Characteristic function pricing with the Heston-LIBOR hybrid model

We derive an approximate characteristic function for a simplified version of the Heston-LIBOR model, which assumes a constant instantaneous volatility structure in the underlying LIBOR market model. We also implement measures to improve the numerical stability of the characteristic function derived in this dissertation as well as the one derived by Grzelak and Oosterlee. The ultimate aim of the dissertation is to prevent these characteristic functions from exploding for given parameter values

Trophodynamics of carnivorous zooplankton in the region of the subtropical convergence within the Indian sector of the Southern Ocean, with particular emphasis on chaetognaths

Trophodynamics of carnivorous zooplankton in the region of the Subtropical Convergence (STC) in the Indian sector of the Southern Ocean was investigated during austral autumn (April 2007) as part of the first cruise of the Southern Ocean Ecosystem Variability Study. Within the region of the study, the STC was well defined by the 14°C surface isotherm which separated the Agulhas Return Current and Subtropical water in the north from Sub-Antarctic waters to the south. Total average abundance (3.89 ± 5.46ind 100m-3) and biomass (0.14 ± 0.27mg Dwt 100m-3) of carnivorous zooplankton south of the front were significantly higher than the total average abundance (1.33 ± 1.81ind 100m-3) and biomass (0.03 ± 0.05mg Dwt 100m-3) north of the front (p0.05 in all cases). There was no evidence of enhanced biomass and abundance values at stations occupied in the immediate vicinity of the front. Total average carnivorous zooplankton abundance was dominated by chaetognaths (Eukrohnia hamata Möbius 1875, Sagitta gazellae Ritler-Záhony 1909 and S. zetesios Fowler 1905) and euphausiids (Nematoscelis megalops Sars 1883, Euphausia longirostris Hansen 1908 and E. spinifera Sars 1883), which contributed up to 86.58 ± 32.91% of the total counts. The total average biomass was dominated by euphausiids and amphipods (Themisto gaudichaudii Guérin-Méneville 1825, Phronima sedentaria Forsskål 1775 and Vibilia armata Bovallius 1887) which contributed up to 71.45 ± 34.85% of the total counts. In general the populations of both the euphausiids and amphipods were dominated by females while the chaetognaths were dominated by juveniles. Numerical analysis identified two major zooplankton groupings within the survey area which did not coincide with the water masses within the survey area. The SIMPER procedure of the PRIMER package indicated differences between the groups were mainly attributed to changes in the abundance of the numerically dominant species rather than the presence or absence of individual species. The absence of any significant spatial patterns in the distribution of the carnivorous zooplankton suggests that the STC did not act as a biogeographical barrier during the present study. The mean feeding rates of the chaetognaths E. hamata, S. gazellae and S. zetesios were 1.82 ± 0.85prey d-1, 3.63 ± 2.08prey d-1 and 2.18 ± 0.59prey d-1, respectively. These rates correspond to a combined predation impact equivalent to <5% of the mesozooplankton standing stock or <10% of the mesozooplankton secondary production. Mesozooplankton, comprising mainly copepods was the dominant prey in the guts of the three chaetognath species. Total predation impact of the euphausiids, chaetognaths and amphipods, estimated using published daily ration data, on the mesozooplankton standing stock and secondary production ranged from 0.01% to 1.53% and from 0.03% to 30.54%, respectively. Among the carnivorous zooplankton, chaetognaths were generally identified as the dominant predators of mesozooplankton. Low predation impact of selected carnivorous zooplankton suggested that these organisms contributed little to the vertical carbon flux within the region of investigation during the study

The impact of wikileaks on the state and its sovereignty

WikiLeaks emerged due to the belief that states (often democratic) were not as transparent as they claimed to be. Prior to WikiLeaks, transparency was largely done through state mechanisms and information provided to the media through official spokespeople. Through its online platform, WikiLeaks has attempted to widen this information net and corridor; allowing anyone with access to information to leak it anonymously. This dissertation investigates the effect of WikiLeaks on state sovereignty. It is crucial that sovereignty is continually investigated in order to understand where human society and the governance of human society are heading. Is the state losing greater sovereignty due to the emergence of WikiLeaks? The dissertation argues that the state is losing some sovereignty due to a WikiLeaks diffusion of sovereignty to citizens globally. However, WikiLeaks (although very well known) is a small part of many developments that underpin greater diffusion of state sovereignty including the growing power of the internet, diversification of media and other new methods that force state accountability.Political Science

Women's experience of their sense of identity at work : a phenomenological study

Although women increasingly contribute their labour to an ever-burgeoning workplace, little is understood about their roles and sense of identity at work. Adopting a phenomenological approach to this study will allow the researcher to discover what women’s experience of their sense of identity at work encompasses. Furthermore, a review of the contemporary literature, and a phenomenological approach to the study employing semi-structured interviews and an explication of the protocols using the ‘modified’ Stevick-Colaizzi-Keen method (Creswell, 1998), may be used to explore women’s experience of their sense of identity in the workplace. Recommendations may be made for future research and organisational practice. The main findings indicated, inter alia, that the participants expressed their sense of identity at work from a ‘collective’ or social identity orientation. This finding also supports various feminist researchers’ viewpoints that women may develop a unique sense of identity relative to the environment in which they find themselves (Ely, 1994; Hakim, 1996). Themes that arose from the interviews with the participants included the concerns women express universally to a greater extent, yet included their interests, abilities, traits and material characteristics to a lesser extent (Ashforth & Mael, 1989; Hogg & Turner, 1987). The study findings also questioned psychology-based “person-centred” ideas about women’s relationships with other women at work, and added credence to the supposition that the demographic composition of an organisation may influence an individual’s experiences at work (Ely, 1994, p. 203). Furthermore, as social v identities are more significant in organisations, due to the incidence of social groups (Fisher, 1986; Mortimer & Simmons, 1978; Van Maanen, 1976), it would appear that as fewer women are employed in management and the upper echelons of organisations, they would therefore not benefit from being involved in the social environment of work, and would therefore not be in a position to adopt the identity of their counterparts (Becker & Carper, 1956). The contribution of this research to understanding women’s experience of their sense of identity, and the provision of a basic framework in this regard, may assist female employees, and their employers and managers, in their relationships at work, and in this way improve the employment prospects and retention of women.Industrial and Organisational PsychologyM.A. (Industrial and Organisational Psychology

Examining the Impact of the Covid-19 Pandemic on South African Air Travel

Logistic

Effects of early life trauma are dependent on genetic predisposition: a rat study

<p>Abstract</p> <p>Background</p> <p>Trauma experienced early in life increases the risk of developing a number of psychological and/or behavioural disorders. It is unclear, however, how genetic predisposition to a behavioural disorder, such as attention-deficit/hyperactivity disorder (ADHD), modifies the long-term effects of early life trauma. There is substantial evidence from family and twin studies for susceptibility to ADHD being inherited, implying a strong genetic component to the disorder. In the present study we used an inbred animal model of ADHD, the spontaneously hypertensive rat (SHR), to investigate the long-term consequences of early life trauma on emotional behaviour in individuals predisposed to developing ADHD-like behaviour.</p> <p>Methods</p> <p>We applied a rodent model of early life trauma, maternal separation, to SHR and Wistar-Kyoto rats (WKY), the normotensive control strain from which SHR were originally derived. The effects of maternal separation (removal of pups from dam for 3 h/day during the first 2 weeks of life) on anxiety-like behaviour (elevated-plus maze) and depressive-like behaviour (forced swim test) were assessed in prepubescent rats (postnatal day 28 and 31). Basal levels of plasma corticosterone were measured using radioimmunoassay.</p> <p>Results</p> <p>The effect of maternal separation on SHR and WKY differed in a number of behavioural measures. Similar to its reported effect in other rat strains, maternal separation increased the anxiety-like behaviour of WKY (decreased open arm entries) but not SHR. Maternal separation increased the activity of SHR in the novel environment of the elevated plus-maze, while it decreased that of WKY. Overall, SHR showed a more active response in the elevated plus-maze and forced swim test than WKY, regardless of treatment, and were also found to have higher basal plasma corticosterone compared to WKY. Maternal separation increased basal levels of plasma corticosterone in SHR females only, possibly through adaptive mechanisms involved in maintaining their active response in behavioural tests. Basal plasma corticosterone was found to correlate positively with an active response to a novel environment and inescapable stress across all rats.</p> <p>Conclusion</p> <p>SHR are resilient to the anxiogenic effects of maternal separation, and develop a non-anxious, active response to a novel environment following chronic mild stress during the early stages of development. Our findings highlight the importance of genetic predisposition in determining the outcome of early life adversity. SHR may provide a model of early life trauma leading to the development of hyperactivity rather than anxiety and depression. Basal levels of corticosterone correlate with the behavioural response to early life trauma, and may therefore provide a useful marker for susceptibility to a certain behavioural temperament.</p

Bench-scale fire tests of Dark Red Meranti and Spruce finger joints in tension

This study investigates the secondary failure of Malaysian Dark Red Meranti (Shorea spp.) and Spruce (Picea abies) finger joints in a glulam beam in a fire test using a bench-scale test set-up. Secondary failure is the occurrence of failure of the bond lines due to fire and the falling off of the outermost tension layers, exposing the uncharred inner layers to a sudden increase of fire intensity. The lack of published work and the difficulties in describing the behaviour of the finger joints after the secondary failure in a full-scale fire test has identified the need for a simple benchscale method, incorporating the conditions of the standard fire test. This paper focusses on the performance of the finger joints which together with other defects such as knots and splits are generally the weakest component in the glulam beam. The finger joints were bonded with structural adhesives, specifically phenol resorcinol formaldehyde (PRF) and polyurethane (PUR). They were tested in tension to imitate the failure of finger joints on the tension side of a standard fire test of a glulam beam. Constant heat flux was introduced to the finger-jointed specimens to replicate the secondary failure of a glulam beam in the standard fire test. The results of this study indicate a relationship between the charring rate and density of the specimens, with higher density Dark Red Meranti showing lower charring rate compared to the lower density Spruce specimens. Factors such as constant heat flux as opposed to the time-increasing heat flux exposure and specimen size influenced the charring rate of the specimens. The char rate was measured at the early stages of the fire test, which is known to have higher values since the build-up of the charred layers was not sufficiently substantial to protect the inner unburnt wood. Overall, the bench-scale fire test set-up was able to differentiate the fire performance of the adhesives, with PRF showing better fire performance compared to the specimens finger-jointed with PUR adhesive. In addition, tensile tests at ambient temperature showed no significant difference in tensile strength between finger joints bonded with different adhesives for the same wood species. The tensile strengths of the finger joints bonded with different adhesives were influenced by the temperature profile through the joint. The proposed bench-scale fire test was used to compare the quality of the adhesives in a fire situation, specifically with respect to secondary failure. The PRF was selected as the reference adhesive

The genus Boccardia (Polychaeta: Spionidae) associated with mollusc shells on the south coast of South Africa

Three species of Boccardia (B. polybranchia, B. pseudonatrix and B. proboscidea) were associated with mollusc shells on the south and south-east coasts of South Africa. Boccardia polybranchia was widely distributed along the coast and falls within the known distribution range of this species. Comparisons with material from other, international, locations showed that some specimens have been misidentified. No characters could be found to characterize distinct species for different regions within the range of B. polybranchia, as currently recognized. Boccardia pseudonatrix was found only at the most eastern site, increasing its known distribution range. Boccardia proboscidea, a non-indigenous species, was found only on abalone farms and was most abundant in the west

Fire performance of hardwood finger joints

This paper investigates the performance of Malaysian hardwood, dark red meranti finger joints in fire. Finger joints were prepared using two load-bearing type adhesives and tested in tension by means of a bench-scale fire test. They were tested in tension to replicate the failure of finger joints in tension layers of a glulam beam, which commonly occurs in a standard fire resistance test. Finger joints from softwood were also prepared and tested for comparison purposes. In addition, tensile tests at ambient temperature were conducted for both the hardwood and softwood finger joints in order to determine the approximate load level applied during the bench-scale fire tests. The time to failure, residual cross section and charring rate were determined and analysed. Results showed that the type of adhesive significantly influenced the time to failure. Furthermore, a lower residual cross-section was found in the finger joints bonded with phenol resorcinol formaldehyde (PRF) compared to the finger-jointed polyurethane (PUR) specimens. Therefore, PRF is better able to resist fire tests, has a higher residual strength and a longer time to failure compared to PUR.</p

Physical and biological processes at the Subtropical Convergence in the South-west Indian Ocean

A detailed hydrographic and biological survey was conducted in the region of the Subtropical Convergence in the Indian sector of the Southern Ocean in April 2007. Hydrographic data revealed that the subsurface expression of the Subtropical Convergence (at 200 m), marked by the 10°C isotherm, appeared to meander considerably between 41°S and 42°15’S. Total surface chlorophyll- a concentration was low and ranged from 0.03 to 0.42 µg l–1 and was always dominated by the pico- ( 0.05). The zooplankton community was dominated, numerically and by biomass, by mesozooplankton comprising mainly copepods of the genera, Oithona,Paraeuchaeta, Pleuromamma, Calanus and Clausocalanus. An exception was recorded at those stations in the region of the front where the tunicate, Salpa thompsoni, dominated the total zooplankton biomass