Network mobility and protocol interoperability in ad hoc networks

The integration of various network-level functions, including routing, management, and security, is critical to the efficient operation of a mobile ad hoc network. In this article we focus on network mobility (rather than node mobility), implying the movement of entire subnetworks with respect to one another, while individual users initially associated with one such subnetwork may also move to other domains. One example is a battlefield network that includes ships, aircraft, and ground troops. In this "network of networks", subnets (e.g. shipboard networks) may be interconnected via a terrestrial mobile wireless network (e.g., between moving ships). We discuss the design and implementation of a new ad hoc routing protocol, a suite of solutions for policy-based network management, and approaches for key management and deployment of IPsec in a MANET. These solutions, in turn, are integrated with real-time middleware, a secure radio link, and a topology monitoring tool. We briefly describe each component of the solution, and focus on the challenges and approaches to integrating these components into a cohesive system to support network mobility. We evaluate the effectiveness of the system through experiments conducted in a wireless ad hoc testbed.     

Amplified enzyme-linked-immunofilter assays enable detection of 50-10(5) bacterial cells within 1 hour

1. The hydrolysis of organophosphate pesticides (OP) and nerve gases by serum paraoxonase (PON1) is an important factor determining their toxicity to mammals including man. The PON1 gene contains 2 polymorphic sites at amino acid positions 55 (L-->M) and 192 (G-->A, classically defined as the A and B genotypes) which result in several alloenzymes of PON1 in human serum. 2. The 192 polymorphism has previously been shown to affect PON1 activity. We have investigated the effect of both polymorphisms on the hydrolysis of paraoxon by serum from 279 healthy human subjects. 3. The 55 polymorphism significantly influenced PON1 activity. MM homozygotes had over 50% less activity towards paraoxon compared to the LL and LM genotypes regardless of the 192 genotype (P < 0.001). 4. Multiple regression analysis indicated that the 192 polymorphism, 55 polymorphism and serum PON1 concentration were responsible for 46, 16 and 13% of the variation in PON1 activity, respectively (all P < 0.001). None of the other parameters investigated significantly affected PON1 activity. 5. Therefore both PON1 polymorphisms affect the hydrolysis of paraoxon. AA/MM and AB/MM individuals may be potentially more susceptible to OP intoxication. 6. Genotyping individuals for both PON1 polymorphisms may provide a method for identifying those individuals at most risk of OP poisoning. The effect of PON1 polymorphisms on activity may also explain why some Gulf War Veterans have developed Gulf War Syndrome and some have not.     

Heterodyne performance of a quasioptical Schottky diode detector: Theoretical and experimental results

A detailed theoretical and experimental study of the heterodyne performance of a quasioptical Schottky diode detector is presented. The experimental results have been obtained by mixing the radiation from a FIR laser with the output of a 67–73 GHz Klystron. The heterodyne signal variation versus various parameters and its relation to the special case of two lasers mixing are described. The mixer characteristics are a NEP value of 2×10^?19W/Hz and a detector bandwidth of at least 9 GHz. Experimental evidence of harmonics generation of submillimetric frequencies at the diode junction is also presented.     

Adolescent sex offenders.

In this article, we review the research literature on sexual offenses committed by adolescents. Given the large number of adolescent sex offenders and the even larger number of their victims, most of whom are younger children, this is a subject matter in need of much more empirical study than it has so far received. Topics covered are incidence statistics, offense and victim characteristics, offender characteristics, and recidivism and treatment. Gaps between the clinical and research literature are highlighted and recommendations for future research are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Determinants of Home Price Appreciation Among Community Reinvestment Homeowners

Homeownership is considered an effective wealth creation mechanism for low-income households. This study examines the appreciation of homes purchased with community reinvestment loans in a national pilot in the USA called the Community Advantage Program (CAP). Homes purchased between 1998 and 2002 are found to have appreciated at a median annual rate of 5.4% between the time of purchase and spring 2003. This is less than the national house price appreciation index of 7.0% (covering 1998–2003) but higher than other types of investments such as the Dow Jones Index (2.78% annual growth rate) and the average rate on a 6-month CD (4.34%) over the same time period. The median increase in net housing wealth of the Community Advantage homeowners is $17 492. Returns have been particularly impressive for the lowest-income borrowers. Borrowers with less than $20 000 in annual household income at the time of purchase had a median down-payment of $1790 and have experienced a median equity increase of $24 724. Price and equity appreciation rates for African Americans are solid, but are about 10% lower than for whites.     

Comparison of professional judgment versus an algorithm for nutrition status classification

OBJECTIVES: The classification of a patient's nutrition status is important for identifying patients who require nutrition care, for designing effective nutrition interventions, and for measuring severity of illness. The objective of this study was to evaluate the reliability and validity of two variants of the Department of Veterans Affairs' nutrition status classification: professional judgment versus an algorithm. METHODS: The study consisted of two phases, both of which included providing a sample of approximately 60 registered dietitians and 60 clinical dietetic technicians with data on 16 (phase I) and 20 (phase II) patients, to which they assigned nutrition statuses using both professional judgment and the algorithm. Improvements in instructions and training were implemented between the two phases. Interrater reliability of the responses was calculated, and content validity was measured by comparing the staff's responses with those of an expert panel. RESULTS: Reliability improved significantly between phases for both professional judgment and the algorithm. Greater reliability and validity were observed with use of the algorithm, by both dietitians and technicians, during both phases. CONCLUSION: Classification of a patient's nutrition status is important in the delivery of cost-effective health care. The Department of Veterans Affairs' nutrition status classification is a good one for assessing nutrition status quickly and reliably, especially when an algorithm is used. The results underscore the advantages of a classification system based on an algorithm when the system is designed to be used by many different staff across multiple facilities.     

Autoactivation of procaspase-9 by Apaf-1-mediated oligomerization

Activation of procaspase-9 by Apaf-1 in the cytochrome c/dATP-dependent pathway requires proteolytic cleavage to generate the mature caspase molecule. To elucidate the mechanism of activation of procaspase-9 by Apaf-1, we designed an in vitro Apaf-1-procaspase-9 activation system using recombinant components. Here, we show that deletion of the Apaf-1 WD-40 repeats makes Apaf-1 constitutively active and capable of processing procaspase-9 independent of cytochrome c an dATP. Apaf-1-mediated processing of procaspase-9 occurs at Asp-315 by an intrinsic autocatalytic activity of procaspase-9 itself. We provide evidence that Apaf-1 can form oligomers and may facilitate procaspase-9 autoactivation by oligomerizing its precursor molecules. Once activated, caspase-9 can initiate a caspase cascade involving the downstream executioners caspase-3, -6, and -7.     

Cytokine induction of platelet activation

A three-dimensional, two-part model of the foot, for use in a simulation of human gait, is presented. Previous simulations of gait have not included the foot segment (e.g. Siegler et al., 1982, J. Biomechanics 15, 415-425) or have fastened it to the ground (e.g. Onyshko and Winter, 1980, J. Biomechanics 13, 361-368). A foot model based on viscoelastic elements (e.g. Meglan, 1991, Ph.D. thesis, Ohio State Univ.), allows more freedom of movement and thus models the physical system more closely. The current model was developed by running simulations of the foot in isolation from just before heel contact to just after toe-off. The driving inputs to the simulation were the resultant ankle joint forces and moments taken from a gait analysis. Nine linear, vertically oriented spring/damper systems, positioned along the midline of the foot were used to model the combined viscoelastic behaviour of the foot, shoe and floor. Associated with each vertical spring/damper system were two orthogonally placed, linear, horizontal dampers used to provide the shear components of the ground reaction force. Torques at the metatarsal-phalangeal joint were supplied by a linear, torsional spring and damper. Control about the vertical axis and the long axis of the foot was achieved by the use of linear, torsional dampers. The predicted kinetic and kinematic values are very similar to those taken from the gait analysis. The model represents an improvement over previous work because the transition from swing to stance was smooth and continuous without the foot being constrained to any specific trajectory.