Some combinatorial arrays related to the Lotka-Volterra system

The purpose of this paper is to investigate the connection between the Lotka-Volterra system and combinatorics. We study several context-free grammars associated with the Lotka-Volterra system. Some combinatorial arrays, involving the Stirling numbers of the second kind and Eulerian numbers, are generated by these context-free grammars. In particular, we present grammatical characterization of some statistics on cyclically ordered partitions.Comment: 15 page

Do job positions matter in emotional labor and in its relationship with job performance?

A central focus of emotional labor research is on the frontline service workers and empirical research on managers has so far been rare (Humphrey 2012). Moreover, only limited research has examined the impact of emotional labor on job performance (Duke et al. 2009) and such paucity is aggravated if we consider samples from China. Considering these gaps in the literature, this study has three research questions. First, do employees at different hierarchical positions report different levels of emotional intelligence or does emotional intelligence increase as the job position increases? Second, do employees at different hierarchical positions report different levels of emotional labour or does emotional labour increase as the job position increases? Third, do levels of emotional labour predict levels of job performance across different positions in organizations? We address the research questions with a sample of 245 managerial professionals from business organizations in mainland China. Significant differences were found on emotional intelligence between those in senior positions (i.e., director or above) and ordinary employees. In addition, the results show that among ordinary employees, emotional intelligence and emotional labor are important predictors of job performance. Moreover, emotional labor has a moderating effect in the association between emotional intelligence and job performance, such that high levels of emotional intelligence were more likely to be associated with high levels of job performance when the demand of emotional labor increased. The relationship does not hold true for the managerial positions in our sample. This study suggests that the interaction effect between emotional intelligence and emotional labor does not hold equally true for employees in different positions.info:eu-repo/semantics/acceptedVersio

Exploring the doctor-patient relationship as a challenge job demand: application of the job demands–resources model in a Chinese public hospital

In the increasingly commercialized healthcare environment in China, doctor-patient relationship (DPR) is a job demand for doctors dat is linked to various motivational outcomes. Drawing on the Job Demands–Resources (JD-R) model, and the conservation of resources theory, we develop a preliminary conceptual model dat links Leader Member Exchange (LMX) as a job resource, and DPR as a challenge job demand, to the levels of work engagement and turnover intentions of doctors working in this healthcare environment. Using two-wave data collected from 381 doctors in a public hospital, we found support for the hypothesized model. Results of a series of SEM analyses revealed dat LMX was positively related to DPR and work engagement, while DPR partially mediates the path from LMX to work engagement. In addition, LMX is negatively related to turnover intentions through DPR and subsequently work engagement. Theoretically, this study contributes to the development of the JD-R model by investigating the concept of challenge job demand, and its role in the motivational process, with new evidence from healthcare occupations in China. Practically, this study contributes to the limited number of studies on managing the changing nature of the DPR in China, and in seeking potential solutions based on established organizational constructs.info:eu-repo/semantics/acceptedVersio

SO(10) Cosmic Strings and Baryon Number Violation

SO(10) cosmic strings formed during the phase transition Spin(10) $\rightarrow$ SU(5) $\times{\cal Z}_2$ are studied. Two types of strings --- one effectively Abelian and one non-Abelian --- are constructed and the string solutions are calculated numerically. The non-Abelian string can catalyze baryon number violation via the ``twisting'' of the scalar field which causes mixing of leptons and quarks in the fermion multiplet. The non-Abelian string is also found to have the lower energy possibly for the entire range of the parameters in the theory. Scattering of fermions in the fields of the strings is analyzed, and the baryon number violation cross section is calculated. The role of the self-adjoint parameters is discussed and the values are computed.Comment: LaTex (RevTex), 36 pages, 6 figures (available upon request), MIT-CTP#215

Making Neutrinos Massive with an Axion in Supersymmetry

The minimal supersymmetric standard model (MSSM) of particle interactions is extended to include three singlet (right-handed) neutrino superfields together with three other singlet superfields. The resulting theory is assumed to be invariant under an anomalous global U(1) (Peccei-Quinn) symmetry with one fundamental mass $m_2$. The soft breaking of supersymmetry at the TeV scale is shown to generate an axion scale $f_a$ of order $m_2$. Neutrino masses are generated by $f_a$ according to the usual seesaw mechanism.Comment: 11 pages, substantially revised with important change

Low-Scale Axion from Large Extra Dimensions

The mass of the axion and its decay rate are known to depend only on the scale of Peccei-Quinn symmetry breaking, which is constrained by astrophysics and cosmology to be between $10^9$ and $10^{12}$ GeV. We propose a new mechanism such that this effective scale is preserved and yet the fundamental breaking scale of $U(1)_{PQ}$ is very small (a kind of inverse seesaw) in the context of large extra dimensions with an anomalous U(1) gauge symmetry in our brane. Unlike any other (invisible) axion model, there are now possible collider signatures in this scenario.Comment: 11 pages, no figur

Processing of false belief passages during natural story comprehension: An fMRI study

The neural correlates of theory of mind (ToM) are typically studied using paradigms which require participants to draw explicit, task-related inferences (e.g., in the false belief task). In a natural setup, such as listening to stories, false belief mentalizing occurs incidentally as part of narrative processing. In our experiment, participants listened to auditorily presented stories with false belief passages (implicit false belief processing) and immediately after each story answered comprehension questions (explicit false belief processing), while neural responses were measured with functional magnetic resonance imaging (fMRI). All stories included (among other situations) one false belief condition and one closely matched control condition. For the implicit ToM processing, we modeled the hemodynamic response during the false belief passages in the story and compared it to the hemodynamic response during the closely matched control passages. For implicit mentalizing, we found activation in typical ToM processing regions, that is the angular gyrus (AG), superior medial frontal gyrus (SmFG), precuneus (PCUN), middle temporal gyrus (MTG) as well as in the inferior frontal gyrus (IFG) billaterally. For explicit ToM, we only found AG activation. The conjunction analysis highlighted the left AG and MTG as well as the bilateral IFG as overlapping ToM processing regions for both implicit and explicit modes. Implicit ToM processing during listening to false belief passages, recruits the left SmFG and billateral PCUN in addition to the “mentalizing network” known form explicit processing tasks

Cosmology and Astrophysical Constraints of Gauss-Bonnet Dark Energy

Cosmological consequences of a string-motivated dark energy scenario featuring a scalar field coupled to the Gauss-Bonnet invariant are investigated. We study the evolution of the universe in such a model, identifying its key properties. The evolution of the homogeneous background and cosmological perturbations, both at large and small scales, are calculated. The impact of the coupling on galaxy distributions and the cosmic microwave background is examined. We find the coupling provides a mechanism to viably onset the late acceleration, to alleviate the coincidence problem, and furthermore to effectively cross the phantom divide at the present while avoiding a Big Rip in the future. We show the model could explain the present cosmological observations, and discuss how various astrophysical and cosmological data, from the Solar system, supernovae Ia, cosmic microwave background radiation and large scale structure constrain it.Comment: 6 pages, 3 figures. References added. Accepted for publication in Phys. Lett.

CP-violating asymmetries in top-quark production and decay in e+e−e^+ e^- annihilation within the MSSM

We obtain analytic formulae for the cross section of the sequential processes of $e^+ e^- \to t \bar t$ and $t \to b l \nu$ in the laboratory frame where the dependence on triple product correlations of the type (\hat(q}_1 x \hat{q}_2 . \hat{q}_3), induced by CP violation both in the production and the decay are explicitely shown. Different observables sensitive to CP violation are defined and calculated in the Minimal Supersymmetric Standard Model (MSSM). The observables sensitive to CP violation are of the order of $10^-3$. The dependence on the masses of the supersymmetric particles is also shown.Comment: 17 pages of LateX plus five uuencoded Postscript figures, LateX file and PS-figures are also available via anonymous ftp at ftp://info.oeaw.ac.at/pub/hephy-pub/62