Metabolic-heat relation for aerobic yeast respiration and fermentation

A specially developed temperature control system on a laboratory scale fermenter enabled continuous measurement of the rate of heat production during undisturbed growth of microbial cultures. Apart from being correlated with oxygen uptake rate, the heat of fermentation was established as an additional indicator of metabolic activity. The ‘aerobic respiration’ energetic activity of Candida utilis, Candida lipolytica and Saccharomyces cerevisiae on different carbon substrates was investigated with cultures of the latter species being also studied under the ‘aerobic fermentation’ conditions induced by glucose catabolite repression.     

Axial pressure profiles in non-newtonian flow: Part I: Theoretical and experimental considerations

The flow behavior of polymeric fluids in tubes can be determined from measurements of the radial stress profile in the flow direction. This subject, the focus of our research, will be examined in Part II of this communication. Part I describes a research designed to test the accuracy of stress measurement with pressure transducers in a variety of recess mount geometries. No mount geometry errors were detected for the fluids used in this work over a shear rate range of 1 to 2000 sec^?1. Part I also contains a survey of the literature and theoretical considerations pertinent to the entire work.     

Distributed envy minimization for resource allocation

Minimizing envy in distributed discrete resource or task allocation, is an unusual distributed optimization challenge, since the quality of the allocation for each of the agents is dependent, not only on its own allocation, but on the allocation of others as well. Thus, in order to perform distributed search for allocations with minimal envy there is a need to design innovative algorithms that can cope with the challenging constraint structure of an envy minimization problem. Distributed methods for minimizing envy among agents in indivisible resource allocation problems are presented. First, Distributed Envy Minimization Problems (DEMP) are formulated as Distributed Constraint Reasoning problems. When the DEMPs are large, and cannot be solved by a complete search an incomplete local search algorithm is presented. Each transfer of a good from one agent to another involves the change of state of more than one agent. Thus, a minimizing envy local search algorithm must build upon actions (transfers) that include multiple agents. Since DEMPs are particularly susceptible to local minima during local search, the paper proposes an algorithm that alternates between two different hill climbing search phases. The first phase uses one-transfer steps while the other exploits envy cycle elimination steps. An algorithm that minimizes envy while preserving efficiency, is proposed. The proposed algorithm finds a Pareto optimal allocation with low envy. In the context of resource allocation problems, a Pareto optimal solution is particularly desirable since it presents a stable solution. The proposed algorithm first finds a divisible Pareto optimal envy-free allocation using a Fisher market equilibrium. This allocation is transferred into an indivisible allocation of goods while maintaining the Pareto optimal characteristic of the allocation and a low envy level among agents.     

The roles of group supervision of supervision.

This article recommends that group supervision of supervision be an integral part of the curriculum of any senior professional who is involved in regular supervision of trainees. Work in the group setting enables use of group dynamics to understand therapeutic events as well as processes of mirroring and identification in the supervision. The supervisory group may promote feelings of security and containment in the supervisors while attenuating and minimizing their potential feelings of vulnerability and validating their perceptions of reality. At the same time, such a group gives rise to difficulties (owing to issues of trust and confidentiality) both inside and outside the group (e.g., among trainees who develop fantasies about the proceedings of the group). Some general resolution of such problems is presented here. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Israeli psychotherapists' reactions and perceptions on the process of psychotherapy during the Gulf War.

64 26–56 yr old psychotherapists (38 still in training), who practiced in areas that were either directly or indirectly threatened by missile attack during the Persian Gulf War, completed a questionnaire addressing well-being as affected by the war, the similarity between the patient's and the therapist's experience of the war, and how psychotherapists perceived the overall functioning of their patients and the extent that their internal conflicts were affected by the war. Therapists more directly threatened by the war reported having a greater positive mood than did Ss more indirectly threatened. Experienced psychotherapists addressed the war to a greater degree during the therapeutic hour; inexperienced Ss reported a greater change in their therapeutic stance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bed expansion in high velocity fluidization

Bed expansion of fine powders was investigated in two high aspect ratio fluid beds, an expanded top bed and a circulating system. The range of gas velocities (0.07 – 8 m/s) spanned the bubbling/slugging, turbulent, fast, and dense conveying fluidization regimes. The two-phase theory was shown generally not to apply in the slugging and the higher velocity fluidization regimes. A modified Richardson-Zaki approach, using an ‘effective’ cluster terminal velocity, was shown to adequately describe bed expansion. Changes in slope of the expansion curve were associated with regime changes, and can prove useful for the analysis of large diameter fluid beds. The effect of particle size distribution was shown to be considerable.     

Octopus: A fault-tolerant and efficient ad-hoc routing protocol

Mobile ad-hoc networks (MANETs) are failure-prone environments; it is common for mobile wireless nodes to intermittently disconnect from the network, e.g., due to signal blockage. This paper focuses on withstanding such failures in large MANETs: we present Octopus, a fault-tolerant and efficient position-based routing protocol. Fault-tolerance is achieved by employing redundancy, i.e., storing the location of each node at many other nodes, and by keeping frequently refreshed soft state. At the same time, Octopus achieves a low location update overhead by employing a novel aggregation technique, whereby a single packet updates the location of many nodes at many other nodes. Octopus is highly scalable: for a fixed node density, the number of location update packets sent does not grow with the network size. And when the density increases, the overhead drops. Thorough empirical evaluation using the ns2 simulator with up to 675 mobile nodes shows that Octopus achieves excellent fault-tolerance at a modest overhead: when all nodes intermittently disconnect and reconnect, Octopus achieves the same high reliability as when all nodes are constantly up. A preliminary version of this paper appears in Proceedings of the 24th IEEE Symposium on Reliable Distributed Systems (SRDS 2005) October 26–28, 2005, Orlando, Florida. Idit Keidar is a faculty member at the department of Electrical Engineering at the Technion Israel Institute of Technology, and a recipient of the national Alon Fellowship for new faculty members. She holds Ph.D., M.Sc. (summa cum laude), and B.Sc (summa cum laude) degrees from the Hebrew University of Jerusalem. She was a postdoctoral research associate at MIT’s laboratory for Computer Science, where she held post-doctoral fellowships from Rothschild Yad-Hanadiv and NSF CISE. Dr. Keidar has consulted for BBN Technologies (a Verizon Company) in the area of fault-tolerance and intrusion tolerance, and for Microsoft Research in the area of fault-tolerant storage systems. Dr. Keidar’s research focuses on reliability in distributed algorithms and system. She is the academic head of Software Systems Laboratory at the Technion. Dr. Keidar served as a member of the Steering Committee of the ACM Symposium on Principles of Distributed Computing (PODC), has served on numerous program committees of leading conferences in the area of distributed and parallel computing, has twice served as a vice-chair for the IEEE International Conference on Distributed Computing Systems (ICDCS), and once served as a vice-chair for Euro-Par. Yoav Barel is a Senior Business Line Manager at Sun Microsystems. He holds a B.Sc from the Technion—Israel Institute of Technology. Mr. Barel works with wireless carriers world wide and assists them in deploying innovative services based on cutting edge Java technologies. Roie Melamed is a research staff member at IBM Haifa Research Laboratory. He holds Ph.D. and B.A. (cum laude) degrees from the Technion—Israel Institute of Technology. Dr. Melamed’s research focuses on reliability in distributed systems.     

Quasi‐One Dimensional in‐Plane Conductivity in Filamentary Films of PEDOT:PSS

The mechanism and magnitude of the in‐plane conductivity of poly(3,4‐ethy‐lenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) thin films is determined using temperature dependent conductivity measurements for various PEDOT:PSS weight ratios with and without a high boiling solvent (HBS). Without the HBS the in‐plane conductivity of PEDOT:PSS is lower and for all studied weight ratios well described by the relation $ \sigma = \sigma _0 {\rm exp}[- \left({{{{T_0}}\over{T}}} \right)^{0.5}] $ with T₀ a characteristic temperature. The exponent 0.5 indicates quasi‐one dimensional (quasi‐1D) variable range hopping (VRH). The conductivity prefactor σ₀ varies over three orders of magnitudes and follows a power law σ₀∝c^3.5_PEDOT with c_PEDOT the weight fraction of PEDOT in PEDOT:PSS. The field dependent conductivity is consistent with quasi‐1D VRH. Combined, these observations suggest that conductance takes place via a percolating network of quasi‐1D filaments. Using transmission electron microscopy (TEM) filamentary structures are observed in vitrified dispersions and dried films. For PEDOT:PSS films with HBS, the conductivity also exhibits quasi‐1D VRH behavior when the temperature is less than 200 K. The low characteristic temperature T₀ indicates that HBS‐treated films are close to the critical regime between a metal and an insulator. In this case, the conductivity prefactor scales linearly with c_PEDOT, indicating the conduction is no longer limited by a percolation of filaments. The lack of observable changes in TEM upon processing with the HBS suggests that the changes in conductivity are due to a smaller spread in the conductivities of individual filaments, or a higher probability for neighboring filaments to be connected rather than being caused by major morphological modification of the material.