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Institution

Carleton University

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


Papers
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Journal ArticleDOI
TL;DR: This article examined the factor structure of a widely used assessment of parenting practices, the Alabama Parenting Questionnaire, and produced a 9-item short scale around its three supported factors: Positive Parenting, Inconsistent Discipline and Poor Supervision.
Abstract: Brief assessments of parenting practices can provide important information about the development of disruptive behavior disorders in children. We examined the factor structure of a widely used assessment of parenting practices, the Alabama Parenting Questionnaire, and produced a 9-item short scale around its three supported factors: Positive Parenting, Inconsistent Discipline and Poor Supervision. The short scale was then validated in independent community samples using confirmatory factor analysis and measures of disruptive behavioral disorders in children. The scale showed good fit to a three-factor model and good convergent validity by differentiating parents of children with disruptive behavioral disorders and parents of children without such disorders. Results indicated that this new measure is an informative tool for researchers and clinicians whom require brief assessments of parenting practices relating to disruptive behavioral disorders in children.

229 citations

Journal ArticleDOI
TL;DR: All primitive Paleozoic pterygote nymphs are now known to have had articulated, freely movable wings reinforced by tubular veins, which suggests that the wings of early Pterygota were engaged in flapping movements, and that the immobilized, fixed, veinless wing pads of Recentnymphs have resulted from a later adaptation affecting only juveniles.
Abstract: In contemporary entomology the morphological characters of insects are not always treated according to their phylogenetic rank. Fossil evidence often gives clues for different interpretations. All primitive Paleozoic pterygote nymphs are now known to have had articulated, freely movable wings reinforced by tubular veins. This suggests that the wings of early Pterygota were engaged in flapping movements, that the immobilized, fixed, veinless wing pads of Recent nymphs have resulted from a later adaptation affecting only juveniles, and that the paranotal theory of wing origin is not valid. The wings of Paleozoic nymphs were curved backwards in Paleoptera and were flexed backwards at will in Neoptera, in both to reduce resistance during forward movement. Therefore, the fixed oblique-backwards position of wing pads in all modern nymphs is secondary and is not homologous in Paleoptera and Neoptera. Primitive Paleozoic nymphs had articulated and movable prothoracic wings which became in some modern insects transformed into prothoracic lobes and shields. The nine pairs of abdominal gillplates of Paleozoic mayfly nymphs have a venation pattern, position, and development comparable to that in thoracic wings, to which they are serially homologous. Vestigial equivalents of wings and legs were present in the abdomen of all primitive Paleoptera and primitive Neoptera. The ontogenetic development of Paleozoic nymphs was confluent, with many nymphal and subimaginal instars, and the metamorphic instar was missing. The metamorphic instar originated by the merging together of several instars of old nymphs; it occurred in most orders only after the Paleozoic, separately and in parallel in all modern major lineages (at least twice in Paleoptera, in Ephemeroptera and Odonata; separately in hemipteroid, blattoid, orthopteroid, and plecopteroid lineages of exopterygote Neoptera; and once only in Endopterygota). Endopterygota evolved from ametabolous, not from hemimetabolous, exopterygote Neoptera. The full primitive wing venation consists of six symmetrical pairs of veins; in each pair, the first branch is always convex and the second always concave; therefore costa, subcosta, radius, media, cubitus, and anal are all primitively composed of two separate branches. Each pair arises from a single veinal base formed from a sclerotized blood sinus. In the most primitive wings the circulatory system was as follows: the costa did not encircle the wing, the axillary cord was missing, and the blood pulsed in and out of each of the six primary, convex-concave vein pair systems through the six basal blood sinuses. This type of circulation is found as an archaic feature in modern mayflies. Wing corrugation first appeared in preflight wings, and hence is considered primitive for early (paleopterous) Pterygota. Somewhat leveled corrugation of the central wing veins is primitive for Neoptera. Leveled corrugation in some modern Ephemeroptera, as well as accentuated corrugation in higher Neoptera, are both derived characters. The wing tracheation of Recent Ephemeroptera is not fully homologous to that of other insects and represents a more primitive, segmental stage of tracheal system. Morphology of an ancient articular region in Palaeodictyoptera shows that the primitive pterygote wing hinge in its simplest form was straight and composed of two separate but adjoining morphological units: the tergal, formed by the tegula and axillaries; and the alar, formed by six sclerotized blood sinuses, the basivenales. The tergal sclerites were derived from the tergum as follows: the lateral part of the tergum became incised into five lobes; the prealare, suralare, median lobe, postmedian lobe and posterior notal wing process. From the tips of these lobes, five slanted tergal sclerites separated along the deep paranotal sulcus: the tegula, first axillary, second axillary, median sclerite, and third axillary. Primitively, all pteralia were arranged in two parallel series on both sides of the hinge. In Paleoptera, the series stayed more or less straight; in Neoptera, the series became V-shaped. Pteralia in Paleoptera and Neoptera have been homologized on the basis of the fossil record. A differential diagnosis between Paleoptera and Neoptera is given. Fossil evidence indicates that the major steps in evolution, which led to the origin first of Pterygota, then of Neoptera and Endopterygota, were triggered by the origin and the diversification of flight apparatus. It is believed here that all above mentioned major events in pterygote evolution occurred first in the immature stages.

229 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed an intelligent micronutrient delivery platform (IMNDP) based on elucidating communication signals between plant roots and soil microorganisms, which can be used to synchronize the release of nutrients from fertilizers with crop demand during growing season.
Abstract: Billions of people and many soils across the planet suffer from micronutrient (MN) deficiencies impairing human health. In general, fertilization of deficient soils, according to soil test, with MNs alone and in combination with nitrogen, phosphorous, and potassium (NPK) baseline treatment increases crop yield. The soil applied fertilizer-MN use efficiency (MUE) by crops is <5 % due to a lack of synchronization between the fertilizer-MN release and their crop demand during growth. Nanotechnology and biotechnology have the potential to play a prominent place in transforming agricultural systems and food production worldwide in the coming years. MNs added in microcapsules and nanocapsules, nanomaterials (NMs), and nanoparticles (NPs) are taken up and translocated within plants when grown to maturity, increasing crop yield and MN concentration in plants. Noteworthy, many of the effects of NPs and NMs on crop yield and quality, human health, and associated environmental risks remain to be explored. Increasing MUE requires synchronizing the release of nutrients from fertilizers with crop demand during the growing season. Development of intelligent MN fertilizer delivery platforms (IMNDP) may be possible on the basis of elucidating communication signals between plant roots and soil microorganisms. Important benefits from the development and farm adoption of intelligent MN delivery platforms include increased MUE, reduced fertilizer use, and minimal toxicity and environmental impacts. This article proposes for the first time a novel model for IMNDP to enhance MUE and food quality by enabling the synchronization of MN release from fertilizers according to crop demand.

228 citations

Proceedings Article
06 Aug 2007
TL;DR: The results suggest that these graphical password schemes appear to be at least as susceptible to offline attack as the traditional text passwords they were proposed to replace.
Abstract: Although motivated by both usability and security concerns, the existing literature on click-based graphical password schemes using a single background image (e.g., PassPoints) has focused largely on usability. We examine the security of such schemes, including the impact of different background images, and strategies for guessing user passwords. We report on both short- and long-term user studies: one lab-controlled, involving 43 users and 17 diverse images, and the other a field test of 223 user accounts. We provide empirical evidence that popular points (hot-spots) do exist for many images, and explore two different types of attack to exploit this hot-spotting: (1) a "human-seeded" attack based on harvesting click-points from a small set of users, and (2) an entirely automated attack based on image processing techniques. Our most effective attacks are generated by harvesting password data from a small set of users to attack other targets. These attacks can guess 36% of user passwords within 231 guesses (or 12% within 216 guesses) in one instance, and 20% within 233 guesses (or 10% within 218 guesses) in a second instance. We perform an image-processing attack by implementing and adapting a bottom-up model of visual attention, resulting in a purely automated tool that can guess up to 30% of user passwords in 235 guesses for some instances, but under 3% on others. Our results suggest that these graphical password schemes appear to be at least as susceptible to offline attack as the traditional text passwords they were proposed to replace.

228 citations


Authors

Showing all 16102 results

NameH-indexPapersCitations
George F. Koob171935112521
Zhenwei Yang150956109344
Andrew White1491494113874
J. S. Keller14498198249
R. Kowalewski1431815135517
Manuella Vincter131944122603
Gabriella Pasztor129140186271
Beate Heinemann129108581947
Claire Shepherd-Themistocleous129121186741
Monica Dunford12990677571
Dave Charlton128106581042
Ryszard Stroynowski128132086236
Peter Krieger128117181368
Thomas Koffas12894276832
Aranzazu Ruiz-Martinez12678371913
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202389
2022381
20212,299
20202,243
20192,017
20181,841