Critical Points in the Linear Sigma Model with Quarks

We employ a simple effective model to study the chiral dynamics of two flavors of quarks at finite temperature and density. In particular, we determine the phase diagram in the plane of temperature and baryon chemical potential as a function of the pion mass. An interesting phase structure occurs which results in zero, one or two critical points depending on the value of the vacuum pion mass.Comment: 16 pages plus 5 figure

An Introduction to 3D User Interface Design

3D user interface design is a critical component of any virtual environment (VE) application. In this paper, we present a broad overview of three-dimensional (3D) interaction and user interfaces. We discuss the effect of common VE hardware devices on user interaction, as well as interaction techniques for generic 3D tasks and the use of traditional two-dimensional interaction styles in 3D environments. We divide most user interaction tasks into three categories: navigation, selection/manipulation, and system control. Throughout the paper, our focus is on presenting not only the available techniques, but also practical guidelines for 3D interaction design and widely held myths. Finally, we briefly discuss two approaches to 3D interaction design, and some example applications with complex 3D interaction requirements. We also present an annotated online bibliography as a reference companion to this article

A randomized trial of brief intervention strategies in patients with alcohol-related facial trauma as a result of interpersonal violence

Facial trauma is associated with male gender, low socioeconomic status, alcohol misuse, and violence. Brief intervention (BI) for alcohol is effective at reducing consumption in patients presenting with facial trauma. Singlesession control of violence for angry impulsive drinkers(SS-COVAID) is a new intervention that attempts to address alcohol-related violence. This study assessed the effect of SS-COVAID and BI on drinking and aggression in facial trauma patients. Male facial trauma patients who sustained their injuries as a result of interpersonal violence while drinking and who had Alcohol Use Disorders Identification Test (AUDIT) scores of ≥8 were randomized to either BI or SS-COVAID. Patients were followed up at six and 12 months, and drinking and aggression outcomes were analyzed. One hundred ninety-nine patients entered the trial, and 187 were included in the analysis. Of these, 165 (89%) considered themselves to be victims, 92 (51%) had sustained a previous alcohol-related injury, and 28 (15%) had previous convictions for violence. Both interventions resulted in a significant decrease in negative drinking outcomes over 12 months of follow-up (p<0.001). Neither intervention had a significant effect on aggression scores, nor was there a significant difference between interventions in terms of either outcome. Both SS-COVAID and BI had a significant effect on drinking variables in this patient cohort. No effect on aggressionwas seen despite the fact that SS-COVAID specifically addresses the relationship between alcohol and violence. One reason for this may be that the facial trauma patients in this study considered themselves to be victims rather than aggressors. Another possibility is that, while BI may successfully address lifestyle factors such as hazardous or harmful drinking, it may not be effective in modifying personality traits such as aggression

First-year experience of chemotherapy for advanced retinoblastoma in Tanzania: disease profile, outcomes, and challenges in 2008.

PURPOSE: To examine the profile of retinoblastoma in a national tertiary referral center in Tanzania and to report first-year outcomes of its treatment using chemotherapy. METHODS: All patients with retinoblastoma referred in 2008 were included. Disease was classified on clinical grounds as ocular, orbital, or metastatic. Those with ocular and orbital disease received chemotherapy. Remission was the main outcome measure and defined as absence of disease at the end of treatment. RESULTS: In 2008, 37 patients (20 males and 17 females) with retinoblastoma were referred to Ocean Road Cancer Institute. The mean delay from the first sign of disease to presentation at hospital was 10.4 ± 8.7 months. Disease was ocular in 32% (12 of 37), orbital in 57% (21 of 37), and metastatic in 11% (4 of 37). Of those with ocular disease, 67% (8 of 12) completed chemotherapy and all (8 of 8) achieved remission. In contrast, 48% (10 of 21) with orbital disease completed chemotherapy and only 50% (5 of 10) achieved remission. The difference in outcome between the groups was statistically significant (P = .001, Fisher exact test). CONCLUSION: The profile of retinoblastoma in Tanzania is skewed toward severe invasive disease. Despite the introduction of chemotherapy, further improvements in mortality and morbidity can only be achieved through emphasis on early detection

Daily energy expenditure of Florida Scrub-Jays (Aphelocoma coerulescens) in suburban and wildland landscapes

Urbanization alters ecological systems, disturbance regimes, food webs, and a variety of other processes that can influence local flora and fauna. In birds, most studies have focused on behavioral or demographic responses to altered conditions; however, the physiological mechanisms associated with these responses have been understudied. We have previously documented shifts in foraging behavior because of the availability of human-provided food; we sought to see if this was driven by or associated with a change in field metabolic rates. We measured field metabolic rates (FMR), a measure of daily energy expenditure (DEE), of Florida Scrub-Jays (Aphelocoma coerulescens) in 2 habitats using doubly labeled water (DLW). One population of jays lived in wildland habitat, the other in a suburban area where the habitat was badly degraded. During the breeding season FMR of suburban males exceeded that of wildland males by over 100%. Female FMR did not differ between sites but increased following incubation. In the wildlands, FMRs of females were barely lower than those of males, but in the suburban landscape, female FMRs were much lower than in males. For both sexes in the wildlands, FMRs were about 3.53 basal rates of metabolism (BMR) during breeding; in the suburbs female FMR exceeded BMR by 43 but did not differ from that of wildland females. Suburban male FMRs exceeded BMR by 7.13. During the nonbreeding seasons of fall and winter, FMR did not differ between habitats, ranging from 1.73 to 2.13 BMR, thus it is the breeding season that separated wildland and suburban jays energetically. In both habitats, a low water economy index (mL/kJ) and low water fluxes indicated that these jays are well adapted to their xeric habitat, but their FMRs distinguished them from desert birds. The very high energetic cost associated with breeding for suburban males may help explain why in the metapopulation of Florida Scrub-Jays, suburban jay populations are sinks. This study underscores the value of physiology in the conservation of listed species

Video games as meaningful entertainment experiences

We conducted an experiment to examine individuals’ perceptions of enjoyable and meaningful video games and the game characteristics and dimensions of need satisfaction associated with enjoyment and appreciation. Participants (N = 512) were randomly assigned to 1 of 2 groups that asked them to recall a game that they found either particularly fun or particularly meaningful, and to then rate their perceptions of the game that they recalled. Enjoyment was high for both groups, though appreciation was higher in the meaningful- than fun-game condition. Further, enjoyment was most strongly associated with gameplay characteristics and satisfaction of needs related to competency and autonomy, whereas appreciation was most strongly associated with story characteristics and satisfaction of needs related to insight and relatedness