44 research outputs found

    Self-leadership as an attribute of service leadership: Its relationship to well-being among university students in Hong Kong

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    IntroductionIn the scientific literature, although conceptual models and empirical evidence have shown that leadership attributes are intimately linked to the well-being of followers, there is a lack of studies focusing on leadership in the service economy. According to the Service Leadership Theory, service leadership is a process that satisfies the needs of self, others, and systems (teams, organizations, communities, and societies) in ethical ways that is characterized by leadership competence, character, and care. With specific reference to self-leadership emphasized in service leadership, higher levels of service leadership attributes should promote personal well-being. However, the relationships between “service leadership attributes” and “well-being” in leaders at the intrapersonal level in leadership education among Chinese university students are rarely examined.MethodsIn this study, we collected data from 198 students to understand the linkages between “service leadership attributes” and “well-being” in university students taking a course on service leadership. For tracking changes in students, we collected both pretest and posttest data on validated measures of “service leadership attributes” (i.e., “knowledge,” “attitude,” and “behavior”) and “well-being” (i.e., “positive youth development attributes” and “life satisfaction”).ResultsResults showed that the posttest scores on all three domains of “service leadership attributes” as well as two dimensions of “well-being” encompassing life satisfaction and positive youth development attributes were higher than the respective pretest scores, suggesting that students experienced a shift in a positive direction after taking the course. Cross-lagged analyses showed that pretest service leadership attitude and behavior predicted posttest positive youth development attributes; pretest service leadership behavior predicted posttest life satisfaction. Pretest life satisfaction also predicted posttest service leadership behavior.DiscussionFindings suggest that there is an intimate relationship between “service leadership attributes” and “well-being” in the “pre-work” context among university students

    Electrophilic boron carboxylate and phosphinate complexes

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    The reactions of a series of carboxylic acids with H2B(C6F5)·SMe2 are shown to afford species of the form [RC(O)OB(C6F5)]2O, (R = Tol 1, Ph 2, C6F53, Me2BrC 4, Me 5) in 87–95% yields with the concurrent reduction of the carboxylic acid to the corresponding aldehyde. A mechanism for the formation of 1–5 is proposed to proceed via a cyclic eight-membered ring species. Analogues of these species were prepared via reactions of carboxylic and phosphinic acids with HB(C6F5)2 and H2B(C6F5)·SMe2, respectively, to give [TolC(O)OB(C6F5)2]26, [(C6F5)C(O)OB(C6F5)2]27, and [Ph2P(O)OBH(C6F5)]28. These products react subsequently to give TolC(O)OBH(C6F5)(NC5H4NMe2) 9 and Ph2P(O)OBH(C6F5)(NC5H4NMe2) 10. The acyloxyborate derivatives 1–4 were shown to be inactive in mediating the direct amidation of carboxylic acids, consistent with previous observations that infer the need for a sterically congested environment about the boron centres

    Exploring the Synthesis and Reactivity of Phosphorus/Boron Frustrated Lewis Pairs and Nitrogen-based Lewis Acids

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    The definition of frustrated Lewis pairs has been broadened from combinations of sterically encumbered Lewis acids and bases to stable classical Lewis adducts, which opens a new avenue as FLPs in challenging small molecule activation and catalysis. The objective for this thesis is to explore the design and fundamental reactivity of Lewis acid and base pairs featuring group 13 and 15 elements within the realm of frustrated Lewis pair chemistry.An FLP strategy was used in the interception of intermediates in mesityl-N-oxide-mediated phosphine oxidation with stable P/B-based Lewis adducts. The FLP 1,3-addition products were shown to react with strong bases allowing the phosphine oxidation to proceed, which provided experimental data supporting the related phosphine oxidation mechanism proposed by Cummins. Highly electrophilic hydridoboranes, H2B(C6F5)·SMe2 and HB(C6F5)2 were demonstrated to yield bicyclic and cyclic boron species when exposed to carboxylic acids or phosphinic acid. The subsequent reactivity of many of these heterocycles with Lewis bases was investigated. Oxygen-bridging P/B molecules featuring a weak Lewis acid centre were prepared and the FLP reactivity of these species was systematically explored. Such POB-containing intramolecular FLPs were found to effect in the capture of N2-surrogate, diazomethanes, which resulted in the formation of unexpected stable heterocycles. Isomeric nitrenium Lewis acids were prepared from alkylation of spiro[fluorene‐9,3’‐indazole] with tBuCl. The chemical properties of the cations were examined and their reactivity with phosphorus and carbon nucleophiles was explored.Ph.D

    Impact of Family Functioning on Adolescent Materialism and Egocentrism in Mainland China: Positive Youth Development Attributes as a Mediator

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    Although adolescent materialism and egocentrism are growing problems in Chinese societies, there are very few studies investigating their predictors and related mediators. Longitudinal studies in this area are also sparse. Based on a short-term longitudinal study (n = 4981), we assessed the impact of family functioning on materialism and egocentrism of Chinese adolescents, with positive youth development attributes as a hypothesized mediating factor. Results showed that family functioning positively predicted positive youth development attributes but negatively predicted adolescent materialism and egocentrism; positive youth development attributes also negatively predicted adolescent materialism and egocentrism. Mediational analyses showed that positive youth development attributes mediated the impact of family functioning on adolescent materialism and egocentrism. The theoretical and methodological advances of the study are discussed

    Evaluation of the relationship between maxillary posterior teeth and the maxillary sinus floor using cone-beam computed tomography

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    Abstract Background Maxillary posterior teeth have close anatomical proximity to the maxillary sinus floor (MSF), and the race, gender, age, side and presence/absence of adjacent teeth may influence the mean distances between the root apices and the MSF. This study aimed to evaluate both the relationship between the maxillary posterior teeth and MSF, and the influence of adjacent teeth loss on the distance between the maxillary posterior roots and MSF. Methods Cone-beam computed tomography images were collected from 1011 Chinese patients. The relationship between the maxillary posterior teeth and the MSF was divided into three types: Type OS (the root apex extending below/outside the MSF), Type CO (the root apex contacting with the MSF), Type IS (the root apex extending above/inside the MSF). The minimum vertical distances between the maxillary posterior roots apices and the MSF were recorded. The correlations of the distances with gender and age were analyzed. The distances between the maxillary posterior root apices and the MSF with different types of adjacent teeth loss was evaluated. Results Type OS was the most common relationship of all posterior root apices (P<0.05). Type IS was highest in the palatal roots (PRs) of the maxillary first molars (MFMs) and the mesiobuccal roots (MBRs) of the maxillary second molars (MSMs) (24.8% and 21.6%) (P<0.05). The frequency of Type IS decreased with age except the premolar roots and PRs of the MSMs (P<0.05). The MBRs of the MSMs had the lowest distances to the MSF (0.8 ± 2.5 mm), followed by the distobuccal roots of the MSMs (1.3 ± 2.7 mm) and the PRs of the MFMs (1.4 ± 3.4 mm) (P<0.05). Age was an important influencing factor to the mean distances while gender had little effects. The distance between the maxillary second premolar root apices and the MSF decreased with the absence of adjacent teeth (P<0.05). Conclusions The maxillary molars showed greater proximity to the MSF than premolars. Age had significant impacts on the relationship between maxillary posterior roots and MSF. The absence of maxillary first molars will influence the proximity of maxillary second premolar root apices to MSF

    Study on Optimal Operation of Hydropower Station Group Based on New Electricity Reform and Deviation Assessment

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    The new electricity system reform has brought power generation companies into the market, and the scheduling target of cascade hydropower stations has been transformed from maximizing power generation to maximizing revenue. Market rules require hydropower generators to pay assessment fees for the power generation deviation. Therefore, in order to obtain the desired revenue, power generators should not only obtain more power generation indicators and higher power prices, but also control the power generation deviation and avoid being assessed. In response to the current market environment, the new requirements of the new electricity system reform for hydropower scheduling were analyzed. And based on regional market rules, a scheduling model for cascade hydropower stations with the goal of minimizing generation deviation was established, taking the example of eight cascade hydropower stations in the downstream of Dadu River in Sichuan province as an example, the effectiveness and applicability of the model were verified. The results show that the deviation in each period can be controlled within 1% and meet the basic requirements of market rules

    Study on Optimal Operation of Hydropower Station Group Based on New Electricity Reform and Deviation Assessment

    No full text
    The new electricity system reform has brought power generation companies into the market, and the scheduling target of cascade hydropower stations has been transformed from maximizing power generation to maximizing revenue. Market rules require hydropower generators to pay assessment fees for the power generation deviation. Therefore, in order to obtain the desired revenue, power generators should not only obtain more power generation indicators and higher power prices, but also control the power generation deviation and avoid being assessed. In response to the current market environment, the new requirements of the new electricity system reform for hydropower scheduling were analyzed. And based on regional market rules, a scheduling model for cascade hydropower stations with the goal of minimizing generation deviation was established, taking the example of eight cascade hydropower stations in the downstream of Dadu River in Sichuan province as an example, the effectiveness and applicability of the model were verified. The results show that the deviation in each period can be controlled within 1% and meet the basic requirements of market rules

    Effect of processing on the alkaloids in Aconitum tubers by HPLC-TOF/MS

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    According to the Chinese Pharmacopoeia 2015, only processed Aconitum tubers can be clinically applied, and the effect of processing is unclear. This research aimed to explore the effect of processing on cardiac efficacy of alkaloids in Aconitum tubers. First, the chemical ingredients in unprocessed and processed Aconitum tubers were identified and compared by using high performance liquid chromatography time-of-flight mass spectrometry (HPLC-TOF/MS) and multivariate pattern recognition methods. Then the representative alkaloids in Aconitum tubers, aconitine, benzoylaconine, and aconine, which belong to diester-diterpenoid alkaloids, monoester-diterpenoid alkaloids, and amine-diterpenoid alkaloids, respectively, were selected for further validation of attenuated mechanism. Subsequent pharmacological experiments with aconitine, benzoylaconine, and aconine in SD rats were used for validate the effect of processing on cardiac functions. After processing the Aconitum tubers, it was found that the contents of diester-diterpenoid alkaloids were reduced, and those of monoester-diterpenoid alkaloids and amine-diterpenoid alkaloids were increased, suggesting that diester-diterpenoid alkaloids were transformed into monoester-diterpenoid alkaloids and amine-diterpenoid alkaloids. Through further decocting the aconitine in boiling water, it was confirmed that the three alkaloids could be progressively transformed. Pharmacological experiments with aconitine, benzoylaconine, and aconine in SD rats showed that aconitine at a dose of 0.01 mg/kg and aconine at a dose of 10 mg/kg enhanced the cardiac function, while benzoylaconine at a dose of 2 mg/kg weakened the cardiac function. The effect of processing is attributed to the transformation of the most toxic diester-diterpenoid alkaloids into less toxic monoester-diterpenoid alkaloids and amine-diterpenoid alkaloids
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