32 channel WDM multiplexer with 1 nm channel spacing and 0.7 nm bandwidth

A high density WDM multiplexer capable of combining 32 channels spaced 1 nm apart onto a monomode fibre is reported. The multiplexer incorporates a microlens array to give a channel bandwidth of 0.7 nm. The wavelength range of operation is 1.5285 mu m to 1.5595 mu m, within the erbium fibre amplification range. The mean insertion loss over the 32 channels is 6.7 dB and the polarisation sensitivity is less than 0.7 dB.<>     

Psychological aspects of severe burn injuries in children.

Discusses 4 phases of the traumatic process associated with severe burn injuries in children. Predisposing factors (i.e., emotional disturbances) in the preinjury phase are discussed. The acute phase centers on treatment directed toward physiological stabilization. The intermediate phase, in which skin grafts and other painful medical procedures are performed, is characterized by dependency on adults and regression, behavior problems, and such emotional reactions as blaming the parents. Strategies for preparing children for and helping them cope with pain are discussed. The rehabilitative phase often involves difficulties in social readjustment. Strategies for dealing with each phase are presented, most of which focus on prevention efforts. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mobile data services — voices in the wilderness

Killer applications or services tend to be a combination of inspiration, form, function and a solution to unmet need. The mobile phone and the iPod are obvious examples, but what will be the next killer application and why. Increasingly, convergence will add a new dimension to the quest for such an application. This paper considers that it may just be time for more than voices in the wilderness.     

Fatty acids and eicosanoids regulate gene expression through direct interactions with peroxisome proliferator-activated receptors alpha and gamma

Peroxisome proliferator-activated receptors (PPARs) alpha and gamma are key regulators of lipid homeostasis and are activated by a structurally diverse group of compounds including fatty acids, eicosanoids, and hypolipidemic drugs such as fibrates and thiazolidinediones. While thiazolidinediones and 15-deoxy-Delta12, 14-prostaglandin J2 have been shown to bind to PPARgamma, it has remained unclear whether other activators mediate their effects through direct interactions with the PPARs or via indirect mechanisms. Here, we describe a novel fibrate, designated GW2331, that is a high-affinity ligand for both PPARalpha and PPARgamma. Using GW2331 as a radioligand in competition binding assays, we show that certain mono- and polyunsaturated fatty acids bind directly to PPARalpha and PPARgamma at physiological concentrations, and that the eicosanoids 8(S)-hydroxyeicosatetraenoic acid and 15-deoxy-Delta12,14-prostaglandin J2 can function as subtype-selective ligands for PPARalpha and PPARgamma, respectively. These data provide evidence that PPARs serve as physiological sensors of lipid levels and suggest a molecular mechanism whereby dietary fatty acids can modulate lipid homeostasis.     

Multi-rate power-controlled link scheduling for mesh broadband wireless access networks

The problem of multi-rate power-controlled collision-free scheduling in spatial time division multiple access (STDMA) wireless mesh networks is formulated as a mathematical program utilising cross layer information. As these mixed integer linear programs are intractable (NP-hard problems), optimal collision-free schedules can be found only for topologies consisting of a few nodes. To this end, approximation algorithms that are based on linear programming relaxation and randomised rounding are studied. The proposed framework, which aims to maximise the spatial timeslot reuse under predefined signal-to-interference noise ratio thresholds, is suitable for providing centralised scheduling in the mesh mode of the IEEE 802.16 standard. Performance aspects of the approximation algorithms under different scenarios are investigated.     

Optical wireless: the story so far

We present a broad review of the optical wireless field, from early experiments through to today's high-performance systems. Emphasis is placed on understanding the benefits and limitations of optical wireless, all of which ultimately define the applications. A variety of systems are examined, each incorporating a different technological solution to suit the particular application     

Comparing apples and oranges: Off‐road pedestrian detection on the National Robotics Engineering Center agricultural person‐detection dataset

Person detection from vehicles has made rapid progress recently with the advent of multiple high‐quality datasets of urban and highway driving, yet no large‐scale benchmark is available for the same problem in off‐road or agricultural environments. Here we present the National Robotics Engineering Center (NREC) Agricultural Person‐Detection Dataset to spur research in these environments. It consists of labeled stereo video of people in orange and apple orchards taken from two perception platforms (a tractor and a pickup truck), along with vehicle position data from Real Time Kinetic (RTK) GPS. We define a benchmark on part of the dataset that combines a total of 76k labeled person images and 19k sampled person‐free images. The dataset highlights several key challenges of the domain, including varying environment, substantial occlusion by vegetation, people in motion and in nonstandard poses, and people seen from a variety of distances; metadata are included to allow targeted evaluation of each of these effects. Finally, we present baseline detection performance results for three leading approaches from urban pedestrian detection and our own convolutional neural network approach that benefits from the incorporation of additional image context. We show that the success of existing approaches on urban data does not transfer directly to this domain.     

Transparent IP radio access for next-generation mobile networks

Advances in network architecture, enhancements in signaling protocols, provisioning of end-to-end QoS, worldwide seamless mobility, and flexible service provision are among the major research challenges toward next-generation wireless networks. The integration and interoperability of all these technologies, along with new truly broadband wireless innovations and intelligent user-oriented services will lead toward the so-called 4G wireless networks. In this article we identify the key issues of an innovative transparent IP radio access system that targets 4G networks.