Internet Protocol Version 6

With the explosion of the World Wide Web and email the 32-bit addresses Internet Protocol version 4 used would run out in the not-so-distant future. In 1994, the Internet Engineering Task Force (IETF) established a working group to define the successor to IPv4, IPv6. In March 2008 the US government issued a memorandum requiring that by June 2008 "all agencies' infrastructure must be using IPv6. This article provides the rationale for the US government's edict, along with the technical features that distinguish IPv6 from its predecessor, IPv4.     

Contingency management is efficacious for cocaine abusers with prior treatment attempts.

Efforts are underway to detect subgroups who may be more or less responsive to contingency management (CM) substance abuse treatments. This study examined the impact of prior treatment attempts on primary and posttreatment outcomes in a combined sample of cocaine abusers randomized to standard care substance abuse outpatient treatment (SC) or SC plus CM. Participants (N = 393) were categorized according to self-reported prior treatment attempts (0-1, ≥2). Participants with multiple prior treatment attempts were older, had more severe alcohol and cocaine use disorders, and had greater employment-related problems. Participants with 0?1 prior treatment attempts had comparable treatment retention, regardless of treatment condition; however, among participants with multiple prior treatment attempts, retention was greater for CM than SC. A similar, but nonsignificant (p = .08) pattern was evident for longest duration of abstinence (LDA). LDA was a significant predictor of negative (for cocaine, alcohol, and opiates) specimen results at Month 9. The results provide support for CM as an advantageous option for individuals with multiple prior treatment attempts, as well as for substance abuse treatment patients in general. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Costs of managing anemia with erythropoiesis‐stimulating agents during hemodialysis: A time and motion study

Use of erythropoiesis‐stimulating agents (ESAs) presents a significant time and cost burden in the management of anemia of chronic kidney disease (CKD). We conducted a prospective, observational, activity‐based costing study to estimate the health care personnel time and resulting direct medical costs associated with administering epoetin 3 times weekly to patients with end‐stage renal disease on dialysis. The study was conducted at 5 US hemodialysis centers. The personnel time and costs were derived from time and motion observations. Predicted time and cost savings were modeled for switching patients to once‐monthly ESA therapy. Patients also completed a survey questionnaire to assess their level of CKD knowledge and information needs. Total per‐patient‐per‐year (PPPY) time expended on anemia management with epoetin averaged 608 minutes (range 512–915 minutes), with an average PPPY cost of $548 (range $342–$651). Use of a once‐monthly ESA, compared with epoetin, could decrease average PPPY time expenditure by 79% (127 minutes [range 96–173 minutes]) and reduce PPPY costs by 81% ($104 [range $79–$136]). The patient questionnaire reported insufficient education on CKD. Use of a once‐monthly ESA to correct anemia in dialysis patients may provide substantial time, resource, and cost savings compared with current treatment practices.     

On the suitability of dynamic languages for hot‐reprogramming a robotics framework: a Python case study

The development of service robots has gained more attention over the last years. Advanced robots have to cope with many different situations emerging at runtime, while executing complex tasks. They should be programmed as dynamically adaptive systems, capable of adapting themselves to the execution environment, including the computing, user, and physical environment. Recently, dynamic languages are becoming widely used because of the high runtime adaptability they offer. Therefore, we have analyzed the suitability of these languages to implement robotic systems with high runtime adaptability requirements, using Python as case study because of its maturity. To evaluate their suitability, we have implemented a reflective robotics framework that can be programmed in both Java and any dynamic language supported by the standard Java Scripting API. An example scenario has been developed using Python to show how its distinguishing meta‐programming features have facilitated the development of runtime‐adaptable robotics services. Copyright © 2012 John Wiley & Sons, Ltd.     

A statistical model including age to predict passenger postures in the rear seats of automobiles

Few statistical models of rear seat passenger posture have been published, and none has taken into account the effects of occupant age. This study developed new statistical models for predicting passenger postures in the rear seats of automobiles. Postures of 89 adults with a wide range of age and body size were measured in a laboratory mock-up in seven seat configurations. Posture-prediction models for female and male passengers were separately developed by stepwise regression using age, body dimensions, seat configurations and two-way interactions as potential predictors. Passenger posture was significantly associated with age and the effects of other two-way interaction variables depended on age. A set of posture-prediction models are presented for women and men, and the prediction results are compared with previously published models. This study is the first study of passenger posture to include a large cohort of older passengers and the first to report a significant effect of age for adults. The presented models can be used to position computational and physical human models for vehicle design and assessment.

Practitioner Summary:

The significant effects of age, body dimensions and seat configuration on rear seat passenger posture were identified. The models can be used to accurately position computational human models or crash test dummies for older passengers in known rear seat configurations.     

Generating effective tests for concurrent programs via AI automated planning techniques

Testing concurrent programs is a challenging problem due to interleaving explosion: even for a fixed set of inputs, there is a huge number of concurrent runs that need to be tested to account for scheduler behavior. Testing all possible schedules is not practical. Consequently, most effective testing algorithms only test a select subset of runs. For example, limiting testing to runs that contain data races or atomicity violations has been shown to capture a large proportion of concurrency bugs. In this paper we present a general approach to concurrent program testing that is based on techniques from artificial intelligence (AI) automated planning. We propose a framework for predicting concurrent program runs that violate a collection of generic correctness specifications for concurrent programs, namely runs that contain data races, atomicity violations, or null-pointer dereferences. Our prediction is based on observing an arbitrary run of the program, and using information collected from this run to model the behavior of the program, and to predict new runs that contain bugs with one of the above noted violation patterns. We characterize the problem of predicting such new runs as an AI sequential planning problem with the temporally extended goal of achieving a particular violation pattern. In contrast to many state-of-the-art approaches, in our approach feasibility of the predicted runs is guaranteed and, therefore, all generated runs are fully usable for testing. Moreover, our planning-based approach has the merit that it can easily accommodate a variety of violation patterns which serve as the selection criteria for guiding search in the state space of concurrent runs. This is achieved by simply modifying the planning goal. We have implemented our approach using state-of-the-art AI planning techniques and tested it within the Penelope concurrent program testing framework [35]. Nevertheless, the approach is general and is amenable to a variety of program testing frameworks. Our experiments with a benchmark suite showed that our approach is very fast and highly effective, finding all known bugs.     

Effect of medium-chain triglycerides on calbindin-D9k expression in the intestine

These studies determined the effect of the saturated fat source in infant formula on the expression of calbindin-D9k (CaBP-9k). Piglets were fed from birth to 8 d with milk or formula containing saturated fatty acids as medium-chain triglycerides (MCT), coconut oil, palm oil (Palm 1), or synthesized triglycerides with 16∶0 directed to thesn-2 position (Palm 2). Levels of intestinal CaBP-9k mRNA were significantly (P<0.01) higher in piglets fed formula with MCT than in piglets fed the other formula or milk; and higher in piglets fed the Palm-1 than in piglets fed Palm-2 formula. This is the first evidence that MCT alter piglet intestinal CaBP-9k mRNA.     

Strong Photoacoustic Signal Enhancement by Coating Gold Nanoparticles with Melanin for Biomedical Imaging

Photoacoustics is a powerful biomedical imaging and detection technique, because it is a noninvasive, nonionizing, and low‐cost method facilitating deep tissue penetration. However, suitable contrast agents need to be developed to increase the contrast for in vivo imaging. Gold nanoparticles are often discussed as potential sonophores due to their large absorption cross‐section and their tunable plasmon resonance. However, disadvantages such as toxicity and low photoacoustic efficiency in the tissue transparency window prevail, preventing their clinical application. As a result, there remains a strong need to develop colloidal photoacoustic contrast agents which absorb in the tissue transparency window, exhibit high photoacoustic signal, and are biocompatible. Here, a facile synthetic approach is presented to produce melanin shells around various gold nanoparticle geometries, from spheres to stars and rods. These hybrid particles show excellent dispersability, better biocompatibility, and augmented photoacoustic responses over the pure melanin or pristine gold particles, with a rod‐shape geometry leading to the highest performance. These experimental results are corroborated using numerical calculations and explain the improved photoacoustic performance with a thermal confinement effect. The applicability of melanin coated gold nanorods as gastrointestinal imaging probes in mouse intestine is showcased.