Light Element Synthesis in High Entropy Relativistic Flows Associated with Gamma Ray Bursts

We calculate and discuss the light element freeze-out nucleosynthesis in high entropy winds and fireballs for broad ranges of entropy-per-baryon, dynamic timescales characterizing relativistic expansion, and neutron-to-proton ratios. With conditions characteristic of Gamma Ray Bursts (GRBs) we find that deuterium production can be prodigious, with final abundance values 2H/H approximately 2%, depending on the fireball isospin, late time dynamics, and the effects of neutron decoupling- induced high energy non-thermal nuclear reactions. This implies that there potentially could be detectable local enhancements in the deuterium abundance associated with GRB events.Comment: 14 pages 3 figure

Moléculas coloreadas

Es un taller optativo orientado a alumnos de quinto año del Bachillerato de Bellas Artes, (UNLP) con 3 horas cátedra, una vez por semana, 20 alumnos y un docente. El objetivo es abordar el conocimiento científico a través de trabajos experimentales, integrando las químicas General, Inorgánica y Orgánica, con los saberes previos adquiridos. Se abordan los siguientes temas: formación de cristales, la acidez del medio, el tema de los alcoholes, como antiséptico, en cosmética y en la alimentación; el fenómeno de corrosión y sus implicancias y cómo se puede evitar. Pigmentos y colorantes. Las metodologías utilizadas orientan a los alumnos a aprender a pensar, a construir un espacio creativo, a adquirir destrezas en el laboratorio, con una mirada desde la Química, a intercambiar ideas, a reconocer, representar y nombrar compuestos químicos, a observar y representar reacciones químicas y porqué tienen color algunas moléculas utilizadas en los trabajos prácticos. En síntesis, los alumnos pueden comprobar que los saberes aprendidos en la teoría se cumplen en la vida cotidiana, les permite reconocer compuestos químicos, diferenciar reacciones químicas y cómo solubilizar diferentes sustancias. Comprueban que algunas sustancias cristalinas hidratadas tienen color, que el azúcar, anhidra, también puede formar cristales. Observan pH en la alimentación, tiñen con flores, hojas, hortalizas, tubérculos.Bachillerato de Bellas Artes "Prof. Francisco A. De Santo

The Spitzer/IRS Infrared Spectrum and Abundances of the Planetary Nebula IC 2448

We present the mid-infrared spectrum of the planetary nebula IC 2448. In order to determine the chemical composition of the nebula, we use the infrared line fluxes from the Spitzer spectrum along with optical line fluxes from the literature and ultraviolet line fluxes from archival IUE spectra. We determine an extinction of C(H-beta) = 0.27 from hydrogen recombination lines and the radio to H-beta ratio. Forbidden line ratios give an electron density of 1860 cm-3 and an average electron temperature of 12700 K. The use of infrared lines allows us to determine more accurate abundances than previously possible because abundances derived from infrared lines do not vary greatly with the adopted electron temperature and extinction, and additional ionization stages are observed. Elements left mostly unchanged by stellar evolution (Ar, Ne, S, and O) all have subsolar values in IC 2448, indicating that the progenitor star formed out of moderately metal deficient material. Evidence from the Spitzer spectrum of IC 2448 supports previous claims that IC 2448 is an old nebula formed from a low mass progenitor star

Changes in the self-esteem, parental attitude, and generalized contentment among teen mothers enrolled in a parent program

Adolescent pregnancy is a serious problem which creates social and emotional consequences for 1 in 10 teenaged girls and their families. Although the severity of the problem has been well documented in the literature, few empirical investigations have been conducted to expand information or to aid in the understanding of the effects of programs designed to meet the unique needs of adolescent mothers. It was the purpose of this study to examine the effects of a teen parent program on the teen mother's well-being. Specifically, the inquiry examined the self-esteem, attitudes toward the child, and generalized contentment of teenaged mothers before and after program participation. The subjects were teenaged mothers between the ages of 16 and 19 living with their biological children in an urban community of a rural county in the Pacific Northwest of the United States. Volunteers for the program were assigned to a treatment group and a control group. Both groups were given the Index of Self-Esteem (ISE), the Index of Parental Attitudes (IPA), and the Generalized Contentment Scale (GCS). The treatment group then participated in a 10-week teen parent program. After the program, the 13 subjects who had completed the program and the 15 subjects in the control group were posttested on the same measures used in the pretesting. Hypotheses related to within group changes were tested with t-tests for correlated means and an analysis of covariance tested the between groups hypotheses. The Pearson product moment correlations tested for possible correlations among the three measures at pre- and posttesting. The findings of the within group analyses showed significant differences between pretest and posttest ISE (p<.05) and IPA (p<.01) scores of the subjects in the treatment group. And, although the GCS scores displayed a strong positive tendency, it did not prove to be statistically significant for the treatment group. There were no significant differences between the pretest and posttest scores on the ISE, IPA and the GCS scores of the subjects in the control group. For the between group analyses, the adjusted posttest IPA (p<.02) and GCS (p<.05) scores were found to be significantly more positive for the treatment group subjects than the control group subjects. The analysis of the ISE (p< .08) was not statistically significant. There were no significant correlations between ISE, IPA, and the GCS scores for both the treatment and control groups at pretest and posttest. the findings in this study indicate that overall there were generally significant improvements in the treatment group's self-esteem, attitude toward their child and generalized contentment after participating in a teen parent program. These results could be very encouraging to supporters of community-based programs designed to provide direct services to meet the unique needs of the adolescent mother

Racial Disparities in Head and Neck Cancers in an Urban Hospital

Introduction: Head and neck cancer incidence rates are higher for white residents in Philadelphia, while related mortality rates are highest for black residents. It is unclear how risk factors like HPV and smoking contribute to these disparities. The goal of this study is to determine which factors are associated with head and neck cancers in a diverse patient population from a Philadelphia hospital. Methods: Cancer registry data from Thomas Jefferson University was used to obtain records from 922 head and neck cancer patients. One patient of other race was excluded. Twenty in-situ cancer cases were excluded. Chi-square tests were used to examine categorical variables. Logistic and Cox regression models were designed to examine associations with advanced disease and time to mortality. Results: Our sample included 901 patients (769 white, 96 black, 36 Asian). Positive HPV status was most prevalent for white patients (p\u3c 0.0001). Oral cancers were most common among Asians (p\u3c.0001). In univariate analysis, black patients were most likely to die from their cancer. In multivariate analysis, time to death was shorter for current smokers (HR=1.95, CI=1.311-2.901) and former smokers (HR=2.94, CI=1.949-4.387). Positive HPV status was protective (HR=0.34, CI=.244-.481). No significant race effects were observed in multivariate analysis. Conclusions: Results suggest that race is not independently associated with head and neck cancer associated mortality. These results also suggest that some risk factors for head and neck cancer and outcomes may be modified by educational and behavioral interventions

Postoperative hyperphosphatemia significantly associates with adverse survival in colorectal cancer patients

BACKGROUND: Hyperphosphatemia has been implicated in the development and treatment of various cancers. However, whether it can be used as a direct prognostic marker of colorectal cancer (CRC) has remained unexplored. Given new insights into the importance of hyperphosphatemia in CRC, we sought to evaluate the association of hyperphosphatemia with the clinical outcomes of this disease. METHODS: In a retrospective analysis of a well-characterized clinic-based cohort with 1,241 CRC patients, we assessed the association of postoperative hyperphosphatemia with patient overall survival. RESULTS: Postoperative hyperphosphatemia measured within the first month after surgery was significantly associated with CRC survival. Compared to patients with a normal phosphate level, those with hyperphosphatemia exhibited a significant unfavorable overall survival with a hazard ratio (HR) of 1.84 (95% confidence interval [CI] 1.49–2.29, P=2.6×10(−8), (log-rank P=1.2×10(−7)). Stratified analyses indicated the association was more pronounced in patients with colon (HR=2.00, 95% CI 1.57–2.56, P=3.17×10(−8)) but not rectal cancer (HR=0.96, 95% CI 0.58–1.59, P=0.889) (P interaction=0.023), as well as in those not receiving chemotherapy (HR=2.15, 95% CI 1.59–2.90, P=6.2×10(−7)) but not in those receiving chemotherapy (HR=1.30, 95% CI 0.92–1.82, P=0.136) (P interaction=0.012). Flexible parametric survival model demonstrated that the increased risk for death conferred by postoperative hyperphosphatemia persisted over 150 months after surgery. CONCLUSION: Our data indicated that postoperative hyperphosphatemia might be used as a prognostic marker of CRC patients after surgery. Since phosphate level is routinely tested in clinics, it may be incorporated into clinical models to predict CRC survival