Isotropic Heating of Galaxy Cluster Cores via Rapidly Reorienting AGN Jets

AGN jets carry more than sufficient energy to stave off catastrophic cooling of the intracluster medium (ICM) in the cores of cool-core clusters. However, in order to prevent catastrophic cooling, the ICM must be heated in a near-isotropic fashion and narrow bipolar jets with $P_{\rm jet}=10^{44-45}$ ergs/s, typical of radio AGNs at cluster centres, are inefficient at heating the gas in the transverse direction to the jets. We argue that due to existent conditions in cluster cores, the SMBHs will, in addition to accreting gas via radiatively inefficient flows, experience short stochastic episodes of enhanced accretion via thin discs. In general, the orientation of these accretion discs will be misaligned with the spin axis of the black holes and the ensuing torques will cause the black hole's spin axis (and therefore, the jet axis) to slew and rapidly change direction. This model not only explains recent observations showing successive generations of jet-lobes-bubbles in individual cool-core clusters that are offset from each other in the angular direction with respect to the cluster center, but also shows that AGN jets {\it can} heat the cluster core nearly isotropically on the gas cooling timescale. Our model {\it does} require that the SMBHs at the centers of cool-core clusters be spinning relatively slowly. Torques from individual misaligned discs are ineffective at tilting rapidly spinning black holes by more than a few degrees. Additionally, since SMBHs that host thin accretion discs will manifest as quasars, we predict that roughly 1--2 rich clusters within $z<0.5$ should have quasars at their centers.Comment: 10 pages; accepted in ApJ; updated to conform with the accepted Journal versio

Calcium Homeostasis in Escherichia coli: Characterization of Mutants and Genome Expression of MG1655

While the role of calcium ions as secondary messengers has been well described in eukaryotic cells, little is known about calcium homeostasis in bacteria at the physiological and molecular levels. Genetic and genomic approaches were used to address calcium regulation and to identify genes (cal) involved in calcium homeostasis. Transposon mutagenesis of Escherichia coli generated several calcium-sensitive mutants that fell into three categories: (i) Ca2+-sensitive chemotaxis mutants, (ii) Ca2+-sensitive cell division mutants, and (iii) Ca2+-sensitive mutants that showed no defects in cell division or chemotaxis. The physiological properties of these Ca2+-sensitive mutants were determined. Besides calcium-sensitivity to 75 mM calcium, all of the mutants exhibited increased sensitivities to several divalent cations including Ni2+, Mg2+, Mn2+, Co2+, Zn2+, Cu2+, and Cd2+. To identify the cal gene sequence in the Ca2+-sensitive mutants, the region of the genes fused to the reporter gene (phoA) on the transposon TnphoA was amplified by PCR and sequenced. The sites of the gene fusion for three cal mutants were at the fdoG, gpt and pqi5 genes. The pleiotropic nature for the cal mutations suggested that many genes may be globally regulated by calcium. We then investigated global gene expression patterns of wild-type E. coli under calcium-depleted (addition of 10 mM EGTA) and calcium-elevated (addition of 75 mM Ca2+) conditions as compared to cultures grown under unstressed conditions. A comprehensive transcriptome analysis using macroarrys exhibited a global regulation of diverse genes within the E. coli genome during calcium homeostasis

Professional Secrecy and Privileged Communication in Medical Practice

A medical professional has the faith and confidence of society in him/her. It is his utmost duty and responsibility to uphold the ethical standards of confidentiality, set forth in the Hippocratic Oath, the Declaration of Geneva, the International Code of Medical Ethics and the World Health Organization. Communication between the physician and his patient is privileged. This information can only be divulged, in part, under special circumstances

Pengaruh Perputaran Modal Kerja, Leverage Dan Pertumbuhan Penjualan Terhadap Profitabilitas (Studi Pada Perusahaan Makanan Dan Minuman Yang Terdaftar Di Bursa Efek Indonesia Pada Tahun 2011-2013)

This research aims to explain the effect of Working Capital Turnover (WCT), Debt Ratio (DR), Debt to Equity Ratio (DER) and Sales Growth on Return on Investment (ROI) and Return on Equity (ROE) simultaneously and partially. The method that is used in this research is explanatory research with purposive sampling as the sampling as the sampling method. This research is using 13 companies as samples out of a total population of 16 companies that is listed on Indonesian Stock Exchange (IDX). The analysis technique that is used on this research is multiple linear regression and hypothesis test. The result of the F test analysis for ROI shows that WCT, DR, DER and Sales Growth have a simultaneously significant impact to ROI. Based on t test for ROI the DR, DER and Sales Growth have a partially signinifivant impact to ROI ehilr the WCT does not. The result of the F analysis for ROE shows that WCT, DR, DER and Sales Growth nave simultaneously significant impact to ROE. Based on t test for ROE the DR, and DER have a partially significant impact to ROI while the WCT and Sales Growth do not