Variation in African American parents' use of early childhood physical discipline

Physical discipline is endorsed by a majority of adults in the U.S. including African American (AA) parents who have high rates of endorsement. Although many studies have examined physical discipline use among AA families, few have considered how early childhood physical discipline varies within the population. Individuals within a cultural group may differ in their engagement in cultural practices (Rogoff, 2003). Furthermore, AA families’ characteristics and their contexts, which are shaped by the interaction of social position, racism, and segregation (García Coll et al., 1996), likely influence how AA families physically discipline their young children. This study examined variation in early childhood physical discipline among AA families living in low-income communities and relations with demographic and contextual factors. Year 1 data from 310 AA parents living in three regionally distinct low-income communities were used from a sequential longitudinal intervention program study of the development and prevention of conduct disorder. Latent class analyses were conducted using parents’ responses on a measure, of the frequency of overall physical discipline, spanking, and hitting during prekindergarten and kindergarten. The associations between latent classes and six demographic and contextual factors were examined using the Bolck, Croon, and Hagenaars (BCH) method. The factors were: child gender (59% male); marital status (51% never married); parental education (66% high school graduates and beyond); income (mean = $16.66K, S.D. = 12.50), family stress, and perception of neighborhood safety. Measures included the Family Information Form, Life Changes, and the Neighborhood Questionnaire. After considering two to seven class solutions, five physical discipline classes or sub-groups were identified. Classes were defined by discipline frequency (‘Infrequent’, ‘Weekly’, ‘Monthly’, ‘Almost-Every-Day’ and ‘Weekly-All’) as well as by discipline type (only parents in the ‘Weekly-All’ class hit their children). Significant associations were found between class membership, and child gender, marital status, income, and perception of neighborhood safety. Girls were more likely to be physically disciplined infrequently, χ2(4, N = 310) = 11.88, p = .05. The ‘Weekly’ class had significantly fewer married parents than all classes except ‘Almost-Every-Day’, χ2(4, N = 310) = 21.56, p < .001. Parents in the ‘Almost-Every-Day’ class had a significantly lower income than parents in all other classes except “Weekly-All”, χ2(4, N = 310) = 10.88, p = .03. Finally, parents in the “Almost-Every-Day” class perceived their neighborhood as significantly less safe compared to those in all other classes except the ‘Weekly-All’ class, χ2(4, N = 310) = 14.13 p = .01. These findings suggest that AA families vary in physical discipline during early childhood; this variation may result in sub-groups with different demographic characteristics. Associations between frequent discipline classes and perceptions of neighborhood safety implies that some AA parents may use physical discipline to protect their children from being harmed if they believe their communities are unsafe. Future research should qualitatively examine how AA parents respond to unsafe neighborhoods in their parenting behaviors, including physical discipline

Architecture and Evolution of an Accretionary Orogen

Much of Earth\u27s continental crust comprises Precambrian through Cenozoic orogens, where preexisting rocks have been variably modified by metamorphism and deformation. Owing to the association between collisional tectonic events and mountain building, this long record of orogenesis provides the most accessible means of reconstructing paleotectonic settings and events that have shaped our planet. Although the Appalachian mountains are widely used toillustrate Earth\u27s tectonic evolution and associated orogenesis, collisional processes and events that drove the Ordovician Taconian orogeny in the Quebec Maine segment of the northern Appalachians remain enigmatic. Deformational features in this region cannot be satisfactorily related to a specific convergent setting or collisional event(s) because the nature of the eastern (present coordinates) Laurentian margin during the early Paleozoic is poorly understood.Interpretations are divided as to whether the orogeny was caused by ophiolite emplacement, island-arc collision, or microcontinent collision. Because the Taconian orogeny initiated the Appalachian mountain-building cycle, understanding its architecture and evolution is essential for understanding the Appalachians as a whole.The PI proposes to investigate structural, metamorphic, and temporal relationships among the rock units that make up the Chain Lakes massif and Boil Mountain ophiolite in order to test competing models and hypotheses for the Taconian orogeny in the northern Appalachians. Their multidisciplinary approach incorporates mapping, structural, microstructural, metamorphic, and geochronological studies. Integrating field and laboratory studies, the PI will establish: (a) the relative and absolute timing of metamorphic and deformational events within the Chain Lakes massif, (b) the crystallization age of the mafic portion of the Boil Mountain ophiolite, (c) the age and kinematics of ophiolite emplacement, (d) whether mafic volcanic rocks near the ophiolite represent a genetic part of the ophiolite, and (e) the age of possibly rift-related mafic dikes in the Chain Lakes massif. The geochronology portion of the project will include in-situ U-Pb analyses of monazite to provide high temporal resolution for metamorphic events, small-number multigrain U-Pb analyses of zircon or baddeleyite from gabbro to determine the crystallization age of the ophiolite, U-Pb analyses of zircon to establish the age of the dikes, and laser step- heating 40 Ar- 39 Ar analysis of muscovite to determine the minimum ophiolite emplacement age. The PI will compare his results with existing interpretations of the Thetford Mines ophiolite and overlying units in southern Quebec, the Maquereau Dome in the Gaspe Peninsula, and the Dashwoods Subzone in Newfoundland in order to evaluate temporal and spatial relationships among these potentially correlative units. Because the extents and boundaries of terranes are fundamental components of the tectonic models, testing the terrane relationships will test the models. The work will clarify the nature of the Taconian orogeny in the northern Appalachians, and will bear on conceptual models describing Iapetan paleogeographic reconstruction and collisional accretionary processes

Coupled Deformation and Metamorphism, Fabric Development, Rheological Evolution and Strain Localization

When Earth\u27s tectonic plates interact with one another the rocks that comprise them are deformed, commonly forming great mountain chains. During this deformation, the minerals that make up the rocks can become spatially or crystallographically aligned to form a fabric. The development of rock fabric is a primary factor affecting the strength, or rheological evolution of deforming rocks. Fabric development commonly involves coupling of both physical and chemical processes. For example, crenulation cleavage is the most common type of fabric in multiply deformed rocks, and its formation leads to extreme mineral segregation and rheological anisotropy. It is also commonly associated with the growth of large metamorphic minerals (porphyroblasts), which are used by structural geologists to infer deformation histories and mechanical quantities such as shear strain, shear strain rate and vorticity. Although crenulation cleavage is common throughout the world\u27s mountain chains, and may play an important role in the localization of deformation across a range of scales, the details of its formation, and its possible mechanical significance, remain poorly understood. The investigators and their students are combining field- and laboratory-based studies with computer modeling to address the effects of rock fabric, particularly crenulation cleavage, on the rheological evolution of rocks. The chosen field area is located in the Appalachian mountains of western Maine. The results of this project will be incorporated into web-based educational modules that are intended as resources for earth-science teachers and students at all levels

Magmatic to Solid-State Fabric Transition in a Post-Tectonic Tonalite Pluton

Magma chambers are an essential component in the construction of oceanic and continental lithosphere, and profoundly influence the thermal and mechanical behavior of the crust and mantle. The mechanical properties of a magma chamber change during cooling and crystallization, as accommodation of deformation changes from magmatic flow to solid-state processes. Thus, to understand the thermo-mechanical evolution of magma chambers, it is crucial to understand the relative importance of magmatic and solid-state flow, and the nature of the transition between them. This project is investigating such a transition preserved in the San Jose pluton, Baja California, Mexico. The pluton postdates the regional deformation, and so the transition from magmatic to solid-state flow reflects internal magma-chamber dynamics. Such transitions are rarely observed in post-tectonic plutons, and our results will benefit others who are working in more complex syntectonic examples. Detailed mapping and collection of spatially oriented samples is taking place along four transects in the pluton. X-ray compositional mapping, microstructural analysis and electron backscatter diffraction studies are being employed to track the chemical evolution of the deforming and crystallizing pluton, and to evaluate deformation mechanisms and the origins of the magmatic foliations. The project is supporting a PhD student, and several senior undergraduates at the University of Maine will participate as part of their Capstone Experience

Collaborative Research: The Tectonothermal Evolution of a Convergent Orogen

Understanding of orogenesis and its relations to mantle convection and plate tectonics relies on integrated studies of the interrelations among processes of deformation, metamorphism and magmatism. A well preserved portion of the northern Appalachian orogen is providing an outstanding laboratory for a truly integrative study of the evolution of mid-crustal processes that strongly influence orogenesis. This project is employing structural, microstructural, petrologic and thermobarometric analyses, and chemical and isotopic dating, to temporally and spatially link deformation, metamorphism and magmatism during the progressive growth of this orogenic belt. This information is being used to set constraints and boundary conditions on coupled, 3-D thermal/mechanical models that, in tandem with the geological observations, are being used used to gain insights into the orogen\u27s evolution and associated plate dynamics

Kinematic Vorticity Gauges and the Rheology of Mylonitic Shear Zones

Many hazards encountered by humans, including earthquakes, volcanic eruptions and tsunamis, result from plate tectonics. How tectonic plates move and interact with one another, and how deformation that occurs at their interacting boundaries is localized into structures like the San Andreas fault in California, are first-order questions in the Earth Sciences. At active tectonic plate boundaries, GPS data have allowed a much clearer understanding of plate interactions, localization of deformation, and relations to seismic and volcanic hazards. However, such data provide little information about plate interaction and deformation at great depth. The most direct way to study these deeper processes is to work in ancient plate boundary zones that have been exhumed by uplift and erosion. Geologists use a range of tools to evaluate the histories of deformation in these exhumed rocks, but the validity of some of these tools still needs to be tested. The primary goal of this project is to test some microstructural tools used to extract from exhumed, deformed rocks an important quantity known as kinematic vorticity. Through this study the investigators hope to clarify under what conditions these tools can be reliably used to measure kinematic vorticity. The work will be conducted in the Norumbega Fault System, which cuts across the entire State of Maine, and is one of the very few ancient analogs for the San Andreas Fault in California. Thus, our results will have applicability to a well-known seismically active fault. More specifically, these researchers will investigate the oblique quartz shape preferred orientation and rigid clast rotation methods for determining kinematic vorticity in a well-characterized mylonitic shear zone with approximately monoclinic strain symmetry. They will provide a detailed analysis of the microstructural factors that may compromise clast methods of kinematic vorticity analysis, and determine if one of the other methods gives consistent results even where clast methods are compromised. In addition, they will develop criteria for estimating the degree of strain localization at clast/matrix boundaries and conduct numerical sensitivity analyses to better understand the effects of clast lubrication on the bulk shear strength of mylonitic shear zones that form the roots of seismically active faults. Detailed microstructural investigations will utilize optical, scanning electron microscopy and electron backscatter diffraction techniques. 2D and 3D parametric numerical sensitivity analyses will be used to investigate a range of parameters that may affect clast kinematics, and assess how the evolution of clast lubrication with increasing strain may contribute to long-lived weakening of shear zones. The preliminary results are novel, and suggest caution when using clast rotation methods for determining the kinematic vorticity number, but they open exciting new possibilities for investigating strain-dependent changes in rock strength that arise from feedbacks among chemical and mechanical processes during deformation

Collaborative Research: Multiscale Analysis of Geological Structures That Influence Crustal Seismic Anisotropy

This project is a study of crustal material anisotropy with a focus on macroscale structural geometries and how they will modify the seismic response of rock fabrics. Seismic anisotropy is the cumulative interplay between propagating seismic waves and anisotropic earth material that manifests itself through the directional dependence of seismic wave speeds. Unraveling this effect in deformed crustal terranes is complex due to several factors, such as 3D geological geometry and heterogeneity, microscale fabric, bending of seismic raypaths due to velocity gradients, field experiments that may not offer full azimuthal coverage, and the observation of anisotropy as second-order waveform or traveltime features. While seismic anisotropy can originate from upper crustal fractures or by organized fine-scale layering of isotropic material, material anisotropy is also a cause and involves at least four factors: (1) microstructural characteristics including spatial arrangement, modal abundances, and crystallographic and shape orientations of constituent minerals(2) inherent azimuthal variation of properties and approximation using symmetry classes,(3) bulk representation (effective media) of material properties at different scales, and (4) the types and internal geometries of macroscale structures. The reorientation of sample-scale material anisotropy by macroscale structures imparts its own effect. A seismic wave will produce one type of signal response due to material; it can produce a different response due to a package of rocks that are reoriented due to the geometry of a structure. The researchers will use the concept of seismic effective media to represent earth volumes through which seismic waves travel. They will employ a representation of earth volumes that allow for a tensorial representation of effective media. This allows via the wave equation an algebraic tensor manipulation to separate the structural geometry and the rocks composing the structure. A primary goal of the project is to define the contributions of structure to form effective media. Each structure has a geometrical impulse response which will modify a rock texture into an effective medium representation of the structure. A second goal of the project is to understand how the role of microscale rock fabrics contribute towards the effective media for given structures. Both combine to produce the net effective medium that a propagating wave responds to. They will conduct a quantitative and systematic study of common crustal structural geometries and how they modify rock anisotropy, and represent structures using analytical geometry surfaces and create a rigorous and integrated methodology to calculate effective media at different scales and their combined effects on seismic wave propagation. They will also examine how the tensorial form of microscale rock fabrics are sensitive to the modal compositions and statistical orientations of constituent minerals. Results of this project will be designed to aid the seismic interpretation of real anisotropic seismic data. This project brings together expertise in seismology, structural/microstructural geology and theoretical/computational mechanics to help develop a quantitative framework for the analysis of material anisotropy and resulting seismic anisotropy in deformed polymineralic rocks of the continental crust