Carleton University

About: Carleton University is a education organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 15852 authors who have published 39650 publications receiving 1106610 citations.

Quantifying ingested debris in marine megafauna: a review and recommendations for standardization

Abstract: Plastic pollution has become one of the largest environmental challenges we currently face. The United Nations Environment Program (UNEP) has listed it as a critical problem, comparable to climate change, demonstrating both the scale and degree of the environmental problem. Mortalities due to entanglement in plastic fishing nets and bags have been reported for marine mammals, turtles and seabirds, and to date over 690 marine species have been reported to ingest plastics. The body of literature documenting plastic ingestion by marine megafauna (i.e. seabirds, turtles, fish and marine mammals) has grown rapidly over the last decade, and it is expected to continue grow as researchers explore the ecological impacts of marine pollution. Unfortunately, a cohesive approach by the scientific community to quantify plastic ingestion by wildlife is lacking, which is now hindering spatial and temporal comparisons between and among species/organisms. Here, we discuss and propose standardized techniques, approaches and metrics for reporting debris ingestion that are applicable to most large marine vertebrates. As a case study, we examine how the use of standardized methods to report ingested debris in Northern Fulmars (Fulmarus glacialis) has enabled long term and spatial trends in plastic pollution to be studied. Lastly, we outline standardized metric recommendations for reporting ingested plastics in marine megafauna, with the aim to harmonize the data that are available to facilitate large-scale comparisons and meta-analyses of plastic accumulation in a variety of taxa. If standardized methods are adopted, future plastic ingestion research will be better able to inform questions related to the impacts of plastics across taxonomic, ecosystem and spatial scales.

The calibration and resolution of confidence in perceptual judgments.

Abstract: Carleton University, Ottawa, Ontariot Canada Confidence rating based calibration and resolution indices were obtained in two experiments requiring perceptual comparisons and in a third with visual gap detection. Four important results were obtained. First, as in the general knowledge domain, subjects were underconfident when judgments were easy and overconfident when they were difficult. Second, paralleling the clear dependence of calibration on decisional difficulty, resolution decreased with increases in decision difficulty arising either from decreases in discriminability or from increasing demands for speed at the expense of accuracy. Third, providing trial-by-trial response feedback on difficult tasks improved resolution but had no effect on calibration. Fourth, subjects can accurately reportsubjective errors (i.e., trials in which they have indicated that they made an error) with their confidence ratings. It is also shown that the properties of decision time, conditionalized on confidence category, impose a rigorous set of constraints on theories of confidence calibration.

A Research Agenda Acknowledging the Persistence of Passwords

Abstract: Despite countless attempts and near-universal desire to replace them, passwords are more widely used and firmly entrenched than ever. The authors' exploration leads them to argue that no silver bullet will meet all requirements-not only will passwords be with us for some time, but in many instances, they're the solution that best fits the scenario of use. Among broad authentication research directions to follow, they first suggest better means to concretely identify actual requirements (surprisingly overlooked to date) and weight their relative importance in target scenarios. Second, for scenarios where passwords appear to be the best-fit solution, they suggest designing better means to support them. The authors also highlight the need for more systematic research and how the premature conclusion that passwords are dead has led to the neglect of important research questions.

Luminosity determination in pp collisions at √s = 8 TeV using the ATLAS detector at the LHC

Abstract: The luminosity determination for the ATLAS detector at the LHC during pp collisions at s√= 8 TeV in 2012 is presented. The evaluation of the luminosity scale is performed using several luminometers ...

Arabidopsis CER8 encodes LONG-CHAIN ACYL-COA SYNTHETASE 1 (LACS1) that has overlapping functions with LACS2 in plant wax and cutin synthesis

Abstract: Plant cuticle is an extracellular lipid-based matrix of cutin and waxes, which covers aerial organs and protects them from many forms of environmental stress. We report here the characterization of CER8/LACS1, one of nine Arabidopsis long-chain acyl-CoA synthetases thought to activate acyl chains. Mutations in LACS1 reduced the amount of wax in all chemical classes on the stem and leaf, except in the very long-chain fatty acid (VLCFA) class wherein acids longer than 24 carbons (C(24)) were elevated more than 155%. The C(16) cutin monomers on lacs1 were reduced by 37% and 22%, whereas the C(18) monomers were increased by 28% and 20% on stem and leaf, respectively. Amounts of wax and cutin on a lacs1-1 lacs2-3 double mutant were much lower than on either parent, and lacs1-1 lacs2-3 had much higher cuticular permeability than either parent. These additive effects indicate that LACS1 and LACS2 have overlapping functions in both wax and cutin synthesis. We demonstrated that LACS1 has synthetase activity for VLCFAs C(20)-C(30), with highest activity for C(30) acids. LACS1 thus appears to function as a very long-chain acyl-CoA synthetase in wax metabolism. Since C(16) but not C(18) cutin monomers are reduced in lacs1, and C(16) acids are the next most preferred acid (behind C(30)) by LACS1 in our assays, LACS1 also appears to be important for the incorporation of C(16) monomers into cutin polyester. As such, LACS1 defines a functionally novel acyl-CoA synthetase that preferentially modifies both VLCFAs for wax synthesis and long-chain (C(16)) fatty acids for cutin synthesis.