461 research outputs found

    Late Neogene planktonic foraminifers in the Caribbean, Gulf of Mexico, and Italian stratotypes

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    67 p., 25 fig., 36b pl., 10 tables.http://paleo.ku.edu/contributions.htm

    Human-Automation Allocations for Current Robotic Space Operations

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    Within the Human Research Program, one risk delineates the uncertainty surrounding crew working with automation and robotics in spaceflight. The Risk of Inadequate Design of Human and Automation/Robotic Integration (HARI) is concerned with the detrimental effects on crew performance due to ineffective user interfaces, system designs and/or functional task allocation, potentially compromising mission success and safety. Risk arises because we have limited experience with complex automation and robotics. One key gap within HARI, is the gap related to functional allocation. The gap states: We need to evaluate, develop, and validate methods and guidelines for identifying human-automation/robot task information needs, function allocation, and team composition for future long duration, long distance space missions. Allocations determine the human-system performance as it identifies the functions and performance levels required by the automation/robotic system, and in turn, what work the crew is expected to perform and the necessary human performance requirements. Allocations must take into account each of the human, automation, and robotic systems capabilities and limitations. Some functions may be intuitively assigned to the human versus the robot, but to optimize efficiency and effectiveness, purposeful role assignments will be required. The role of automation and robotics will significantly change in future exploration missions, particularly as crew becomes more autonomous from ground controllers. Thus, we must understand the suitability of existing function allocation methods within NASA as well as the existing allocations established by the few robotic systems that are operational in spaceflight. In order to evaluate future methods of robotic allocations, we must first benchmark the allocations and allocation methods that have been used. We will present 1) documentation of human-automation-robotic allocations in existing, operational spaceflight systems; and 2) To gather existing lessons learned and best practices in these role assignments, from spaceflight operational experience of crew and ground teams that may be used to guide development for future systems. NASA and other space agencies have operational spaceflight experience with two key Human-Automation-Robotic (HAR) systems: heavy lift robotic arms and planetary robotic explorers. Additionally, NASA has invested in high-fidelity rover systems that can carry crew, building beyond Apollo's lunar rover. The heavy lift robotic arms reviewed are: Space Station Remote Manipulator System (SSRMS), Japanese Remote Manipulator System (JEMRMS), and the European Robotic Arm (ERA, designed but not deployed in space). The robotic rover systems reviewed are: Mars Exploration Rovers, Mars Science Laboratory rover, and the high-fidelity K10 rovers. Much of the design and operational feedback for these systems have been communicated to flight controllers and robotic design teams. As part of the mitigating the HARI risk for future human spaceflight operations, we must document function allocations between robots and humans that have worked well in practice

    IGERT: Sensor Science, Engineering, and Informatics

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    This Sensor Science, Engineering and Informatics (SSEI) IGERT program will provide multidisciplinary doctoral training in the area of sensor systems ranging from the science and engineering of new materials and sensing mechanisms to the interpretation of sensor data. The design and management of effective sensor systems requires a holistic understanding of how information is collected, stored, integrated, evaluated, and communicated within sensing systems and to decision makers in diverse application contexts. The SSEI IGERT weaves together three research focus areas: (1) Sensor Materials and Devices, (2) Sensor Systems and Networks, and (3) Sensor Informatics. The intellectual merit of the project includes education and research activities that are designed to ensure a feedback loop so that SSEI IGERT trainees are able to transform new knowledge from sensor-generated data to further development of sensor systems and networks and advances in sensor materials and devices, and vice versa. Innovative components of the program include (1) development and use of a testbed prototype that will require interdisciplinary interaction across the three research areas; (2) a tight integration of the social, legal, ethical, and economic dimensions of sensing environments in both research and training, (3) expanded relationships with companies and federal laboratories engaged in sensor research, (4) international collaborations, and (5) synergistic integration with sensor science and engineering education at the middle, high school, and undergraduate level. The broader impacts of the SSEI IGERT program are a new breed of scientists and engineers who will be versatile in dealing with the diverse technical components that contribute to sensing systems, knowledgeable in the legal, social, and ethical contexts of heavily sensed environments, and aware of the human values that must be preserved, protected and promoted within such systems. IGERT is an NSF-wide program intended to meet the challenges of educating U.S. Ph.D. scientists and engineers with the interdisciplinary background, deep knowledge in a chosen discipline, and the technical, professional, and personal skills needed for the career demands of the future. The program is intended to catalyze a cultural change in graduate education by establishing innovative new models for graduate education and training in a fertile environment for collaborative research that transcends traditional disciplinary boundaries

    Iron bioavailability: UK Food Standards Agency workshop report

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    The UK Food Standards Agency convened a group of expert scientists to review current research investigating factors affecting iron status and the bioavailability of dietary iron. Results presented at the workshop show menstrual blood loss to be the major determinant of body iron stores in premenopausal women. In the presence of abundant and varied food supplies, the health consequences of lower iron bioavailability are unclear and require further investigatio

    Impacts of abiotic stresses on the physiology and metabolism of cool-season grasses:A review

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    Grasslands cover more than 70% of the world's agricultural land playing a pivotal role in global food security, economy, and ecology due to their flexibility and functionality. Climate change, characterized by changes in temperature and precipitation patterns, and by increased levels of greenhouse gases in the atmosphere, is anticipated to increase both the frequency and severity of extreme weather events, such as drought, heat waves, and flooding. Potentially, climate change could severely compromise future forage crop production and should be considered a direct threat to food security. This review aimed to summarize our current understanding of the physiological and metabolic responses of temperate grasses to those abiotic stresses associated with climate change. Primarily, substantial decreases in photosynthetic rates of coolā€season grasses occur as a result of high temperatures, waterā€deficit or waterā€excess, and elevated ozone, but not CO2 concentrations. Those decreases are usually attributed to stomatal and nonā€stomatal limitations. Additionally, while membrane instability and reactive oxygen species production was a common feature of the abiotic stress response, total antioxidant capacity showed a stressā€specific response. Furthermore, climate changeā€related stresses altered carbohydrate partitioning, with implications for biomass production. While waterā€deficit stress, increased CO2, and ozone concentrations resulted in higher carbohydrate content, the opposite occurred under conditions of heat stress and flooding. The extent of damage is greatly dependent on location, as well as the type and intensity of stress. Fortunately, temperate forage grass species are highly heterogeneous. Consequently, through intraā€ and in particular interā€specific plant hybridization (e.g., Festuca x Lolium hybrids) new opportunities are available to harness, within single genotypes, gene combinations capable of combating climate change

    Blood levels of trace metals and amyotrophic lateral sclerosis

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    Some trace metals may increase risk of amyotrophic lateral sclerosis (ALS), whereas others may be beneficial. Our goal was to examine associations of ALS with blood levels of selenium (Se), zinc (Zn), copper (Cu), and manganese (Mn). We conducted a case-control study of 163 neurologist confirmed patients from the National Registry of Veterans with ALS and 229 frequency-matched veteran controls. We measured metal levels in blood using inductively coupled plasma mass spectrometry and estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between ALS and a doubling of metal levels using unconditional logistic regression, adjusting for age, gender, and race/ethnicity. ALS was inversely associated with both Se (OR=0.4, 95% CI: 0.2ā€“0.8) and Zn (OR=0.4, 95% CI: 0.2ā€“0.8). Inverse associations with Se were stronger in patients with bulbar compared to spinal onset, worse function, longer diagnostic delay, and longer collection delay; inverse associations with Zn were stronger for those with worse function and longer collection delay. In contrast, ALS was positively associated with Cu (OR=3.4, 95% CI: 1.5ā€“7.9). For Mn, no linear trend was evident (OR=0.9, 95% CI: 0.6ā€“1.3, Ptrend=0.51). Associations of Se, Zn, Cu, and Mn with ALS were independent of one another. Adjustment for lead levels attenuated the positive association of ALS with Cu but did not change associations with Se, Zn, or Mn. In conclusion, Se and Zn were inversely associated with ALS, particularly among those with worse function, suggesting that supplementation with these metals may benefit such patients, while Cu was positively associated with ALS. Deficiencies of Se and Zn and excess Cu may have a role in ALS etiology

    Body Mass Index and Amyotrophic Lateral Sclerosis: A Study of US Military Veterans

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    Abstract Amyotrophic lateral sclerosis (ALS) may be associated with low body mass index (BMI) at the time of diagnosis. However, the role of premorbid BMI in the development of ALS and survival after diagnosis remains unclear. In 2005ā€“2010, we interviewed 467 patients with ALS from the US National Registry of Veterans with ALS and 975 frequency-matched veteran controls. In this sample, we evaluated the association of BMI and BMI change at different ages with ALS risk using unconditional logistic models and with survival after ALS diagnosis using Cox proportional hazards models. After adjustment for confounders, compared with a moderate increase in BMI between ages 25 and 40 years, stable or decreasing BMI was positively associated with ALS risk (odds ratio (OR) = 1.61, 95% confidence interval (CI): 1.20, 2.16). A 1-unit increase in BMI at age 40 years (OR = 0.95, 95% CI: 0.91, 0.98) but not at age 25 years (OR = 0.99, 95% CI: 0.95, 1.03) was inversely associated with ALS. These associations were similar for bulbar and spinal ALS but stronger for those with a delay of less than 1 year between symptom onset and diagnosis. We found no association between prediagnosis BMI and survival. A decreasing BMI from early to middle age and a low BMI in middle age may be positively associated with ALS risk

    Military service, deployments, and exposures in relation to amyotrophic lateral sclerosis etiology

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    Factors underlying a possible excess of amyotrophic lateral sclerosis (ALS) among military veterans remain unidentified. Limitations of previous studies on this topic include reliance on ALS mortality as a surrogate for ALS incidence, low statistical power, and sparse information on military-related factors

    Near Equilibrium ^(13)C-^(18)O Bonding During Inorganic Calcite Precipitation under Chemo-Stat Conditions

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    We report results of ^(13)C/^(12)C, ^(18)O/^(16)O, and ^(13)C-^(18)O ā€œclumpedā€ isotope analyses from a series of calcite precipitation experiments from aqueous solutions under laboratory conditions. Chemoā€stat precipitation experiments were performed to synthetically form calcite from aqueous solution onto ^(43)Caā€labeled calcite seed crystals. Formation rate was controlled during the experiments to investigate the effect of precipitation rate and temperature on ^(13)C-^(18)O bonding in calcite, where rates ranged from 10^(āˆ’6.88) to 10^(āˆ’8.20)mol m^(āˆ’2) s^(āˆ’1) at three temperatures (10, 20, and 30Ā°C). No relation was observed between precipitation rate and ^(13)C-^(18)O bonding proportion over the range of precipitation rates used. The relation between Ī”_(47) and temperature produced was comparable to calibration studies which report a relatively high sensitivity of ^(13)C-^(18)O bonding to temperature over the range investigated. Comparing solution conditions across multiple experimental data sets indicates an inverse relation between saturation state and ^(13)C-^(18)O bonding, where high superā€saturation conditions are likely to be furthest from equilibrium ^(13)C-^(18)O partitioning. Carbon fractionation between calcite and HCO-_(3(aq)) was found to be a temperature independent value of +1.6ā€°. The temperatureā€dependent calciteā€water ^(18)O/^(16)O fractionation relation determined in this study is slightly different (larger Ī±_(calcite-H_2O) value) than those measured in several previous investigations. Significantly, we observe a dependence of the 18O/16O isotope fractionation factor on growth rate. Taken together, these findings suggest carbonate growth in our experiments approached equilibrium more closely than previous experiments of this type, yet did not achieve full O isotope equilibrium

    Military service, deployments, and exposures in relation to amyotrophic lateral sclerosis survival

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    Military veterans may have higher rates of amyotrophic lateral sclerosis (ALS) mortality than non-veterans. Few studies, with sparse exposure information and mixed results, have studied relationships between military-related factors and ALS survival. We evaluated associations between military-related factors and ALS survival among U.S. military veteran cases
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