Investment Dynamics in a DSGE Model with Heterogeneous Firms and Corporate Taxation

In this paper I study a new business cycle fact recently documented by Bachmann and Bayer (2011): the dispersion of the distribution of investment rates across firms is procyclical. Using data from German firm, the authors find a correlation coefficient between the standard deviation of investment distribution and the cyclical component of output of 0.45. They also report a correlation coefficient for US economy of 0.33. Using a model similar to Khan and Thomas's (2003), that is standard to heterogeneous firms literature, I obtain a correlation coefficient of 0.57. In the model I also consider a government sector that collects taxes on corporate profits. In such model, with a corporate tax of 23.5%, which corresponds to German economy, I obtain a correlation coefficient of 0.46 and when I consider a corporate tax rate of 18.79% that corresponds to US economy I find a correlation coefficient of 0.51.

Medium Modification of the Jet Properties

In the case that a dense medium is created in a heavy ions collision, high-E_t jets are expected to be broadened by medium-modified gluon emission. This broadening is directly related, through geometry, to the energy loss measured in inclusive high-p_t particle suppression. We present here the modifications of jet observables due to the presence of a medium for the case of azimuthal jet energy distributions and k_t-differential multiplicities inside the jets.Comment: 4 pages, 3 postscript figures. Proceedings for Quark Matter 200

Antiangular Ordering of Gluon Radiation in QCD Media

We investigate angular and energy distributions of medium-induced gluon emission off a quark-antiquark antenna in the framework of perturbative QCD as an attempt toward understanding, from first principles, jet evolution inside the quark-gluon plasma. In-medium color coherence between emitters, neglected in all previous calculations, leads to a novel mechanism of soft-gluon radiation. The structure of the corresponding spectrum, in contrast with known medium-induced radiation, retains some properties of the vacuum case; in particular, it exhibits a soft divergency. However, as opposed to the vacuum, the collinear singularity is regulated by the pair opening angle, leading to a strict angular separation between vacuum and medium-induced radiation, denoted as antiangular ordering. We comment on the possible consequences of this new contribution for jet observables in heavy-ion collisions.Comment: 4 pages, 2 figures; v2. a number of minor improvements, figures updated, accepted for publication in PR

How Happiness and Optimism Relate to Smoking

Cigarette smoking decreases health and increases mortality. Researchers have devoted much attention to factors that promote smoking (e.g., depression), but have paid little attention to factors that buffer against smoking. Positive psychology may provide a useful framework to complement our current knowledge of cigarette smoking and treatment. The current study investigated the relation between positive psychology constructs (i.e., happiness and optimism) and smoking status, smoker type, and cessation success using path analysis with data from college students (SONA) and an online sample (MTurk). Data from 1,292 (NSONA = 582, NMTurk = 710) participants showed that most pasticipants were female (66.3%), single (59.4%) or married (24.1%), and Caucasian (67.2%) or African American (23.1%). Approximately 17% were current smokers, 62.8% were non-smokers, 6.5% were light smokers, 5.6% were heavy smokers, 12.1% were stable ex-smokers, and 2.7% were recent ex-smokers. Due to the significant differences between SONA and MTurk samples, analyses were performed separately. Path analysis for SONA showed non-significant relations or were inconclusive possibly due to the small sample sizes. Path analysis for MTurk revealed a significant relation between depression and dispositional optimism and cessation success. Dispositional optimism was a stronger predictor of cessation success relative to depression. However, dispositional optimism and depression predicted a higher likelihood of being a recent (vs. stable) ex-smoker. Future research should establish the relation between positive constructs and smoking by including larger and more diverse samples, applying sophisticated statistical methos, evaluating pilot studies, and comparing positive psychology models with other traditional models of addiction

Clinical communication skills training in dental medical education: The covid-19 pandemic challenge

It is very important for healthcare professionals to have good clinical communication skills, especially dentists. Patient-centred care results in patient satisfaction, better outcomes, and less complaints from dental patients. Due to the onset of the COVID-19 pandemic, the clinical communications skills programme of the pre-graduate course in dental medicine at the University of Porto had to be transformed to an online format. Based on their role as faculty, the authors aimed to recount their initial reflections and concerns within this perspective, and to share how they adapted to the new reality of teaching clinical communication skills online, as well as the conclusions of our experience, in the hope that this will help others who may have to go through a similar process. The authors acknowledged that the students achieved the pre-established goals of the clinical communications skills programme through the new online format

Evolving Lorentzian wormholes supported by phantom matter with constant state parameters

In this paper we study the possibility of sustaining an evolving wormhole via exotic matter made out of phantom energy. We show that this exotic source can support the existence of evolving wormhole spacetimes. Explicitly, a family of evolving Lorentzian wormholes conformally related to another family of zero-tidal force static wormhole geometries is found in Einstein gravity. Contrary to the standard wormhole approach, where first a convenient geometry is fixed and then the matter distribution is derived, we follow the conventional approach for finding solutions in theoretical cosmology. We derive an analytical evolving wormhole geometry by supposing that the radial tension (which is negative to the radial pressure) and the pressure measured in the tangential directions have barotropic equations of state with constant state parameters. At spatial infinity this evolving wormhole, supported by this anisotropic matter, is asymptotically flat, and its slices $t=$ constant are spaces of constant curvature. During its evolution the shape of the wormhole expands with constant velocity, i.e without acceleration or deceleration, since the scale factor has strictly a linear evolution.Comment: 9 pages, 2 figures, Accepted for publication in Phys. Rev.

Weak boson production measured in PbPb and pp collisions by CMS

The unprecedented center-of-mass energy available at the LHC offers unique opportunities for studying the properties of the strongly-interacting QCD matter created in PbPb collisions at extreme temperatures and very low parton momentum fractions. Electroweak boson production is an important benchmark process at hadron colliders. Precise measurements of Z production in heavy-ion collisions can help to constrain nuclear PDFs as well as serve as a standard candle of the initial state in PbPb collisions at the LHC energies. The inclusive and differential measurements of the Z boson yield in the muon decay channel will be presented, establishing that no modification is observed with respect to next-to-leading order pQCD calculations, scaled by the number of incoherent nucleon-nucleon collisions. The status of the Z measurement in the electron decay channel, as well as the first observation of W \rightarrow \mu {\nu} in heavy ion collisions will be given. The heavy-ion results will be presented in the context of those obtained in pp collisions with the CMS detector.Comment: Quark Matter 2011 conference proceeding

A Chern–Simons gravity action in d=4

AbstractRecently, Antoniadis, Konitopoulos and Savvidy have introduced in Refs. [1–4] a procedure to construct background-free gauge invariants, using non-abelian gauge potentials described by forms of higher degree. Their construction is particularly useful because it can be used in both, odd- and even-dimensional spacetimes. Using their technique, we generalize the Chern–Weil theorem and construct a gauge-invariant, (2n+2)-dimensional transgression form, and study its relationship with the generalized Chern–Simons forms introduced in Refs. [1,2].Using the methods for FDA manipulation and decomposition in 1-forms developed in Ref. [5] and applied in Refs. [6] and [7], we construct a four-dimensional Chern–Simons gravity action, which is off-shell gauge invariant under the Maxwell algebra

Self-assembly of anisotropic soft particles in two dimensions

The self assembly of core-corona discs interacting via anisotropic potentials is investigated using Monte Carlo computer simulations. A minimal interaction potential that incorporates anisotropy in a simple way is introduced. It consists in a core-corona architecture in which the center of the core is shifted with respect to the center of the corona. Anisotropy can thus be tuned by progressively shifting the position of the core. Despite its simplicity, the system self organize in a rich variety of structures including stripes, triangular and rectangular lattices, and unusual plastic crystals. Our results indicate that the amount of anisotropy does not alter the lattice spacing and only influences the type of clustering (stripes, micells, etc.) of the individual particles.Comment: submitte