Clinical and Experimental Studies of Gastro-Intestinal Anastomotic Techniques

Introduction Recent years have witnessed the introduction and increasing application of surgical stapling instruments in gastro-intestinal surgery. This thesis is directed towards an investigation of the potential implications of this new technology with respect to both immediate and long term post-operative outcome. Clinical and experimental studies were carried out and these are considered separately. Clinical Studies: Despite the increasing use of automated stapling devices for the construction of gastro-intestinal anastomoses, few attempts have been made to objectively compare these instruments with conventional manual suturing methods. In an attempt to clarify the role of stapling in modern surgical practice, a multicentre controlled clinical trial was designed with the aim of comparing the immediate clinical results associated with sutured and stapled anastomotic techniques. Experimental Studies: For many surgeons, the introduction of the circular stapling instrument has enabled them to construct anastomoses deeper within the pelvis than was previously possible with traditional manual suturing methods. Combined with a general trend away from abdomino-perineal excision of the rectum for rectal cancer in favour of sphincter preserving procedures, this has led to a much greater proportion of patients with this disease undergoing low anterior resection. There has, however, been some concern regarding a possible association between stapled colorectal anastomoses and an increased incidence of local recurrence of colorectal carcinoma. The experimental work carried out for this thesis was designed to explore the possible mechanisms of local recurrence and to investigate the potential influence of the choice of anastomotic suture material. (Abstract shortened by ProQuest.)

Macroeconomic impact of ageing population in Scotland: a computable general equilibrium analysis

This paper combines a multi-period economic Computable General Equilibrium (CGE) modelling framework with a demographic model to analyse the macroeconomic impact of the projected demographic trends in Scotland. Demographic trends are defined by the existing fertility-mortality rates and the level of annual net-migration. We employ a combination of a demographic and a CGE simulation to track the impact of changes in demographic structure upon macroeconomic variables under different scenarios for annual migration. We find that positive net migration can cancel the expected negative impact upon the labour market of other demographic changes. (Pressure on wages, falling employment). However, the required size of the annual net-migration is far higher than the current trends. The policy implication suggested by the results is that active policies are needed to attract migrants. We nevertheless report results when varying fertility and mortality assumptions. The impact of varying those assumptions is rather small

When voters decide: Causes, correlates and effects of the time-of-voting-decision

Why do individuals make their vote decisions at the point in time at which they do, and what impact does the time-of-voting-decision (TOVD) have upon other important political variables? Through a series of integrated articles, this dissertation explores the causes, correlates and effects of TOVD in Canada. The first two articles explore the relationships between TOVD and political attitudes, employing TOVD as both an independent and dependent variable. The first examines the impact that consistency, intensity and direction of summary political attitudes have on TOVD, and introduces a new measure of attitudinal ambivalence. The second article employs cognitive dissonance theory to argue that TOVD can influence attitudes towards parties, after an election occurs. The third and fourth articles respectively consider the relationships between TOVD and vote sincerity, and an individual’s ability to vote for the party that best reflects his or her own policy preferences. Insincere voters are found to have a relatively late TOVD, which the third article attributes to the fact that these individuals are able to use the campaign period to update their expectations about the competitive prospects of candidates and parties. The fourth and final article uses TOVD as a mediating variable to evaluate the impact of the campaign period on correct voting rates. It finds that late deciders, who are able to use the campaign period to collect information to inform their vote decisions, are actually less likely to vote correctly than are early deciders. The dissertation also includes a research note which outlines a new method of identifying invalid TOVD responses, and illustrates the importance of removing such cases. As a whole, this dissertation adds significantly to our knowledge of TOVD, a variable which, until now, has received relatively little scholarly attention

Macroeconomic impacts of demographic change in Scotland : a computable general equilibrium analysis

This paper combines a multi-period economic Computable General Equilibrium (CGE) modelling framework with a demographic model to analyse the macroeconomic impact of the projected demographic trends in Scotland. Demographic trends are defined by the existing fertility-mortality rates and the level of annual net-migration. We employ a combination of a demographic and a CGE simulation to track the impact of changes in demographic structure upon macroeconomic variables under different scenarios for annual migration. We find that positive net migration can cancel the expected negative impact upon the labour market of other demographic changes. (Pressure on wages, falling employment). However, the required size of the annual net-migration is far higher than the current trends. The policy implication suggested by the results is that active policies are needed to attract migrants. We nevertheless report results when varying fertility and mortality assumptions. The impact of varying those assumptions is rather small

Structural Characterization of Zn(II)-, Co(II)-, and Mn(II)-loaded Forms of the argE-encoded \u3cem\u3eN\u3c/em\u3e-acetyl-L-ornithine Deacetylase from \u3cem\u3eEscherichia coli\u3c/em\u3e

The Zn, Co, and Mn K-edge extended X-ray absorption fine structure (EXAFS) spectra of the N-acetyl-l-ornithine deacetylase (ArgE) from Escherichia coli, loaded with one or two equivalents of divalent metal ions (i.e., [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)], [Co(II)Co(II)(ArgE)], [Mn(II)_(ArgE)], and [Mn(II)Mn(II)(ArgE)]), were recorded. The Fourier transformed data (FT) for [Zn(II)_(ArgE)], [Zn(II)Zn(II)(ArgE)], [Co(II)_(ArgE)] and [Co(II)Co(II)(ArgE)] are dominated by a peak at 2.05 Å, that can be fit assuming five or six light atom (N,O) scatterers. Inclusion of multiple-scattering contributions from the outer-shell atoms of a histidine-imidazole ring resulted in reasonable Debye–Waller factors for these contributions and a slight reduction in the goodness-of-fit value (f′). Furthermore, the data best fit a model that included a M–M vector at 3.3 and 3.4 Å for Zn(II) and Co(II), respectively, suggesting the formation of a dinuclear site. Multiple scattering contributions from the outer-shell atoms of a histidine-imidazole rings are observed at ~ 3 and 4 Å for Zn(II)- and Co(II)-loaded ArgE suggesting at least one histidine ligand at each metal binding site. Likewise, EXAFS data for Mn(II)-loaded ArgE are dominated by a peak at 2.19 Å that was best fit assuming six light atom (N,O) scatterers. Due to poor signal to noise ratios for the Mn EXAFS spectra, no Mn–Mn vector could be modeled. Peak intensities for [M(II)_(ArgE)] vs. [M(II)M(II)(ArgE)] suggest the Zn(II), Co(II), and Mn(II) bind to ArgE in a cooperative manner. Since no structural data has been reported for any ArgE enzyme, the EXAFS data reported herein represent the first structural glimpse for ArgE enzymes. These data also provide a structural foundation for the future design of small molecules that function as inhibitors of ArgE and may potentially function as a new class of antibiotics

Macroeconomic Impact of Ageing Population in Scotland. A Computable General Equilibrium Analysis.

This paper combines a multi-period economic Computable General Equilibrium (CGE) modelling framework with a demographic model to analyse the macroeconomic impact of the projected demographic trends in Scotland. Demographic trends are defined by the existing fertility-mortality rates and the level of annual net-migration. We employ a combination of a demographic and a CGE simulation to track the impact of changes in demographic structure upon macroeconomic variables under different scenarios for annual migration. We find that positive net migration can cancel the expected negative impact upon the labour market of other demographic changes. (Pressure on wages, falling employment). However, the required size of the annual net-migration is far higher than the current trends. The policy implication suggested by the results is that active policies are needed to attract migrants. We nevertheless report results when varying fertility and mortality assumptions. The impact of varying those assumptions is rather small.

Global Value Chains in Africa

This paper provides evidence on the extent of Global Value Chain (GVC) participation by Africa as a region and for individual African countries. We find that Africa as a whole is heavily involved in GVCs, being more engaged in GVCs than many developing country regions as well as developed countries such as the USA. This overall finding hides the fact that much of Africa's participation in GVCs is in upstream production, with African firms providing primary inputs to firms in countries further down the value chain. The possibility of upgrading within GVCs in Africa is likely to be limited therefore, something which the current analysis suggests. Despite this, we observe a great deal of heterogeneity in terms of GVC participation and upgrading across African countries, with a number of African countries participating in GVCs to a relatively large extent. (authors' abstract

The Lasting Benefits of Multiyear Camp Programming for Youth from Low-Income Backgrounds

Summer camps are a common youth development setting in North America; however, youth from lowincome backgrounds often cannot attend because of financial barriers. Subsequently, although a robust camp literature exists, little is known about the lasting benefits for youth from low-income backgrounds. Even less is known about how these outcomes may differ based on the number of years youth attend a multi-year camp. The purpose of this study was to examine the long-term outcomes camp alumni reported as attributable to camp and that remain important in their life today. Eighteen outcomes examined via a cross-sectional retrospective survey completed by 449 camp alumni between the ages of 18 and 40 (mage = 22.1, SD = 5.17) were analyzed using repeated-measures analysis of variance to examine the within-subject and between-subject associations between years attended camp and alumni reported outcomes. Alumni of multi-year camps for youth from low-income backgrounds reported that camp was important to the development of many outcomes that are useful to their lives today. The more years that alumni attended a multi-year camp program, the greater the impact they reported that camp had on outcomes important to them today and the more likely they were to have completed post-secondary education. The results of this study provide evidence that practitioners and policy makers may use to advocate for funding to make camp programs more accessible and supportive for youth from low-income backgrounds, and to support youth year-round to stay engaged with camp programs

Temperature-dependent Hall scattering factor and drift mobility in remotely doped Si:B/SiGe/Si heterostructures

Hall-and-Strip measurements on modulation-doped SiGe heterostructures and combined Hall and capacitance–voltage measurements on metal-oxide-semiconductor (MOS)-gated enhancement mode structures have been used to deduce Hall scattering factors, rH, in the Si1 – xGex two-dimensional hole gas. At 300 K, rH was found to be equal to 0.4 for x = 0.2 and x = 0.3. Knowing rH, it is possible to calculate the 300 K drift mobilities in the modulation-doped structures which are found to be 400 cm2 V – 1 s – 1 at a carrier density of 3.3 × 1011 cm – 2 for x = 0.2 and 300 cm2 V – 1 s – 1 at 6.3 × 1011 cm – 2 for x = 0.3, factors of between 1.5 and 2.0 greater than a Si pMOS control