The influence of pasture age, plant density, and genotype on intraspecific diversity of Trifolium repens (white clover)

1996 ◽  
Vol 74 (7) ◽  
pp. 1189-1192 ◽  
Author(s):  
Jack Maze ◽  
Roy Turkington
Keyword(s):  
Trifolium Repens ◽  
Plant Density ◽  
Intraspecific Diversity ◽  
Genetic Origin ◽  
Plant Variation ◽  
Age Related ◽  
The Relationship ◽  
Over Time ◽  
Pasture Age ◽  
Phenotypic Responses

Morphological variation, as expressed in PCA axis scores, for clovers growing in different aged pastures, was apportioned to pasture age, quadrats within pastures, intraspecific densities within quadrats, and genets within densities. Of those factors that have an effect on variation, genets is the greatest, followed by quadrats, intraspecific density, and age of the pasture. There is also an age-related decline in variation in plants of Trifolium repens as seen in genetic origin, quadrats within a pasture, and intraspecific density. These results indicate a need to determine more accurately the relationship between genetic and phenotypic responses in the decline in among-plant variation over time. Keywords: Trifolium repens, variation.

THE RELATIONSHIP BETWEEN FINAL YIELD AND PHOTOSYNTHESIS AT FLOWERING IN INDIVIDUAL MAIZE PLANTS

1979 ◽  
Vol 59 (3) ◽  
pp. 585-601 ◽  
Author(s):  
G. O. EDMEADES ◽  
T. B. DAYNARD
Keyword(s):  
Grain Yield ◽  
Shoot Growth ◽  
Plant Density ◽  
Meteorological Data ◽  
Dry Weight ◽  
Plant Variation ◽  
Final Yield ◽  
Black Layer ◽  
Maize Plants ◽  
The Relationship

In an attempt to explain plant-to-plant variation in dry weight of maize (Zea mays L.), a computer program was developed to predict daily assimilation per plant and its distribution throughout the shoot at flowering. Inputs to the model were meteorological data, photosynthetic rate-irradiance curves, measurements of intraplant assimilate distribution at flowering, and the positions of individual leaves of plants grown in the field at three densities (50 000, 100 000 and 150 000 plants/ha). Dry weights were recorded on these same plants following black layer formation. Predicted effects of plant density on shoot growth compared favorably with available data. The correlation coefficient between predicted assimilation 1 day after anthesis and grain yield on the same plants, with treatment effects removed, was 0.67 (N = 360). The coefficient of variation of predicted assimilate flux per plant increased significantly with increasing density, and the fluxes were generally normally distributed. Results supported the concept of a threshold assimilation rate per plant below which grain would not normally form, and this appears to be the cause of the bimodal frequency distribution of grain yield per plant observed at high densities.

scholarly journals The influence of diet patterns on Alzheimer’s risk: a concise systematic review

2021 ◽  
Vol 14 (3) ◽  
Author(s):  
Sayonara Carrijo Machado ◽  
Idiberto José Zotarelli Filho
Keyword(s):  
Oxidative Stress ◽  
Neurodegenerative Disorder ◽  
Cognitive Disorders ◽  
Health Concern ◽  
Eating Patterns ◽  
Diet Patterns ◽  
Age Related ◽  
Neurochemical Changes ◽  
The Relationship ◽  
Over Time

Alzheimer's disease (AD) is a progressive neurodegenerative disorder responsible for the main cause of dementia, and the increasing worldwide prevalence of AD is a major public health concern. Studies suggest that diet and nutrition may be important modifiable risk factors for AD. In addition, intestinal microbial metabolites and their effects on host neurochemical changes can increase or decrease the risk of AD. The aim of this literature review article is to discuss the relationship between dietary patterns, foods, gut microbiota, micro and macronutrients, and cognitive disorders, especially Alzheimer's. The results show that the excessive generation and accumulation of reactive pro-oxidant species over time can damage proteins, lipids, carbohydrates, and nucleic acids. Over time, this oxidative stress can contribute to a variety of age-related degenerative diseases. Therefore, antioxidant foods and healthy eating patterns, such as the Mediterranean diet, can contribute to reducing oxidative stress and consequently reducing the risk of Alzheimer's.

scholarly journals THE RELATIONSHIP BETWEEN OLDER DRIVERS’ RESILIENCE AND SELF-REPORTED DRIVING MEASURES OVER 5 YEARS

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S344-S344
Author(s):  
Renée M St Louis ◽  
Judith Charlton ◽  
Sjaan Koppel ◽  
Lisa J Molnar ◽  
Marilyn Di Stefano ◽  
...  
Keyword(s):  
Older Drivers ◽  
Future Research ◽  
Driving Frequency ◽  
Older Adulthood ◽  
Resilience Scale ◽  
Age Related ◽  
Positive Correlations ◽  
Changes Over Time ◽  
The Relationship ◽  
Over Time

Abstract As people age into older adulthood, they are more likely to experience events that impact their driving, such as age-related cognitive and functional declines, serious illness, or disability. The ability to demonstrate resilience following such adversity may influence one’s decisions and feelings about driving. This study investigated whether resilience of older drivers changes over time, and if relationships between resilience, gender, and self-reported driving-related abilities, perceptions and practices remain stable or change. Participants were from the Candrive/Ozcandrive study, a prospective cohort study of older drivers from Canada, Australia and New Zealand. Analyses are presented from a subset of Ozcandrive participants (n=125) from Australia who completed a resilience scale at two time points approximately five years apart, as well as measures of driving comfort during the day and night, perceived driving abilities, and driving frequency. Participants were primarily male (67.2%) with a mean age of 81.6 years (SD=3.3, Range=76.0-90.0) at Time 1. Resilience increased significantly from Time 1 to Time 2 (Median=82.0/84.00, z=-2.9, p<.01). Although females had significantly higher resilience than males at both Time 1 (Median=84.0/81.0, U=2.3, p=.02) and Time 2 (Median=86.5/82.0, U=2.1, p=.03), there was a statistically significant increase in resilience of males over five years (p<.01) and no statistical change for females. Results show small but significant positive correlations, and increasingly stronger relationships over time between older drivers’ resilience and driving comfort as well as perceived driving abilities. Future research will use modelling to examine the association of various factors on the change in resilience and driving-related measures.

scholarly journals Modeling Leaf Age-Related Susceptibility and Rust Eruption Dynamics in Peanut

2000 ◽  
Vol 27 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Z. Z. Wang ◽  
K. H. Lin
Keyword(s):  
Leaf Age ◽  
Relative Number ◽  
Eruption Dynamics ◽  
Infection Frequency ◽  
Degree Days ◽  
Age Related ◽  
Relationship Of ◽  
The Relationship ◽  
Field Inoculum ◽  
Over Time

Abstract To improve simulation of epidemics of peanut rust, information on the effects of leaf age and pustule eruption dynamics is needed. An analysis was made of the change of leaf susceptibility of rust with leaf aging using plants exposed to field inoculum. The youngest leaf was most susceptible to rust infection. As leaves aged, susceptibility decreased quickly. The relationship of infection frequency (Y, relative number of pustules) to leaf age (X, leaf position downward on the main stem) was described by a mathematical model Y = 2.17X(-0.83). The dynamics of pustule eruption also was studied using artificial inoculation. Analysis showed that after inoculation, pustule eruption over time was distributed in a logistic pattern. Rust eruption began at 130 and reach a peek at 250 rust degree days—that is, between 7 and 15 d after inoculation. Mathematical models of leaf age-related susceptibility and rust eruption dynamics will be incorporated into simulation model of rust epidemics.

Age Differences in Adults' Self-Reports of Memory Ability: It Depends on How and What You Ask

1987 ◽  
Vol 24 (4) ◽  
pp. 271-277 ◽  
Author(s):  
John C. Cavanaugh
Keyword(s):  
Age Differences ◽  
Memory Ability ◽  
Age Related ◽  
Self Reports ◽  
Changes Over Time ◽  
The Relationship ◽  
Over Time

Self-reports of memory abilities and skills were obtained from fifty younger ( M = 20.2) and fifty older ( M = 68.7) adults. General rating questions (e.g., How good do you feel your memory is?) and specific questions about memory for certain types of content (e.g., people's names) were included. Consistent age-related decrements were found only for general questions, especially those assessing perceived changes over time. Less consistent differences were found for specific questions. Results were interpreted in terms of implications for assessing self-reported memory ability, and in terms of their meaning for research on the relationship between self-reported and actual memory ability.

Age Differences in Context-Cue Forgetting

2005 ◽  
Vol 96 (3_suppl) ◽  
pp. 879-888 ◽  
Author(s):  
Sharon Bertsch ◽  
Raymond E. Sanders
Keyword(s):  
Older Adult ◽  
Context Effects ◽  
Target Information ◽  
Age Related ◽  
Retention Intervals ◽  
Context Cues ◽  
Changes Over Time ◽  
Relationship Of ◽  
The Relationship ◽  
Over Time

Episodic or context dependent memory is often studied as a function of the context cues in immediate retrieval of target information. Little research has been done on how the relationship of context cues to target retrieval changes over time, and none with older adult subjects. The current research investigated how the influence of context on accuracy of memory changes over time, and age-related differences in those influences. Using immediate, 2- and 7-day retention intervals, our results indicate that, while context initially supports the retrieval of information, assistance is temporary and fades before the memory for the target information. These changes in context effects were not different for younger and older adult groups.

Investment Traits and Intelligence in Adulthood

2013 ◽  
Vol 34 (2) ◽  
pp. 82-89 ◽  
Author(s):  
Sophie von Stumm
Keyword(s):  
Individual Differences ◽  
Personality Traits ◽  
Fluid Intelligence ◽  
Need For Cognition ◽  
Openness To Experience ◽  
Intelligence Tests ◽  
Crystallized Intelligence ◽  
New Knowledge ◽  
The Relationship ◽  
Over Time

Intelligence-as-knowledge in adulthood is influenced by individual differences in intelligence-as-process (i.e., fluid intelligence) and in personality traits that determine when, where, and how people invest their intelligence over time. Here, the relationship between two investment traits (i.e., Openness to Experience and Need for Cognition), intelligence-as-process and intelligence-as-knowledge, as assessed by a battery of crystallized intelligence tests and a new knowledge measure, was examined. The results showed that (1) both investment traits were positively associated with intelligence-as-knowledge; (2) this effect was stronger for Openness to Experience than for Need for Cognition; and (3) associations between investment and intelligence-as-knowledge reduced when adjusting for intelligence-as-process but remained mostly significant.

Power Values and Power Distance Moderate the Relationship Between Workplace Supervisory Power and Job Satisfaction

2020 ◽  
Vol 19 (3) ◽  
pp. 135-141
Author(s):  
Kenneth D. Locke
Keyword(s):  
Job Satisfaction ◽  
Multilevel Modeling ◽  
Power Distance ◽  
European Social Survey ◽  
Social Survey ◽  
The Relationship ◽  
Workplace Power ◽  
Over Time

Abstract. Person–job (or needs–supplies) discrepancy/fit theories posit that job satisfaction depends on work supplying what employees want and thus expect associations between having supervisory power and job satisfaction to be more positive in individuals who value power and in societies that endorse power values and power distance (e.g., respecting/obeying superiors). Using multilevel modeling on 30,683 European Social Survey respondents from 31 countries revealed that overseeing supervisees was positively associated with job satisfaction, and as hypothesized, this association was stronger among individuals with stronger power values and in nations with greater levels of power values or power distance. The results suggest that workplace power can have a meaningful impact on job satisfaction, especially over time in individuals or societies that esteem power.

Cognitive Factors Mediate the Relation Between Age and Flight Path Maintenance in General Aviation

2016 ◽  
Vol 6 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Kathleen Van Benthem ◽  
Chris M. Herdman
Keyword(s):  
Cognitive Functioning ◽  
Flight Path ◽  
General Aviation ◽  
Cognitive Factors ◽  
Pilot Performance ◽  
Pilot Error ◽  
Age Related ◽  
And Performance ◽  
Relationship Of ◽  
The Relationship

Abstract. Identifying pilot attributes associated with risk is important, especially in general aviation where pilot error is implicated in most accidents. This research examined the relationship of pilot age, expertise, and cognitive functioning to deviations from an ideal circuit trajectory. In all, 54 pilots, of varying age, flew a Cessna 172 simulator. Cognitive measures were obtained using the CogScreen-AE ( Kay, 1995 ). Older age and lower levels of expertise and cognitive functioning were associated with significantly greater flight path deviations. The relationship between age and performance was fully mediated by a cluster of cognitive factors: speed and working memory, visual attention, and cognitive flexibility. These findings add to the literature showing that age-related changes in cognition may impact pilot performance.

Emotional Impact Feedback Changes How We Remember Negative Autobiographical Experiences

2010 ◽  
Vol 57 (5) ◽  
pp. 354-359 ◽  
Author(s):  
Melanie K. T. Takarangi ◽  
Deryn Strange
Keyword(s):  
Well Being ◽  
The Other ◽  
Personal Perspective ◽  
Emotional Impact ◽  
Potential Mechanism ◽  
Negative Experiences ◽  
Negative Memory ◽  
The Relationship ◽  
Negative Memories ◽  
Over Time

When people are told that their negative memories are worse than other people’s, do they later remember those events differently? We asked participants to recall a recent negative memory then, 24 h later, we gave some participants feedback about the emotional impact of their event – stating it was more or less negative compared to other people’s experiences. One week later, participants recalled the event again. We predicted that if feedback affected how participants remembered their negative experiences, their ratings of the memory’s characteristics should change over time. That is, when participants are told that their negative event is extremely negative, their memories should be more vivid, recollected strongly, and remembered from a personal perspective, compared to participants in the other conditions. Our results provide support for this hypothesis. We suggest that external feedback might be a potential mechanism in the relationship between negative memories and psychological well-being.

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