Massive Accretion Disks

Recent high resolution near infrared (HST-NICMOS) and mm-interferometric imaging have revealed dense gas and dust accretion disks in nearby ultra-luminous galactic nuclei. In the best studied ultraluminous IR galaxy, Arp 220, the 2 micron imaging shows dust disks in both of the merging galactic nuclei and mm-CO line imaging indicates molecular gas masses approx. 10^9 M_sun for each disk. The two gas disks in Arp 220 are counterrotating and their dynamical masses are approx. 2x10^9 M_sun, that is, only slightly larger than the gas masses. These disks have radii approx 100 pc and thickness 10-50 pc. The high brightness temperatures of the CO lines indicate that the gas in the disks has area filling factors of approx. 25-50% and mean densities of >~ 10^4 cm^(-3). Within these nuclear disks, the rate of massive star formation is undoubtedly prodigious and, given the high viscosity of the gas, there will also be high radial accretion rates, perhaps >~ 10 M_sun/yr. If this inflow persists to very small radii, it is enough to feed even the highest luminosity AGNs.Comment: LaTex, 6 pages with 1 postscript and 1 jpg figure, and 1 postscript table, To appear in the proc. of the Ringberg workshop on "Ultraluminous Galaxies: Monsters or Babies" (Ringberg castle, Sept. 1998), Ap&SS, in pres

The Extreme Nuclear Environments of Sgr A* and Arp 220

The dense ISM which is the fuel for both nuclear starbursts is believed to be accreted to the nucleus by stellar bars and galactic interactions. In this contribution, I summarize the observational results for two galactic nuclei at the extreme ends of starburst/AGN activity − our own Galactic nucleus with SgrA* and the ULIRG Arp 220. I discuss theoretical considerations for the properties of the ISM − its density and scale height, whether it is likely to clump into gravitational bound GMCs − and the self-regulation of SB and AGN fueling due to radiation pressure support of the ISM. The latter yields an Eddington-like limit on the activity for both SB and AGN, corresponding to approximately 500 L_ʘ/M_ʘ for optically thick regions in which the radiation has been degraded to the NIR

Aneuploidy and proteotoxic stress in cancer

Although nearly ubiquitous in cancer, aneuploidy exerts detrimental effects on human cells. We recently demonstrated that aneuploid human cells exhibit impaired heat shock factor protein 1 (HSF1) and HSP90 function, suggesting a functional link between two recurring features of cancer cells: aneuploidy and proteotoxic stress. Further, our fi ndings implicate HSF1 as a key factor in mitigating the effects of aneuploid

Examining employee attitudes and behaviours towards organisational change using supervisor and peer relations

This study focuses on employee workplace and demographic predictors to know the employee attitudes and behaviours regarding organisational change. Five hundered fifty six surveys out of one thousand were returned from full time academics working in public sector universities of Pakistan. The findings indicate significant relationships between readiness for change and workplace and demographic factors. First time supervisor and peer relations predictor has been examined to readiness for change. Results indicate positive and significant relationships between readiness for change and supervisor and peer relations. However, from demographic characteristics only two i.e. number of dependents and younger employees have positive and significant relationships to readiness for change. This study contribute in the literature on change management particularly for developing countries i.e. Pakistan and assist the management and practitioners of human resources management (HRM), organisational development (OD) and change agents in assessing, designing and evaluating new or existing programs for organisational change

Impact of employees psychological and financial predictors for readiness to organizational change

This study focuses on employees’ psychological and financial predictors to know the employees reaction regarding change. One hundred forty one surveys were returned from full time teaching staff working in public sector universities of Pakistan. The findings indicate significant relationships between readiness to change and psychological and financial predictors. First time job involvement, training and skills development, pays/wages/fringe benefits and promotions predictors have been examined for readiness to change. Results indicate no relationship between readiness to change and employees’ organizational commitment. However, employees’ job involvement, training and skills development pays/wages/fringe benefits, and promotions have positive impact on readiness to change. This study may contribute in the literature on change management particularly for developing countries and may assist the management and practitioners of Human Resources Management (HRM), Human Resources Development (HRD), and Organizational Behaviour (OB) in assessing, designing and evaluating new or existing programs for organisational change

M-ATTEMPT: A New Energy-Efficient Routing Protocol for Wireless Body Area Sensor Networks

In this paper, we propose a new routing protocol for heterogeneous Wireless Body Area Sensor Networks (WBASNs); Mobility-supporting Adaptive Threshold-based Thermal-aware Energy-efficientMulti-hop ProTocol (M-ATTEMPT). A prototype is defined for employing heterogeneous sensors on human body. Direct communication is used for real-time traffic (critical data) or on-demand data while Multi-hop communication is used for normal data delivery. One of the prime challenges in WBASNs is sensing of the heat generated by the implanted sensor nodes. The proposed routing algorithm is thermal-aware which senses the link Hot-spot and routes the data away from these links. Continuous mobility of human body causes disconnection between previous established links. So, mobility support and energy-management is introduced to overcome the problem. Linear Programming (LP) model for maximum information extraction and minimum energy consumption is presented in this study. MATLAB simulations of proposed routing algorithm are performed for lifetime and successful packet delivery in comparison with Multi-hop communication. The results show that the proposed routing algorithm has less energy consumption and more reliable as compared to Multi-hop communication.Comment: arXiv admin note: substantial text overlap with arXiv:1208.609