160 research outputs found
The Insertion of Human Factors Concerns into NextGen Programmatic Decisions
Since the costs of proposed improvements in air traffic management exceed available funding, FAA decision makers must select and prioritize what actually gets implemented. We discuss a set of methods to help forecast operational and human performance issues and benefits before new automation is introduced. This strategy could minimize the impact of politics, assist decision makers in selecting and prioritizing potential improvements, make the process more transparent and strengthen the link between the engineering and human factors domains
Near Equilibrium ^(13)C-^(18)O Bonding During Inorganic Calcite Precipitation under Chemo-Stat Conditions
We report results of ^(13)C/^(12)C, ^(18)O/^(16)O, and ^(13)C-^(18)O “clumped” isotope analyses from a series of calcite precipitation experiments from aqueous solutions under laboratory conditions. Chemo‐stat precipitation experiments were performed to synthetically form calcite from aqueous solution onto ^(43)Ca‐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^(−6.88) to 10^(−8.20)mol m^(−2) s^(−1) at three temperatures (10, 20, and 30°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 Δ_(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 super‐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 +1.6‰. The temperature‐dependent calcite‐water ^(18)O/^(16)O fractionation relation determined in this study is slightly different (larger α_(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
The Second-Generation Guide Star Catalog: Description and Properties
The GSC-II is an all-sky database of objects derived from the uncompressed
DSS that the STScI has created from the Palomar and UK Schmidt survey plates
and made available to the community. Like its predecessor (GSC-I), the GSC-II
was primarily created to provide guide star information and observation
planning support for HST. This version, however, is already employed at some of
the ground-based new-technology telescopes such as GEMINI, VLT, and TNG, and
will also be used to provide support for the JWST and Gaia space missions as
well as LAMOST, one of the major ongoing scientific projects in China. Two
catalogs have already been extracted from the GSC-II database and released to
the astronomical community. A magnitude-limited (R=18.0) version, GSC2.2, was
distributed soon after its production in 2001, while the GSC2.3 release has
been available for general access since 2007.
The GSC2.3 catalog described in this paper contains astrometry, photometry,
and classification for 945,592,683 objects down to the magnitude limit of the
plates. Positions are tied to the ICRS; for stellar sources, the all-sky
average absolute error per coordinate ranges from 0.2" to 0.28" depending on
magnitude. When dealing with extended objects, astrometric errors are 20% worse
in the case of galaxies and approximately a factor of 2 worse for blended
images. Stellar photometry is determined to 0.13-0.22 mag as a function of
magnitude and photographic passbands (B,R,I). Outside of the galactic plane,
stellar classification is reliable to at least 90% confidence for magnitudes
brighter than R=19.5, and the catalog is complete to R=20.Comment: 52 pages, 33 figures, to be published in AJ August 200
Iron Isotope Fractionations Reveal a Finite Bioavailable Fe Pool for Structural Fe(III) Reduction in Nontronite
© 2016 American Chemical Society. This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes. The definitive version is available via: http://dx.doi.org/10.1021/acs.est.6b02019We report on stable Fe isotope fractionation during microbial and chemical reduction of structural Fe(III) in nontronite NAu-1. Fe-56/Fe-54 fractionation factors between aqueous Fe(II) and structural Fe(III) ranged from -1.2 to +0.8 parts per thousand. Microbial (Shewanella oneidensis and Geobacter sulfurreducens) and chemical (dithionite) reduction experiments revealed a two-stage process. Stage 1 was characterized by rapid reduction of a finite Fe(III) pool along the edges of the clay particles, accompanied by a limited release to solution of Fe(II), which partially adsorbed onto basal planes. Stable Fe isotope compositions revealed that electron transfer and atom exchange (ETAE) occurred between edge-bound Fe(II) and octahedral (structural) Fe(III) within the clay lattice, as well as between aqueous Fe(II) and structural Fe(III) via a transient sorbed phase. The isotopic fractionation factors decreased with increasing extent of reduction as a result of the depletion of the finite bioavailable Fe(III) pool. During stage 2, microbial reduction was inhibited while chemical reduction continued. However, further ETAE between aqueous Fe(II) and structural Fe(III) was not observed. Our results imply that the pool of bioavailable Fe(III) is restricted to structural Fe sites located near the edges of the clay particles. Blockage of ETAE distinguishes Fe(III) reduction of layered clay minerals from that of Fe oxyhydroxides, where accumulation of structural Fe(II) is much more limited.Ontario Early Researcher Award; NSERC; NASA Astrobiology Institute; Canada Excellence Research Chair (CERC) progra
Tick-, mosquito-, and rodent-borne parasite sampling designs for the National Ecological Observatory Network
Parasites and pathogens are increasingly recognized as significant drivers of ecological and evolutionary change in natural ecosystems. Concurrently, transmission of infectious agents among human, livestock, and wildlife populations represents a growing threat to veterinary and human health. In light of these trends and the scarcity of long-term time series data on infection rates among vectors and reservoirs, the National Ecological Observatory Network (NEON) will collect measurements and samples of a suite of tick-, mosquito-, and rodent-borne parasites through a continental-scale surveillance program. Here, we describe the sampling designs for these efforts, highlighting sampling priorities, field and analytical methods, and the data as well as archived samples to be made available to the research community. Insights generated by this sampling will advance current understanding of and ability to predict changes in infection and disease dynamics in novel, interdisciplinary, and collaborative ways. (Résumé d'auteur
A Reaction-Diffusion Model of ROS-Induced ROS Release in a Mitochondrial Network
Loss of mitochondrial function is a fundamental determinant of cell injury and death. In heart cells under metabolic stress, we have previously described how the abrupt collapse or oscillation of the mitochondrial energy state is synchronized across the mitochondrial network by local interactions dependent upon reactive oxygen species (ROS). Here, we develop a mathematical model of ROS-induced ROS release (RIRR) based on reaction-diffusion (RD-RIRR) in one- and two-dimensional mitochondrial networks. The nodes of the RD-RIRR network are comprised of models of individual mitochondria that include a mechanism of ROS-dependent oscillation based on the interplay between ROS production, transport, and scavenging; and incorporating the tricarboxylic acid (TCA) cycle, oxidative phosphorylation, and Ca2+ handling. Local mitochondrial interaction is mediated by superoxide (O2.−) diffusion and the O2.−-dependent activation of an inner membrane anion channel (IMAC). In a 2D network composed of 500 mitochondria, model simulations reveal ΔΨm depolarization waves similar to those observed when isolated guinea pig cardiomyocytes are subjected to a localized laser-flash or antioxidant depletion. The sensitivity of the propagation rate of the depolarization wave to O2.− diffusion, production, and scavenging in the reaction-diffusion model is similar to that observed experimentally. In addition, we present novel experimental evidence, obtained in permeabilized cardiomyocytes, confirming that ΔΨm depolarization is mediated specifically by O2.−. The present work demonstrates that the observed emergent macroscopic properties of the mitochondrial network can be reproduced in a reaction-diffusion model of RIRR. Moreover, the findings have uncovered a novel aspect of the synchronization mechanism, which is that clusters of mitochondria that are oscillating can entrain mitochondria that would otherwise display stable dynamics. The work identifies the fundamental mechanisms leading from the failure of individual organelles to the whole cell, thus it has important implications for understanding cell death during the progression of heart disease
Tick-, Mosquito-, and Rodent-Borne Parasite Sampling Designs for the National Ecological Observatory Network [Special Feature: NEON Design]
Parasites and pathogens are increasingly recognized as significant drivers of ecological and evolutionary change in natural ecosystems. Concurrently, transmission of infectious agents among human, livestock, and wildlife populations represents a growing threat to veterinary and human health. In light of these trends and the scarcity of long-term time series data on infection rates among vectors and reservoirs, the National Ecological Observatory Network (NEON) will collect measurements and samples of a suite of tick-, mosquito-, and rodent-borne parasites through a continental-scale surveillance program. Here, we describe the sampling designs for these efforts, highlighting sampling priorities, field and analytical methods, and the data as well as archived samples to be made available to the research community. Insights generated by this sampling will advance current understanding of and ability to predict changes in infection and disease dynamics in novel, interdisciplinary, and collaborative ways
Finding meaning: HIV self-management and wellbeing among people taking antiretroviral therapy in Uganda
© 2016 Russell et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in anymedium, provided the original author and source are credited. The health of people living with HIV (PLWH) and the sustained success of antiretroviral therapy (ART) programmes depends on PLWH's motivation and ability to self-manage the condition over the long term, including adherence to drugs on a daily basis. PLWH's selfmanagement of HIV and their wellbeing are likely to be interrelated. Successful self-management sustains wellbeing, and wellbeing is likely to motivate continued self-management. Detailed research is lacking on PLWH's self-management processes on ART in resourcelimited settings. This paper presents findings from a study of PLWH's self-management and wellbeing in Wakiso District, Uganda. Thirty-eight PLWH (20 women, 18 men) were purposefully selected at ART facilities run by the government and by The AIDS Support Organisation in and around Entebbe. Two in-depth interviews were completed with each participant over three or four visits. Many were struggling economically, however the recovery of health and hope on ART had enhanced wellbeing and motivated self-management. The majority were managing their condition well across three broad domains of self-management. First, they had mobilised resources, notably through good relationships with health workers. Advice and counselling had helped them to reconceptualise their condition and situation more positively and see hope for the future, motivating their work to self-manage. Many had also developed a new network of support through contacts they had developed at the ART clinic. Second, they had acquired knowledge and skills to manage their health, a useful framework to manage their condition and to live their life. Third, participants were psychologically adjusting to their condition and their new 'self': They saw HIV as a normal disease, were coping with stigma and had regained self-esteem, and were finding meaning in life. Our study demonstrates the centrality of social relationships and other nonmedical aspects of wellbeing for self-management which ART programmes might explore further and encourage
Crop Updates 2005 - Katanning
This session covers twenty five papers from different authors
KEYNOTE
How Farmers Can Work Together for a More Sustainable and Profitable Business, Brian McAlpine Farmer, Nuffield Scholar
GENERAL
2005 Seasonal Outlook, David Stephens and Nicola Telcik, Department of Agriculture
Essentials for cereal leaf disease management, K. Jayasena, R. Loughman, G. Thomas, C. Beard, and B. Paynter, Department of Agriculture
Benefits to the grower of grain licensing, Colin Mann, Grain Licensing Authority SOIL & NUTRIENTS
The effect of higher nitrogen fertiliser prices on rotation and fertiliser strategies in cropping systems, Ross Kingwell, Department of Agriculture
Effect of stubble burning and seasonality on microbial processes and nutrient cycling, Francis Hoyle, University of Western Australia
Soil Biology and Crop Production in Western Australian Farming Systems, D.V. Murphy, N. Milton, M. Osman, F.C. Hoyle, L.K Abbott, W.R. Cookson and S. Darmawanto, University of Western Australia
Nutrient Management to get optimal production, Bill Bowden, Department of Agriculture
OTHER CROPS
Which malting barley variety and why? Blakely Paynter, Department of Agriculture
KASPA AND OTHER NEW PULSE VARIETIES, 1. New Pulse varieties and where they fit in, K. Regan, P. White, Department of Agriculture & CLIMA, K. Siddique, CLIMA, K. Adhikari, Department of Agriculture & CLIMA, M. Harries, CLIMA
Kaspa in the WA Grain Belt 2003-2004, Ian Pritchard, Department of Agriculture
New annual pastures for Mediterranean farming systems, Angelo Loi, Phil Nichols, Clinton Revell & David Ferris, Department of Agriculture
Challenging herbicide resistant ryegrass, Bill Roy, Agricultural Consulting & Research Services Pty.Ltd
WEED MANAGEMENT
Ingest, incinerate or invert? The pro’s and con’s of 3 weed seed removal tactics, Sally Peltzer1, Dave Minkey1 and Michael Walsh2 Department of Agriculture 1 and Western Australian Herbicide Resistance lnitiative2
A good use guide for pre-emergent herbicides, Alexandra Douglas, Department of Agriculture
OTHER USEFUL INFORMATION
17.Growing season outlook, Meredith Fairbanks, Ian Foster, Geraldine Pasqual, David Stephens, Nicola Telcik, David Tennant, Department of Agriculture
18. Status Of Department Of Agriculture Western Australia Crop Varieties
19. Seed Licensee Details
20. Gene technology for growers. What is it? How does it Work? Belinda Barr, Australian Centre for Plant Functional Genomics, Dr Heather Bray, Molecular Plant Breeding Cooperative Research Centre.
21. Agronomic package for EGA Eagle Rock, Steve Penny, Department of Agriculture
22. Nutrient timing and requirements for increased crop yields in the high rainfall cropping zone, Narelle Hill, Ron McTaggart, Dr. Wal Anderson and Ray Tugwell Department of Agriculture
23. Insect contamination of cereal grain at harvest, Svetlana Micic and Phil Michael, Department of Agriculture
24. Crop leftovers: what’s in stubble for sheep? Roy Butler and Keith Croker, Department of Agriculture
25. Mandelup – Narrow-leafed lupi
- …