1 |
The Interactive Effects of Water Salinity and Management on Symbiotic Nitrogen Fixation in AlfalfaKeck, Thomas J. 01 May 1982 (has links)
A greehhouse study was conducted to assess the interactive effects of three irrigation water salinity levels (1 . 0, 3. 0, and 9 . 0 mmho/cm) and three quantities of water app lied per irrigation (120 , 240, 360 ml) on plant growth and nitrogen fixation by alfalfa (Medicago sativa L. cv. Resistador). Harvest dates corresponded t o 10, 30, and 50 days after the initiation of salt and water treatments which were started after nodulation had been established in young plants.
Alfalfa top growth was limited by both salt and water s tresses. Irrigation water s alinity had a grea t er effec t on top growt h than root grm;th while root distribution was unaffected by either the quant i ty of water app l ied or by water salinity. The effects of salinity on pl ant growth were reduced in the presence of l imi ting moisture. The specific nodul e act ivi t y (mmol c2H4/hr/g) of water s tressed alfalfa pl ants was enhanced by increasing the quantity of wat er applied a t each irriga t ion and was adversely effected by increased irrigation water salinity . In contrast, both nodulation and nodule growth were insensitive t o salt stress and sensi tive only to severe mo i s ture s tress . Alfalfa plants continued to exhibit acetylene reducing capacity at the third harvest even under severe moisture and salt stress. The species apparently continues to fix nitrogen even though environmental stress is quite substantial.
|
2 |
The Interaction between Victim Race and Gender on Capital Sentencing Outcomes: An Exploration of Previous ResearchReckdenwald, Amy 26 March 2004 (has links)
This study is an exploration and extension of previous research on the interactive effects of victim-race and victim-gender on death sentence outcomes. Williams and Holcomb's (2004) study suggests that an interactive effect exists between victim-race and victim-gender on Ohio death sentencing outcomes, such that killers of White women are especially singled out for capital punishment. The current study analyzes a sample of death eligible cases at the trial level in North Carolina to determine if Williams & Holcomb's findings hold up for a different sample of cases and in a different state. Logistic regression is used to determine if there are direct and/or interactive effects of victim's race and victim's gender on capital sentencing outcomes, controlling for the variety of other factors that influence that decision. Results suggest that the interactive effects reported by Williams and Holcomb do not exist in North Carolina at the sentencing/penalty processing phase of capital trials.
|
3 |
The conditional influence of criminological constructs on juvenile delinquency: An examination of the moderating effects of self-controlYarbrough, Angela 01 June 2007 (has links)
Self-control and various elements comprising this construct have received much credit over the years as it has been able to account for a large amount of variance in delinquency rates. Some research has suggested that individual difference factors (e.g., self-control) can overwhelm external factors (e.g., neighborhoods; see Loeber & Wikström, 2000). Others have found that social influences (e.g., employment; see Wright, et al, 2001) have more pronounced effects for those most at-risk. Because of the equivocal nature of the empirical findings, this study seeks to replicate and extend previous efforts. Specifically, the influence of constructs derived from social learning, control, deterrence, and strain are examined to see if any vary in their influence on adolescent offending as a function of self-control. Results indicate that all of these theoretical constructs (with the exception of paternal attachment) played a more important role among those who evinced the highest levels of self-control. Implications for criminological theory and criminal justice policy are discussed.
|
4 |
Comunidades herbáceas terrícolas em floresta atlântica primária e secundária no sul do BrasilSantos Junior, Ronaldo dos January 2014 (has links)
As espécies herbáceas terrícolas têm papel fundamental nas interações bióticas que ocorrem no interior de florestas. Entender as relações ecológicas que envolvem este grupo de plantas é essencial para a compreensão da dinâmica de florestas tropicais, sobretudo em ambientes perturbados e complexos, como a floresta tropical atlântica brasileira. O objetivo deste estudo foi avaliar como as comunidades herbáceas terrícolas se relacionam com as características ambientais de floresta tropical atlântica primária e secundária, no sul do Brasil. Nós coletamos dados sobre composição e estrutura (riqueza, cobertura e altura média) de comunidades herbáceas em 16 parcelas de 36m² em cada habitat florestal. Nós analisamos a variação da composição herbácea nos dois habitats através de Análise de Variância Multivariada por Permutação (PerManova) e executamos uma análise de caminhos, utilizando a abordagem PLS-PM (Partial Least Square Path modeling), para testar efeitos diretos e indiretos da estrutura do componete arbóreo, fertilidade do solo, luminosidade e do componente lenhoso regenerativo na estrutura das comunidades herbáceas. Os resultados da PerManova mostraram que as comunidades herbáceas foram diferentes entre floresta primária e floresta secundária; as variáveis ambientais que significamente contribuiram para essa variação foram a abertura da copa, o pH e o teor de matéria orgânica. A análise de caminhos mostrou que na floresta primária a estrutura da comunidade herbácea foi afetada direta e positivamente pela fertilidade do solo e indireta e negativamente pela estrutura do componente arbóreo através de sua influência direta no componente lenhoso regenerativo; na floresta secundária a estrutura da comunidade herbácea foi afetada diretamente, tanto positivamente pela disponibilidade de luz, quanto negativamente pelo componente lenhoso regenerativo. De uma forma geral, as variáveis consideradas explicaram bem a variação nos dados das comunidades herbáceas. As comunidades herbáceas de florestas primárias e secundárias são diferentes em resposta ao ambiente biótico e abiótico peculiar de cada habitat florestal. A interação entre espécies herbáceas e o componente lenhoso regenerativo parece aumentar na floresta secundária, reforçando a ideia de que as relações entre esses grupos de plantas são intensificadas em ambientes perturbados. / Terrestrial herbs play a fundamental role in biotic interactions occurring inside forests. The study of the ecological relationships involving this plant group is essential for the understanding of the dynamics of tropical forests, especially in complex and disturbed environments, as the Brazilian Atlantic forest. The objective of this study was to evaluate how herb communities are related to environmental characteristics of old-growth and secondary tropical Atlantic Forest in southern Brazil. We collected data on composition and structure (cover, richness and average height) of herbaceous communities in 16 plots with 36 m² in each forest habitat. We used a permutation multivariate analysis of variance (PerMANOVA) to evaluate the variation in composition of herb communities in old-growth and secondary forest and performed a path analysis to test direct and indirect effects of tree component structure, canopy openness, soil fertility and understory woody component on herb community structure. PerMANOVA results showed that composition of herb communities were different between old-growth and secondary forest; the environment variables canopy openness, organic matter, and pH significantly explained a proportion of the variability of the composition of herb communities. Path analysis indicated that in old-growth forest the herb community structure was affected direct and positively by soil fertility and indirect and negatively by the structure of tree component structure as above mediated by its influence on understory woody component. In secondary forest the herb community structure was affected directly and positively by light availability and negatively by the understory woody component. In general, the analysed variables explained well the variation in the herbaceous community data. Herb communities in old-growth and secondary forests respond differently to biotic and abiotic variables. Interactions between woody regeneration and herbaceous communities seem to increase in secondary forest, reinforcing the idea that relations between these plant groups are intensified in disturbed environments.
|
5 |
Comunidades herbáceas terrícolas em floresta atlântica primária e secundária no sul do BrasilSantos Junior, Ronaldo dos January 2014 (has links)
As espécies herbáceas terrícolas têm papel fundamental nas interações bióticas que ocorrem no interior de florestas. Entender as relações ecológicas que envolvem este grupo de plantas é essencial para a compreensão da dinâmica de florestas tropicais, sobretudo em ambientes perturbados e complexos, como a floresta tropical atlântica brasileira. O objetivo deste estudo foi avaliar como as comunidades herbáceas terrícolas se relacionam com as características ambientais de floresta tropical atlântica primária e secundária, no sul do Brasil. Nós coletamos dados sobre composição e estrutura (riqueza, cobertura e altura média) de comunidades herbáceas em 16 parcelas de 36m² em cada habitat florestal. Nós analisamos a variação da composição herbácea nos dois habitats através de Análise de Variância Multivariada por Permutação (PerManova) e executamos uma análise de caminhos, utilizando a abordagem PLS-PM (Partial Least Square Path modeling), para testar efeitos diretos e indiretos da estrutura do componete arbóreo, fertilidade do solo, luminosidade e do componente lenhoso regenerativo na estrutura das comunidades herbáceas. Os resultados da PerManova mostraram que as comunidades herbáceas foram diferentes entre floresta primária e floresta secundária; as variáveis ambientais que significamente contribuiram para essa variação foram a abertura da copa, o pH e o teor de matéria orgânica. A análise de caminhos mostrou que na floresta primária a estrutura da comunidade herbácea foi afetada direta e positivamente pela fertilidade do solo e indireta e negativamente pela estrutura do componente arbóreo através de sua influência direta no componente lenhoso regenerativo; na floresta secundária a estrutura da comunidade herbácea foi afetada diretamente, tanto positivamente pela disponibilidade de luz, quanto negativamente pelo componente lenhoso regenerativo. De uma forma geral, as variáveis consideradas explicaram bem a variação nos dados das comunidades herbáceas. As comunidades herbáceas de florestas primárias e secundárias são diferentes em resposta ao ambiente biótico e abiótico peculiar de cada habitat florestal. A interação entre espécies herbáceas e o componente lenhoso regenerativo parece aumentar na floresta secundária, reforçando a ideia de que as relações entre esses grupos de plantas são intensificadas em ambientes perturbados. / Terrestrial herbs play a fundamental role in biotic interactions occurring inside forests. The study of the ecological relationships involving this plant group is essential for the understanding of the dynamics of tropical forests, especially in complex and disturbed environments, as the Brazilian Atlantic forest. The objective of this study was to evaluate how herb communities are related to environmental characteristics of old-growth and secondary tropical Atlantic Forest in southern Brazil. We collected data on composition and structure (cover, richness and average height) of herbaceous communities in 16 plots with 36 m² in each forest habitat. We used a permutation multivariate analysis of variance (PerMANOVA) to evaluate the variation in composition of herb communities in old-growth and secondary forest and performed a path analysis to test direct and indirect effects of tree component structure, canopy openness, soil fertility and understory woody component on herb community structure. PerMANOVA results showed that composition of herb communities were different between old-growth and secondary forest; the environment variables canopy openness, organic matter, and pH significantly explained a proportion of the variability of the composition of herb communities. Path analysis indicated that in old-growth forest the herb community structure was affected direct and positively by soil fertility and indirect and negatively by the structure of tree component structure as above mediated by its influence on understory woody component. In secondary forest the herb community structure was affected directly and positively by light availability and negatively by the understory woody component. In general, the analysed variables explained well the variation in the herbaceous community data. Herb communities in old-growth and secondary forests respond differently to biotic and abiotic variables. Interactions between woody regeneration and herbaceous communities seem to increase in secondary forest, reinforcing the idea that relations between these plant groups are intensified in disturbed environments.
|
6 |
Comunidades herbáceas terrícolas em floresta atlântica primária e secundária no sul do BrasilSantos Junior, Ronaldo dos January 2014 (has links)
As espécies herbáceas terrícolas têm papel fundamental nas interações bióticas que ocorrem no interior de florestas. Entender as relações ecológicas que envolvem este grupo de plantas é essencial para a compreensão da dinâmica de florestas tropicais, sobretudo em ambientes perturbados e complexos, como a floresta tropical atlântica brasileira. O objetivo deste estudo foi avaliar como as comunidades herbáceas terrícolas se relacionam com as características ambientais de floresta tropical atlântica primária e secundária, no sul do Brasil. Nós coletamos dados sobre composição e estrutura (riqueza, cobertura e altura média) de comunidades herbáceas em 16 parcelas de 36m² em cada habitat florestal. Nós analisamos a variação da composição herbácea nos dois habitats através de Análise de Variância Multivariada por Permutação (PerManova) e executamos uma análise de caminhos, utilizando a abordagem PLS-PM (Partial Least Square Path modeling), para testar efeitos diretos e indiretos da estrutura do componete arbóreo, fertilidade do solo, luminosidade e do componente lenhoso regenerativo na estrutura das comunidades herbáceas. Os resultados da PerManova mostraram que as comunidades herbáceas foram diferentes entre floresta primária e floresta secundária; as variáveis ambientais que significamente contribuiram para essa variação foram a abertura da copa, o pH e o teor de matéria orgânica. A análise de caminhos mostrou que na floresta primária a estrutura da comunidade herbácea foi afetada direta e positivamente pela fertilidade do solo e indireta e negativamente pela estrutura do componente arbóreo através de sua influência direta no componente lenhoso regenerativo; na floresta secundária a estrutura da comunidade herbácea foi afetada diretamente, tanto positivamente pela disponibilidade de luz, quanto negativamente pelo componente lenhoso regenerativo. De uma forma geral, as variáveis consideradas explicaram bem a variação nos dados das comunidades herbáceas. As comunidades herbáceas de florestas primárias e secundárias são diferentes em resposta ao ambiente biótico e abiótico peculiar de cada habitat florestal. A interação entre espécies herbáceas e o componente lenhoso regenerativo parece aumentar na floresta secundária, reforçando a ideia de que as relações entre esses grupos de plantas são intensificadas em ambientes perturbados. / Terrestrial herbs play a fundamental role in biotic interactions occurring inside forests. The study of the ecological relationships involving this plant group is essential for the understanding of the dynamics of tropical forests, especially in complex and disturbed environments, as the Brazilian Atlantic forest. The objective of this study was to evaluate how herb communities are related to environmental characteristics of old-growth and secondary tropical Atlantic Forest in southern Brazil. We collected data on composition and structure (cover, richness and average height) of herbaceous communities in 16 plots with 36 m² in each forest habitat. We used a permutation multivariate analysis of variance (PerMANOVA) to evaluate the variation in composition of herb communities in old-growth and secondary forest and performed a path analysis to test direct and indirect effects of tree component structure, canopy openness, soil fertility and understory woody component on herb community structure. PerMANOVA results showed that composition of herb communities were different between old-growth and secondary forest; the environment variables canopy openness, organic matter, and pH significantly explained a proportion of the variability of the composition of herb communities. Path analysis indicated that in old-growth forest the herb community structure was affected direct and positively by soil fertility and indirect and negatively by the structure of tree component structure as above mediated by its influence on understory woody component. In secondary forest the herb community structure was affected directly and positively by light availability and negatively by the understory woody component. In general, the analysed variables explained well the variation in the herbaceous community data. Herb communities in old-growth and secondary forests respond differently to biotic and abiotic variables. Interactions between woody regeneration and herbaceous communities seem to increase in secondary forest, reinforcing the idea that relations between these plant groups are intensified in disturbed environments.
|
7 |
Interactive effects of meloidogyne species and sugarcane aphid (melanaphis sacchari) on nematode resistance in sweet stem sorghum and effects of terpenoid-containing phytonematicides on both pestsMaleka, Koena Gideon January 2020 (has links)
Thesis (Ph.D. Agriculture (Plant Production)) -- University of Limpopo, 2020 / Worldwide, both root-knot (Meloidogyne species) and sugarcane aphid (Melanaphis
sacchari Zehntner), are economic pests on sugarcane and sorghum crops. In most
cases, each of the two pests is managed using host plant resistance due to the
economic benefits derived from this management strategy. The highly nematode
resistant sweet stem sorghum (Sorghum bicolor L.) cv. 'Ndendane-X1' used in ethanol
production, is highly sensitive to sugarcane aphid, with some indication that the latter
could interfere with nematode resistance in the sorghum cultivar. This study had four
objectives which collectively intended to investigate the interactive effects of infection
by three Meloidogyne species and infestation by aphid under different conditions on
resistance to nematode in a nematode-resistant sorghum cultivar. The research
objectives were achieved through four trials. In each trial a 2 × 2 factorial experiment,
each with and without nematode and aphid as first and second factors, respectively,
were conducted. Treatments were arranged in a randomised complete block design,
with six replications, and each experiment validated in time. At 150 days, after
emergence, the nematode × aphid interaction significantly reduced sucrose by 17, 74
and 42% in Meloidogyne enterolobii, Meloidogyne incognita and Meloidogyne javanica
trials, respectively. Aphid infestation of sorghum significantly increased the
reproductive potentials of the three respective Meloidogyne species by 196, 320 and
152%, but significantly, reduced plant growth variables from 20-44 and 48-51% in two
respective trials. The mineral nutrients S and Zn were reduced in leaf tissues of the
test cultivar in Trial 1, whereas Ca and Zn were respectively reduced by 24 and 51%
in Trial 2 and by 52 and 51% in Trial 3. Since the reproductive potential values for
Meloidogynqe species on the test sorghum cultivar were greater than unity and
nematode infection reduced the plant variables, cv. 'Ndendane-X1' lost resistance to xx
the test Meloidogyne species. In achieving Objective 2, procedures were similar to
those in Objective 1 except that the study was conducted under field conditions under
mixed nematode populations of M. enterolobii, M. incognita and M. javanica. Sorghum
seedlings were raised at 0.3 m × 0.3 m inter and intra row spacings. Soon after
emergence, plants were thinned to one per station, randomly selected for nematode
and nematode-aphid treatments. Mixed populations of Meloidogyne species (M.
enterolobii, M. incognita and M. javanica) at approximately 1:1:1 (v/v) ratio were
applied at 300 eggs + J2 per plants after thinning at the five plants which were used
as nematode alone treatments. The latter were also infested with 20 sugarcane aphids
to constitute a nematode + aphid treatments. Buffer zone plants separating the
treatments were monitored for aphids and stock borer, which were sprayed when
necessary. At 150 days after infestation, relative to nematode alone, nematode-aphid
significantly reduced degrees Brix from 13% to 61%, but significantly increased the
reproductive potential of mixed Meloidogyne species and root galls by 279 and 199%,
respectively. Also, the combined effect significantly reduced plant growth variables
from 35 to 55% and the mineral nutrient elements in leaf tissues of the cultivar from
33 to 73%. At 150 days after the treatment, the second and first order interaction
(Nemarioc-AL × Nemafric-BL × Mordica and Nemafric-BL × Mordica) had significantly
increased sucrose content from 48 to 66%, increased plant growth variables from 49
to 163%, increased accumulation of certain nutrient elements from 164 to 206%. The
terpenoid-containing phytonematicides could have potential future application in the
husbandry of ethanol-producing sweet stem sorghum cultivars in relation to increasing
sucrose above the 16% minimum for premium delivery fees and increased plant
growth. Under field conditions, in pest-free condition (Objective 3), drenched
terpenoid-containing phytonematicides significantly increased sucrose content at xxi
middle and bottom part of SSS cv. 'Ndendane-X1' by 66 and 48%. However, these
products did not significantly increase plant variables, except tiller number, which was
increased by 163 under first order interaction from Nemafric-BL and Mordica
phytonematicides. Similarly, nutrient elements variables had generally not been
increased by the interaction of these products, except Ca and K, which were increased
by 206 and 164%. In achieving Objective 4, a 2 × 2 × 2, with the first, second and third
factor being Nemarioc-AL (with and without), Nemafric-BL (with and without) and
Mordica (with and without) phytonematicides, respectively. on sorghum cultivar
infected with a mixture of Meloidogyne species and infested with aphids, under
microplot conditions, untreated control sucrose content remained below the standard
of 16 degrees Brix, whereas the second order interaction increased the variable far
above the standard, along with various plant growth variables also increased.
However, both nematode and aphid population densities were significantly reduced by
the interactions. Findings in this thesis constituted the first report where aphid
infestation broke resistance to Meloidogyne species in sweet stem sorghum cv.
'Ndendane-X1'. Therefore, the successful use of nematode resistance in the cultivar
in areas with high nematode population densities would depend upon the effective
management of the sugarcane aphid population densities. Also, the three terpenoid-containing phytonematicides would when combined or used alone have the potential future in the husbandry of sweet stem sorghum cultivars intended for ethanol
production and suppression of nematode population densities / National Research Foundation (NRF)
|
8 |
Asymptotic Efficiency of Estimates for Panel Data Models with Fixed Effect / s固定効果パネルモデルにおける推定の漸近的効率性に関する研究Iwakura, Haruo 24 March 2014 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(経済学) / 甲第18037号 / 経博第490号 / 新制||経||268(附属図書館) / 30895 / 京都大学大学院経済学研究科経済学専攻 / (主査)教授 西山 慶彦, 准教授 奥井 亮, 講師 末石 直也 / 学位規則第4条第1項該当 / Doctor of Economics / Kyoto University / DGAM
|
9 |
Investigation of the independent and interactive effects of short-term exposure to particulate matter on human morbidity using epidemiological approaches / 粒子状物質への短期曝露が人の疾患に及ぼす単独影響および相互影響に関する疫学的アプローチを用いた検討Arthit, Phosri 25 September 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第21362号 / 工博第4521号 / 新制||工||1704(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 高野 裕久, 教授 米田 稔, 准教授 上田 佳代 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
|
10 |
Interaction entre le stress parental maternel et paternel en lien avec les problèmes de comportement intériorisés et extériorisés de l’enfantLapolice Thériault, Rose 08 1900 (has links)
De nombreuses études montrent une association robuste entre le stress parental et les difficultés socioaffectives de l’enfant. Toutefois, la majorité de ces études ont seulement pris en considération le stress parental de la mère en omettant complètement de considérer celui du père. Bien que les pères soient de plus en plus inclus dans la littérature, plusieurs études récentes sur le stress parental déplorent l’absence de données paternelles. Pourtant, il est bien établi que les pères s’investissent de façon importante dans le développement de leurs enfants et qu’ils peuvent ressentir des niveaux de stress parental comparables à ceux des mères. Ainsi, l’objectif de la présente étude était d’examiner l’association entre le stress parental des deux parents et le développement de problèmes de comportement extériorisés et intériorisés chez l’enfant. L’interaction entre le stress parental paternel et maternel a également été vérifiée dans l’association avec les problèmes de comportement de l’enfant. L’échantillon de l’étude était composé de 157 enfants et leurs parents. Afin d’évaluer leurs niveaux de stress parental, les deux parents ont complété le Parental Stress Index- Short Form alors que leur enfant était âgé de 18 mois. Ils ont ensuite évalué la sévérité des problèmes extériorisés et intériorisés chez leur enfant alors qu’il était âgé de 4 ans, à l’aide du Child Behavior Checklist. Les résultats suggèrent que seul le stress parental paternel prédit la sévérité des problèmes extériorisés (mais non intériorisés) chez l’enfant. Les résultats suggèrent également une interaction entre le stress parental du père et de la mère, de sorte que l’association entre le stress paternel et les comportements extériorisés diminue à mesure que le stress maternel augmente. En somme, la présente étude souligne le rôle du stress paternel quant au développement socioaffectif de l’enfant, particulièrement pour les problèmes extériorisés. / Numerous studies highlight a robust association between parenting stress and child socioemotional difficulties. However, the majority of these studies have only considered maternal parenting stress, failing to consider paternal stress. Although fathers are increasingly considered in recent literature, several recent studies on parenting stress note the absence of paternal data. Yet, it is well established that fathers are involved in their children's development and experience levels of parenting stress comparable to those of mothers. Thus, the purpose of the present study was to examine the association between both parents’ parenting stress and child externalizing and internalizing behavior problems. The interaction between paternal and maternal parenting stress was also examined in association with child behavior problems. The study sample consisted of 157 children and their parents. To assess their levels of parenting stress, both parents completed the Parental Stress Index-Short Form when their child was 18 months old. They then assessed their child’s externalizing and internalizing behaviors when children were 4 years old, using the Child Behavior Checklist. The results suggest that only paternal parenting stress predicts subsequent child externalizing (though not internalizing) behaviors. The results also suggest an interaction between paternal and maternal parenting stress, such that the association between paternal stress and externalizing behaviors decreases as maternal stress increases. In sum, this study underscores the role that paternal stress may play in child socio-emotional development, particularly in the development of externalizing behaviors.
|
Page generated in 0.0837 seconds