Self-engineering capabilities of bacteria.

Under natural growth conditions, bacteria can utilize intricate communication capabilities (e.g. quorum-sensing, chemotactic signalling and plasmid exchange) to cooperatively form (self-organize) complex colonies with elevated adaptability-the colonial pattern is collectively engineered according to the encountered environmental conditions. Bacteria do not genetically store all the information required for creating all possible patterns. Instead, additional information is cooperatively generated as required for the colonial self-organization to proceed. We describe how complex colonial forms (patterns) emerge through the communication-based singular interplay between individual bacteria and the colony. Each bacterium is, by itself, a biotic autonomous system with its own internal cellular informatics capabilities (storage, processing and assessment of information). These afford the cell plasticity to select its response to biochemical messages it receives, including self-alteration and the broadcasting of messages to initiate alterations in other bacteria. Hence, new features can collectively emerge during self-organization from the intracellular level to the whole colony. The cells thus assume newly co-generated traits and abilities that are not explicitly stored in the genetic information of the individuals.     

Regulation of a dpp target gene in the Drosophila embryo

EnvZ is an inner membrane protein present in Escherichia coli that is important for osmosensing and required for porin gene regulation. EnvZ is phosphorylated by intracellular ATP, and EnvZ-P phosphorylates OmpR, which then binds to the porin promoters to regulate their expression. An overexpressed, truncated form of the enzyme, EnvZ115, was used to characterize the kinase reaction in vitro. Using a filter binding assay, we report the first direct measurements of the kinase activity, including the apparent affinity for ATP of 200 microM. The phosphorylation reaction is dependent on MgCl2, and the phosphoenzyme has the expected stability of a phosphohistidine; i.e., it is stable in base and less stable in acid at room temperature. The addition of OmpR and ATP to solutions containing EnvZ resulted in an OmpR-stimulated, EnvZ-dependent ATPase activity that was not vanadate-sensitive. The in vivo kinase activity of EnvZ and two mutants that were deficient in porin expression were studied using an immune complex kinase reaction. Interestingly, a mutation located in the periplasmic domain of EnvZ exhibited kinase activity that was identical to that of the wild-type enzyme, while a mutation located close to the phosphorylation site showed a significant decrease in both kinase and phosphotransferase activities. These data provide support for models of EnvZ consisting of separate sensing and kinase domains.     

AIDS Clinical Trials Group Study 094: a phase I/II trial of ABV chemotherapy with zidovudine and recombinant human GM-CSF in AIDS-related Kaposi''s sarcoma

The aim of this study was to evaluate psychosocial quality of life after heart transplantation. We examined 29 patients (25 M and 4 F), average age was 43.5 y (18-62 y). The age at time of heart transplantation was 43 years (17-55 y). The time after heart transplantation was 3.3 year (0.3-9 y). Spielberger's Questionnaire of Anxiety, Knobloch's inventory of neuroticism, Freiburg's Personality Inventory and Quality of Life Inventory were used, 33% of patients demonstrated increasing frequency and 29% of patients increasing intensity of neurotic symptoms. 23% of patients presented increasing levels of anxiety (as a state). The personality dimensions (depression, excitability and low emotional stability) displayed high frequency. The results showed that patients were more satisfied with family support, with sexual activities, and less satisfied with financial situation, social activities, social isolations, sleep, memory, excitability, fatigue. 41.5% of patients returned back to work. The results indicate that these psychosocial factors play an important role in quality of life after heart transplantation. That is why if is necessary to dedicate an increasing attention to them. (Tab. 1, Fig. 6, Ref. 14.)     

Authenticated routing for ad hoc networks

Initial work in ad hoc routing has considered only the problem of providing efficient mechanisms for finding paths in very dynamic networks, without considering security. Because of this, there are a number of attacks that can be used to manipulate the routing in an ad hoc network. In this paper, we describe these threats, specifically showing their effects on ad hoc on-demand distance vector and dynamic source routing. Our protocol, named authenticated routing for ad hoc networks (ARAN), uses public-key cryptographic mechanisms to defeat all identified attacks. We detail how ARAN can secure routing in environments where nodes are authorized to participate but untrusted to cooperate, as well as environments where participants do not need to be authorized to participate. Through both simulation and experimentation with our publicly available implementation, we characterize and evaluate ARAN and show that it is able to effectively and efficiently discover secure routes within an ad hoc network.     

Risky decision making assessed with the gambling task in adults with HIV.

Decision making was assessed using a laboratory gambling task in 67 adults with the Human Immunodeficiency Virus (HIV+) and in 19 HIV-seronegative (HIV-) control participants. Neurocognitive test performance across several domains was also analyzed to examine potential cognitive mechanisms of gambling task performance. As predicted, the HIV+ group performed worse on the gambling task, indicating greater risky decision making. Specifically, the HIV+ group selected more cards from the "risky" or disadvantageous deck that included relatively large payoffs but infrequent large penalties. The control group also selected such risky cards but quickly learned to avoid them. Exploratory analyses also indicated that in the HIV+ group, but not in the control group, gambling task performance was correlated with Stroop Interference performance and long delay free recall on the California Verbal Learning Test, suggesting the role of inhibitory processes and verbal memory in the poorer gambling task performance in HIV. These findings indicate the usefulness of the gambling task as a laboratory tool to examine risky decision making and cognition in the HIV population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)