Environmental Dependence of Local Luminous Infrared Galaxies

We study the environmental dependence of local luminous infrared galaxies (LIRGs) and ultraluminous infrared galaxies (ULIRGs) found in the Sloan Digital Sky Survey (SDSS) data. The LIRG and ULIRG samples are constructed by cross-correlating spectroscopic catalogs of galaxies of the SDSS Data Release 7 and the Infrared Astronomical Satellite Faint Source Catalog. We examine the effects of the large-scale background density (Sigma_5), galaxy clusters, and the nearest neighbor galaxy on the properties of infrared galaxies (IRGs). We find that the fraction of LIRGs plus ULIRGs among IRGs (f_(U)LIRGs) and the infrared luminosity (L_IR) of IRGs strongly depend on the morphology of and the distance to the nearest neighbor galaxy: the probability for an IRG to be a (U)LIRG (f_(U)LIRGs) and its L_IR both increase as it approaches a late-type galaxy, but decrease as it approaches an early-type galaxy (within half the virial radius of its neighbor). We find no dependence of f_(U)LIRGs on the background density (surface galaxy number density) at fixed stellar mass of galaxies. The dependence of f_(U)LIRGs on the distance to galaxy clusters is also found to be very weak, but in highest-density regions such as the center of galaxy clusters, few (U)LIRGs are found. These environmental dependence of LIRGs and ULIRGs and the evolution of star formation rate (SFR)-environment relation from high redshifts to low redshifts seem to support the idea that galaxy-galaxy interactions/merging play a critical role in triggering the star formation activity of LIRGs and ULIRGs.Comment: 14 pages, 17 figures. To appear in A&A. Paper with high resolution figures is available at http://astro.kias.re.kr/~hshwang/doc/ms_hwang_lirg.pd

``Superfast'' Reaction in Turbulent Flow with Potential Disorder

We explore the regime of ``superfast'' reactivity that has been predicted to occur in turbulent flow in the presence of potential disorder. Computer simulation studies confirm qualitative features of the previous renormalization group predictions, which were based on a static model of turbulence. New renormalization group calculations for a more realistic, dynamic model of turbulence show that the superfast regime persists. This regime, with concentration decay exponents greater than that for a well-mixed reaction, appears to be a general result of the interplay among non-linear reaction kinetics, turbulent transport, and local trapping by potential disorder.Comment: 14 pages. 4 figures. Uses IOP styles. To appear in J. Phys. A: Math. Ge

Reactive Turbulent Flow in Low-Dimensional, Disordered Media

We analyze the reactions $A+A \to \emptyset$ and $A + B \to \emptyset$ occurring in a model of turbulent flow in two dimensions. We find the reactant concentrations at long times, using a field-theoretic renormalization group analysis. We find a variety of interesting behavior, including, in the presence of potential disorder, decay rates faster than that for well-mixed reactions.Comment: 6 pages, 4 figures. To appear in Phys. Rev.

A Meta-Analysis on the Effectiveness of Computer-Based Education in Nursing

Objectives: The purpose of this study was to conduct a comparative analysis of education effectiveness between computerbased education and traditional education methods in nursing. Methods: Medical and nursing literature databases were searched to identify studies regarding the effectiveness of computer-based education in nursing. Overall effect sizes for three outcome variables (knowledge, attitude, and practice level) were calculated. The effects of study characteristics on the outcome variables were analyzed. Results: Twenty-seven studies published from 1990 to February 2009, which that met the inclusion criteria, were included in the analysis. The meta-analysis showed that computer-based education generally had positive effects on knowledge, attitude, and practice, with overall effect sizes of 0.43, 0.35, and 0.34, respectively. This study also showed that the type of learner and the total education period had different effects on knowledge. Conclusions: This metaanalysis found that computer-based education in nursing had positive effects on knowledge, attitude, and practice. Keywords: Meta-analysis, Computer-based, Education, Nursing I

Identification of regulatory network hubs that control lipid metabolism in Chlamydomonas reinhardtii

HighlightCharacterization of regulatory networks in Chlamydomonas reinhardtii led to the identification of regulatory hubs that control the repatterning of cellular metabolism that leads to triacylglycerol accumulation in microalgae.Microalgae-based biofuels are promising sources of alternative energy, but improvements throughout the production process are required to establish them as economically feasible. One of the most influential improvements would be a significant increase in lipid yields, which could be achieved by altering the regulation of lipid biosynthesis and accumulation. Chlamydomonas reinhardtii accumulates oil (triacylglycerols, TAG) in response to nitrogen (N) deprivation. Although a few important regulatory genes have been identified that are involved in controlling this process, a global understanding of the larger regulatory network has not been developed. In order to uncover this network in this species, a combined omics (transcriptomic, proteomic and metabolomic) analysis was applied to cells grown in a time course experiment after a shift from N-replete to N-depleted conditions. Changes in transcript and protein levels of 414 predicted transcription factors (TFs) and transcriptional regulators (TRs) were monitored relative to other genes. The TF and TR genes were thus classified by two separate measures: up-regulated versus down-regulated and early response versus late response relative to two phases of polar lipid synthesis (before and after TAG biosynthesis initiation). Lipidomic and primary metabolite profiling generated compound accumulation levels that were integrated with the transcript dataset and TF profiling to produce a transcriptional regulatory network. Evaluation of this proposed regulatory network led to the identification of several regulatory hubs that control many aspects of cellular metabolism, from N assimilation and metabolism, to central metabolism, photosynthesis and lipid metabolism

Polymorphisms of High-Affinity IgE Receptor and Histamine-Related Genes in Patients with ASA-Induced Urticaria/Angioedema

The pathogenic mechanism of ASA-induced urticaria/angioedema (AIU) is still poorly understood, but it has been known that histamine releasing by cutaneous mast cell activation is considered to be an important role. Considering the importance of histamine in AIU, we speculated that a genetic abnormality of histamine-related genes such as a high-affinity IgE receptor, a metabolic enzyme of histamines and histamine receptors, may be involved in the development of AIU. Enrolled in the study were 110 patients with AIU, 53 patients without ASA hypersensitivity who had various drug allergies presenting as exanthematous skin symptoms, and 99 normal healthy controls (NC). Eleven single nucleotide polymorphisms (SNPs) of the β chain of the high-affinity IgE receptor (FCER1B) and three histamine-related genes-histamine N-methyltransferase (HNMT), histamine H1 receptor (HRH1), histamine H2 receptor (HRH2)-were screened using the SNP-IT assay based on a single base extension method. No significant differences were observed in allele and genotype frequencies, and haplotype frequencies of all the SNPs of FCER1B, HNMT, HRH1, and HRH2 among the three groups (p>0.05, respectively). These results suggest that the polymorphisms of FCER1B and the three histamine-related genes may not contribute to the development of AIU phenotype in the Korean population

The Inhibitory Effect of siRNAs on The High Glucose-Induced Overexpression of TGF-β1 in Mesangial Cells

Diabetic nephropathy is characterized by an expansion of the glomerular mesangium, caused by mesangial cell proliferation and an excessive accumulation of extracellar matrix (ECM) proteins, which eventually leading to glomerulosclerosis. TGF-β1 was found to play an important role in the accumulation of ECM in the kidney. In this study, TGF-β1 RNA interference was used as an effective therapeutic strategy. The inhibitory effect of TGF-β1 small interfering RNAs (siRNAs) on the high glucose-induced overexpression of TGF-β1 in rat mesangial ceys (RMCs). A high levels of glucose induces TGF-β1 mRNA and protein, and TGF-β1 siRNAs reduce the ability of high glucose to stimulate their expression. We also examined the inhibitory effect of TGF-β1 siRNAs on the expression of plasminogen activator inhibitor (PAI)-1 and Collagen Type I which are down-regulators of TGF-β1. The expression of TGF-β1, PAI-1 and Collagen Type I was increased in RMCs that were stimulated by 30 mM glucose. TGF-β1 siRNAs reduces high glucose-induced TGF-β1, PAI-1, and Collagen Type I mRNA and protein expression in a dose-dependent manner. In conclusion, the present study demonstrates that TGF-β1 siRNAs effectively inhibits TGF-β1 mRNA and protein expression in RMCs. These suggest that TGF-β1 siRNAs through RNAi may be a useful tool for developing new therapeutic applications for the treatment of diabetic nephropathy

Multiphase segregation and metal-insulator transition in single crystal La(5/8-y)Pr(y)Ca(3/8)MnO3

The insulator-metal transition in single crystal La(5/8-y)Pr(y)Ca(3/8)MnO3 with y=0.35 was studied using synchrotron x-ray diffraction, electric resistivity, magnetic susceptibility, and specific heat measurements. Despite the dramatic drop in the resistivity at the insulator-metal transition temperature Tmi, the charge-ordering (CO) peaks exhibit no anomaly at this temperature and continue to grow below Tmi. Our data suggest then, that in addition to the CO phase, another insulating phase is present below Tco. In this picture, the insulator-metal transition is due to the changes within this latter phase. The CO phase does not appear to play a major role in this transition. We propose that a percolation-like insulator-metal transition occurs via the growth of ferromagnetic metallic domains within the parts of the sample that do not exhibit charge ordering. Finally, we find that the low-temperature phase-separated state is unstable against x-ray irradiation, which destroys the CO phase at low temperatures.Comment: 9 pages, 9 encapsulated eps figure

Effect of Antisense TGF-β1 Oligodeoxynucleotides in Streptozotocin-Induced Diabetic Rat Kidney

Transforming growth factor (TGF)-β1 is an important fibrogenic factor that is involved in the pathogenesis of diabetic nephropathy. We evaluated the effect of circular antisense TGF-β1 oligodeoxynucleotides (ODNs) on the TGF-β1 expression in the rat mesangial cell culture and in streptozotocin (STZ)-induced diabetic rats. Circular antisense TGF-β1 ODNs were found to be stable in rat serum, significantly decreasing TGF-β1 mRNA expression compared with linear antisense ODNs in the rat mesangial cell culture. Circular antisense TGF-β1 ODNs were introduced into the tail vein of normal rats using hemagglutinating virus of Japan (HVJ)-liposome-mediated gene transfer method and were confirmed to be delivered effectively into the kidney, liver, lungs, and spleen. To inhibit the overexpression of TGF-β1 in diabetic kidneys, we introduced circular antisense TGF-β1 ODNs into the STZ-induced diabetic rats. On day 13 after circular antisense TGF-β1 ODNs injection, TGF-β1 mRNA and protein expression markedly decreased and urinary TGF-β1 excretion rate also dropped in the circular antisense TGF-β1 ODNs-treated diabetic rats. These results suggest that circular antisense TGF-β1 ODNs may be a useful tool for developing new therapeutic application for progressive diabetic nephropathy