Genetic studies on drosophila pseudo-obscura

The thesis consists of the following papers: -(1) New Mutants and Linkage Data for Drosophila pseudo -obscura (in press, Journal of Genetics)(2) On the Genetical Constitution of Drosophila pseudo -obscura, Race A (in press, Journal of Genetics)(3) On the Suppression of Tangled in Drosophila pseudo -obscura (to be read before The Royal Society of Edinburgh)(4) Fecundity in Drosophila pseudo -obscura Race A (to be extended before publication

Reconfiguring passenger ship internal environment for damage stability enhancement

The traditional risk control option adopted in naval architecture to meet safety-related objectives is by regulations, targeting damage limitation, nominally instigated in the wake of maritime accidents claiming heavy loss of life. These primarily concern the introduction of watertight bulkheads, i.e., permanent (passive) reconfiguration of the internal ship environment to enhance damage stability. This has been the most common measure, manifesting itself in the wake of every serious flooding accident since the beginning, back in the 19th century. However, traditional flooding protection through watertight subdivision, to an extent dictated by IMO regulations, has a physical limit which, if exceeded, a safety plateau is reached. This is currently the case and with damage stability standards progressively increasing, the safety gap between existing and new ships is dangerously widening and with design stability margins progressively eroding, stability management is unsustainable, leading to loss of earnings at best. The need for managing the residual risk through active intervention/protection over the life-cycle of the vessel drives industry to searching and adopting a new normal. This new normal is the innovation being explained in this paper by addressing safety enchantment through a systematic reconfiguration of the ship environment for passive and active protection in flooding accidents. In this respect, the "design-optimal" internal arrangement of a vessel, is adapted and reconfigured, using passive and active containment systems for flooding incidents, in the form of high-expansion foam products. The innovation is briefly explained, claiming transformational reduction in flooding risk in the most cost-effective way available. To support wider understanding and appreciation for the latter, the paper critically reviews the whole evolution of internal ship space reconfiguration, chronologically and systematically, concluding that new technological developments and breakthroughs will bring sustainable changes to the traditional evolutionary maritime safety enhancement

Bulk commodities and the Liverpool and London markets of the mid-19th century

We study British prices and the degree of commodity market integration between Liverpool, the bulk commodity port of mid-19th century, and London. A new wholesale commodity price index is presented for Liverpool and this is compared with the Klovland-Sauerbeck index. Next, we examine the relationship between Liverpool and London markets in specific bulk commodities. Our data consist of price indices for identically described goods in both Liverpool and London: three commodity groups (metal products, wood products, and processed foods), and the specific commodities of wheat and flour. Tests for cointegration reveal convergence among the six price pairs. We also find that the markets were highly integrated in the short-run because three of the commodity group pairs (processed foods, wheat, and flour) shared common features or cycles. A common cycle implies that transitory price shocks in Liverpool had the same impact on prices in London and vice versa. The importance of the London and Liverpool common cycle to a shock is brief. Its shock explains less than 20 percent of the variation in the relevant price levels after twelve months, on average.

An alternative system for damage stability enhancement

There is an ongoing and continuous initiative to improve the survivability of passenger vessels and in the past increasing safety standards have generally been catered for through the use of design(passive) measures. However, this approach is becoming saturated and any such measures to improve damage stability severly erode ship earning potential and are being resisted by industry. In a change of direction, this paper aims to explore the use of operational(active) measures for damage stability enhancement in line with IMO Circular 1455 on equivalents. An alternative system for damage stability enhancement is intorduced that involves injecting highly expandable foam in the compartment(s) undergoing flooding during the initial post-accident flooding phase thus enhancing damage stability and survivability of RoPax vessels well beyond the design levels in the most cost-effective way currently available. This is a mind-set changing innovation that is likely to revolutionise design and operation of most ship types and RoPax, in particular. A case study has been performed on a large RoPax vessel with impressive results that will challenge the current established practice and open possibilities for novel and innovative design configuration

The Effect of Photoperiod on Sexual Development in Young Boars

The effects of photoperiod in stimulating reproductive function in prepubertal boars was studied in 40 crossbred boars. One group of boars was exposed to a regimen where day length was increased from 12 to 14.5 h/d (from 8 to 20 weeks of age) and then decreased from 14.5 to 12 h/d (from 20 to 32 weeks of age); whereas, the other group of boars was exposed to a regimen where day length was decreased from 12 to 9.5 h/d and then increased from 9.5 to 12 h/d. Exposing prepubertal boars to a long photoperiod inhibited the development of the testis at 24 weeks of age. The inhibitory effect of long days on testis development at 24 weeks of age was overcome by decreasing the photoperiod. Short days reduced the level of sexual behavior at 25 and 26 weeks of age. The inhibitory effects of short days on sexual behavior was overcome by exposing boars to a longer period. This study implies that young boars reared during short days may need to be exposed to a longer photoperiod before expressing an adequate level of sexual behavior and young boars reared during long days may need to be exposed to shorter days to increase their sperm production capability

Impact assessment of wave statistics on ship survivability

This paper presents a brief summary of the work conducted by the MSRC at Strathclyde University in which the effect of operational location on the estimation of a vessel’s survival probability has been investigated and new s-factor formulations proposed. Further work is presented in which updated accident wave statistics have been used in order to assess the impact of vessel specific data on the predicted survivability. A test case on a large container ship has been conducted in order to gauge the effect of the new s-factor formula on the Attained Subdivision Index and thus the vessel safety level with regards to collision damage

Designing for damage stability beyond design level

This paper describes the background and provides the rationale and the framework to embrace all feasible measures (passive/design and active/operational – normal and emergencies) for improving the damage survivability of RoRo Passenger ships. The ideas elaborated in the paper is an attempt to elucidate and assess the impact on options for new and existing ships of increasing the required subdivision index R, the former in response to the higher damage stability standards recom- mended following the conclusion of the EMSA III project and the latter in case IMO decided to apply higher damage stability requirements retrospectively, particularly in the aftermath of an accident. Such a framework would provide the motivation for instigating and estab- lishing novel damage stability enhancing paradigms in line with IMO Circular 1455 on equivalents, for alter- native compliance. This, in turn, would enable the industry to focus on all credible measures for damage stability enhancement in case of a flooding accident. This represents a step change both in the mind-set of naval architects and in safety legislation but the impact will be immense and mostly positive. This paper paves the way in this direction by providing the background and rationale for such a framework and by introducing an alternative system for damage stability enhancement that involves injecting highly expandable foam in the compartment(s) undergoing flooding during the intimal post-accident flooding phase thus enhancing damage stability and survivability of RoPax vessels well beyond the design levels in the most cost-effective way currently available. This is a mind-set changing innovation that is likely to revolutionise design and operation of most ship types and RoPax, in particular. A number of applications are considered in the paper for a range of ship sizes with impressive results that will challenge the cur- rent established practice

Symmetry reduction and shape effects in concave chiral plasmonic structures

Chiral metamaterials have shown a number of interesting properties which result from the interaction of the chiral near-field they produce with light and matter. We investigate the influence of structural imperfections on the plasmonic properties of a chiral gold “gammadion”, using electron energy loss spectroscopy to directly inform simulations of realistic, imperfect structures. Unlike structures of simple convex geometry, the lowest energy modes of the ideal concave gammadion have a quadrupole and dipole character, with the mode energies determined by the nature of electrostatic coupling between the gammadion arms. These modes are strongly affected by structural imperfections that are inherent to the material properties and lithographic patterning. Even subwavelength-scale imperfections reduce the symmetry, lift mode degeneracies convert dark modes into bright ones and significantly alter the mode energy, its near-field strength, and chirality. Such effects will be common to a number of multitipped concave structures currently being investigated for the chiral fields they support

Exploring smart methodologies for critical flooding scenarios detection in the damage stability assessment of passenger ships

A more contemporary damaged stability assessment of a passenger ship can be addressed with a non-zonal approach, assessing multiple damage types and environmental conditions and employing dynamic analysis for ship survivability. This direct method necessitates the generation and simulation of many damage scenarios. However, the probabilistic models for damage characteristics describe many damages that are not critical for ship survivability. To restrict the number of damage scenarios, hence calculation time, designers currently apply empirical rules, such as critical damages are only above two compartments, considering that damage stability regulations currently in force to ensure survivability levels beyond this damage extent. However, a rigorous approach is lacking. The present work explores the use of more scientific methods as damage filters. The first method uses preliminary static calculations. The second uses the energy absorbed by the ship during an impact, and the third is suitable for a purely dynamic approach. The paper critically compares the three methodologies on two sample passenger ships for collision damages, showing their respective advantages and disadvantages

A new era of fishing vessel safety emerges

Commercial fishing is one of the least safe activities taking place within the EU and the worldwide community today. Several accidents and fatalities have been recorded over the past years stemming from various causes related to the operation, design of the vessels and severe weather conditions. This paper describes the background while attempting to elucidate and assess the impact of a new flooding containment system for new and existing fishing vessels, leading to high levels of survivability in the damaged condition. Highly expanded foam is injected in the most vulnerable compartments, rendering the whole ship a lifeboat. One case study is presented to provide the requisite evidence