5,874 research outputs found
Comparing Live-Capture Methods for Nutria: Single- Versus Multiple-Capture Cage Traps
Herbivory and burrowing by nutria (Myocastor coypus) cause substantial ecological and economic damage. Trapping is a common, effective practice for reducing nutria damage; however, trapping approaches must continually be adapted to keep pace with evolving animal welfare and ethical issues and to more effectively target pest species of interest. Our objective was to evaluate the efficacy of 2 nonlethal trap types for nutria: single-capture (SCT) and multi-capture (MCT) cage traps. We established 3 MCTs and 3 SCTs at each of 7 sites on a 10,500-ha mixed-use island located 15 km northwest of Portland, Oregon, USA. We pre-baited using carrots, apples, and sweet potatoes for ≥3 consecutive days before trapping. We checked traps daily, and an infrared motion camera was established near each MCT to document activity. We captured 26 nutria over 724 trap nights, and all captures occurred at 4 sites. Nutria captured by MCTs were larger (6.38 ± 1.68 [SD] kg, n = 10) than nutria captured by SCTs (4.21 ± 2.48 [SD] kg, n = 16; F1,25 = 5.51,P = 0.02). Camera surveillance showed multiple nutria present in an MCT on ≥2 occasions, although individual
Efficacy of Plastic Mesh Tubes in Reducing Herbivory Damage by the Invasive Nutria (Myocastor coypus) in an Urban Restoration Site
The restoration of stream corridors is becoming an increasingly important component of urban landscape planning, and the high cost of these projects necessitates the need to understand and address potential ecological obstacles to project success. The nutria (Myocastor coypus) is an invasive, semi-aquatic rodent native to South America that causes detrimental ecological impacts in riparian and wetland habitats throughout its introduced range, and techniques are needed to reduce nutria herbivory damage to urban stream restoration projects. We assessed the efficacy of standard Vexar® plastic mesh tubes in reducing nutria herbivory damage to newly established woody plants. The study was conducted in winter-spring 2009 at Delta Ponds, a 60-ha urban waterway in Eugene, Oregon. Woody plants protected by Vexar® tubes demonstrated 100% survival over the 3-month initial establishment period, while only 17% of unprotected plantings survived. Nutria demonstrated a preference for black cottonwood(Populus balsamifera ssp trichocarpa) over red osier dogwood (Cornus sericea) and willow (Salix spp). Camera surveillance showed that nutria were more active in unprotected rather than protected treatments. Our results suggest that Vexar® plastic mesh tubing can be an effective short-term herbivory mitigation tool when habitat use by nutria is low. Additionally, planting functionally equivalent woody plant species that are less preferred by nutria, and other herbivores, may be another method for reducing herbivory and improving revegetation success. This study highlights the need to address potential wildlife damage conflicts in the planning process for stream restoration in urban landscapes
Comparing Live Capture Methods for Nutria (Myocastor coypus): Single Versus Multiple-Capture Cage Traps
Herbivory and burrowing by nutria (Myocastor coypus) cause substantial ecological and economic damage. Trapping is a common practice for reducing nutria damage; however, trapping approaches must continually be adapted to keep pace with evolving animal welfare and ethical issues and to more effectively target species of interest. Our objective was to evaluate the efficacy of 2 non-lethal trap types for nutria: single-capture (SCT) and multi-capture (MCT) cage traps. We established 3 MCT and 3 SCT at each of 7 sites on a 10,500 ha mixed-use island, located 15 km northwest of Portland, Oregon. Pre-baiting was accomplished using carrots, apples, and sweet potatoes for ≥ 3 consecutive days before trapping. Traps were checked daily, and an infrared motion camera was established near each MCT to document activity. A total of 26 nutria were captured over 724 trap nights, with all captures occurring at 4 sites. Nutria captured by MCT were larger (6.38 ± 1.68 [SD] kg, n = 10), than nutria captured by SCT (4.21 ± 2.48 [SD] kg, n = 16; F1,25 = 5.51, P = 0.02). Camera surveillance showed multiple nutria present in a MCT on ≥ 2 occasions, although individuals \u3c 3.7 kg were able to escape. MCT were more expensive, larger, heavier, and more difficult to transport and deploy compared to SCT. However, MCT were much less likely to capture non-targets, capturing only 1 individual while the SCT had 35 non-target captures of 7species. Alterations to MCT door design would likely increase multiple catch opportunities and decrease escapes
The Economic Impact of Implementing Nondestructive Testing of Reinforced Concrete Bridge Decks in Indiana
The deck is among the most expensive components of a bridge over its lifetime because of the frequent and costly maintenance and rehabilitation required. Currently, the Indiana Department of Transportation (INDOT) performs visual inspections of a bridge deck as the principal means of determining its condition, which enables the inspector to definitively document the surface condition while the unseen condition below the deck surface is left to the inspector’s expert judgement. To compensate for this lack of data, INDOT supplements visual inspections with programmatic scheduling for major work actions, which is very effective for INDOT but costly. In this continuing era of funding shortfalls, INDOT commissioned this study to investigate nondestructive testing (NDT) methods to fill their data gap to inform its work action decision. The NDT methods have been shown to accurately locate corrosion and delamination and are a cost-effective alternative. A project level comparison between the NDT methods was performed to show which method, as well as which combination of methods, were the best choices from a cost perspective. A project level analysis of 30 bridge decks was performed, and those costs were compared to the costs of the current INDOT programmatic schedules. Finally, the analysis was expanded to the network level, which included the entire bridge inventory in Indiana. The results of this study indicate that implementing the NDT methods is cost-effective for INDOT at both the project and network levels
Tuberculosis in Dr Granville's mummy: a molecular re-examination of the earliest known Egyptian mummy to be scientifically examined and given a medical diagnosis
‘Dr Granville's mummy’ was described to the Royal Society of London in 1825 and was the first ancient Egyptian mummy to be subjected to a scientific autopsy. The remains are those of a woman, Irtyersenu, aged about 50, from the necropolis of Thebes and dated to about 600 BC. Augustus Bozzi Granville (1783–1872), an eminent physician and obstetrician, described many organs still in situ and attributed the cause of death to a tumour of the ovary. However, subsequent histological investigations indicate that the tumour is a benign cystadenoma. Histology of the lungs demonstrated a potentially fatal pulmonary exudate and earlier studies attempted to associate this with particular disease conditions. Palaeopathology and ancient DNA analyses show that tuberculosis was widespread in ancient Egypt, so a systematic search for tuberculosis was made, using specific DNA and lipid biomarker analyses. Clear evidence for Mycobacterium tuberculosis complex DNA was obtained in lung tissue and gall bladder samples, based on nested PCR of the IS6110 locus. Lung and femurs were positive for specific M. tuberculosis complex cell-wall mycolic acids, demonstrated by high-performance liquid chromatography of pyrenebutyric acid–pentafluorobenzyl mycolates. Therefore, tuberculosis is likely to have been the major cause of death of Irtyersenu
Transverse Fivebranes in Matrix Theory
M-theory on the maximally supersymmetric plane wave background of
eleven-dimensional supergravity admits spherical BPS transverse M5-branes with
zero light-cone energy. We give direct evidence that the single M5-brane state
corresponds to the trivial (X=0) classical vacuum in the large N limit of the
plane wave matrix theory. In particular, we show that the linear fluctuation
spectrum of the spherical fivebrane matches exactly with the set of exactly
protected excited states about the X=0 vacuum in the matrix model. These states
include geometrical fluctuations of the sphere, excitations of the worldvolume
two-form field, and fermion excitations. In addition, we propose a description
of multiple fivebrane states in terms of matrix model vacua.
Finally, we discuss how to obtain the continuum D2/M2 and NS5/M5 theories on
spheres from the matrix model. The matrix model can be viewed as a
regularization for these theories.Comment: Latex file, 2 eps figures, 22 pages; v2: typo correcte
Driver behaviour with adaptive cruise control
This paper reports on the evaluation of adaptive cruise control (ACC) from a psychological perspective. It was anticipated that ACC would have an effect upon the psychology of driving, i.e. make the driver feel like they have less control, reduce the level of trust in the vehicle, make drivers less situationally aware, but workload might be reduced and driving might be less stressful. Drivers were asked to drive in a driving simulator under manual and ACC conditions. Analysis of variance techniques were used to determine the effects of workload (i.e. amount of traffic) and feedback (i.e. degree of information from the ACC system) on the psychological variables measured (i.e. locus of control, trust, workload, stress, mental models and situation awareness). The results showed that: locus of control and trust were unaffected by ACC, whereas situation awareness, workload and stress were reduced by ACC. Ways of improving situation awareness could include cues to help the driver predict vehicle trajectory and identify conflicts
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