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Search Results: 1 - 10 of 1602 matches for " Malcolm Atkinson "
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Ad hoc Cloud Computing: From Concept to Realization
Gary Andrew McGilvary,Adam Barker,Malcolm Atkinson
Computer Science , 2015,
Abstract: This paper presents the first complete, integrated and end-to-end solution for ad hoc cloud computing environments. Ad hoc clouds harvest resources from existing sporadically available, non-exclusive (i.e. primarily used for some other purpose) and unreliable infrastructures. In this paper we discuss the problems ad hoc cloud computing solves and outline our architecture which is based on BOINC.
V-BOINC: The Virtualization of BOINC
Gary A. McGilvary,Adam Barker,Ashley Lloyd,Malcolm Atkinson
Computer Science , 2013,
Abstract: The Berkeley Open Infrastructure for Network Computing (BOINC) is an open source client-server middleware system created to allow projects with large computational requirements, usually set in the scientific domain, to utilize a technically unlimited number of volunteer machines distributed over large physical distances. However various problems exist deploying applications over these heterogeneous machines using BOINC: applications must be ported to each machine architecture type, the project server must be trusted to supply authentic applications, applications that do not regularly checkpoint may lose execution progress upon volunteer machine termination and applications that have dependencies may find it difficult to run under BOINC. To solve such problems we introduce virtual BOINC, or V-BOINC, where virtual machines are used to run computations on volunteer machines. Application developers can then compile their applications on a single architecture, checkpointing issues are solved through virtualization API's and many security concerns are addressed via the virtual machine's sandbox environment. In this paper we focus on outlining a unique approach on how virtualization can be introduced into BOINC and demonstrate that V-BOINC offers acceptable computational performance when compared to regular BOINC. Finally we show that applications with dependencies can easily run under V-BOINC in turn increasing the computational potential volunteer computing offers to the general public and project developers.
Same formula, different figures: Change and persistence in class inequalities
Sociologia, Problemas e Práticas , 2010,
Abstract: many contemporary social theorists have argued that the social changes of the last few decades have shattered the hold of class over life histories, identities and politics and put in its place reflexive choice and individualism. this paper presents a summary of a recently completed research project in the uk designed to put these claims to the test. starting out from a “phenomeno-bourdieusian” model of class and deploying life history interviews it reveals not the decline of class in advanced capitalism, but its reinvention. new practices and pathways have emerged, but they represent only the shifting substance of class - the underlying structure of relational difference that defines class and produces different outcomes remains as patent as ever.
An e-Infrastructure for Collaborative Research in Human Embryo Development
Adam Barker,Jano I. van Hemert,Richard A. Baldock,Malcolm P. Atkinson
Computer Science , 2009,
Abstract: Within the context of the EU Design Study Developmental Gene Expression Map, we identify a set of challenges when facilitating collaborative research on early human embryo development. These challenges bring forth requirements, for which we have identified solutions and technology. We summarise our solutions and demonstrate how they integrate to form an e-infrastructure to support collaborative research in this area of developmental biology.
Enhanced Usability of Managing Workflows in an Industrial Data Gateway
Gary A. McGilvary,Malcolm Atkinson,Sandra Gesing,Alvaro Aguilera,Richard Grunzke,Eva Sciacca
Computer Science , 2015,
Abstract: The Grid and Cloud User Support Environment (gUSE) enables users convenient and easy access to grid and cloud infrastructures by providing a general purpose, workflow-oriented graphical user interface to create and run workflows on various Distributed Computing Infrastructures (DCIs). Its arrangements for creating and modifying existing workflows are, however, non-intuitive and cumbersome due to the technologies and architecture employed by gUSE. In this paper, we outline the first integrated web-based workflow editor for gUSE with the aim of improving the user experience for those with industrial data workflows and the wider gUSE community. We report initial assessments of the editor's utility based on users' feedback. We argue that combining access to diverse scalable resources with improved workflow creation tools is important for all big data applications and research infrastructures.
C2MS: Dynamic Monitoring and Management of Cloud Infrastructures
Gary A. McGilvary,Josep Rius,í?igo Goiri,Francesc Solsona,Adam Barker,Malcolm Atkinson
Computer Science , 2013,
Abstract: Server clustering is a common design principle employed by many organisations who require high availability, scalability and easier management of their infrastructure. Servers are typically clustered according to the service they provide whether it be the application(s) installed, the role of the server or server accessibility for example. In order to optimize performance, manage load and maintain availability, servers may migrate from one cluster group to another making it difficult for server monitoring tools to continuously monitor these dynamically changing groups. Server monitoring tools are usually statically configured and with any change of group membership requires manual reconfiguration; an unreasonable task to undertake on large-scale cloud infrastructures. In this paper we present the Cloudlet Control and Management System (C2MS); a system for monitoring and controlling dynamic groups of physical or virtual servers within cloud infrastructures. The C2MS extends Ganglia - an open source scalable system performance monitoring tool - by allowing system administrators to define, monitor and modify server groups without the need for server reconfiguration. In turn administrators can easily monitor group and individual server metrics on large-scale dynamic cloud infrastructures where roles of servers may change frequently. Furthermore, we complement group monitoring with a control element allowing administrator-specified actions to be performed over servers within service groups as well as introduce further customized monitoring metrics. This paper outlines the design, implementation and evaluation of the C2MS.
Analytical Evaluation of Omega 3 Fatty Acids Imbedded in Hydrophobic Starch in the Rumen  [PDF]
Malcolm Ballard
Open Journal of Animal Sciences (OJAS) , 2018, DOI: 10.4236/ojas.2018.84032
Abstract: Two experiments were conducted to assess the value of hydrophobic starch as a method to encapsulate a supplement consisting of refined fish oil intended for use as a feed supplement for ruminant animals. In Study 1, the product was incubated in vitro for 24 hours. The entire media was analyzed to determine fatty acid composition. In Study 2, the test material was incubated for 0, 2, 4, 6, 8, 10, 12 and 24 hours in order to determine rate of loss of dry matter, as well as the fatty acid profile of the dry matter remaining at 24 hours. Results from Study 1 indicated that 61.1 % of the eicosapentaenoic acid (C20:5) and 75.3% docosahexaenoic acid (C22:6) were still intact after the 24 hour incubation period. In Study 2, 39.1% of the test material was solubilized in the 24 hour period. However, the losses in C20:5 and C22:6 fatty acids were less (25.32% and 27.90% respectively) indicating that the majority of the test product was protected against biohydrogenation. It was concluded that hydrophobic starch can be used to ruminally protected fish oil and to deliver C20:5 and C22:6 fatty acids past the rumen.
Signs of selection in our genes
Nick Atkinson
Genome Biology , 2005, DOI: 10.1186/gb-spotlight-20050506-01
Abstract: Building on an earlier study, Cornell University's Rasmus Nielsen and colleagues compared over 13,000 annotated human genes and their chimp equivalents, using the ratio of synonymous to nonsynonymous mutations as evidence of positive selection. Their aim, Nielsen said, was to determine "which genes have been changing as humans and chimpanzees have evolved into their modern forms."The team subjected orthologous human–chimp gene pairs from published human data and polymerase chain reaction data obtained from a single male chimpanzee to likelihood analysis, which revealed any differences in mutation type ratio. They excluded genes with fewer than three nucleotide differences.Nielsen's team made several surprising discoveries, including increased positive selection on the X chromosome and a relative lack of positive selection on genes expressed in the brain. Many genes that showed signs of positive selection were involved in sensory perception or immune defenses, they report, and some of the strongest evidence for selection was seen in genes involved in apoptosis. The latter finding offers "a possible link between selfish mutations during spermatogenesis and cancer prevalence," Nielsen told The Scientist.Apoptosis kills a large proportion of cells during spermatogenesis. A mutation allowing a cell to avoid such a fate should spread in the population because it would confer a selective advantage. However, cancer cells are also eliminated by apoptosis, so any positive selection would be balanced against an increased risk of cancer. "Much of the same molecular machinery is used to destroy cancer cells," Nielsen explained.Justin Fay, a geneticist at Washington University's School of Medicine, said Nielsen's team has done "a great job of squeezing out any evidence for positive selection on protein coding sequences." However, he pointed to the limitations of their statistical modeling technique, which is only able to detect positive selection on a gene when it has multiple se
Little fire ant males are clones
Nick Atkinson
Genome Biology , 2005, DOI: 10.1186/gb-spotlight-20050630-01
Abstract: Denis Fournier, from Université Libre de Bruxelles in Belgium, and colleagues studied the DNA of queens, workers, males, and their sperm from 34 little ant nests in French Guiana. They expected to find a typical haplodiploidy genetic system, but instead discovered that queens possessed only maternally derived DNA, and males possessed only paternally derived DNA."If males are potentially in an evolutionary dead end, as is true in the little fire ant where workers are sterile and all queens are clonally produced, they do not have a means to transmit their genes to the next generation," said Fournier. Queens produce gynes (reproductively competent females) clonally, a strategy that denies males the opportunity to pass on their genes. Males are still required, however, in the production of workers, upon which a queen's own reproductive success depends even though males themselves gain nothing.The males' response has been to evolve their own means of clonal reproduction, Fournier and colleagues say. They propose that at some stage after fertilization, maternal genetic material is lost and a haploid male offspring, encoded solely by the sperm's DNA, develops. "We could think of the males as a separate, parasitic species that uses host eggs for its own reproduction," said Fournier."The reality with natural history is that if you look close enough, you find remarkable patterns," commented Greg Hurst, at University College London. This well-known ant species was previously thought to have a "classic bee-ant system of genetics," in which diploid females exist alongside maternally derived haploid males. But the "fascinating bit of natural history" uncovered by Fournier and colleagues tells a more complex story, in which males and females both reproduce asexually and have thus separated into distinct genetic lineages."In essence, the male-female interaction in this species has become like an obligate symbiosis—the females need the males for worker production and the males need
Lice tell mankind's story
Nick Atkinson
Genome Biology , 2004, DOI: 10.1186/gb-spotlight-20041006-01
Abstract: Modern humans - Homo sapiens - are generally thought to have passed through a tight population genetic "bottleneck" somewhere between 10,000 and 20,000 years ago. Parasites such as lice tend to be highly species specific, so by unravelling their evolutionary history it's possible to see past the bottleneck, according to the Florida Museum of Natural History's David Reed, lead author of the paper."The addition of parasite data to studies of primate and human evolutionary history is similar to having multiple camera angles recording an event," Reed told us. "We aim to create a better picture of human evolutionary history by studying lice, which might tell us something that human genetic studies alone either have not or cannot."Humans today play host to two separate genetic lineages of head and body lice. Although both occupy the same ecological niche, their most recent common ancestor lived over a million years ago, the study reports. One lineage has a global distribution, whereas the other appears to be limited to the New World.Reed and his colleagues present evidence that the New World lineage originally co-evolved with Homo erectus, but switched hosts to Homo sapiens around 25,000 years ago. The switch took place in Asia, the authors suggest, before the colonization of North America across the Bering Straits. The effective isolation of New World human populations until only a few hundred years ago allowed this second louse lineage to persist.Todd Disotell, of New York University's Department of Anthropology, was impressed by the study. "When I read this paper I was both intrigued and excited by Reed et al.'s findings," he said."I think that the conclusion that there was contact [in Asia] between remnant Homo erectus populations and modern Homo sapiens is correct, but the exact nature of that contact will be a continuing controversy," said Disotell. Physical contact certainly took place for the transmission of lice to be possible, but this doesn't necessarily equate
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