3,318 research outputs found
Testing Luminescence Dating Methods for Small Samples from Very Young Fluvial Deposits
The impetus behind this study is to understand the sedimentological dynamics of very young fluvial systems in the Amazon River catchment and relate these to land use change and modern analogue studies of tidal rhythmites in the geologic record. Initial quartz optically stimulated luminescence (OSL) dating feasibility studies have concentrated on spit and bar deposits in the Rio Tapajós. Many of these features have an appearance of freshly deposited pristine sand, and these observations and information from anecdotal evidence and LandSat imagery suggest an apparent decadal stability. The characteristics of OSL from small (~5 cm) sub-samples from ~65 cm by ~2 cm diameter vertical cores are quite remarkable. Signals from medium-sized aliquots (5 mm diameter) exhibit very high specific luminescence sensitivity, have excellent dose recovery and recycling, essentially independent of preheat, and show minimal heat transfer even at the highest preheats. These characteristics enable measurement of very small signals with reasonable precision and, using modified single-aliquot regenerative-dose (SAR) approaches, equivalent doses as low as ~4 mGy can be obtained. Significant recuperation is observed for samples from two of the study sites and, in these instances, either the acceptance threshold was increased or growth curves were forced through the origin; recuperation is considered most likely to be a measurement artefact given the very small size of natural signals. Dose rates calculated from combined inductively coupled plasma mass spectrometry/inductively coupled plasma optical emission spectrometry (ICP-MS/ICP-OES) and high-resolution gamma spectrometry range from ~0.3 to 0.5 mGya−1 , and OSL ages for features so far investigated range from 13 to 34 years to several 100 years. Sampled sands are rich in quartz and yields of 212–250 µm or 250–310 µm grains indicate high-resolution sampling at 1–2 cm intervals is possible. Despite the use of medium-sized aliquots to ensure the recovery of very dim natural OSL signals, these results demonstrate the potential of OSL for studying very young active fluvial processes in these settings
Refuge or Reservoir? The Potential Impacts of the Biofuel Crop Miscanthus x giganteus on a Major Pest of Maize
BACKGROUND: Interest in the cultivation of biomass crops like the C4 grass Miscanthus x giganteus (Miscanthus) is increasing as global demand for biofuel grows. In the US, Miscanthus is promoted as a crop well-suited to the Corn Belt where it could be cultivated on marginal land interposed with maize and soybean. Interactions (direct and indirect) of Miscanthus, maize, and the major Corn Belt pest of maize, the western corn rootworm, (Diabrotica virgifera virgifera LeConte, WCR) are unknown. Adding a perennial grass/biomass crop to this system is concerning since WCR is adapted to the continuous availability of its grass host, maize (Zea mays). METHODOLOGY/PRINCIPAL FINDINGS: In a greenhouse and field study, we investigated WCR development and oviposition on Miscanthus. The suitability of Miscanthus for WCR development varied across different WCR populations. Data trends indicate that WCR populations that express behavioural resistance to crop rotation performed as well on Miscanthus as on maize. Over the entire study, total adult WCR emergence from Miscanthus (212 WCR) was 29.6% of that from maize (717 WCR). Adult dry weight was 75-80% that of WCR from maize; female emergence patterns on Miscanthus were similar to females developing on maize. There was no difference in the mean no. of WCR eggs laid at the base of Miscanthus and maize in the field. CONCLUSIONS/SIGNIFICANCE: Field oviposition and significant WCR emergence from Miscanthus raises many questions about the nature of likely interactions between Miscanthus, maize and WCR and the potential for Miscanthus to act as a refuge or reservoir for Corn Belt WCR. Responsible consideration of the benefits and risks associated with Corn Belt Miscanthus are critical to protecting an agroecosystem that we depend on for food, feed, and increasingly, fuel. Implications for European agroecosystems in which Miscanthus is being proposed are also discussed in light of the WCR's recent invasion into Europe
Adaptive Data-based Predictive Control for Short Take-off and Landing (STOL) Aircraft
Data-based Predictive Control is an emerging control method that stems from Model Predictive Control (MPC). MPC computes current control action based on a prediction of the system output a number of time steps into the future and is generally derived from a known model of the system. Data-based predictive control has the advantage of deriving predictive models and controller gains from input-output data. Thus, a controller can be designed from the outputs of complex simulation code or a physical system where no explicit model exists. If the output data happens to be corrupted by periodic disturbances, the designed controller will also have the built-in ability to reject these disturbances without the need to know them. When data-based predictive control is implemented online, it becomes a version of adaptive control. The characteristics of adaptive data-based predictive control are particularly appropriate for the control of nonlinear and time-varying systems, such as Short Take-off and Landing (STOL) aircraft. STOL is a capability of interest to NASA because conceptual Cruise Efficient Short Take-off and Landing (CESTOL) transport aircraft offer the ability to reduce congestion in the terminal area by utilizing existing shorter runways at airports, as well as to lower community noise by flying steep approach and climb-out patterns that reduce the noise footprint of the aircraft. In this study, adaptive data-based predictive control is implemented as an integrated flight-propulsion controller for the outer-loop control of a CESTOL-type aircraft. Results show that the controller successfully tracks velocity while attempting to maintain a constant flight path angle, using longitudinal command, thrust and flap setting as the control inputs
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Password-manager friendly (PMF): Semantic annotations to improve the effectiveness of password managers
Retrospective Study of Midazolam Protocol for Prehospital Behavioral Emergencies
Introduction: Agitated patients in the prehospital setting pose challenges for both patient care and emergency medical services (EMS) provider safety. Midazolam is frequently used to control agitation in the emergency department setting; however, limited data exist in the prehospital setting. We describe our experience treating patients with midazolam for behavioral emergencies in a large urban EMS system. We hypothesized that using midazolam for acute agitation leads to improved clinical conditions without causing significant clinical deterioration.Methods: We performed a retrospective review of EMS patient care reports following implementation of a behavioral emergencies protocol in a large urban EMS system from February 2014–June 2016. For acute agitation, paramedics administered midazolam 1 milligram (mg) intravenous (IV), 5 mg intramuscular (IM), or 5 mg intranasal (IN). Results were analyzed using descriptive statistics, Levene’s test for assessing variance among study groups, and t-test to evaluate effectiveness based on route.Results: In total, midazolam was administered 294 times to 257 patients. Median age was 30 (interquartile range 24–42) years, and 66.5% were male. Doses administered were 1 mg (7.1%) and 5 mg (92.9%). Routes were IM (52.0%), IN (40.8%), and IV (7.1%). A second dose was administered to 37 patients. In the majority of administrations, midazolam improved the patient’s condition (73.5%) with infrequent adverse events (3.4%). There was no significant difference between the effectiveness of IM and IN midazolam (71.0% vs 75.4%; p = 0.24).Conclusion: A midazolam protocol for prehospital agitation was associated with reduced agitation and a low rate of adverse events
Public perceptions of drinking water: A postal survey of residents with private water supplies
Background: In Canada, the legal responsibility for the condition of private water supplies,
including private wells and cisterns, rests with their owners. However, there are reports that
Canadians test these water supplies intermittently and that treatment of such water is uncommon.
An estimated 45% of all waterborne outbreaks in Canada involve non-municipal systems. An
understanding of the perceptions and needs of Canadians served by private water supplies is
essential, as it would enable public health professionals to better target public education and
drinking water policy. The purpose of this study was to investigate the public perceptions of private
water supplies in the City of Hamilton, Ontario (Canada), with the intent of informing public
education and outreach strategies within the population.
Methods: A cross-sectional postal survey of 246 residences with private water supplies was
conducted in May 2004. Questions pertained to the perceptions of water quality and alternative
water sources, water testing behaviours and the self-identified need for further information.
Results: Private wells, cisterns or both, were the source of household water for 71%, 16% and
13% of respondents, respectively. Although respondents rated their water quality highly, 80% also
had concerns with its safety. The most common concerns pertained to bacterial and chemical
contamination of their water supply and its potential negative effect on health. Approximately 56%
and 61% of respondents used in-home treatment devices and bottled water within their homes,
respectively, mainly due to perceived improvements in the safety and aesthetic qualities compared
to regular tap water. Testing of private water supplies was performed infrequently: 8% of
respondents tested at a frequency that meets current provincial guidelines. Two-thirds of
respondents wanted more information on various topics related to private water supplies. Flyers
and newspapers were the two media reported most likely to be used.
Conclusion: Although respondents rated their water quality highly, the majority had concerns
regarding the water from their private supply, and the use of bottled water and water treatment
devices was extensive. The results of this study suggest important lines of inquiry and provide
support and input for public education programs, particularly those related to private water testing,
in this population
Expression of hemagglutinin protein from the avian influenza virus H5N1 in a baculovirus/insect cell system significantly enhanced by suspension culture
10.1186/1471-2180-6-16BMC Microbiology
To have and have not: Variations on secret sharing to model user presence
We address the problem of locking and unlocking a device, such as a laptop, a phone or a security token, based on the absence or presence of the user. We detect user presence by sensing the proximity of a subset of their possessions, making the process automatic and effortless. As in previous work, a master key unlocks the device and a secret-sharing scheme allows us to reconstruct this master key in the presence of k-out-of-n items. We extend this basic scheme in various directions, e.g. by allowing items to issue a dynamically variable number of shares based on how confident they are that the user is present. The position we argue in this paper is that a multi-dimensional approach to authentication that fuses several contextual inputs, similar to that already adopted by major web sites, can also bring advantages at the local scale.This is the author accepted manuscript. The final published version is available at http://dl.acm.org/citation.cfm?id=2641705&CFID=518729474&CFTOKEN=85977065
Impact of Caloric Intake on Parenteral Nutrition–Associated Intestinal Morphology and Mucosal Barrier Function
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142275/1/jpen0474.pd
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