Optimum Physical-Layer Frame Size for Maximising the Application-Layer Rateless Code’s Effective Throughput

The tolerable packet-loss ratio of an Internet Protocol (IP) based wireless networks varies according to the specific services considered. File transfer for example must be error free but tolerates higher delays, whereas maintaining a low delay is typically more important in interactive Voice Over IP (VOIP) or video services. Classic Forward Error Correction (FEC) may be applied to the data to provide resilience against bit errors. A wireless IP network provides the opportunity for the inclusion of FEC at the physical, transport and application layers. The demarcation between the analogue and digital domain imposed at the Physical layer (PHY) predetermines the nature of the FEC scheme implemented at the various layers. At the PHY individual packets may be offered FEC protection, which increases the likelihood of their error-free insertion into the protocol stack. Higher layers receive packets that are error free and the purpose of a FEC scheme implemented here is to regenerate any missing packets obliterated for example by the Binary Erasure Channel (BEC) of the IP network’s routers. A rateless code may be beneficially employed at a higher Open Systems Interconnection (OSI) layer for replenishing the obliterated packets, but unless the characteristics of the channel are considered, the ultimate rate achieved by such a code may be compromised, as shown in this contribution

Rehab Tracker: Framework for Monitoring and Enhancing NMES Patient Compliance

We describe the development of a cyber-physical system (Rehab Tracker) for improving patient compliance with at-home physical rehabilitation using neuromuscular electrical stimulation (NMES) therapy. Rehab Tracker consists of three components: 1) hardware modifications to sense and store use data from an FDA-approved NMES therapy device and provide Bluetooth communication capability, 2) an iOS-based smartphone/tablet application to receive and transmit NMES use data and serve as a conduit for patient-provider interactions and 3) a back-end server platform to receive device use data, display compliance data for provider review and provide automated positive and remedial push notifications to patients to improve compliance. This system allows for near real-time compliance monitoring via a secure web portal and offers a novel conduit for patient-provider communication during at-home rehabilitation to improve compliance. The system was tested in patients (n=5) who suffered anterior cruciate ligament rupture and surgical repair to provide proof-of-principal evidence for system functionality and an initial assessment of system usability. The system functioned as designed, recording 89% of rehabilitation sessions. Thus, Rehab Tracker is a functionally correct system with the potential to be used as a tool for studying NMES and mobile communication methodologies at scale and improving compliance with at-home rehabilitation programs

Quantifying the shifted baseline in breeding bird communities for Native American tribes relocated to Oklahoma

Ecosystem services are often recognized for their importance in productivity (e.g., Nitrogen fixation) or biosphere support (Oxygen production from photosynthesis). Cultural ecosystem services (e.g., biodiversity appreciation) are no less important to human well-being but are undervalued when incremental losses go unrecognized by subsequent generations. This phenomenon referred to as generational amnesia or more commonly a shifted baseline of biodiversity understanding. The baseline serves as a control for what is considered normal in that ecosystem and what changes are measured against. Shifted baselines are especially damaging in cultures for which a connection to Nature is emphasized as a point of identity. In the United States, the forced relocation of Native Americans to Oklahoma Territory in the 19th and 20th centuries represents an extreme shifted baseline that severed important biodiversity connections in a single generation. The main purpose of this study was to quantify shifted baselines of breeding bird biodiversity for multiple Native American tribes now based in Oklahoma. The data used for this project was collected through eBird, a volunteer-based citizen science database, from fifteen different tribes who currently have jurisdictions in Oklahoma. Additionally, data from geographic regions where these tribes are originally from prior to their relocation to Oklahoma was also collected. We used beta diversity to quantify estimates of bird community difference and loss between ancestral and Oklahoma lands. Results showed eleven of the fifteen tribes experienced a community dissimilarity over 50% between their ancestral lands and Oklahoma areas. This means these tribes experienced a change in over half of the bird communities, ancestral baseline species, they encountered upon relocation to Oklahoma. This not only shows a significant shift in bird communities experienced by the tribes, but could also provide insight to other drastic shifting baselines these tribes had to endure upon their forced removal from their ancestral lands.Robert E. McNair Post-Baccalaureate Achievement ProgramNational Institute of Food and Agriculture (U.S.)Natural Resource Ecology and Managemen

Chandra and XMM-Newton Observations of NGC 4214: The Hot Interstellar Medium and the Luminosity Function of Dwarf Starbursts

We present results from Chandra and XMM-Newton X-ray observations of NGC 4214, a nearby dwarf starburst galaxy containing several young regions of very active star-formation. Starburst regions are known to be associated with diffuse X-ray emission, and in this case the X-ray emission from the galaxy shows an interesting morphological structure within the galaxy, clearly associated with the central regions of active star-formation. Of the two main regions of star-formation in this galaxy, X-ray emission associated with the older is identified whereas little is detected from the younger, providing an insight into the evolutionary process of the formation of superbubbles around young stellar clusters. The spectra of the diffuse emission from the galaxy can be fitted with a two temperature component thermal model with kT=0.14keV and 0.52keV, and analysis of this emission suggests that NGC 4214 will suffer a blow-out in the future. The point source population of the galaxy has an X-ray luminosity function with a slope of -0.76. This result, together with those for other dwarf starburst galaxies (NGC 4449 and NGC 5253), was added to a sample of luminosity functions for spiral and starburst galaxies. The slope of the luminosity function of dwarf starbursts is seen to be similar to that of their larger counterparts and clearly flatter than those seen in spirals. Further comparisons between the luminosity functions of starbursts and spiral galaxies are also made.Comment: 16 pages, 12 figures. Accepted for publication in MNRA