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Alternating Phases (alternating + phase)
Selected AbstractsAppalachian basin stratigraphic response to convergent-margin structural evolutionBASIN RESEARCH, Issue 4 2001J. W. Castle ABSTRACT From study of Palaeozoic formations in the Appalachian foreland basin, a predictive stratigraphic model is proposed based on facies tract development during convergent-margin structural evolution. Five major facies tracts are recognized: shallow-water carbonates that formed during interorogenic quiescence and initial foreland subsidence; deep-water siliciclastics that accumulated in the proximal foreland basin during early collision; syn-collisional shallow-water siliciclastics; syn-collisional, channellized fluvial sandstones that aggraded in the proximal foreland; and progradational shoreline sandstones that were deposited in response to filling of the proximal foreland. Two other facies tracts that occur are organic-rich siliciclastics (,black shales'), which accumulated in oxygen-deficient areas of low clastic-sediment influx, and incised valley-fill deposits, which formed where subsidence rate was low. Because the origin of each facies tract is dependent upon a unique combination of rate of accommodation change and rate of sediment supply, facies tract distribution is predictable from spatial and temporal patterns of subsidence and uplift associated with plate convergence. Alternating phases of thrust loading and quiescence caused fluctuations between underfilled and overfilled conditions during Palaeozoic evolution of the Appalachian basin. Along-strike variations in stratigraphic thickness, facies tract distribution, and development of unconformities in the Appalachian basin reflect the influence of structural irregularities along the collisional margin. In distal parts of the Appalachian foreland and in areas of structural recesses, eustatic influence on stratigraphic patterns is expressed more clearly than in areas of higher subsidence rate. [source] Forecasting high-frequency financial data with the ARFIMA,ARCH modelJOURNAL OF FORECASTING, Issue 7 2001Michael A. Hauser Abstract Financial data series are often described as exhibiting two non-standard time series features. First, variance often changes over time, with alternating phases of high and low volatility. Such behaviour is well captured by ARCH models. Second, long memory may cause a slower decay of the autocorrelation function than would be implied by ARMA models. Fractionally integrated models have been offered as explanations. Recently, the ARFIMA,ARCH model class has been suggested as a way of coping with both phenomena simultaneously. For estimation we implement the bias correction of Cox and Reid (1987). For daily data on the Swiss 1-month Euromarket interest rate during the period 1986,1989, the ARFIMA,ARCH (5,d,2/4) model with non-integer d is selected by AIC. Model-based out-of-sample forecasts for the mean are better than predictions based on conditionally homoscedastic white noise only for longer horizons (, > 40). Regarding volatility forecasts, however, the selected ARFIMA,ARCH models dominate. Copyright © 2001 John Wiley & Sons, Ltd. [source] Changes in emotion regulation and psychological adjustment following use of a group psychosocial support program for women recently diagnosed with breast cancerPSYCHO-ONCOLOGY, Issue 3 2007Linda D. Cameron Abstract This study assesses the efficacy of a group intervention in altering emotion regulation processes and promoting adjustment in women with breast cancer. Using a design with 10 alternating phases of availability of the intervention versus standard care, we assessed women participating in one of three conditions: a 12-week group intervention (N = 54); a decliner group who refused the intervention (N = 56), and a standard care group who were not offered the intervention (N = 44). The intervention included training in relaxation, guided imagery, meditation, emotional expression, and exercises promoting control beliefs and benefit-finding. Emotion regulation processes and adjustment were assessed at baseline (following diagnosis), 4 months (corresponding with the end of the intervention), 6 months, and 12 months. At 4 months, intervention participants (compared to decliners and standard care participants) reported greater increases in use of relaxation-oriented techniques, perceived control, emotional well-being, and coping efficacy, and, greater decreases in perceived risk of recurrence, cancer worry, and anxiety. Intervention participants also reported relatively greater decreases in emotional suppression from baseline to 12 months, suggesting that the intervention had a delayed impact on these tendencies. The findings suggest an emotion regulation intervention can beneficially influence emotional experiences and regulation over the first year following diagnosis. Copyright © 2006 John Wiley & Sons, Ltd. [source] 3D seismic analysis of slope-confined canyons from the Plio,Pleistocene of the Ebro Continental Margin (Western Mediterranean)BASIN RESEARCH, Issue 1 2005Claudia Bertoni This paper documents the importance of three-dimensional (3D) seismic data for integrated stratigraphic,morphological analysis of slope systems. Furthermore, it contributes to the general understanding of the evolutionary mechanisms of slope-confined submarine canyons on continental margins and their significance in a sequence stratigraphic framework. Recently acquired 3D seismic data from the Ebro Continental Margin (Western Mediterranean) have been used to study a series of remarkably well-imaged submarine canyons in the Plio-Pleistocene succession. Detailed mapping shows that these canyons are restricted to the slope, and thus can be compared with slope-confined canyons observed on the present day seabed of many continental margins. The slope-confined canyons are typically 0.5,2 km wide, 10,15 km long, and incise more than 50 m into the slope units. Their most striking characteristic is an upslope branching geometry in the head region involving up to three orders of bifurcation, with downslope development of a single incisional axis. The submarine canyons are characterized by a nested stacking pattern, undergoing alternating phases of cutting and filling. Limited parts of the upper and middle slope remain outside the canyon system, confined in sharp depositional ridges. The canyons are observed on closely spaced surfaces and exhibit a geometry that allowed the construction and discussion of a local sequence stratigraphic model for their evolution. In general, active incision of the canyons is observed at times throughout almost the entire cycle of base-level change. However, erosional activity is more significant during the later stages of the relative sea level rise and the entire falling stage, with the timing of maximum erosion observed at the end of the cycle. The minimum erosional activity of the canyons is linked instead to the earliest part of the relative sea level rise. [source] Omega-3 fatty acids, vitamin C and Zn supplementation in asthmatic children: a randomized self-controlled studyACTA PAEDIATRICA, Issue 4 2009Mohammed Al Biltagi Abstract Objectives: Bronchial asthma is a chronic inflammatory airways disease. Nutritional intervention is an important tool to decrease the severity of many chronic inflammatory diseases including asthma. The aim of this study is to evaluate the role of omega-3 fatty acids, vitamin C and Zn in children with moderately persistent asthma. Patients and Methods: Randomly assigned, placebo-self-controlled 60 children with moderate persistent asthma completed the study, were subjected to alternating phases of supplementation with omega-3 fatty acids, vitamin C and Zn either singly or in combination separated with washout phases. Childhood asthma control test (C-ACT), pulmonary function tests and sputum inflammatory markers were evaluated at the beginning of the study and at the end of each therapeutic phase. Results: There was a significant improvement of C-ACT, pulmonary function tests and sputum inflammatory markers with diet supplementation with omega-3 fatty acids, vitamin C and Zn (p < 0.001*). There was also significant improvement with the combined use of the three supplementations than single use of any one of them (p < 0.001*). Conclusion: Diet supplementation with omega-3 fatty acids, Zn and vitamin C significantly improved asthma control test, pulmonary function tests and pulmonary inflammatory markers in children with moderately persistent bronchial asthma either singly or in combination. [source] | ||||||||||