4 results on '"Mcmillan, D."'
Search Results
2. Investigations of volatility in intra-day UK futures market data
- Author
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McMillan, D. C.
- Subjects
332 - Abstract
The aim of this study is to provide a systematic investigation of volatility in high-frequency intra-day financial futures data. There are several motivations for such a study. First, to examine whether the empirical results achieved with daily and lower frequency data, for example, the high persistence of volatility to shocks, continue to hold with intra-day data. Second, to examine hypotheses concerning the intra-day patterns in volatility and volume, the cause of ARCH volatility clustering in financial data, and the temporal aggregation properties of intra-day data. Third, to examine some of the issues raised by other researchers currently examining such data, particularly those pertaining to the degree of non-linearity within the data, whether a model from the GARCH class can adequately account for this non-linearity and whether that result is frequency dependent. In sum, graphical and simple regression evidence suggests a 'U'-shape intra-day pattern in both volatility and volume, interspersed by spikes resulting from the release of macroeconomic news. Non-linear dependence is reported in conditional variance, this taking GARCH form with high persistence to shocks. Evidence of an asymmetric response to these shocks is, however, limited. The model orders and coefficient estimates of temporally aggregated data suggest some support for established theoretical results. Residual diagnostics for GARCH models become insignificant at the one hour and lower frequencies, but indicate remaining non-linear structure in higher frequencies and five-minute returns in particular. The inclusion of volume in the GARCH equation suggests support for the information flow hypothesis as the cause of volatility clustering, but remaining significant GARCH parameters suggest that it is not the full explanation. Non-linear dependence in conditional mean at higher frequencies is also reported, and models of smooth transition threshold behaviour prove able to account for some but not all of this structure.
- Published
- 1998
3. The role of prostaglandins in the control of protein turnover in tissues of the rat and the rainbow trout (Salmo Gairdneri, Richardson)
- Author
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McMillan, D. Nelson
- Subjects
572 ,Prostaglandin synthesis - Abstract
The possible role of the prostaglandins (PGs) in the regulation of protein turnover was investigated, firstly in hypertrophying rat skeletal muscle at 20 hours, 3 days and 7 days after synergist tenotomy, and secondly, in various tissues of the rainbow trout (Salmo gairdneri, Richardson) following re-feeding. An inhibitor of PG synthesis was used in both cases (fenbufen and indomethacin, respectively). 1) Fenbufen (at a dose of 1200mg/kg of diet) did not inhibit the hypertrophy of the soleus and plantaris muscles although there appeared to be an initial reduction in muscle RNA content. 2) Muscle growth was generally increased in fenbufen fed rats by 7 days after synergist tenotomy (10 days on fenbufen diet). 3) The fractional rate of protein synthesis in both control and overloaded muscles was reduced by fenbufen at this time (in 86g rats). The calculated rates of protein breakdown were also reduced in these muscles but to a greater extent than synthesis. This inhibition of protein degradation was most marked in the overloaded soleus and plantaris muscles. 4) The tenotomised gastrocnemius muscle experienced a true atrophy in the fenbufen-treated rats by 7 days. This atrophy involved greatly elevated rates of protein degradation when compared to the tenotomised muscle from rats fed a normal diet. In 6 day fasted rainbow trout, tissue protein synthesis was measured at 3 hours, 6 hours and 12 hours after re-feeding. The rapidity of the stimulation of protein synthesis by re-feeding and the nature of the response was tissue-specific. The administration of indomethacin (at a dose of 2mg/100g body weight) one hour prior to the meal, partially blocked the re-feeding response of protein synthesis in the gill at 6 hours after the meal, but stimulated protein synthesis in the liver and white muscle at this time.
- Published
- 1987
4. Maladaptive cognitive processes during exposure in people with OCD (checking subtype)
- Author
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Robson, Stacey, McMillan, D., and Morley, S.
- Subjects
155 - Abstract
Cognitive Behaviour Therapy (CBT) is regarded as one of the most efficacious psychological treatments of Obsessive Compulsive Disorder (OCD) and is recommended in the recent National Institute for Clinical Excellence guidelines (NICE, 2006). Despite this, comparative studies have consistently shown CBT to be no more effective than Exposure and Response Prevention (ERP; McLean et al., 2001). Recently, cognitive theories of OCD have identified specific cognitive mechanisms involved in symptom-based subtypes of OCD (OCCWG, 1997,2005). It is possible that specifically targeting these mechanisms may increase the efficacy of the cognitive component of treatment (McKay et al., 2004). This study aims to expand on recent research that suggests that repeated checking behaviours are maladaptive coping strategies that serve to maintain the difficulty (Rachman, 2002). Because previous research suggests that individuals with checking rituals are more likely to have an intolerance of uncertainty (Tolin et al., 2003), it is possible that they will also use specific cognitive safety behaviours to try to manage their anxiety during exposure. The current study hypothesized that the use of a memory search and a reasoning task during exposure would lead to a decrease in memory detail and confidence,and an increase in urge to check and anxiety. Data were collected from five participants currently on the waiting list for clinical psychology services. A single case experimental design with counterbalancing was used to test each hypothesis. The results of the study were mixed and showed little change in all four experimental conditions. Furthermore, mean change scores were inconsistent with the research hypotheses. That is, the use of a memory search and a reasoning task did not appear to have a maladaptive effect. The clinical and research implications of the results are discussed along with several limitations of the study. On the basis of the findings, it was concluded that OCD is a heterogeneousd isorder and that further research is needed to examine the suitability of subtyping in OCD and the implications this has for treatment.
- Published
- 2007
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