Analysis of fragment yield ratios in the nuclear phase transition

The critical phenomena of the liquid-gas phase transition has been investigated in the reactions 78,86Kr+58,64Ni at beam energy of 35 MeV/nucleon using the Landau free energy approach with isospin asymmetry as an order parameter. Fits to the free energy of fragments showed three minima suggesting the system to be in the regime of a first order phase transition. The relation m =-{\partial}F/{\partial}H, which defines the order parameter and its conjugate field H, has been experimentally verified from the linear dependence of the mirror nuclei yield ratio data, on the isospin asymmetry of the source. The slope parameter, which is a measure of the distance from a critical temperature, showed a systematic decrease with increasing excitation energy of the source. Within the framework of the Landau free energy approach, isoscaling provided similar results as obtained from the analysis of mirror nuclei yield ratio data. We show that the external field is primarily related to the minimum of the free energy, which implies a modification of the source concentration \Delta used in isospin studies

Measuring the Temperature of Hot Nuclear Fragments

A new thermometer based on fragment momentum fluctuations is presented. This thermometer exhibited residual contamination from the collective motion of the fragments along the beam axis. For this reason, the transverse direction has been explored. Additionally, a mass dependence was observed for this thermometer. This mass dependence may be the result of the Fermi momentum of nucleons or the different properties of the fragments (binding energy, spin etc..) which might be more sensitive to different densities and temperatures of the exploding fragments. We expect some of these aspects to be smaller for protons (and/or neutrons); consequently, the proton transverse momentum fluctuations were used to investigate the temperature dependence of the source

Analysis of fragment yield ratios in the nuclear phase transition

The critical phenomena of the liquid-gas phase transition has been investigated in the reactions 78,86Kr+58,64Ni at beam energy of 35 MeV/nucleon using the Landau free energy approach with isospin asymmetry as an order parameter. Fits to the free energy of fragments showed three minima suggesting the system to be in the regime of a first order phase transition. The relation m =-{\partial}F/{\partial}H, which defines the order parameter and its conjugate field H, has been experimentally verified from the linear dependence of the mirror nuclei yield ratio data, on the isospin asymmetry of the source. The slope parameter, which is a measure of the distance from a critical temperature, showed a systematic decrease with increasing excitation energy of the source. Within the framework of the Landau free energy approach, isoscaling provided similar results as obtained from the analysis of mirror nuclei yield ratio data. We show that the external field is primarily related to the minimum of the free energy, which implies a modification of the source concentration \Delta used in isospin studies

Evaluation of the Anticancer Activity of Bioactive Fraction G Extracted from \u3cem\u3ePavetta crassipes\u3c/em\u3e in Malignant Brain Tumor Cell Lines

Objective: Natural products have served as sources of lead compounds that are commonly used in the treatment of human diseases including cancer. Pavetta crassipes has been widely demonstrated to have ethnopharmacological potential in the management of malaria, gastrointestinal conditions, central nervous system behavioral disorders, hypertension, and cancer. The goal of our study was to evaluate the biological and molecular effects of Fraction G, obtained from the plant Pavetta crassipes, on glioblastoma invasive growth and survival. Methodology: The antiproliferative effects of Fraction G, obtained from Pavetta crassipes, was evaluated using the trypan blue exclusion, (3-(4, 5-Dimethylthiazol- 2yl)-2, 5-Diphenyltetrazolium Bromide; MTT), and lactate dehydrogenase (LDH) assays. Flow cytometry and Western blotting analyses were carried out to examine the effects of Fraction G on cell cycle check-points and its effects on epidermal growth factor receptor-mediated signaling of AKT and MAPK pathways. Results: In this paper, we report that the Fraction G obtained from the plant Pavetta crassipes induced a reduction in glioma cell viability and proliferation as well as induced an increase in apoptosis as evidenced by cleaved PARP, increased caspase 3/7 activity, and cell cycle arrest in the G0/G1 check point. Furthermore, we report that Fraction G inhibited the phosphorylation of AKT and MAPK following EGF treatment. Conclusion: Taken together, our results demonstrate that Fraction G has potent inhibitory effects on pathways involved in glioblastoma proliferation and survival

Blood Lead Levels Among Pregnant Women: Historical Versus Contemporaneous Exposures

Blood lead among pregnant women, even at modest levels, may impair offspring cognitive development. We examine whether blood lead levels (BLLs) result from current versus historic exposures, among a cohort of pregnant women. Cumulative logit models were used to characterize the relationship between maternal risk factors and higher BLLs. Maternal blood lead levels more likely result from lead remobilization from historic versus contemporaneous exposures. Even if all lead sources were abated immediately, women and their fetuses would experience lead exposure for decades. This work emphasizes the importance of addressing sources of environmental lead exposure in the United States and internationally

Knowledge management related training strategies in Kingdom of Saudi Arabia construction industry: An empirical study

The growing popularity of knowledge management (KM) in the construction industry has, unfortunately, not been matched by parallel empirical research in training and benefits of KM for construction industry in the Kingdom of Saudi Arabia (KSA). This paper discusses the KM related training strategies implemented in the Kingdom of Saudi Arabia construction industry. Given the relatively new and unexplored nature of the research problem, qualitative research method was adopted to collect and analyse data. Results are based on the analysis of data from 46 professionals from KSA construction organisations. This paper concludes that training interventions are a complex and context-embedded activity. The current study results suggests that for effective implementation of KM strategies, there is an urgent need for KSA construction industry to develop and deploy appropriate KM related management training programmes. Leadership plays an important role in breaking down barriers in achieving KM strategies. The practical implication of this research is that the KM should not only focus on the specific knowledge to be captured, shared, mapped and transferred between individuals but should also address strategic concerns at group and organisational levels