37 research outputs found
Moduli Dynamics of AdS_3 Strings
We construct a general class of solutions for a classical string in AdS_3
spacetime. The construction is based on a Pohlmeyer type reduction, with the
sinh-Gordon model providing the general N-soliton solutions. The corresponding
exact spiky string configurations are then reconstructed through the inverse
scattering method. It is shown that the string moduli are determined entirely
by those of the solitons.Comment: 22 pages, no figures; references adde
Increased Production of the Soluble Tumor-Associated Antigens CA19-9, CA125, and CA15-3 in Rheumatoid Arthritis
Some tumor-associated antigens (TAAs) are expressed on inflammatory cells. We previously detected carcinoembryonic antigen (CEA; CD66) in the rheumatoid (RA) synovium. The production of CEA, CA19-9, CA125, and CA15.3, may be increased in patients with RA, scleroderma, lupus, and SjÖgren's syndrome (SS). Some of these TAAs contain sialylated carbohydrate motifs and they are involved in tumor-associated cell adhesion and metastasis. We assessed levels of TAAs in the sera of RA patients and healthy subjects. Serum TAA levels were correlated with disease markers including serum rheumatoid factor (RF), C-reactive protein (CRP), and anti-CCP antibody levels, DAS28, age disease duration. TAAs including CEA, CA15-3, CA72-4, CA125, and CA19-9, and neuron-specific enolase (NSE) were assessed by immunoassay in the sera of 75 patients with RA and 50 age- and sex-matched healthy controls. Normal upper limits for these TAAs were 3.4 Μg/L, 25 kU/L, 6.9 kU/L, 35 kU/L, 34 kU/L, and 16.3 Μg/L, respectively. There were significantly more RA patients showing abnormally high levels of CA125 (10.8% versus 7.1%), CA19-9 (8.1% versus 0%), and CA15-3 (17.6% versus 14.3%) in comparison to controls ( P < 0.05). The mean absolute serum levels of CA125 (23.9 ± 1.8 versus 16.8 ± 2.2 kU/L) and CA19-9 (14.2 ± 1.2 versus 10.5 ± 1.6 kU/L) were also significantly higher in RA compared to controls ( P < 0.05). Among RA patients, serum CEA showed significant correlation with RF ( r = 0.270; P < 0.05). None of the assessed TAAs showed any correlation with CRP, anti-CCP, DAS28, age or disease duration. The concentration of some TAAs may be elevated in the sera of patients with established RA in comparison to healthy subjects. CEA, CA19-9, CA125, and CA15-3 contain carbohydrate motifs and thus they may be involved in synovitis-associated adhesive events. Furthermore, some TAAs, such as CEA, may also correlate with prognostic factors, such as serum RF levels.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73224/1/annals.1422.037.pd
Analytical Results for Individual and Group Selection of Any Intensity
The idea of evolutionary game theory is to relate the payoff of a game to reproductive success (= fitness). An underlying assumption in most models is that fitness is a linear function of the payoff. For stochastic evolutionary dynamics in finite populations, this leads to analytical results in the limit of weak selection, where the game has a small effect on overall fitness. But this linear function makes the analysis of strong selection difficult. Here, we show that analytical results can be obtained for any intensity of selection, if fitness is defined as an exponential function of payoff. This approach also works for group selection (= multi-level selection). We discuss the difference between our approach and that of inclusive fitness theory
Ammonia formation rates in biomass pyrolysis
For the development and design of advanced biomass conversion equipment, accurate experimental data of fundamental processes are highly important. To contribute to a better description of the chemical and physical processes occurring in biomass pyrolysis, the results of biomass pyrolysis experiments, in which biomass is heated very fast on a metal grid, are presented. Specific focus is on the product evolution rate of NH3, an important precursor for NOx formation. Very little ammonia was produced from fresh wood. However, it was substantial for other fuels. Urea and melamine components released nitrogen in the form of NH3, HCN, and HNCO. The production rates of these components were expressed in the form of first order kinetics. These kinetic data are vital for an accurate description of NOx formation in biomass conversion equipment. This is an abstract of a paper presented at the 2006 AIChE Annual Meeting (San Francisco, CA 11/12-17/2006)
Potential Barriers of Patient Involvement in Health Technology Assessment in Central and Eastern European Countries
Patients' perspectives are important to identify preferences, estimate values and appreciate unmet medical needs in the process of research and development and subsequent assessment of new health technologies. Patient and public involvement in health technology assessment (HTA) is essential in understanding and assessing wider implications of coverage and reimbursement decisions for patients, their relatives, caregivers, and the general population. There are two approaches to incorporating the patients' voice in HTA, preferably used in a mix. In the first one, patients, caregivers and/or their representatives directly participate at discussions in different stages of the HTA process, often at the same table with other stakeholders. Secondly, patient involvement activities can be supported by evidence on patient value and experience collected directly from patients, caregivers and/or their representatives often by patient groups Patient involvement practices, however, are limited in Central and Eastern European (CEE) countries without clear methodology or regulatory mechanisms to guide patient involvement in the HTA process. This poses the question of transferability of practices used in other countries, and might call for the development of new CEE-specific guidelines and methods. In this study we aim to map potential barriers of patient involvement in HTA in countries of the CEE region
The role of gender stereotypes in perceptions of entrepreneurs and intentions to become an entrepreneur
In this study we examine the role of socially constructed gender stereotypes in entrepreneurship and their influence on men and women's entrepreneurial intentions. Data on characteristics of males, females, and entrepreneurs were collected from young adults in three countries. As hypothesized, entrepreneurs were perceived to have predominantly masculine characteristics. Additional results revealed that although both men and women perceive entrepreneurs to have characteristics similar to those of males (masculine gender-role stereotype), only women also perceived entrepreneurs and females as having similar characteristics (feminine gender-role stereotype). Further, though men and women did not differ in their entrepreneurial intentions, those who perceived themselves as more similar to males (high on male gender identification) had higher entrepreneurial intentions than those who saw themselves as less similar to males (low male gender identification). No such difference was found for people who saw themselves as more or less similar to females (female gender identification). The results were consistent across the three countries. Practical implications and directions for future research are discussed