The engagement model of reading development suggests that instruction improves students' reading ... more The engagement model of reading development suggests that instruction improves students' reading comprehension to the extent that it increases students' engagement processes in reading. We compared how Concept-Oriented Reading Instruction (CORI) (support for cognitive and motivational processes in reading), strategy instruction (support for cognitive strategies in reading), and traditional instruction in fourth-grade classrooms differentially influenced students' reading comprehension, strategy use, and engagement in reading. Students experiencing CORI were significantly higher than both comparison groups on reading comprehension, reading strategies, and reading engagement. When students' level of reading engagement was statistically controlled, the differences between the treatment groups were not significant. We infer that the level of students' reading engagement during classroom work mediated the instructional effects on reading outcomes.
Based on an engagement perspective of reading development, we investigated the extent to which an... more Based on an engagement perspective of reading development, we investigated the extent to which an instructional framework of combining motivation support and strategy instruction (Concept-Oriented Reading Instruction-CORI) influenced reading outcomes for third-grade children. In CORI, five motivational practices were integrated with six cognitive strategies for reading comprehension. In the first study, we compared this framework to an instructional framework emphasizing Strategy Instruction (SI), but not including motivation support. In the second study, we compared CORI to SI and to a traditional instruction group (TI), and used additional measures of major constructs. In both studies, class-level analyses showed that students in CORI classrooms were higher than SI and/or TI students on measures of reading comprehension, reading motivation, and reading strategies.
Two species of lepidopteran herbivores, Manduca sexta (Sphingidae) and Trichoplusia ni (Noctuidae... more Two species of lepidopteran herbivores, Manduca sexta (Sphingidae) and Trichoplusia ni (Noctuidae), were reared on synthetic diet containing either the alkaloid nicotine or the flavonoid rutin. Survival and pupal weight of the specialist M. sexta did not differ when larvae were reared on diet containing nicotine or rutin. In contrast, the generalist T. ni did not survive on diet containing 0.125% nicotine or greater, whereas larvae survived on all concentrations of rutin. These data demonstrate that the alkaloid nicotine is inhibitory toward generalist, but not specialist herbivores, whereas the flavonoid rutin has no effect on specialist herbivores and limited effects on generalist herbivores. Five species of Pseudomonas bacterial pathogens: P. syringae, P. syringae pv. angulata, P. syringae pv. tabaci, P. fluorescens, and P. solanacearum were grown on nutrient agar containing nicotine or rutin at concentrations ranging from 0.0 to 1.0% wet weight in 0.1% intervals. No species of Pseudomonas grew at concentrations greater than 0.5% nicotine when 106 colony forming units (cfu) were used, but growth occurred at all concentrations of rutin when 102 cfu were used. These data indicate that nicotine was inhibitory to growth of both herbivores and pathogens, suggesting that certain plant secondary chemicals with high toxicity are of a generalized nature and affect multiple species. Differences in the sensitivity of organisms to allelochemicals such as generalist or specialist can make it appear that specific allelochemicals affect specific organisms, when in fact it is the tolerance of the organism to the plant chemical that is responsible. In four separate studies, the growth of M. sexta, T. ni and Helicoverpa zea was significantly lower on plants inoculated with P. solanacearum. Alteration in leaf quality by P. solanacearum was due to either reductions in leaf nutrients or increases in allelochemicals. We speculate that localized or systemic induction by both herbivores and pathogens can cause changes in leaf quality, effecting each other's subsequent colonization. The generalized nature of plant secondary compounds and potential reciprocal effects on induction by both species suggests that herbivores and pathogens may affect plant quality through induction and diffuse interactions of disparate species can alter the community of organisms colonizing a plant.
Vol. 130, No. 1 The American Naturalist July 1987 INFLUENCE OF ALKALOIDS ON FEEDING PREFERENCE OF... more Vol. 130, No. 1 The American Naturalist July 1987 INFLUENCE OF ALKALOIDS ON FEEDING PREFERENCE OF EASTERN DECIDUOUS FOREST TREES BY THE GYPSY MOTH LYMANTRIA DISPAR Pedro Barbosa and Vera Aber Krischik Department of Entomology, University of ...
Page 1. INFLUENCE OF NATURAL DIETS AND LARVAL DENSITY ON GYPSY MOTH, LYMANTRZA DZSPAR (LEPIDOPTER... more Page 1. INFLUENCE OF NATURAL DIETS AND LARVAL DENSITY ON GYPSY MOTH, LYMANTRZA DZSPAR (LEPIDOPTERA: ORGYIIDAE), EGG MASS CHARACTERISTICS' JOHN L. CAP IN ERA"^^ PEDRO BARBOSA Department of Entomology, University of Massachusetts ...
Field studies of dispersal by first instar gypsy moth larvae indicate that almost all larvae unde... more Field studies of dispersal by first instar gypsy moth larvae indicate that almost all larvae undergo an initial dispersal episode. However, in laboratory studies large larvae (from large eggs) disperse more frequently than small larvae (from small eggs) in the presence of favored food. Large larvae may be better adapted for dispersal. When larvae encounter unacceptable food or are denied food, larvae disperse more frequently and dispersal by small larvae is nearly as frequent as dispersal by large larvae. Factors affecting egg size may contribute to shifts in dispersal patterns of gypsy moth larvae and distribution of populations.
Canadian Journal of Zoology-revue Canadienne De Zoologie, 1977
Abstract: The host species consumed by larval gypsy moths have significant influences on their de... more Abstract: The host species consumed by larval gypsy moths have significant influences on their development. Feeding on red maple, red oak, synthetic food, and a diet of both oak and maple results in differences in mean frass production, pupal weights, and development times. ...
Canadian Journal of Zoology-revue Canadienne De Zoologie, 1981
AGRIS record. Record number, CA8209214. Titles, Influence of food quantity and quality on polymor... more AGRIS record. Record number, CA8209214. Titles, Influence of food quantity and quality on polymorphic dispersal behaviors in the gypsy moth, Lymantria dispar. Personal Authors, Barbosa, P. (Dep. Entomology, Univ. Massachusetts ...
1. Most insect species occur at low abundance but a greater research effort has been devoted to s... more 1. Most insect species occur at low abundance but a greater research effort has been devoted to so-called outbreak species and little research is available on scarce (low abundance) species that are typical of most insect species. ... 2. Larval free-feeding macrolepidoptera of two ...
Early theories on plant chemical defense against herbivory emphasized that apparent and unapparen... more Early theories on plant chemical defense against herbivory emphasized that apparent and unapparent plants were primarily defended by different types of compounds. More and more evidence suggests that both quantitative and qualitative defenses are found in apparent plants and that they can play a defensive role against herbivores. A survey of the literature on the gypsy moth suggests not only that there is a large variety of qualitative compounds, as well as the expected quantitative ones, but that unfavored hosts of the gypsy moth are associated with the presence of alkaloids. Foliage of three tree species,Liriodendron tulipifera L.,Acer rubrum L., andCornus florida L., was examined to confirm the presence of alkaloids and other major secondary metabolites. The known sesquiterpene lactone, lipiferolide, and the sugar derivative, liriodendritol, were components ofL. tulipifera leaves, along with a bisphenylpropanoid previously found only in nutmeg. Alkaloid content [i.e., (−)-N-methylcrotsparine content] was low and leaves tested positive for HCN. Leaves ofA. rubrum L. were examined for the presence of gramme, but none could be detected. No alkaloids were detected inCornus florida.
The engagement model of reading development suggests that instruction improves students' reading ... more The engagement model of reading development suggests that instruction improves students' reading comprehension to the extent that it increases students' engagement processes in reading. We compared how Concept-Oriented Reading Instruction (CORI) (support for cognitive and motivational processes in reading), strategy instruction (support for cognitive strategies in reading), and traditional instruction in fourth-grade classrooms differentially influenced students' reading comprehension, strategy use, and engagement in reading. Students experiencing CORI were significantly higher than both comparison groups on reading comprehension, reading strategies, and reading engagement. When students' level of reading engagement was statistically controlled, the differences between the treatment groups were not significant. We infer that the level of students' reading engagement during classroom work mediated the instructional effects on reading outcomes.
Based on an engagement perspective of reading development, we investigated the extent to which an... more Based on an engagement perspective of reading development, we investigated the extent to which an instructional framework of combining motivation support and strategy instruction (Concept-Oriented Reading Instruction-CORI) influenced reading outcomes for third-grade children. In CORI, five motivational practices were integrated with six cognitive strategies for reading comprehension. In the first study, we compared this framework to an instructional framework emphasizing Strategy Instruction (SI), but not including motivation support. In the second study, we compared CORI to SI and to a traditional instruction group (TI), and used additional measures of major constructs. In both studies, class-level analyses showed that students in CORI classrooms were higher than SI and/or TI students on measures of reading comprehension, reading motivation, and reading strategies.
Two species of lepidopteran herbivores, Manduca sexta (Sphingidae) and Trichoplusia ni (Noctuidae... more Two species of lepidopteran herbivores, Manduca sexta (Sphingidae) and Trichoplusia ni (Noctuidae), were reared on synthetic diet containing either the alkaloid nicotine or the flavonoid rutin. Survival and pupal weight of the specialist M. sexta did not differ when larvae were reared on diet containing nicotine or rutin. In contrast, the generalist T. ni did not survive on diet containing 0.125% nicotine or greater, whereas larvae survived on all concentrations of rutin. These data demonstrate that the alkaloid nicotine is inhibitory toward generalist, but not specialist herbivores, whereas the flavonoid rutin has no effect on specialist herbivores and limited effects on generalist herbivores. Five species of Pseudomonas bacterial pathogens: P. syringae, P. syringae pv. angulata, P. syringae pv. tabaci, P. fluorescens, and P. solanacearum were grown on nutrient agar containing nicotine or rutin at concentrations ranging from 0.0 to 1.0% wet weight in 0.1% intervals. No species of Pseudomonas grew at concentrations greater than 0.5% nicotine when 106 colony forming units (cfu) were used, but growth occurred at all concentrations of rutin when 102 cfu were used. These data indicate that nicotine was inhibitory to growth of both herbivores and pathogens, suggesting that certain plant secondary chemicals with high toxicity are of a generalized nature and affect multiple species. Differences in the sensitivity of organisms to allelochemicals such as generalist or specialist can make it appear that specific allelochemicals affect specific organisms, when in fact it is the tolerance of the organism to the plant chemical that is responsible. In four separate studies, the growth of M. sexta, T. ni and Helicoverpa zea was significantly lower on plants inoculated with P. solanacearum. Alteration in leaf quality by P. solanacearum was due to either reductions in leaf nutrients or increases in allelochemicals. We speculate that localized or systemic induction by both herbivores and pathogens can cause changes in leaf quality, effecting each other's subsequent colonization. The generalized nature of plant secondary compounds and potential reciprocal effects on induction by both species suggests that herbivores and pathogens may affect plant quality through induction and diffuse interactions of disparate species can alter the community of organisms colonizing a plant.
Vol. 130, No. 1 The American Naturalist July 1987 INFLUENCE OF ALKALOIDS ON FEEDING PREFERENCE OF... more Vol. 130, No. 1 The American Naturalist July 1987 INFLUENCE OF ALKALOIDS ON FEEDING PREFERENCE OF EASTERN DECIDUOUS FOREST TREES BY THE GYPSY MOTH LYMANTRIA DISPAR Pedro Barbosa and Vera Aber Krischik Department of Entomology, University of ...
Page 1. INFLUENCE OF NATURAL DIETS AND LARVAL DENSITY ON GYPSY MOTH, LYMANTRZA DZSPAR (LEPIDOPTER... more Page 1. INFLUENCE OF NATURAL DIETS AND LARVAL DENSITY ON GYPSY MOTH, LYMANTRZA DZSPAR (LEPIDOPTERA: ORGYIIDAE), EGG MASS CHARACTERISTICS' JOHN L. CAP IN ERA"^^ PEDRO BARBOSA Department of Entomology, University of Massachusetts ...
Field studies of dispersal by first instar gypsy moth larvae indicate that almost all larvae unde... more Field studies of dispersal by first instar gypsy moth larvae indicate that almost all larvae undergo an initial dispersal episode. However, in laboratory studies large larvae (from large eggs) disperse more frequently than small larvae (from small eggs) in the presence of favored food. Large larvae may be better adapted for dispersal. When larvae encounter unacceptable food or are denied food, larvae disperse more frequently and dispersal by small larvae is nearly as frequent as dispersal by large larvae. Factors affecting egg size may contribute to shifts in dispersal patterns of gypsy moth larvae and distribution of populations.
Canadian Journal of Zoology-revue Canadienne De Zoologie, 1977
Abstract: The host species consumed by larval gypsy moths have significant influences on their de... more Abstract: The host species consumed by larval gypsy moths have significant influences on their development. Feeding on red maple, red oak, synthetic food, and a diet of both oak and maple results in differences in mean frass production, pupal weights, and development times. ...
Canadian Journal of Zoology-revue Canadienne De Zoologie, 1981
AGRIS record. Record number, CA8209214. Titles, Influence of food quantity and quality on polymor... more AGRIS record. Record number, CA8209214. Titles, Influence of food quantity and quality on polymorphic dispersal behaviors in the gypsy moth, Lymantria dispar. Personal Authors, Barbosa, P. (Dep. Entomology, Univ. Massachusetts ...
1. Most insect species occur at low abundance but a greater research effort has been devoted to s... more 1. Most insect species occur at low abundance but a greater research effort has been devoted to so-called outbreak species and little research is available on scarce (low abundance) species that are typical of most insect species. ... 2. Larval free-feeding macrolepidoptera of two ...
Early theories on plant chemical defense against herbivory emphasized that apparent and unapparen... more Early theories on plant chemical defense against herbivory emphasized that apparent and unapparent plants were primarily defended by different types of compounds. More and more evidence suggests that both quantitative and qualitative defenses are found in apparent plants and that they can play a defensive role against herbivores. A survey of the literature on the gypsy moth suggests not only that there is a large variety of qualitative compounds, as well as the expected quantitative ones, but that unfavored hosts of the gypsy moth are associated with the presence of alkaloids. Foliage of three tree species,Liriodendron tulipifera L.,Acer rubrum L., andCornus florida L., was examined to confirm the presence of alkaloids and other major secondary metabolites. The known sesquiterpene lactone, lipiferolide, and the sugar derivative, liriodendritol, were components ofL. tulipifera leaves, along with a bisphenylpropanoid previously found only in nutmeg. Alkaloid content [i.e., (−)-N-methylcrotsparine content] was low and leaves tested positive for HCN. Leaves ofA. rubrum L. were examined for the presence of gramme, but none could be detected. No alkaloids were detected inCornus florida.
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