4,254 research outputs found
CRYSTALLINE NANO STRUCTURES
The present invention comprises nano obelisks and nanostructures and methods and processes for same. The nano obelisks of the present invention are advantageous structures for use as electron source emitters. For example, the ultra sharp obelisks can be used as an emitter source to generate highly coherent and high energy electrons with high current
Genome-wide detection of segmental duplications and potential assembly errors in the human genome sequence
BACKGROUND: Previous studies have suggested that recent segmental duplications, which are often involved in chromosome rearrangements underlying genomic disease, account for some 5% of the human genome. We have developed rapid computational heuristics based on BLAST analysis to detect segmental duplications, as well as regions containing potential sequence misassignments in the human genome assemblies. RESULTS: Our analysis of the June 2002 public human genome assembly revealed that 107.4 of 3,043.1 megabases (Mb) (3.53%) of sequence contained segmental duplications, each with size equal or more than 5 kb and 90% identity. We have also detected that 38.9 Mb (1.28%) of sequence within this assembly is likely to be involved in sequence misassignment errors. Furthermore, we have identified a significant subset (199,965 of 2,327,473 or 8.6%) of single-nucleotide polymorphisms (SNPs) in the public databases that are not true SNPs but are potential paralogous sequence variants. CONCLUSION: Using two distinct computational approaches, we have identified most of the sequences in the human genome that have undergone recent segmental duplications. Near-identical segmental duplications present a major challenge to the completion of the human genome sequence. Potential sequence misassignments detected in this study would require additional efforts to resolve
Computer modelling of transient heat flow in mines
PhD ThesisThe traditional method to predict air temperatures in mine roadways is based on
the assumption that the ventilation air temperature remains constant over the
ventilated age of the roadway. Hence, a steady-state solution prevails. As the capital
investment of providing an acceptable working environment in hot and deep mines is
increasing, more accurate and reliable temperature predictions in mine roadways will
be needed in future mine ventilation planning. For this reason, a transient model to
predict weekly air temperatures in mine roadways is developed.
The transient model is presented in the form of a computer program. It is
constructed from the mathematical techniques developed for calculating the transient
heat flow from strata (Cheung, 1988), conveyed coal (Cheung and Rabia, 1989) and
structural steel (Maneylaws, 1988), and the empirical equations developed by
Browning et al (1981) for estimating the heat from machinery. Duhamel's Theorem
is used in the mathematical technique for calculating the transient heat flow from
strata and conveyed coal. Details of these techniques are derived. In addition, the
algorithm of the computer program is presented in terms of flow charts.
Climatic investigations were undertaken at British Coal Collieries; three sites at
Wearmouth Colliery, Sunderland, and one site at Whitemoor Colliery, Selby. During
the investigations, temperature surveys were conducted at all the sites. Using the data
collected from these sites, the transient model is validated against field measurements
and agreeable correlation achieved. Moreover, recommendations are made to improve
the model
The “Journey” of Doctoral Study in Applied Psychology: Lived Experiences of Students in Counseling, Clinical, and School Psychology
A qualitative methodology was adopted to explore the lived experiences of doctoral level students in applied psychology. A total of 15 students ranging in age from 24 to 43, who were at varying levels of their doctoral education, participated in individual semi-structured interviews exploring themes related to influences for the pursuit of graduate study, experiences in their program of study, and general reflections of the graduate school journey. All interviews were conducted from a constructivist-interpretivist model, transcribed verbatim, and analyzed using a phenomenological coding approach (Creswell, 2012; Moustakas, 1994). Emergent broad themes included antecedents leading to graduate study, current experience of doctoral education, and reflections on the doctoral experience. Implications for future research are discussed and recommendations for graduate programs based on findings are provided
Duplication and relocation of the functional DPY19L2 gene within low copy repeats
BACKGROUND: Low copy repeats (LCRs) are thought to play an important role in recent gene evolution, especially when they facilitate gene duplications. Duplicate genes are fundamental to adaptive evolution, providing substrates for the development of new or shared gene functions. Moreover, silencing of duplicate genes can have an indirect effect on adaptive evolution by causing genomic relocation of functional genes. These changes are theorized to have been a major factor in speciation. RESULTS: Here we present a novel example showing functional gene relocation within a LCR. We characterize the genomic structure and gene content of eight related LCRs on human Chromosomes 7 and 12. Two members of a novel transmembrane gene family, DPY19L, were identified in these regions, along with six transcribed pseudogenes. One of these genes, DPY19L2, is found on Chromosome 12 and is not syntenic with its mouse orthologue. Instead, the human locus syntenic to mouse Dpy19l2 contains a pseudogene, DPY19L2P1. This indicates that the ancestral copy of this gene has been silenced, while the descendant copy has remained active. Thus, the functional copy of this gene has been relocated to a new genomic locus. We then describe the expansion and evolution of the DPY19L gene family from a single gene found in invertebrate animals. Ancient duplications have led to multiple homologues in different lineages, with three in fish, frogs and birds and four in mammals. CONCLUSION: Our results show that the DPY19L family has expanded throughout the vertebrate lineage and has undergone recent primate-specific evolution within LCRs
CRYSTALLINE NANO STRUCTURES
The present invention comprises nano obelisks and nanostructures and methods and processes for same. The nano obelisks of the present invention are advantageous structures for use as electron source emitters. For example, the ultra sharp obelisks can be used as an emitter source to generate highly coherent and high energy electrons with high current
New Directions in Cloud Programming
Nearly twenty years after the launch of AWS, it remains difficult for most
developers to harness the enormous potential of the cloud. In this paper we lay
out an agenda for a new generation of cloud programming research aimed at
bringing research ideas to programmers in an evolutionary fashion. Key to our
approach is a separation of distributed programs into a PACT of four facets:
Program semantics, Availablity, Consistency and Targets of optimization. We
propose to migrate developers gradually to PACT programming by lifting familiar
code into our more declarative level of abstraction. We then propose a
multi-stage compiler that emits human-readable code at each stage that can be
hand-tuned by developers seeking more control. Our agenda raises numerous
research challenges across multiple areas including language design, query
optimization, transactions, distributed consistency, compilers and program
synthesis
Recommending anchor points in structure-preserving hypertext document retrieval
Traditional WWW search engines index and recommend individual Web pages to assist users in locating relevant documents. Users are often overwhelmed by the large answer set recommended by the search engines. The logical starting point of the hyper-document is thus hidden among the large basket of matching pages. Users need to spend a lot of effort browsing through the pages to locate the starting point, a very time consuming process. This paper studies the anchor point indexing problem. The anchor points of a given user query is a small set of key pages from which the larger set of documents that are relevant to the query can be easily reached. The use of anchor points help solve the problems of huge answer set and low precision suffered by most search engines by considering the hyper-link structures of the relevant documents, and by providing a summary view of the result set.published_or_final_versio
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