Implementation of the Articulated Total Body (ATB) Model on an Apollo Workstation

The Articulated Total Body Model (ATB) is used for predicting gross segmented body response in various dynamic environments. The ATB computer program, originally written by the Department of Transportation as a Crash Victim Simulation (CVS) program, was later modified by the Calspan Corporation and More recently by the Armstrong Aerospace Medical Research Laboratory (AAMRL) to allow for aerodynamic force applications, harness belt capabilities and hyper-ellipsoidal graphical display of the modeled segments. The ATB model has been successfully used to investigate gross human body responses to bodies placed in such complex dynamic environments as high-speed aircraft ejection. This ATB model is quite versatile due to the variety of inputs it can handle. Because of this versatility , a wide range of physical systems may be simulated. In this work, the ATB computer program has been modified for use on the Apollo workstation and utilized to predict limb and joint limitations a modeled human arm for the purpose of creating more effective rehabilitation schedules. A patient’s left shoulder, left-upper and left-lower arm have been modeled for a case study. The required information consists of segment physical dimensions, weight .center of gravity and maximum forces and torques obtainable from various body muscles. From this information, forces a graphical display of desired segment positions, and numerical approximations of forces, torques, positions, velocities, and accelerations of any desired point of the modeled segment. A comparison of this numerical output found from the ATB will be made with actual patient response, further input will be created tracking the patient\u27s rehabilitation progress. A mathematical model of this will be incorporated into the ATB for the purpose of predicting future patient responses and a predicted schedule for disabled patient rehabilitation.An accurate numerical and visual prediction of patient responses and limitations would be very beneficial in the creation of rehabilitation schedules. For such a service to be obtainable in a hospital environment, the ATB must be executable on a personal computing level. The Apollo workstation was selected for this project due to its relative mobility and availability. Many similar computing systems could be used where the criteria of mobility, large memory capabilities and superior graphics are obtainable. These criteria must be met so that the ATB could eventually be used by physicians in a clinic or office environment

Current forest carbon fixation fuels stream CO2 emissions

Stream CO2 emissions contribute significantly to atmospheric climate forcing. While there are strong indications that groundwater inputs sustain these emissions, the specific biogeochemical pathways and timescales involved in this lateral CO2 export are still obscure. Here, via an extensive radiocarbon (14C) characterisation of CO2 and DOC in stream water and its groundwater sources in an old-growth boreal forest, we demonstrate that the 14C-CO2 is consistently in tune with the current atmospheric 14C-CO2 level and shows little association with the 14C-DOC in the same waters. Our findings thus indicate that stream CO2 emissions act as a shortcut that returns CO2 recently fixed by the forest vegetation to the atmosphere. Our results expose a positive feedback mechanism within the C budget of forested catchments, where stream CO2 emissions will be highly sensitive to changes in forest C allocation patterns associated with climate and land-use changes

Energy input is primary controller of methane bubbling in subarctic lakes

Emission of methane (CH4) from surface waters is often dominated by ebullition (bubbling), a transport mode with high‐spatiotemporal variability. Based on new and extensive CH4 ebullition data, we demonstrate striking correlations (r2 between 0.92 and 0.997) when comparing seasonal bubble CH4 flux from three shallow subarctic lakes to four readily measurable proxies of incoming energy flux and daily flux magnitudes to surface sediment temperature (r2 between 0.86 and 0.94). Our results after continuous multiyear sampling suggest that CH4 ebullition is a predictable process, and that heat flux into the lakes is the dominant driver of gas production and release. Future changes in the energy received by lakes and ponds due to shorter ice‐covered seasons will predictably alter the ebullitive CH4 flux from freshwater systems across northern landscapes. This finding is critical for our understanding of the dynamics of radiatively important trace gas sources and associated climate feedback

Carbon dioxide transport across the hillslope-riparian-stream continuum in a boreal headwater catchment

Headwater streams export CO2 as lateral downstream export and vertical evasion from the stream surface. CO2 in boreal headwater streams generally originates from adjacent terrestrial areas, so determining the sources and rate of CO2 transport along the hillslope–riparian–stream continuum could improve estimates of CO2 export via the aquatic pathway, especially by quantifying evasion at higher temporal resolutions. Continuous measurements of dissolved CO2 concentrations and water table were made along the hillslope–riparian–stream continuum in the Västrabäcken sub-catchment of the Krycklan catchment, Sweden. Daily water and CO2 export from the hillslope and riparian zone were estimated over one hydrological year (October 2012–September 2013) using a flow-concentration model and compared with measured lateral downstream CO2 export. Total water export over the hydrological year from the hillslope was 230 mm yr−1 compared with 270 mm yr−1 from the riparian zone. This corresponds well (proportional to the relative upslope contributing area) to the annual catchment runoff of 265 mm yr−1. Total CO2 export from the riparian zone to the stream was 3.0 g CO2-C m−2 yr−1. A hotspot for riparian CO2 export was observed at 30–50 cm depth (accounting for 71 % of total riparian export). Seasonal variability was high with export peaks during the spring flood and autumn storm events. Downstream lateral CO2 export (determined from stream water dissolved CO2 concentrations and discharge) was 1.2 g CO2-C m−2 yr−1. Subtracting downstream lateral export from riparian export (3.0 g CO2-C m−2 yr−1) gives 1.8 g CO2-C m−2 yr−1 which can be attributed to evasion losses (accounting for 60 % of export via the aquatic pathway). The results highlight the importance of terrestrial CO2 export, especially from the riparian zone, for determining catchment aquatic CO2 losses and the importance of the CO2 evasion component to carbon export via the aquatic conduit

Summer CO2 evasion from streams and rivers in the Kolyma River basin, north-east Siberia

Inland water systems are generally supersaturated in carbon dioxide (CO2) and are increasingly recognized as playing an important role in the global carbon cycle. The Arctic may be particularly important in this respect, given the abundance of inland waters and carbon contained in Arctic soils; however, a lack of trace gas measurements from small streams in the Arctic currently limits this understanding.We investigated the spatial variability of CO2 evasion during the summer low-flow period from streams and rivers in the northern portion of the Kolyma River basin in north-eastern Siberia. To this end, partial pressure of carbon dioxide (pCO2) and gas exchange velocities (k) were measured at a diverse set of streams and rivers to calculate CO2 evasion fluxes. We combined these CO2 evasion estimates with satellite remote sensing and geographic information system techniques to calculate total areal CO2 emissions. Our results show that small streams are substantial sources of atmospheric CO2 owing to high pCO2 and k, despite being a small portion of total inland water surface area. In contrast, large rivers were generally near equilibrium with atmospheric CO2. Extrapolating our findings across the Panteleikha-Ambolikha sub-watersheds demonstrated that small streams play a major role in CO2 evasion, accounting for 86% of the total summer CO2 emissions from inland waters within these two sub-watersheds. Further expansion of these regional CO2 emission estimates across time and space will be critical to accurately quantify and understand the role of Arctic streams and rivers in the global carbon budget

Human Interaction in Learning Ecosystems based on Open Source Solutions

Technological ecosystems are software solutions based on the integration of heterogeneous software components through information flows in order to provide a set of services that each component separately does not offer, as well as to improve the user experience. In particular, the learning ecosystems are technological ecosystems focused on learning and knowledge management in different contexts such as educational institutions or companies. The ecosystem metaphor comes from biology field and it has transferred to technology field to highlight the evolving component of software. Taking into account the definitions of natural ecosystems, a technological ecosystem is a set of people and software components that play the role of organisms; a series of elements that allow the ecosystem works (hardware, networks, etc.); and a set of information flows that establish the relationships between the software components, and between these and the people involved in the ecosystem. Human factor has a main role in the definition and development of this kind of solutions. In previous works, a metamodel has been defined and validated to support Model-Driven Development of learning ecosystems based on Open Source software, but the interaction in the learning ecosystem should be defined in order to complete the proposal to improve the development process of technological ecosystems. This paper presents the definition and modelling of the human interaction in learning ecosystem

Linking Customer Interaction and Innovation: The Mediating Role of New Organizational Practices

The notion that firms can improve their innovativeness by tapping users and customers for knowledge has become prominent in innovation studies. Similar arguments have been made in the marketing literature. We argue that neither literatures take sufficient account of firm organization. Specifically, firms that attempt to leverage user and customer knowledge in the context of innovation must design an internal organization appropriate to support it. This can be achieved in particular through the use of new organizational practices, notably, intensive vertical and lateral communication, rewarding employees for sharing and acquiring knowledge, and high levels of delegation of decision rights. In this paper, six hypotheses were developed and tested on a data set of 169 Danish firms drawn from a 2001 survey of the 1,000 largest firms in Denmark. A key result is that the link from customer knowledge to innovation is completely mediated by organizational practices

The determinants of electronic payment systems usage from consumers’ perspective

Electronic Payment Systems (EPS) have been improving individuals’ quality of life through providing ease of payment for online transactions. The effects of trust and security on the use of EPS have long been recognised in e-commerce literature. However, very few studies have examined these two concepts from the viewpoint of users. This study has developed a conceptual model to examine the determinants of perceived security and trust as well as the impact of perceived security and trust on the use of EPS. A sample of 299 respondents was analysed through structural equation modelling (SEM); the findings indicate that both perceived security and trust have a significant influence on EPS use. Technical protection and past experience have been found to be the common determinants of perceived security and trust. Managerial implications of the findings are discussed in light of the study’s limitations and suggestions for further research indicated

Lake salinization drives consistent losses of zooplankton abundance and diversity across coordinated mesocosm experiments

Human-induced salinization increasingly threatens inland waters; yet we know little about the multifaceted response of lake communities to salt contamination. By conducting a coordinated mesocosm experiment of lake salinization across 16 sites in North America and Europe, we quantified the response of zooplankton abundance and (taxonomic and functional) community structure to a broad gradient of environmentally relevant chloride concentrations, ranging from 4 to ca. 1400 mg Cl- L-1. We found that crustaceans were distinctly more sensitive to elevated chloride than rotifers; yet, rotifers did not show compensatory abundance increases in response to crustacean declines. For crustaceans, our among-site comparisons indicate: (1) highly consistent decreases in abundance and taxon richness with salinity; (2) widespread chloride sensitivity across major taxonomic groups (Cladocera, Cyclopoida, and Calanoida); and (3) weaker loss of functional than taxonomic diversity. Overall, our study demonstrates that aggregate properties of zooplankton communities can be adversely affected at chloride concentrations relevant to anthropogenic salinization in lakes.Peer reviewe