Galaxies and clusters as probes of the large-scale structure of the Universe

The large-scale structure of the Universe is delineated by the spatial distributions of galaxies and clusters of galaxies. This thesis describes three projects concerned with the use of galaxies and clusters as cosmological probes, following the presentation of necessary background material in Chapter 1.Chapter 2 is concerned with spatial correlations of clusters of galaxies. After compre­hensively reviewing previous work addressing this topic from both observational and theoretical points of view, we present, test and apply an important new method for computing theoretical cluster correlations. Our method combines the theory of peaks in Gaussian random fields with the evolution of the cosmological density field by the Zeldoviclr Approximation: this is the first analytic calculation of the cluster correlation function to take account of the nonlinear evolution of the cosmological density field on cluster scales. We find good agreement between our results and those from recent nu­merical simulations, except for the richest cluster samples, for which our method yields stronger clustering. Comparison of our predicted correlations with those observed in recent optical cluster samples reveal that the once-popular Einstein - de Sitter Cold Dark Matter (CDM) model lacks the large-scale power required to match the observed clustering. We also apply our method in the first theoretical study of the spatial corre­lations of ROSAT clusters. Our results here favour cosmogonies with more large-scale power than CDM, in accordance with those we obtained from optical cluster samples.The projects in Chapters 3 and 4 are concerned with galaxy clustering. In Chapter 3 we consider the redshift-space clustering of samples of IRAS galaxies selected on the basis of their dust emission temperature, having argued that there might be a relation between the temperature of the galaxy and density of the environment in which the galaxy is located. We find, however, no conclusive evidence for a difference in the clustering strength of the “warm” and “cool” samples in redshift space. This validates the use of redshift samples of IRAS galaxies as tracers of large-scale structure, as well as constraining models of merger-induced star formation.In Chapter 4 we show, through the novel analysis of liigli-resolution numerical simulation data, how the observed power spectra of optical and IRAS galaxy clustering constrain the initial power spectrum of density fluctuations and the relation between the galaxy dis­tribution and the underlying density field. Motivated by recent N-body/hydrodynamic simulations, we employ a biasing prescription in which the local galaxy number density at redshift zero is determined by the present local mass density. We determine which combinations of initial power spectrum and biasing prescription are consistent with the observed clustering of optical galaxies and use the observed relation between the dis­tributions of optical and IRAS galaxies to predict corresponding redshift-spa.ee IRASpower spectra. These are compared with observations, as are the pairwise velocity dis­persions predicted by the models. In this way, building, in part, on our results from Chapter 3, we are able to construct a coherent picture of galaxy clustering which is in accord with our results 011 cluster correlations from Chapter 2, showing that galaxies and clusters are consistent probes of the large-scale structure of the Universe

Imagining a silicon Savannah? Technological and conceptual connectivity in Kenya's BPO and software development sectors

This is a paper about expectations surrounding a potentially highly transformative moment in East Africa’s history: the arrival of underwater fibre-optic broadband communications cables into the Indian Ocean port of Mombasa. It combines a media content analysis with findings from interviews with business owners in Kenya’s nascent business process outsourcing (BPO) and software development sectors in order to explore how such moments of technological ‘connectivity’ are imagined, marketed and enacted within economic development. It argues that connectivity is not just a matter of boosting physical/material capacity but also about redressing conceptual connectivity; bringing places ‘closer together’ involves rehabilitating the images of places in peoples’ minds and removing imagined senses of distance. As such, technologies of connectivity are marketed not just as tools of altered communications affordances, but more importantly, as momentary opportunities for revisiting the image of places from afar. Additionally, the cables reveal the importance of fostering internal linkages in order to better build international recognition and connections. ‘Moments of expectation’ that surround new ICT technologies reveal how discourse and representation play a strong role in enabling markets to form and change. The very idea of ‘connectivity’ itself is driving plans and policies throughout the region

The domestic turn: business processing outsourcing and the growing automation of Kenyan organisations

After observing the growth of the Indian and Filipino Business Process Outsourcing (BPO) sectors, Kenyan policy-makers and managers made substantial investments in international internet infrastructure and BPO marketing campaigns. While observers continue to discuss the sector in terms of its international work opportunities, in recent years the sector has increasingly focused on contracts sourced from Kenyan and other East African clients. The government has also refocused efforts on attracting international BPO companies. This domestic turn signals both the difficulties of gaining access to overseas work due to the power of incumbents and the increasing use of the internet and ICT-enabled automation within Kenyan organisations. In effect, better connectivity has enabled a two-way globalisation of services: Kenyan BPO companies can access international work opportunities but connectivity has also contributed to the inflow of international business practices into Kenya. The conclusion examines what these shifts might entail for the sector and its workers in future

UKCA Chemistry and Aerosol Tutorials at vn10.4 using Rose & Cylc

Tutorials covering how to use the United Kingdom Chemistry and Aerosols Composition-Climate Model at Unified Model version 10.

UKCA Chemistry and Aerosol Tutorials for UM8.4

Tutorials covering how to use the United Kingdom Chemistry and Aerosols Composition-Climate Model at Unified Model version 8.

ISEEK, a tool for high speed, concurrent, distributed forensic data acquisition

Electronic discovery (also written as e-discovery or eDiscovery) and digital forensics are processes in which electronic data is sought, located, secured, and processed with the expectation that it may be used as evidence in legal proceedings. Electronic evidence plays a fundamental role in many aspects of litigation (Stanfield, 2009). However, both eDiscovery and digital forensic approaches that rely on the creation of an index as part of their processing are struggling to cope with the huge increases in hard disk storage capacity. This paper introduces a novel technology that meets the existing and future data volume challenges faced by practitioners in these areas. The technology also addresses the concerns of those responsible for maintaining corporate networks as it does not require installation of ‘agents’ nor does it have any significant impact on network bandwidth during the search and collection process, even when this involves many computers. The technology is the embodiment of a patented process that opens the way for the development of new functionality, such as the detection of malware, compliance with corporate Information Technology (IT) policies and IT auditing. The technology introduced in this paper has been incorporated into a commercial tool called ISEEK that has already been successfully deployed in a variety of environments

Geographies of Connectivity in East Africa: Trains, Telecommunications, and Technological Teleologies.

The paper analyses and compares two transformative moments of technologically-mediated change in East Africa, the construction of the Uganda railway between Mombasa and Lake Victoria (1896-1903) and the introduction of fibre-optic cables that landed into the ports of Dar Es Salaam and Mombasa in 2009. It uses discourse analysis to examine how technologically-mediated connectivity has been represented by political and economic actors during these transformative moments. In both cases, we explore the origins of the expectations of connectivity and the hope and fear associated with them. Building on Massey’s notion of power-geometry and Sheppard’s concept of positionality the paper focuses on power relationships in discussions of connectivity and asks how people understand the abilities of transformative technologies to modify positionalities and alter relational distance and proximity. Ultimately, by examining historical and contemporary expectations of connectivity in East Africa, this paper allows us to work towards creating more grounded and historicised understandings of the coming-together of technology and connectivity

The Internet and Business Process Outsourcing in East Africa: Value Chains and Networks of Connectivity-Based Enterprises in Kenya and Rwanda

Internet connectivity is widely considered to be a game changer for knowledge economies of developing countries. The arrival of submarine fibre-optic underwater cables in East Africa in 2009 and 2010 is seen by many as a strong case in point. The fast evolution of the information and communication technology (ICT) landscape of Kenya and Rwanda that ensued has attracted the attention of actors from private investors, development agencies, NGOs, policymakers and many other groups. Kenya became a role model for its wide-spread adoption of mobile money services and a burgeoning ICT application development sector; Rwanda’s government became known for its explicitly ICT-oriented development agenda as well as large-scale ICT projects in government, health and education that aimed to latch onto fast-growing mobile subscription rates and 3G network roll-outs. For this report, we set out to examine the role that changing connectivity has played for a particular component of the ICT sector in Kenya and Rwanda: ICT-enabled business process outsourcing (BPO). BPO has been a priority in the national ICT strategies of both countries, so we anticipated this sector to provide a fertile ground for comparing expectations and practices of the roles that changing connectivity has played following the deployment of fibre-optic cable infrastructure. BPO is also an interesting sector because internet connectivity is at the heart of its value chain: At first glance, fast internet connections should go a long way in bridging geographical distance and enabling Kenyan and Rwandan businesses to tap into continuously growing BPO demand from all over the world. BPO is also inherently a global, or at least a widely geographically distributed, industry. Our analysis was therefore designed to shed light on the risks and opportunities of establishing connectivity-based local sectors that are bound to be exposed to international markets and competition. However, the development of ICT sectors fell short of many original hopes. Internet connectivity proved to only function as a catalyst for economic growth in combination with other enablers. Competitive advantage is always relative, and, in the case of Kenya’s and Rwanda’s BPO sectors, India and other Asian BPO destinations have maintained the edge in international markets. Despite the overall positive evolution of ICT-based subsectors in Kenya and Rwanda, the role of internet connectivity for growth in knowledge economies continues to be a complicated one, including for connectivity-based enterprises. Future opportunities might actually lie in ‘close’ (local and regional) markets, and policymakers (and indeed all economic actors) will need to continue to learn and adjust to other unexpected developments brought about by internet connectivity

The Internet and Business Process Outsourcing in East Africa: Value Chains and Networks of Connectivity-Based Enterprises in Kenya and Rwanda

Internet connectivity is widely considered to be a game changer for knowledge economies of developing countries. The arrival of submarine fibre-optic underwater cables in East Africa in 2009 and 2010 is seen by many as a strong case in point. The fast evolution of the information and communication technology (ICT) landscape of Kenya and Rwanda that ensued has attracted the attention of actors from private investors, development agencies, NGOs, policymakers and many other groups. Kenya became a role model for its wide-spread adoption of mobile money services and a burgeoning ICT application development sector; Rwanda’s government became known for its explicitly ICT-oriented development agenda as well as large-scale ICT projects in government, health and education that aimed to latch onto fast-growing mobile subscription rates and 3G network roll-outs. For this report, we set out to examine the role that changing connectivity has played for a particular component of the ICT sector in Kenya and Rwanda: ICT-enabled business process outsourcing (BPO). BPO has been a priority in the national ICT strategies of both countries, so we anticipated this sector to provide a fertile ground for comparing expectations and practices of the roles that changing connectivity has played following the deployment of fibre-optic cable infrastructure. BPO is also an interesting sector because internet connectivity is at the heart of its value chain: At first glance, fast internet connections should go a long way in bridging geographical distance and enabling Kenyan and Rwandan businesses to tap into continuously growing BPO demand from all over the world. BPO is also inherently a global, or at least a widely geographically distributed, industry. Our analysis was therefore designed to shed light on the risks and opportunities of establishing connectivity-based local sectors that are bound to be exposed to international markets and competition. However, the development of ICT sectors fell short of many original hopes. Internet connectivity proved to only function as a catalyst for economic growth in combination with other enablers. Competitive advantage is always relative, and, in the case of Kenya’s and Rwanda’s BPO sectors, India and other Asian BPO destinations have maintained the edge in international markets. Despite the overall positive evolution of ICT-based subsectors in Kenya and Rwanda, the role of internet connectivity for growth in knowledge economies continues to be a complicated one, including for connectivity-based enterprises. Future opportunities might actually lie in ‘close’ (local and regional) markets, and policymakers (and indeed all economic actors) will need to continue to learn and adjust to other unexpected developments brought about by internet connectivity