TMB: Automatic Differentiation and Laplace Approximation

TMB is an open source R package that enables quick implementation of complex nonlinear random effect (latent variable) models in a manner similar to the established AD Model Builder package (ADMB, admb-project.org). In addition, it offers easy access to parallel computations. The user defines the joint likelihood for the data and the random effects as a C++ template function, while all the other operations are done in R; e.g., reading in the data. The package evaluates and maximizes the Laplace approximation of the marginal likelihood where the random effects are automatically integrated out. This approximation, and its derivatives, are obtained using automatic differentiation (up to order three) of the joint likelihood. The computations are designed to be fast for problems with many random effects (~10^6) and parameters (~10^3). Computation times using ADMB and TMB are compared on a suite of examples ranging from simple models to large spatial models where the random effects are a Gaussian random field. Speedups ranging from 1.5 to about 100 are obtained with increasing gains for large problems. The package and examples are available at http://tmb-project.org

Nested Radar Systems for Remote Coastal Observations

Advances in radar technology now allow the observation of sea surface features at multiple scales, from kilometers, down to metres. In the same manner that nested models are used at different resolutions, nested radars of different frequencies can be used to provide data on sea surface features at various resolutions. A new radar system in the millimeter wave-band has now been demonstrated with a resolution of <1m. This MMW-radar was deployed in a nested configuration with an X-band marine radar from a beach near Faro in Portugal. The results from the two systems show how the MMW-radar can image fine detail surf zone and swash processes to a range of O(200m), while the marine radar provides lower resolution images of O(10m) to longer ranges of O(2km). Data from the two nested radars are shown from a recent deployment on a barrier beach in the Ria Formosa region of the Algarve, Portugal. The data from these nested radars are analysed to map wavelengths in 2-D and a non-linear bathymetric inversion is used on both sets of data to estimate the bathymetry of the imaged area. Comparisons with in-situ surveys demonstrate the accuracy of this technique

Unnecessary Workup of Asymptomatic Neonates in the Era of Group B Streptococcus Prophylaxis

Asymptomatic term neonates born to mothers who are Group B Streptococcus (GBS) unknown or GBS positive but “inadequately” treated prior to delivery do not require invasive laboratory evaluation. We conducted a retrospective cohort study of mother/baby dyads born from January 1, 2005 until September 30, 2007 at the Medical College of Georgia. Their current protocol is to obtain a Complete Blood Count with Differential (CBC with D), Blood Culture (BC), and C-reactive protein (CRP) after birth. Mother/baby dyads (n = 242) that met inclusion criteria were reviewed. Of these 242 babies 25 (10%) were started on antibiotics after the initial lab values were known. None of the blood cultures were positive and the CRP's were normal. The 2002 GBS guidelines call for laboratory evaluation of “at-risk” neonates, but the workup of these babies is not only costly, it does not provide any advantage over old fashioned clinical observation for the evaluation and treatment of early onset GBS sepsis

The Evolution of Protoplanetary Disks Around Millisecond Pulsars: The PSR 1257 +12 System

We model the evolution of protoplanetary disks surrounding millisecond pulsars, using PSR 1257+12 as a test case. Initial conditions were chosen to correspond to initial angular momenta expected for supernova-fallback disks and disks formed from the tidal disruption of a companion star. Models were run under two models for the viscous evolution of disks: fully viscous and layered accretion disk models. Supernova-fallback disks result in a distribution of solids confined to within 1-2 AU and produce the requisite material to form the three known planets surrounding PSR 1257+12. Tidal disruption disks tend to slightly underproduce solids interior to 1 AU, required for forming the pulsar planets, while overproducing the amount of solids where no body, lunar mass or greater, exists. Disks evolving under 'layered' accretion spread somewhat less and deposit a higher column density of solids into the disk. In all cases, circumpulsar gas dissipates on $\lesssim 10^{5}$ year timescales, making formation of gas giant planets highly unlikely.Comment: 16 pages, 17 figures, Accepted for publication in The Astrophysical Journal (September 20, 2007 issue

Grapevine Remote Sensing Analysis of Phylloxera Early Stress (GRAPES): Remote Sensing Analysis Summary

High spatial resolution airborne imagery was acquired in California's Napa Valley in 1993 and 1994 as part of the Grapevine Remote sensing Analysis of Phylloxera Early Stress (GRAPES) project. Investigators from NASA, the University of California, the California State University, and Robert Mondavi Winery examined the application of airborne digital imaging technology to vineyard management, with emphasis on detecting the phylloxera infestation in California vineyards. Because the root louse causes vine stress that leads to grapevine death in three to five years, the infested areas must be replanted with resistant rootstock. Early detection of infestation and changing cultural practices can compensate for vine damage. Vineyard managers need improved information to decide where and when to replant fields or sections of fields to minimize crop financial losses. Annual relative changes in leaf area due to phylloxera infestation were determined by using information obtained from computing Normalized Difference Vegetation Index (NDVI) images. Two other methods of monitoring vineyards through imagery were also investigated: optical sensing of the Red Edge Inflection Point (REIP), and thermal sensing. These did not convey the stress patterns as well as the NDVI imagery and require specialized sensor configurations. NDVI-derived products are recommended for monitoring phylloxera infestations

Functional Mobility Outcomes in Telehealth and In-Person Assessments for Wheeled Mobility Devices

The purpose of this study was to compare telehealth and in-person service delivery models for wheeled mobility devices in terms of functional outcomes. We hypothesized that clinically significant improvements in functional mobility measured by the Functional Mobility Assessment (FMA) will occur in individuals receiving both telehealth and in-person clinic evaluations. A total of 27 Veterans receiving telehealth visits were compared to 27 individuals seen in clinic, selected from a database, matching for age, gender, and primary diagnosis. All mean individual item and total FMA scores in both groups increased from Time 1 to Time 2. Within the telehealth group, all changes in individual item and total FMA scores were statistically significant, with changes in 8 of 10 items meeting threshold for clinical significance (change &gt;1.85 points). Within the clinic group, changes in 7 of 10 individual items and total FMA scores were statistically significant, and these same 7 items met threshold for clinical significance. Change scores for individual item and total FMA scores did not differ significantly between the two groups. A larger and clinically significant change in transfer score was seen in the telehealth group, suggesting telehealth visits may confer an advantage in being able to assess and address transfer issues in the home

Simulated firefighting task performance and physiology under very hot conditions

Purpose: To assess the impact of very hot (45°C) conditions on the performance of, and physiological responses to, a simulated firefighting manual-handling task compared to the same work in a temperate environment (18°C). Methods: Ten male volunteer firefighters performed a 3-h protocol in both 18°C (CON) and 45°C (VH). Participants intermittently performed 12 × 1-min bouts of raking, 6 × 8-min bouts of low-intensity stepping, and 6 × 20-min rest periods. The area cleared during the raking task determined work performance. Core temperature, skin temperature, and heart rate were measured continuously. Participants also periodically rated their perceived exertion (RPE) and thermal sensation. Firefighters consumed water ad libitum. Urine specific gravity (USG) and changes in body mass determined hydration status. Results: Firefighters raked 19% less debris during the VH condition. Core and skin temperature were 0.99 ± 0.20 and 5.45 ± 0.53°C higher, respectively, during the VH trial, and heart rate was 14–36 beats.min−1 higher in the VH trial. Firefighters consumed 2950 ± 1034 mL of water in the VH condition, compared to 1290 ± 525 in the CON trial. Sweat losses were higher in the VH (1886 ± 474 mL) compared to the CON trial (462 ± 392 mL), though both groups were hydrated upon protocol completion (USG < 1.020). Participants' average RPE was higher in the VH (15.6 ± 0.9) compared to the CON trial (12.6 ± 0.9). Similarly, the firefighers' thermal sensation scores were significantly higher in the VH (6.4 ± 0.5) compared to the CON trial (4.4 ± 0.4). Conclusions: Despite the decreased work output and aggressive fluid replacement observed in the VH trial, firefighters' experienced increases in thermal stress, and exertion. Fire agencies should prioritize the health and safety of fire personnel in very hot temperatures, and consider the impact of reduced productivity on fire suppression efforts

New discoveries at Woolsey Mound, MC118, northern Gulf of Mexico

Woolsey Mound, a 1km-diameter carbonate-gas hydrate complex in the northern Gulf of Mexico, is the site of the Gulf’s only seafloor monitoring station-observatory in its only research reserve, Mississippi Canyon 118. Active venting, outcropping hydrate, and a thriving chemosynthetic community recommend the site for study. Since 2005, the Gulf of Mexico Hydrates Research Consortium has been conducting multidisciplinary studies to 1. Characterize the site, 2. Establish a facility for real-time monitoring-observing of gas hydrates in a natural setting, 3. Study the effects of gas hydrates on seafloor stability, 4. Establish fluid migration routes and estimates of fluid-flux at the site, 5. Establish the interrelationships between the organisms at the vent site and the association-dissociation of hydrates. A variety of novel geological, geophysical, geochemical and biological studies has been designed and conducted, some in survey mode, others in monitoring mode. Geophysical studies involving merging multiple seismic data acquisition systems accompanied by the application of custom processing techniques verify communication of surface features with deep structures. Supporting geological data derive from innovative recovery techniques. Geochemical sensors, used experimentally in survey mode, including aboard an AUV, double as monitoring devices. A suite of pore-fluid sampling devices has returned data that capture change at the site in daily increments; using only noise as an energy source, hydrophones have returned daily fluctuations in physical properties. Ever-expanding capabilities of a custom-ROV have been determined by research needs. Processing of new as well as conventional data via unconventional means has resulted in the discovery of new features…..vents, faults, benthic fauna…..and modification of others including pockmarks, hydrate outcrops, vent activity, and water-column chemical plumes. Though real-time monitoring awaits communications and power link to land, periodic data-collection reveals a carbonate-hydrate mound, part of an immensely complex hydrocarbon system

Assets and Needs Assessment of Senior Residents in the West Bloomington Neighborhood

The experience and process of aging has become a prominent topic of discussion nationwide and Central Illinois is no exception, due to the rapid growth within the senior population in the area. The 60 and over population of Illinois is projected to grow by 87% during the next 30 years (The Maturing of Illinois). An initiative has been developed to evaluate how prepared local communities are for older adults by conducting needs assessments, which can also serve as vital tools for those who plan and provide human services in communities. Often community leaders will form policies and allocate limited resources based on assumptions about the needs of the senior population and outdated information (Parsons and Higley 1995). This report is part of a larger needs assessment that will serve as a resource for community leaders to use in future policies and projects that will involve senior West Bloomington residents. This report examines needs of the senior population of West Bloomington as well as how organizations provide for those needs as evaluated by the senior population themselves. Based on our findings and recognizing the limitations of the study, we make recommendations for action and future research

The effects of simulated wildland firefighting tasks on core temperature and cognitive function under very hot conditions

Background: The severity of wildland fires is increasing due to continually hotter and drier summers. Firefighters are required to make life altering decisions on the fireground, which requires analytical thinking, problem solving, and situational awareness. This study aimed to determine the effects of very hot (45&deg;C; HOT) conditions on cognitive function following periods of simulated wildfire suppression work when compared to a temperate environment (18&deg;C; CON). Methods: Ten male volunteer firefighters intermittently performed a simulated fireground task for 3 h in both the CON and HOT environments, with cognitive function tests (paired associates learning and spatial span) assessed at baseline (cog 1) and during the final 20-min of each hour (cog 2, 3, and 4). Reaction time was also assessed at cog 1 and cog 4. Pre- and post- body mass were recorded, and core and skin temperature were measured continuously throughout the protocol. Results: There were no differences between the CON and HOT trials for any of the cognitive assessments, regardless of complexity. While core temperature reached 38.7&deg;C in the HOT (compared to only 37.5&deg;C in the CON; p &lt; 0.01), core temperature declined during the cognitive assessments in both conditions (at a rate of -0.15 &plusmn; 0.20&deg;C&middot;hr-1 and -0.63 &plusmn; 0.12&deg;C&middot;hr-1 in the HOT and CON trial respectively). Firefighters also maintained their pre-exercise body mass in both conditions, indicating euhydration. Conclusions: It is likely that this maintenance of euhydration and the relative drop in core temperature experienced between physical work bouts was responsible for the preservation of firefighters\u27 cognitive function in the present study