J/Psi and Psi' Suppression in Hadronic Matter

We present a microscopic calculation of the breakup cross sections of $J/\psi$ and $\psi'$ on pions and nucleons as a function of the kinetic energy. These cross sections are used for the investigation of the $J/\psi$ to continuum and $\psi'/J/\psi$ ratios in ultrarelativistic heavy ion collisions. The contribution of produced comoving pions to the $\psi'/J/\psi$ signal is calculated. While this model can account for the data, the uncertainties in the parameter values do not allow to exclude the possibility of additional sources for charmonium absorption, like a resonance gas or the quark gluon plasma.Comment: LaTeX, 6 pages including 2 EPS files, to be published in Prog. Part. Nucl. Phys., [email protected]

Probing the gluon density of the proton in the exclusive photoproduction of vector mesons at the LHC: A phenomenological analysis

The current uncertainty on the gluon density extracted from the global parton analysis is large in the kinematical range of small values of the Bjorken - $x$ variable and low values of the hard scale $Q^2$. An alternative to reduces this uncertainty is the analysis of the exclusive vector meson photoproduction in photon - hadron and hadron - hadron collisions. This process offers a unique opportunity to constrain the gluon density of the proton, since its cross section is proportional to the gluon density squared. In this paper we consider current parametrizations for the gluon distribution and estimate the exclusive vector meson photoproduction cross section at HERA and LHC using the leading logarithmic formalism. We perform a fit of the normalization of the $\gamma h$ cross section and the value of the hard scale for the process and demonstrate that the current LHCb experimental data are better described by models that assume a slow increasing of the gluon distribution at small - $x$ and low $Q^2$.Comment: 8 pages, 6 figures, 1 table. Version published in European Physical Journal

Continuous Opinions and Discrete Actions in Opinion Dynamics Problems

A model where agents show discrete behavior regarding their actions, but have continuous opinions that are updated by interacting with other agents is presented. This new updating rule is applied to both the voter and Sznajd models for interaction between neighbors and its consequences are discussed. The appearance of extremists is naturally observed and it seems to be a characteristic of this model.Comment: 10 pages, 4 figures, minor changes for improved clarit

Equilibria in reflexive Banach lattices with a continuum of agents.

We consider exchange economies with a measure space of agents and for which the commodity space is a separable and reflexive Banach lattice. Under assumptions imposing uniform bounds on marginal rates of substitution, positive results on core-Walras equivalence were established in Rustichini-Yannelis [27] and Podczeck [25]. In this paper we prove that under similar assumptions on marginal rates of substitution, the set of competitive equilibria (and thus the core) is non-empty.Competitive equilibria; Continuum of agents; Reflexive Banach lattice commodity spaces; Uniform properness;

Cosmological Consequences of String-forming Open Inflation Models

We present a study of open inflation cosmological scenarios in which cosmic strings form betwen the two inflationary epochs. It is shown that in these models strings are stretched outside the horizon due to the inflationary expansion but must necessarily re-enter the horizon before the epoch of equal matter and radiation densities. We determine the power spectrum of cold dark matter perturbations in these hybrid models, finding good agreement with observations for values of $\Gamma=\Omega_0h\sim0.3$ and comparable contributions from the active and passive sources to the CMB. Finally, we briefly discuss other cosmological consequences of these models.Comment: 11 LaTeX pages with 3 eps figure

Implications of motivational interviewing and oral hygiene instruction for the reduction of oral health disparities among pregnant women

Pregnancy is a teachable moment during which women may be particularly amenable to making health behavior changes that can have significant impact, not only on themselves, but also on their offspring. Dental complications during pregnancy, such as periodontal disease, have been linked to low birth weight and premature birth. Additionally, mothers\u27 oral health status has been related to childhood caries, through the direct transmission of oral pathogens. Motivational Interviewing (MI) is a promising intervention in the oral health care arena. MI has been empirically supported as a treatment for substance abuse, as well as other health issues including, diabetes, HIV, hypertension, and smoking. This study sought to understand the effectiveness of motivational interviewing and oral hygiene instruction (OHI) to increase motivation to engage in positive oral health behaviors (e.g., proper oral hygiene and needed treatment). The hypotheses of this study were addressed by assessing oral health care behaviors, oral health values, and issues related to dental care utilization in 85 pregnant women using a 2 (intervention group: motivational interviewing or oral hygiene instruction) X 2 (time of measurement: pre-test vs. follow-up) mixed design with random assignment. It was hypothesized that level of Streptococcus mutans would significantly decrease and that tooth brushing, flossing, and dental visit frequency, and dental knowledge would significantly increase after the interventions. It was hypothesized that oral health values would significantly improve after MI and OHI. MI was predicted to contribute to greater change in the dependent variables compared to OHI. There were four variables that were included for exploratory purposes: dental fear, oral health quality of life, toothpaste use, and floss use. Participants were asked to provide a saliva sample to estimate the number of Streptococcus mutans using the Dentocult strip-test, and to complete the Dental Neglect Survey (DNS), the Dental Fear Survey (DFS), the Oral Health Impact Profile-14 (OHIP-14), and the Dental Knowledge Inventory. Two follow-up phone calls were conducted, at two weeks and one month after the initial assessment, during which motivation and oral health behavior was assessed. Participants provided another saliva sample, and completed the DNS, DFS, and OHIP-14 at follow-up six weeks later. Data analysis was conducted in six phases: (a) preliminary examination of data, (b) exploration of the psychometric properties of the primary dependent variable instruments, (c) examination of groups at baseline, (d) group comparisons, (e) exploratory analyses, and (f) correlational analyses. The present study examined six primary dependent measures: (a) tooth brushing frequency, (b) flossing frequency, (c) dental visit frequency, (d) oral health values, (e) dental knowledge, and (f) level of Streptococcus mutans. Tooth brushing frequency, flossing frequency, oral health values, and dental knowledge were significantly higher at follow-up among participants. Amount of toothpaste and floss returned were significantly lower at follow-up among participants. OHI was found to significantly increase dental knowledge among women. No significant differences in level of Streptococcus mutans, dental fear, dental visit frequency, or oral health quality of life were noted at follow-up; MI and OHI interventions generally were found to similarly affect the dependent variables. Several study limitations were noted and future research in this area is encouraged. Effective interventions with this group may have preventive implications related to oral health care, such as increased utilization of dental care services and the reduction of treatment barriers, for a group that is in need