6,549 research outputs found
Selection, inheritance, and the evolution of parent-offspring interactions
Very few studies have examined parent-offspring interactions from a quantitative genetic perspective. We used a cross-fostering design and measured genetic correlations and components of social selection arising from two parental and two offspring behaviors in the burying beetle Nicrophorus vespilloides. Genetic correlations were assessed by examining behavior of relatives independent of common social influences. We found positive genetic correlations between all pairs of behaviors, including between parent and offspring behaviors. Patterns of selection were assessed by standardized performance and selection gradients. Parental provisioning had positive effects on offspring performance and fitness, while remaining near the larvae without feeding them had negative effects. Begging had positive effects on offspring performance and fitness, while increased competition among siblings had negative effects. Coadaptations between parenting and offspring behavior appear to be maintained by genetic correlations and functional trade-offs; parents that feed their offspring more also spend more time in the area where they can forage for themselves. Families with high levels of begging have high levels of sibling competition. Integrating information from genetics and selection thus provides a general explanation for why variation persists in seemingly beneficial traits expressed in parent-offspring interactions and illustrates why it is important to measure functionally related suites of behaviors
The relation of Christian education to pastoral theology: with reference to the function-centered theology of Seward Hiltner
Thesis (Ph.D)--Boston University1. Problem.--The problem of this dissertation is to examine the relation of Christian education to pastoral theology, utilizing the function-centered theology of Seward Hiltner as the frame of reference and theories of three Christian educators. There will be an attempt to clarify the nature and structure of pastoral theology and to arrive at some implications for its reformulation as a coordinate theology of the functions of ministry.
2. Methodology.--The study is set in a historical and contemporary perspective by a brief historical survey of practical and pastoral theology, including the rise of specialization within the functional ministry and a survey of recent attempts to reformulate pastoral theology. A descriptive analysis of Seward Hiltner's function-centered theology provides the frame of reference for describing and analyzing the general theory of pastoral theology and/or ministry and the relation of Christian education in the writings of Reuel L. Howe, Lewis J. Sherrill, and Ross Snyder. Inferences as to the relation of Christian education to pastoral theology and implications for a reformulation of pastoral theology are made [TRUNCATED
1976 Research results
Dock Control. To reduce the density of old dock plants in a pasture to less than one per square metre three to four years spraying with dicamba is necessary... Dock control - Dicamba in pastures - 73AL38, 73AR9, 73BU9. Dock control in pasture (Effect of treatments 1973-1975) - 73BU6. Dock control in pasture (1976 treatments) - 73BU6. Dock control in cereals - 76A130. Weed control in lupins. Post emergence herbicides in lupins - 76AL9, 76BA29, 76C5, 76E7, 76NA13. Comparison of simazine formulations in lupins - 76BA8. Weed control in vineyards. Alachlor, atrazine and simazine gave excellent control of weeds and minimal effect on vines in the year of transplanting. Atrazine 2.5 kg/ha was the cheapest, Chlorthal, a commonly used herbicide in nurseries caused a marked reduction in growth... The tolerance of young vines to herbicides - Upper Swan Research Station. Tolerance of 2nd year vines to herbicides - Upper Swan Research Station. The tolerance of vines to glyphosate - Upper Swan Research Station
Coadaptation of prenatal and postnatal maternal effects
In a wide variety of species, a female's age of first reproduction influences offspring size and survival, suggesting that there exists an optimal timing of reproduction. Mothers in many species also influence offspring size and survival after birth through variation in parental care. We experimentally separated these effects in the burying beetle Nicrophorus vespilloides to test for coadaptation between prenatal and postnatal maternal effects associated with age at first reproduction. Females that reproduced early produced offspring with lower birth weight. The amount of parental care depended on the age of first reproduction of the caretaker, as did the extent of offspring begging. As predicted for a coadaptation of maternal effects, prenatal and postnatal effects were opposite for different-aged mothers, and larval weight gain and survival was greatest when the age of the caretaker and birth mother matched. Thus, prenatal effects intrinsically associated with age of first reproduction can be ameliorated by innate plasticity in postnatal care. A coadaptation of prenatal and postnatal maternal effects may evolve to allow variable timing of the first reproductive attempt. Such a coadaptation might be particularly valuable when females are constrained from reproducing at an optimal age, as, for example, in species that breed on scarce and unpredictable resources
Durrington Walls to West Amesbury by way of Stonehenge: a major transformation of the Holocene landscape
A new sequence of Holocene landscape change has been discovered through an investigation of sediment sequences, palaeosols, pollen and molluscan data discovered during the Stonehenge Riverside Project. The early post-glacial vegetational succession in the Avon valley at Durrington Walls was apparently slow and partial, with intermittent woodland modification and the opening-up of this landscape in the later Mesolithic and earlier Neolithic, though a strong element of pine lingered into the third millennium BC. There appears to have been a major hiatus around 2900 cal BC, coincident with the beginnings of demonstrable human activities at Durrington Walls, but slightly after activity started at Stonehenge. This was reflected in episodic increases in channel sedimentation and tree and shrub clearance, leading to a more open downland, with greater indications of anthropogenic activity, and an increasingly wet floodplain with sedges and alder along the river’s edge. Nonetheless, a localized woodland cover remained in the vicinity of DurringtonWalls throughout the third and second millennia BC, perhaps on the higher parts of the downs, while stable grassland, with rendzina soils, predominated on the downland slopes, and alder–hazel carr woodland and sedges continued to fringe the wet floodplain. This evidence is strongly indicative of a stable and managed landscape in Neolithic and Bronze Age times. It is not until c 800–500 cal BC that this landscape was completely cleared, except for the marshy-sedge fringe of the floodplain, and that colluvial sedimentation began in earnest associated with increased arable agriculture, a situation that continued through Roman and historic times
The Rural-Urban Continuum and Environmental Concerns
Studies have generally found rural residents to be less concerned about environmental problems than urbanites. This difference has been attributed primarily to a nature-exploitative attitude of farmers. The present study finds little support for this proposition, but an alternative explanation, derived from rational choice and exchange theory, is supported. Owner-operator farmers are different from tenants and absentee owners in their level of environmental concern and shift positions across the range of environmental issues, as do rural nonfarm and small town residents. Furthermore, urban respondents are not consistently more likely than all rural categories to show the greatest environmental concern
Eastern gamagrass seed dormancy
Eastern gamagrass has considerable value as a forage source and conservation aid, but can be very difficult to establish because its seed does not germinate easily, even with all the necessary environmental factors present. Understanding seed dormancy in eastern gamagrass is the major objective of this work
Coherent phonon scattering effects on thermal transport in thin semiconductor nanowires
The thermal conductance by phonons of a quasi-one-dimensional solid with
isotope or defect scattering is studied using the Landauer formalism for
thermal transport. The conductance shows a crossover from localized to Ohmic
behavior, just as for electrons, but the nature of this crossover is modified
by delocalization of phonons at low frequency. A scalable numerical
transfer-matrix technique is developed and applied to model
quasi-one-dimensional systems in order to confirm simple analytic predictions.
We argue that existing thermal conductivity data on semiconductor nanowires,
showing an unexpected linear dependence, can be understood through a model that
combines incoherent surface scattering for short-wavelength phonons with nearly
ballistic long-wavelength phonons. It is also found that even when strong
phonon localization effects would be observed if defects are distributed
throughout the wire, localization effects are much weaker when defects are
localized at the boundary, as in current experiments.Comment: 13 page
Land evaluation standards for land resource mapping : assessing land qualities and determining land capability in south-western Australia
This report describes the standard method for attributing and evaluating conventional land resource survey maps in the south-west agriculture region of Western Australia so that strategic decisions about the management, development and conservation of land resources can be based on the best information available. The standards described are similar to the land suitability assessment (stage one of the two stage) methods described by the Food and Agriculture Organisation (FAO, 1976, 1983)
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