Can the catastrophizing interview technique be used to develop understanding of childhood worry?

Background: The current research-base into childhood worry is extremely limited, in part owing to the lack of appropriately validated measures of worry suitable for use with children. Although some adult measures of worry have successfully been adapted for use with children, as of yet no measure suitable for use within an experimental paradigm has been developed, meaning that the majority of the existing research is based on correlational designs and therefore does not allow exploration of causative relationships between childhood worry and other factors. Aim: This thesis aimed to explore the use of the catastrophizing interview technique with children, with the goal of validating this technique as an experimental measure of childhood worry. Method: A mixed methodology was employed, using both single group correlation and between group comparisons. Additionally, a qualitative aspect to the design allowed greater exploration of the interview responses given by participants. The data from 88 participants aged 9 – 11 was used for the analysis. Participants completed a number of interviewer-assisted measures of worry, verbal reasoning, verbal fluency and tendency to respond in a socially desirable manner, before completing two catastrophizing tasks. Results: Limited evidence was found for a relationship between the catastrophizing interview responses and tendency to worry. However, when confounding variables such as verbal ability were controlled, a relationship between the number of steps generated using the interview and tendency to worry was found. Additionally, high worriers were more likely to respond in an extreme or circular manner, than low worriers. Discussion: Although this study found limited support for using the catastrophizing interview technique with children, there were a number of methodological issues with the study design that may have affected results. Given the need for a greater understanding of the processes of childhood worry, further exploration of using the catastrophizing interview technique is warranted

Sequence Stratigraphy and Onlap History of the Donets Basin, Ukraine: Insight into Carboniferous Icehouse Dynamics

The degree to which Permo-Carboniferous cyclothemic successions archive evidence for long-term variations in ice volume during the Late Paleozoic Ice Age is insufficiently resolved. Here we develop the sequence stratigraphy and onlap-offlap history for a 33-my interval of the Carboniferous using the U-Pb calibrated succession of the Donets Basin, Ukraine, in order to assess the relationship between sea-level, high-latitude changes in glacial extent, and climate. Integrated subsurface and outcrop data permit meter-scale correlation of 242 biostratigraphically constrained limestones and coals, and in turn individual cyclothems, across ~250 km of the Donets Basin. Rapid uniform subsidence and basinwide continuity of marker beds indicate Pennsylvanian deposition under relatively stable tectonic conditions. Three scales of sequences (avg. durations of ~140 ky, ~480 ky and 1.6 my) are recognized on the basis of stratigraphic stacking patterns and basinwide architecture of marine to terrestrial facies assemblages. The hierarchy of sequences and the geographic and stratigraphic positions of shifts in base-level sensitive facies across the Donets ramp permit the construction of an onlap-offlap history at a sub-400 ky scale. Major sea-level lowstands occur across the mid-Carboniferous boundary and during the early Moscovian. These lowstands coincide with glacial maxima inferred from high-latitude glacigenic deposits. The middle to late Pennsylvanian is characterized by a stepwise onlap, culminating in an earliest Gzhelian highstand, suggesting contraction of Carboniferous ice sheets prior to the initiation of Early Permian glaciation. The stratigraphic position of climate sensitive facies within individual Donets cyclothems indicates a turnover from seasonal sub-humid or semi-arid climate to everwet conditions during the late lowstand and maximum ice sheet accumulation. Comparison of the stratigraphic and aerial distribution of coals and evaporites in the Donets Basin with the onlap-offlap history further indicates everwet conditions during lowstands and inferred glacial maxima and drier climate during onlap and inferred ice sheet contraction at the intermediate (~0.8 to 1.6 my) and long (106 yr) time-scales. Taken together, the relationship between inferred climate and glacioeustasy suggests a likely teleconnection between high-latitude ice sheet behavior and low-latitude atmospheric dynamics

Investigating the preservation of orbital forcing in peritidal carbonates

Peer reviewedPostprin

Two-dimensional modeling of carbonate ramp sequences and component cycles

Two-dimensional stratigraphic models incorporating antecedent platform topography, rotational and regional driving subsidence, sediment and water loading using an elastic beam model, water-depth-dependent sedimentation rates and rock types, lag time of the flexural response, depositional lag time following initial platform flooding, and third- to fifth-order complex sea-level curves can be used to understand the development of cyclic carbonate platforms. Sea-level curves dominated by approximately 100-k.y. or 40-k.y. fluctuations developed a platform stratigraphy characterized by only a few cycles, whereas numerous cycles develop where the sea-level curve is dominated by 19-23 k.y. fluctuations. Low-amplitude sea-level curves in which the 100-k.y. fluctuation is greater than the 40-k.y. fluctuation, which in turn is greater than the 19-23-k.y. fluctuations, form a platform stratigraphy dominated by stacked cycles. Increased amplitude of the lower-frequency oscillations forms a shingled stacking pattern on the platform. Also, the increased amplitudes cause deposition of cycles with decreased thickness of tidal flat caps and longer duration of capping disconformities. Superimposing high-frequency sea-level fluctuations (20-100 k.y.) on longer-term 1-3-m.y. fluctuations generates synthetic platforms composed of stacked depositional sequences consisting of 1-10-m (3.3-33-ft) cycles. The model output illustrates how the systems tracts and their component cycles are related to the input sea-level curves. Erosion in the model decreases the thickness of tidal flat caps, increases the subtidal facies thicknesses of cycles because it increases accommodation, and bevels the highstand systems tract during long-term fall through erosion. The models show why picking boundaries between systems tracts is difficult when individual measured sections of cyclic platforms are used. Fischer plots were generated from the model output. The plots, when constructed for outer platform sections, are useful in estimating third-order sea-level fluctuations and in defining the positions of the systems tract boundaries

Two-dimensional modeling of carbonate ramp sequences and component cycles

Two-dimensional stratigraphic models incorporating antecedent platform topography, rotational and regional driving subsidence, sediment and water loading using an elastic beam model, water-depth-dependent sedimentation rates and rock types, lag time of the flexural response, depositional lag time following initial platform flooding, and third- to fifth-order complex sea-level curves can be used to understand the development of cyclic carbonate platforms. Sea-level curves dominated by approximately 100-k.y. or 40-k.y. fluctuations developed a platform stratigraphy characterized by only a few cycles, whereas numerous cycles develop where the sea-level curve is dominated by 19-23 k.y. fluctuations. Low-amplitude sea-level curves in which the 100-k.y. fluctuation is greater than the 40-k.y. fluctuation, which in turn is greater than the 19-23-k.y. fluctuations, form a platform stratigraphy dominated by stacked cycles. Increased amplitude of the lower-frequency oscillations forms a shingled stacking pattern on the platform. Also, the increased amplitudes cause deposition of cycles with decreased thickness of tidal flat caps and longer duration of capping disconformities. Superimposing high-frequency sea-level fluctuations (20-100 k.y.) on longer-term 1-3-m.y. fluctuations generates synthetic platforms composed of stacked depositional sequences consisting of 1-10-m (3.3-33-ft) cycles. The model output illustrates how the systems tracts and their component cycles are related to the input sea-level curves. Erosion in the model decreases the thickness of tidal flat caps, increases the subtidal facies thicknesses of cycles because it increases accommodation, and bevels the highstand systems tract during long-term fall through erosion. The models show why picking boundaries between systems tracts is difficult when individual measured sections of cyclic platforms are used. Fischer plots were generated from the model output. The plots, when constructed for outer platform sections, are useful in estimating third-order sea-level fluctuations and in defining the positions of the systems tract boundaries

Estuarine Response to Disturbance: A Holocene Record of Storm Episodes and Seismicity as Preserved in Coastal Systems

Southern California is highly susceptible to hazards related to seismic activity and storms linked with El Niños and Atmospheric Rivers. These hazards are capable of incurring flooding, debris flow, coastal inundation, and rapid coastal erosion. Although much work has been done using lacustrine and deep marine sediment records to reconstruct the frequency of these past events, coastal records from lagoons and estuaries are less well documented. Here we present detailed sedimentologic and geochemical analysis of sediment cores, constrained by radiocarbon dates, from two estuarine/lagoon systems from coastal Southern California, Campus Lagoon and Las Salinas Lagoon. Our results record multiple occurrences of marine inundation thought to record storms of similar or greater magnitude as the catastrophic winter storms of 1861-1862. At least three of these events occurred pre 149 calibrated years before present (CYBP), one between 149 and 397 ± 22, two between 397 ± 22 and 617 ± 105 CYBP, and three between 1050 ± 200 and 3400 ±190 CYBP. These events establish a historic recurrence interval of ~660 years, and a post 2000 CYBP interval of 320 years, comparable to other California records. However, two of these pre-1 ka events may be the result of tsunami washover rather than storm washover as they correlate to large magnitude seismic earthquakes along the Pitas Point fault at 1050 ± 200 and 2250 ± 300 CYBP. A simultaneous environmental shift from an open lagoon to barrier-lagoon is observed in both lagoons at 4300 ± 250 CYBP that is interpreted to represent the onset of beach progradation in the Santa Barbara Channel in response to slowing sea-level rise

Integrated Sr isotope variations and sea-level history of Middle to Upper Cambrian platform carbonates: Implications for the evolution of Cambrian seawater 87 Sr/ 86 Sr

ABSTRACT A high-resolution Sr isotope study of Middle to Upper Cambrian platform carbonates of the southern Great Basin significantly refines the structure of the existing seawater Sr isotope curve. Samples were selected using rigorous stratigraphic, petrographic, and geochemical criteria in order to minimize the effects of diagenetic alteration and contamination from noncarbonate components

Clear Lake sediments: Anthropogenic changes in physical sedimentology and magnetic response

We analyzed the sedimentological characteristics and magnetic properties of cores from the three basins of Clear Lake, California, USA, to assess the depositional response to a series of land use changes that occurred in the watershed over the 20th century. Results indicate that distinct and abrupt shifts in particle size, magnetic concentration/mineralogy, and redox conditions occur concurrently with a variety of ecological and chemical changes in lake bed sediments. This coincidence of events occurred around 1927, a datum determined by an abrupt increase in total mercury (Hg) in Clear Lake cores and the known initiation of open-pit Hg mining at the Sulphur Bank Mercury Mine, confirmed by ²¹⁰Pb dating. Ages below the 1927 horizon were determined by accelerator mass spectrometry on ¹⁴C of coarse organic debris. Calculated sedimentation rates below the 1927 datum are ~1 mm/yr, whereas rates from 1927 to 2000 are up to an order of magnitude higher, with averages of ~3.5–19 mm/yr. In both the Oaks and Upper Arms, the post-1927 co-occurrence of abrupt shifts in magnetic signatures with color differences indicative of changing redox conditions is interpreted to reflect a more oxygenated diagenetic regime and rapid burial of sediment below the depth of sulfate diffusion. Post-1927 in the Oaks Arm, grain size exhibits a gradual coarsening-upward pattern that we attribute to the input of mechanically deposited waste rock related to open-pit mining activities at the mine. In contrast, grain size in the Upper Arm exhibits a gradational fining-upward after 1927 that we interpret as human-induced erosion of fine-grained soils and chemically weathered rocks of the Franciscan Assemblage by heavy earthmoving equipment associated with a road- and home-building boom, exacerbated by stream channel mining and wetlands destruction. The flux of fine-grained sediment into the Upper Arm increased the nutrient load to the lake, and that in turn catalyzed profuse cyanobacterial blooms through the 20th century. The resulting organic biomass, in combination with the increased inorganic sediment supply, contributed to the abrupt increase in sedimentation rate after 1927.KEYWORDS: Clear Lake, California, USA, particle size trends, ¹⁴C, paleolimnology, late Holocene, land use patterns, Sulphur Bank Mercury Mine, mercury, magnetic dissolutio

Mercury flux to sediments of Lake Tahoe, California-Nevada

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Water, Air, & Soil Pollution 210 (2010): 399-407, doi:10.1007/s11270-009-0262-y.We report estimates of mercury (Hg) flux to the sediments of Lake Tahoe, California-Nevada: 2 and 15-20 µg/m2/yr in preindustrial and modern sediments, respectively. These values result in a modern to preindustrial flux ratio of 7.5-10, which is similar to flux ratios recently reported for other alpine lakes in California, and greater than the value of 3 typically seen worldwide. We offer plausible hypotheses to explain the high flux ratios, including (1) proportionally less photoreduction and evasion of Hg with the onset of cultural eutrophication and (2) a combination of enhanced regional oxidation of gaseous elemental Hg and transport of the resulting reactive gaseous Hg to the surface with nightly downslope flows of air. If either of these mechanisms is correct, it could lead to local/regional solutions to lessen the impact of globally increasing anthropogenic emissions of Hg on Lake Tahoe and other alpine ecosystems.Funding was provided by Miami University, EPA-STAR, the Postdoctoral Scholar Program at Woods Hole Oceanographic Institution, and the USGS