadiene and ent-cassadien-2-one, which may be relevant to oryzadione and phytocassane biosynthesis, respectively

    Age Differences in Stress and Coping: Problem-Focused Strategies Mediate the Relationship between Age and Positive Affect

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    The present study examined the different types of stressors experienced by adults of different ages, their coping strategies, and positive/negative affect. A mediation hypothesis of coping strategies was tested on the relationships between age and positive/negative affect. One-hundred and ninety-six community-dwelling adults (age range 18-89 years old) reported the most stressful situation they experienced in the past month and coping strategies. Levels of positive and negative affect in the past month were also measured. Content analysis revealed age differences in different types of stressors adults reported. Three types of coping strategies were found: problem-focused, positive emotion-focused, and negative emotion-focused coping. Older adults were less likely than younger adults to use problem-focused coping and reported lower levels of positive affect. Path analysis supported the mediation hypothesis, showing that problem-focused coping mediated the relationship between age and positive affect. Implications are discussed on the importance of promoting problem-focused coping among older adults

    Hot Stamping of High Strength Steel with Tailored Properties by Two Methods

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    AbstractHot stamped components with full martensite exhibit ultrahigh tensile strength and hardness, whereas the poor ductility restricts their application on certain components, such as B pillar, which needs multi strength in different regions. It is essential to partly achieve softer structure with high ductility, to enhance the crashworthiness and energy absorption of the whole component and thus improving the safety performance. This work described the hot stamping of high strength steel with tailored properties by two methods, namely applying different die temperatures and annealing processes. The hardness distribution, tensile strength and ductility in different regions of the hot stamped components were gained under the conditions of above two methods to realize the tailored properties. Regardless of the decrease of tensile strength, the total elongation of annealed zone can reaches 20.6% while the heating zone can only obtain its elongation of 10.8%. The results show that annealing hardened part to get tailored properties brings about better performance

    Fighting For Time: Spillover and Crossover Effects of Long Work Hours Among Dual-Earner Couples

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    Drawing upon the spillover-crossover model, this study examined the extent to which one\u27s work time demands spilled over to the family domain, and crossed over to his or her spouse, utilizing data of 365 dual-earner couples from the 500 Family Study. The results of the distinguishable actor-partner interdependence model indicated that there was gender symmetry in the spillover processes such that the effects of work hours were identical between men and women. Further, although there was more bi-directional crossover between partners within couples, we observed some unidirectional crossover from husbands to wives. Specifically, husbands only increased their contribution to domestic work in response to wives\u27 work fatigue, whereas wives increased their contribution to domestic work in response to husbands\u27 work fatigue and high workloads. Finally, husbands\u27 housework hours negatively related to wives\u27 marital satisfaction and positively related to wives\u27 depression, whereas wives\u27 housework hours negatively related to husbands\u27 marital satisfaction and depression. These findings have practical implications for improving the work-family balance, health, and well-being of dual-earner couples

    Neural correlates of segmental and tonal information in speech perception

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    The Chinese language provides an optimal window for investigating both segmental and suprasegmental units. The aim of this cross‐linguistic fMRI study is to elucidate neural mechanisms involved in extraction of Chinese consonants, rhymes, and tones from syllable pairs that are distinguished by only one phonetic feature (minimal) vs. those that are distinguished by two or more phonetic features (non‐minimal). Triplets of Chinese monosyllables were constructed for three tasks comparing consonants, rhymes, and tones. Each triplet consisted of two target syllables with an intervening distracter. Ten Chinese and English subjects were asked to selectively attend to targeted sub‐syllabic components and make same‐different judgments. Direct between‐group comparisons in both minimal and non‐minimal pairs reveal increased activation for the Chinese group in predominantly left‐sided frontal, parietal, and temporal regions. Within‐group comparisons of non‐minimal and minimal pairs show that frontal and parietal activity varies for each sub‐syllabic component. In the frontal lobe, the Chinese group shows bilateral activation of the anterior middle frontal gyrus (MFG) for rhymes and tones only. Within‐group comparisons of consonants, rhymes, and tones show that rhymes induce greater activation in the left posterior MFG for the Chinese group when compared to consonants and tones in non‐minimal pairs. These findings collectively support the notion of a widely distributed cortical network underlying different aspects of phonological processing. This neural network is sensitive to the phonological structure of a listener's native language
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