929 research outputs found
Servant Leadership and Related Issues in Chinese Hotel Industry
Because of the economy growth and the Open Door Policy, Chinese hotel industry was under a huge expansion. Since more and more western customers are visiting and Chinese customers are having more hotel experience abroad, the service Chinese hotels used to provide dose not meet the standard anymore. So the managers and leaders need to find an appropriate approach to encourage their employees to improve the service to their customers. This research went through over 40 articles about Chinese hotel industry and Chinese culture and found out that servant leadership style should be the best approach to engage the employees
Structural and Electrochemical Properties of Oxo-Functionalized Graphene
In 1855, Brodie described the formation of graphite oxide for the first time. Graphene oxide (GO) has experienced more than 150 years of development, and a variety of preparation methods have emerged. In this thesis, oxo-functionalized graphene (oxoG) was used as a model to investigate the structural and electrochemical properties of oxoG and related materials. OxoG is a derivative of GO with a defined density of defects and well-controlled surface chemistry. Overall, the controllable structure of oxoG is further explored in the thesis. In the first part, the controllable fabrication of the pores at the single-layer level is carried out. The pores and the electron-withdrawing groups at the rims of pores enhance the photoluminescence of MoS2. The second part is about vacancy defects (small pores) and their oxygen functionalization. In addition, in terms of electrochemistry, the second part discusses that the defects of electrochemical oxygen functionalization are active sites for oxygen reduction catalysts to produce H2O2. The third part is about flake size of oxoG, morphology of oxoG film, and loading effect on the electrochemical reduction of oxoG film.Im Jahr 1855 beschrieb Brodie zum ersten Mal die Bildung von Graphitoxid. Graphenoxid (GO) hat mehr als 150 Jahre der Entwicklungen erlebt, und eine Vielzahl von Darstellungsmethoden entstanden. In dieser Arbeit wurde oxo-funktionalisiertes Graphen (oxoG) als Modell verwendet, um die strukturellen und elektrochemischen Eigenschaften von oxoG und verwandten Materialien zu untersuchen. OxoG ist ein Derivat von GO mit einer definierten Dichte von Defekten und einer gut kontrollierten OberflÀchenchemie.
Insgesamt wird in dieser Arbeit die kontrollierbare Struktur von oxoG weiter erforscht. Im ersten Teil wird die kontrollierbare Herstellung der Poren auf Einzelschichtebene durchgefĂŒhrt. Die Poren und die elektronenanziehenden Gruppen an den RĂ€ndern der Poren verstĂ€rken die Photolumineszenz von MoS2. Der zweite Teil befasst sich mit Leerstandsdefekten (kleine Poren) und deren Sauerstofffunktionalisierung. In Bezug auf die Elektrochemie wird im zweiten Teil erörtert, dass die Defekte der elektrochemischen Sauerstofffunktionalisierung
aktive Stellen fĂŒr Sauerstoffreduktionskatalysatoren zur Erzeugung von H2O2 sind. Der dritte Teil befasst sich mit der FlockengröĂe von oxoG, der Morphologie des oxoG-Films und dem Einfluss der Beladung auf die elektrochemische Reduktion des oxoG-Films
A study of authentic leadership adopting the job demands and resources approach in predicting work-related flow and job performance
The authentic leadership model posits that authentic leaders can foster personal development of their subordinates in order to produce better job outcomes. The current study has investigated authentic leadership using the job demands and resources (JD-R) approach to examine how leadersâ authenticity can empower employees in terms of resources-building (e.g. PsyCap, supervisor support); and to examine how these resources can offset negative stressors (e.g. work overload, emotional demands) so that employees may achieve a peak psychological state of flow (Bakker, 2005, 2008) and better job performances. To date, very few studies have tried to explain authentic leader behaviors in the JD-R model which is posited to be widely applicable to different work contexts, let alone studies of such type conducted in Chinese organizations. The current study consists of Study One and Study Two. The major purpose of Study One is to examine the reliability and validity of the authentic leadership and the work-related flow scale in Chinese organizational settings. The major purpose of Study Two is to test the hypotheses of the overall research model using Chinese working samples.
Study One was conducted among Chinese workers in Shanghai (N=135). Confirmatory factor analysis was carried out for the reliability and validity of the authentic leadership and the work-related flow scale. Results confirmed that authentic leadership is best to be depicted as a second-order construct and the Cronbachâs alpha is .94 for the overall instrument. In addition, results also demonstrated that work-related flow has good reliability (Cronbachâs alpha is .96) and construct validity as a three-factor construct.
Study Two aimed to test the proposed research model of the current study. 869 self-reported questionnaires were successfully collected from organizations in Shanghai. Performance was rated by employeesâ supervisors to avoid common method bias. Structural equation modeling methods were adopted for data analyses. Results supported most of the hypotheses. Supervisor support (job resource) and PsyCap (personal resource) mediate the relationships between authentic leadership and two job outcomes (work-related flow, performance). Work overload and emotional demands moderate the positive indirect effects of authentic leadership on the job outcomes through supervisor support and PsyCap.
This study has several contributions. First, it has provided a more comprehensive explanation of leadership and the consequent followersâ work behaviors via the JD-R approach. Second, it has linked the similarities in the JD-R model and the flow literature, which were previously studied in separate fields, demonstrating that high flow experience can be obtained only when resources become salient under high demands. Last but not least, the study has provided practical implications on leadership trainings and employee development programs, by pointing out several solutions of organizational improvement for the top management teams
THE ROLE OF GUT MICROBIOME AND HOST METABOLOME IN DIET AND CARDIOVASCULAR RISK FACTORS
High blood pressure (BP) and high adiposity are leading risk factors for cardiovascular morbidity and mortality. Excessive sodium, low potassium, and low fiber intake are among the main contributors to elevated BP and adiposity. We hypothesize that the gut microbiota and host metabolites are influenced by diet and have effects on cardiovascular health. Numerous animal model studies have suggested that dietary intake impacts host BP and adiposity particularly through microbiota-mediated short-chain fatty acids (SCFAs). Yet, there is limited empirical evidence in humans to inform current understanding. To address this research gap, we used a cross-sectional adult cohort from the population-based Chinese Health and Nutrition Survey (CHNS) with rich gut microbiota (16S rRNA) and plasma metabolomics data, high-quality diet data from three-consecutive 24-h validated recalls and household food inventories, and health data from physical examinations. We first examined the association between sodium and potassium with gut microbiota and plasma metabolites. We then investigated the associations between gut microbiota and plasma metabolites with systolic (SBP) and diastolic BP (DBP). Last, we assessed the associations between plasma SCFAs and two adiposity measures, body mass index (BMI) and waist-to-height ratio (WHtR). After accounting for geographic variation in microbiota, we found that that sodium and potassium consumption was associated with microbiota and metabolites, including Staphylococcus, microbiota-derived phenolics and SCFAs previously linked to inflammation, hypertension and adiposity. While we did not observe statistical evidence for an association between SCFAs and BP, we found that sphingomyelins, acyl-carnitines, and a lipids pattern characterized by long-chain fatty acids were positively associated with BP. We also found positive associations between SCFAs with BMI and WHtR. Our results suggest that gut microbiota and related metabolites may play an important role in the dietary etiology of cardiovascular disease (CVD). As such, our findings provide insights into potential dietary interventions targeting microbiota or metabolites for disease prevention and treatment. Future longitudinal and randomized-controlled studies are needed to determine the causal relationships between diet, gut microbiome, host metabolome, and CVD risk factors.Doctor of Philosoph
Periodontal health and quality of life in patients with chronic obstructive pulmonary disease
SummaryObjectiveTo evaluate the association of periodontal health and parameters of quality of life assessed in 306 Chinese patients with chronic obstructive pulmonary disease (COPD).MethodsPeriodontal status and respiratory function in 306 COPD patients were clinically evaluated and their quality of life was assessed using the standardized St Georgeâs Respiratory Questionnaire (SGRQ).ResultsThe SGRQ scores were all significantly correlated with major lung function parameters (r2 = â0.37 to â0.28; all p < 0.0001) and Medical Research Council dyspnoea scale (r2 = 0.23 to 0.30; all p < 0.0001). The SGRQ scores also correlated with the 6-min walk test (r2 = â0.15 to â0.13; all p < 0.05). Of periodontal health parameters, missing tooth number and plaque index appeared to be related to the scores of quality of life. The age- and gender-adjusted Pearsonâs correlation coefficients between missing teeth and total score, symptoms score, and activity score were 0.09, 0.12, and 0.12, respectively (all p < 0.05). The Pearsonâs correlation coefficients between plaque index and symptoms score and activity score were 0.09 and 0.09 (p < 0.05). After adjusting for age, gender, body mass index, and smoking status, missing teeth remained significantly associated with symptom score (p = 0.030) and activity score (p = 0.033) while plaque index was significantly associated with symptom score (p = 0.007).ConclusionsPoor periodontal health as reflected by missing teeth and plaque index was significantly associated with lower quality of life in COPD patients. Our findings indicate the importance of promoting dental care in current public health strategies to improve the quality of life in COPD patients
Opinion Dynamics in Two-Step Process: Message Sources, Opinion Leaders and Normal Agents
According to mass media theory, the dissemination of messages and the
evolution of opinions in social networks follow a two-step process. First,
opinion leaders receive the message from the message sources, and then they
transmit their opinions to normal agents. However, most opinion models only
consider the evolution of opinions within a single network, which fails to
capture the two-step process accurately. To address this limitation, we propose
a unified framework called the Two-Step Model, which analyzes the communication
process among message sources, opinion leaders, and normal agents. In this
study, we examine the steady-state opinions and stability of the Two-Step
Model. Our findings reveal that several factors, such as message distribution,
initial opinion, level of stubbornness, and preference coefficient, influence
the sample mean and variance of steady-state opinions. Notably, normal agents'
opinions tend to be influenced by opinion leaders in the two-step process. We
also conduct numerical and social experiments to validate the accuracy of the
Two-Step Model, which outperforms other models on average. Our results provide
valuable insights into the factors that shape social opinions and can guide the
development of effective strategies for opinion guidance in social networks
Embedding dimension gaps in sparse codes
We study the open and closed embedding dimensions of a convex 3-sparse code
, which records the intersection pattern of lines in the Fano
plane. We show that the closed embedding dimension of is three,
and the open embedding dimension is between four and six, providing the first
example of a 3-sparse code with closed embedding dimension three and differing
open and closed embedding dimensions. We also investigate codes whose canonical
form is quadratic, i.e. ``degree two" codes. We show that such codes are
realizable by axis-parallel boxes, generalizing a recent result of Zhou on
inductively pierced codes.
We pose several open questions regarding sparse and low-degree codes. In
particular, we conjecture that the open embedding dimension of certain 3-sparse
codes derived from Steiner triple systems grows to infinity.Comment: 16 pages, 8 figure
Modeling Information Acquisition and Social Learning Dynamics: A Rational Inattention Perspective
Social learning, a fundamental process through which individuals shape their
beliefs and perspectives via observation and interaction with others, is
critical for the development of our society and the functioning of social
governance. Prior works on social learning usually assume that the initial
beliefs are given and focus on the update rule. With the recent proliferation
of online social networks, there is an avalanche amount of information, which
may significantly influence users' initial beliefs. In this paper, we use the
rational inattention theory to model how agents acquire information to form
initial beliefs and assess its influence on their adjustments in beliefs.
Furthermore, we analyze the dynamic evolution of belief distribution among
agents. Simulations and social experiments are conducted to validate our
proposed model and analyze the impact of model parameters on belief dynamics.Comment: 10 pages, 6 figures, submitted to ICASSP 202
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