616 research outputs found
The isotherm follower
The isotherm follower is an instrument that is capable of seeking out a given isotherm in the sea, locking on to the isotherm, following it up and down, and recording its depth with respect to time. This instrument has been employed singly and in triangular arrangements of three to provide the speed and direction of internal waves. It has proven to be valuable in determining the nature of vertical oscillations of sea temperature
Performance Analysis of On-Line Camera-Based Web Inspection Sensors: A Pilot-Scale Experimental Study
Camera-based web inspection sensors have been available in the paper industry for many years. However, in recent years because of a market demand for high-quality paper products, the need for realtime flaw-detection systems has increased significantly. In addition to flaw-detection capabilities, these systems should be capable of doing defect classification (e.g., relative to size and type of flaws) as well as defect localization (providing information on location of flaws). The technique employed in flaw detection and measurement principles used in common systems are based on laser, CCD (charge coupled device) camera, or infrared technology. The study was designed to determine the capabilities of commercially available CCD camerabased systems. A CCD camera-based commercial sensor was installed on a pilot paper coater machine with the production speed capability of 1524 m/min (5000 ft/min) that could accept paper rolls with a width of 76.2 cm (30 inches). Various paper grades consisting of newsprint, coated paper, coated board, and linerboard which had typical grade-related defects were provided by various paper mills for testing. The purpose of this manuscript is to describe the operational principle, capabilities, and performance of various sensors used in paper industry in detecting various flaws and defects and to provide a summary of the results obtained using a commercial sensor
Physical oceanographic investigations in the Eastern Bering and Chukchi Seas during the summer of 1947
New information on the physical properties of the waters in the eastern Bering and Chukchi seas is discussed. It shows that, in summer, the water masses of this area are complicated by the circulation and advective processes. In general, the southern Bering Sea water flows northward and is modified by warm low-salinity water from rivers along the Alaskan coast and from intrusions of cold high-salinity water from the western Bering Sea. This mixture of water funn els through the Bering Strait principally at the surface on the eastern side...
The effect of nitrogen fertilization and no-till duration on soil nitrogen availability and greenhouse gas emissions
Non-Peer ReviewedWith a world population now greater than seven billion, it is imperative to conserve the
arable land base, which is increasingly being leveraged by global demands for producing food,
feed, fibre, and fuel. A key component of sustainable agriculture involves the restoration of
unproductive lands that have been rendered unsuitable for agricultural production through
anthropogenic soil degradation. The objective of this study was to determine the effect of
varying fertilizer N rates on soil N availability and N2O and CO2 emissions of three soils
collected at adjacent locations with contrasting management histories: native prairie or short-term
(10 years) and long-term (32 years) no-till continuous multi-crop (wheat-pea-canola)
cropping systems receiving five fertilizer N rates (0, 30, 60, 90, and 120 kg N/ha) for the
previous nine years. Intact soil cores were collected from each site, maintained at field capacity,
and incubated (22 oC) for six weeks. Weekly assessments of soil nutrient availability and N2O
and CO2 emissions were completed to assess the impact of prolonged variable rates of fertilizer
N and duration of no-till management of degraded agricultural soil relative to an adjacent native
prairie soil. At the end of the six-week incubation, there was no significant difference (P > 0.15)
in cumulative soil N supply rate between the unfertilized long-term no-till soil and native soil.
Annual fertilizer N additions of 120 kg N/ha for the previous nine years were required to restore
the N supplying power of the short-term no-till soil to that of the native soil, through the build-up
of mineralizable N levels. As expected, repeated applications of fertilizer N increased the
residual soil N levels in the cultivated soils compared to the native soil. The estimated
cumulative CO2-C and N2O-N emissions at the end of the six-week incubation ranged from
231.8-474.7 g/m2 to 183.9-862.5 mg/m2, respectively. Repeated applications of ≥ 60 kg N/ha
supported larger N2O-N fluxes in the long-term no-till soil compared to the unfertilized control.
Highest CO2-C fluxes from the native prairie soil are consistent with its high organic matter
content and contributions from root respiration. Surprisingly, the native prairie soil N2O-N
emissions were equal to those from LTNT and STNT soils receiving repeated fertilizer N
applications at typical agronomic rates and is probably characteristic of rapid denitrification rates
during the dormant vegetative period after snow melt prior to the growing season within
temperate native grassland environments. The use of modern no-till continuous multi-crop
cropping systems, along with application of fertilizer N, enhances the soil N supplying power
over the long-term through the build-up of mineralizable N and appears to be an effective
management strategy for improving degraded soils, thus enhancing the productive capacity of
agricultural ecosystems. However, accounting for N2O emissions associated with repeated
fertilizer N applications is imperative for properly assessing the net global warming potential of
any land management system
Supplementary report to the final report of the coral reef expert group: S8. Monitoring site planner - choosing where to monitor coral reefs on the Great Barrier Reef
[Extract] In this project we develop a multi-criteria analysis and optimisation tool, called the Monitoring Site Planner, to assist in the evaluation of the existing and new proposed coral reef monitoring programs for the Great Barrier Reef (the Reef). This tool allows the performance of a given monitoring survey design (a set of reefs that will be monitored) to be evaluated against a set of performance criteria. This tool can be run as an interactive web application that is available for use from https://tools.eatlas.org.au/msp.An accessible copy of this report is not yet available from this repository, please contact [email protected] for more information
Inferring Energy Bounds via Static Program Analysis and Evolutionary Modeling of Basic Blocks
The ever increasing number and complexity of energy-bound devices (such as
the ones used in Internet of Things applications, smart phones, and mission
critical systems) pose an important challenge on techniques to optimize their
energy consumption and to verify that they will perform their function within
the available energy budget. In this work we address this challenge from the
software point of view and propose a novel parametric approach to estimating
tight bounds on the energy consumed by program executions that are practical
for their application to energy verification and optimization. Our approach
divides a program into basic (branchless) blocks and estimates the maximal and
minimal energy consumption for each block using an evolutionary algorithm. Then
it combines the obtained values according to the program control flow, using
static analysis, to infer functions that give both upper and lower bounds on
the energy consumption of the whole program and its procedures as functions on
input data sizes. We have tested our approach on (C-like) embedded programs
running on the XMOS hardware platform. However, our method is general enough to
be applied to other microprocessor architectures and programming languages. The
bounds obtained by our prototype implementation can be tight while remaining on
the safe side of budgets in practice, as shown by our experimental evaluation.Comment: Pre-proceedings paper presented at the 27th International Symposium
on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur,
Belgium, 10-12 October 2017 (arXiv:1708.07854). Improved version of the one
presented at the HIP3ES 2016 workshop (v1): more experimental results (added
benchmark to Table 1, added figure for new benchmark, added Table 3),
improved Fig. 1, added Fig.
Development of scale down models for perfusion bioreactor medium optimization
Due to the complex nature of balancing \u3e50 individual media components, the development and optimization of bioreactor medium for high performing perfusion bioreactors is a resource intensive, multivariate problem that greatly benefits from the availability of predictive high through-put scale-down models that simulate the bioreactor system. For that purpose, both a 10 mL long-term block model and 50 mL shaker tube model were developed and optimized to settings that balance oxygen transfer, culture health, and productivity. The long-term block model was limited by the volume needed for culture sampling; as a result, the shaker tube model was developed with a 7.5x increase in working volume. This shaker tube model was then applied to adequately characterize cell nutrient consumption profiles and subsequently inform medium development through multivariate design of experiments (DOE). Within two rounds of studies in the scale-down models, Regeneron’s first-generation perfusion medium formulation achieved approximately 100% increase in productivity compared to the initial medium. The improved nutrient strategy optimized in shaker tubes translated to several cell lines in the benchtop and pilot scale bioreactor perfusion system, indicating the predictive capabilities of the small-scale model. These results highlight the benefits of using small-scale models to shorten development time for perfusion process implementation
On strongly chordal graphs that are not leaf powers
A common task in phylogenetics is to find an evolutionary tree representing
proximity relationships between species. This motivates the notion of leaf
powers: a graph G = (V, E) is a leaf power if there exist a tree T on leafset V
and a threshold k such that uv is an edge if and only if the distance between u
and v in T is at most k. Characterizing leaf powers is a challenging open
problem, along with determining the complexity of their recognition. This is in
part due to the fact that few graphs are known to not be leaf powers, as such
graphs are difficult to construct. Recently, Nevries and Rosenke asked if leaf
powers could be characterized by strong chordality and a finite set of
forbidden subgraphs.
In this paper, we provide a negative answer to this question, by exhibiting
an infinite family \G of (minimal) strongly chordal graphs that are not leaf
powers. During the process, we establish a connection between leaf powers,
alternating cycles and quartet compatibility. We also show that deciding if a
chordal graph is \G-free is NP-complete, which may provide insight on the
complexity of the leaf power recognition problem
Character Displacement in the Midst of Substantial Background Evolution in Anolis Lizard Island Populations
Negative interactions between species can generate divergent selection that causes character displacement. However, other processes cause similar divergence. We use spatial and temporal replication across island populations of Anolis lizards to assess the importance of negative interactions in driving trait shifts. Previous work showed that the establishment of Anolis sagrei on islands drove resident Anolis carolinensis to perch higher and evolve larger toepads. To further test the interaction\u27s causality and predictability, we resurveyed a subset of islands nine years later. Anolis sagrei had established on one island between surveys. We found that A. carolinensis on this island now perch higher and have larger toepads. However, toepad morphology change on this island was not distinct from shifts on six other islands whose Anolis community composition had not changed. Thus, the presence of A. sagrei only partly explains A. carolinensis trait variation across space and time. We also found that A. carolinensis on islands with previously established A. sagrei now perch higher than a decade ago, and that current A. carolinensis perch height is correlated with A. sagrei density. Our results suggest that character displacement likely interacts with other evolutionary processes in this system, and that temporal data are key to detecting such interactions
Economic evaluation of the OSAC randomised controlled trial:oral corticosteroids for non-asthmatic adults with acute lower respiratory tract infection in primary care
ObjectiveTo estimate the costs and outcomes associated with treating non-asthmatic adults (nor suffering from other lung-disease) presenting to primary care with acute lower respiratory tract infection (ALRTI) with oral corticosteroids compared with placebo.DesignCost-consequence analysis alongside a randomised controlled trial. Perspectives included the healthcare provider, patients and productivity losses associated with time off work.SettingFifty-four National Health Service (NHS) general practices in England.Participants398 adults attending NHS primary practices with ALRTI but no asthma or other chronic lung disease, followed up for 28 days.Interventions2× 20 mg oral prednisolone per day for 5 days versus matching placebo tablets.Outcome measuresQuality-adjusted life years using the 5-level EuroQol-5D version measured weekly; duration and severity of symptom. Direct and indirect resources related to the disease and its treatment were also collected. Outcomes were measured for the 28-day follow-up.Results198 (50%) patients received the intervention (prednisolone) and 200 (50%) received placebo. NHS costs were dominated by primary care contacts, higher with placebo than with prednisolone (£13.11 vs £10.38) but without evidence of a difference (95% CI £3.05 to £8.52). The trial medication cost of £1.96 per patient would have been recouped in prescription charges of £4.30 per patient overall (55% participants would have paid £7.85), giving an overall mean ‘profit’ to the NHS of £7.00 (95% CI £0.50 to £17.08) per patient. There was a quality adjusted life years gain of 0.03 (95% CI 0.01 to 0.05) equating to half a day of perfect health favouring the prednisolone patients; there was no difference in duration of cough or severity of symptoms.ConclusionsThe use of prednisolone for non-asthmatic adults with ALRTI, provided small gains in quality of life and cost savings driven by prescription charges. Considering the results of the economic evaluation and possible side effects of corticosteroids, the short-term benefits may not outweigh the long-term harms.Trial registration numbersEudraCT 2012-000851-15 and ISRCTN57309858; Pre-results
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