181 research outputs found

    Modelling of the Occurrence of Hydrogen Sulphide in Coal Seams

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    Hydrogen Sulphide (H2S) has been encountered within a number of Bowen Basin collieries, Central Queensland, Australia. High concentration occurrence during mining of a longwall panel raises a number of potential problems, which demand greater understanding to allow efficient mining while maintaining safe and healthy environmental conditions. Longwall panels at Mine A and Mine B have recently mined through H2S zones. The high H2S zone mined through at Mine A was wide and covering the whole length of the face comparing to the narrow H2S zone which was cutting the panel at 45° at Mine B. Longwall panels had been sampled for H2S in pre-mining phases with vertical and inseam exploration boreholes and rib sampling of gateroad development headings. During mining face coal samples were collected in an intensive program and tested in a drum tumbler to determine an indicated seam concentration level through contouring that could be used to calculate the concentrations of H2S liberated to the atmosphere. Data was analysed to determine a geostatistical method, which would best represent the indicated seam concentration level from the given data and the block dimension of the data set. This study discusses the different sampling methods used, selection of the most suitable geostatistical method and the impact of grid size on results of data analysis. Some general observations are made correlating indicated seam H2S concentrations from production face sampling with both predictions made from exploration and liberation rates during mining of the longwall panel

    Welcome to the new world disorder: conflict and transformation in Ian McEwan’s saturday

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    Ian McEwan‘s novel Saturday deals with the complex issues of conflict and transformation in the age of terrorism. The plot presents one internal dilemma and several interpersonal altercations that occur within a mere twenty-four hours: a) Perowne (the protagonist) vs. himself, in face of his ambivalent thoughts regarding British military participation in the war in the Middle East; b) The protagonist vs. Baxter, a ruffian from East End, in the context of a car accident; c) Perowne vs. a fellow anaesthetist, Jay Strauss, during a squash game; d) Perowne‘s daughter, Daisy vs. her grandfather, John Grammaticus, both poets and rivals; e) Perowne‘s family vs. Baxter, who intrudes the protagonist‘s house. In this paper, I exemplify, analyse and discuss how: a) Understanding the causes of what we call evil constitutes an important step towards mutual understanding; b) Both science and arts (which Perowne considers, at first, irrelevant) are important elements in the process of transformation; c) Both personal and interpersonal conflicts are intrinsic to human nature — but they also propitiate healthy changes in behaviour and opinion, through reflection. In order to do so, I resort to Saturday, and to the work of several specialists in the field of conflict management.O romance Saturday, de Ian McEwan, aborda as complexas questões do conflito e da transformação na era do terrorismo. O enredo apresenta um dilema interno e várias altercações interpessoais que ocorrem em apenas vinte e quatro horas: a) Perowne (o protagonista) vs. ele próprio, perante opiniões ambivalentes acerca da participação britânica na guerra do Médio Oriente; o protagonista vs. Baxter, um rufia de East End, no contexto de um acidente rodoviário; c) Perowne vs. um colega anestesista, Jay Strauss, no decorrer de uma partida de squash; d) Daisy, a filha de Perowne vs. o avô, John Grammaticus, ambos poetas e rivais; e) A família de Perowne vs. Baxter, que invade a residência do protagonista. Neste artigo, exemplifico, analiso e debato como: a) Compreender as causas daquilo a que chamamos o mal constitui um passo importante para uma compreensão mútua; b) Tanto a ciência como a arte (que Perowne considera, inicialmente, irrelevante) são elementos importantes no processo de transformação; c) Os conflitos pessoais e interpessoais são intrínsecos à natureza humana, mas também propiciam saudáveis mudanças de comportamento e ideias, através da reflexão. Para tanto, recorro ao romance Saturday e ao trabalho de vários especialistas no campo da gestão de conflitos

    High prevalence of respiratory symptoms among workers in the development section of a manually operated coal mine in a developing country: A cross sectional study

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    BACKGROUND: Few studies of miners have been carried out in African countries; most are from South Africa, where the working conditions are assumed to be better than in the rest of Africa. Several studies have focused on respiratory disorders among miners, but development workers responsible for creating underground road ways have not been studied explicitly. This is the first study assessing the associations between exposure to dust and quartz and respiratory symptoms among coal mine workers in a manually operated coal mine in Tanzania, focusing on development workers, as they have the highest exposure to coal dust. METHODS: A cross-sectional study was carried out among 250 production workers from a coal mine. Interviews were performed using modified standardized questionnaires to elicit information on occupational history, demographics, smoking habits and acute and chronic respiratory symptoms. The relationships between current dust exposure as well as cumulative respirable dust and quartz and symptoms were studied by group comparisons as well as logistic regression. RESULTS: Workers from the development group had the highest dust exposure, with arithmetic mean of 10.3 mg/m(3 )for current respirable dust and 1.268 mg/m(3 )for quartz. Analogous exposure results for mine workers were 0.66 mg/m(3 )and 0.03 mg/m(3), respectively; and for other development workers were 0.88 mg/m(3 )and 0.10 mg/m(3), respectively. The workers from the development section had significantly higher prevalence of the acute symptoms of dry cough (45.7%), breathlessness (34.8%) and blocked nose (23.9%). In addition, development workers had significantly more chronic symptoms of breathlessness (17.0%) than the mine workers (6.4%) and the other production workers (2.4%). The highest decile of cumulative exposure to respirable dust was significantly associated with cough (OR = 2.91, 95% CI 1.06, 7.97) as were cumulative exposure to quartz and cough (OR = 2.87, CI 1.05, 7.88), compared with the reference consisting of the group of workers with the lowest quartile of the respective cumulative exposure. CONCLUSION: The development workers in a coal mine had more acute and chronic respiratory symptoms than the mine and the other production workers. In addition, there was an association between high cumulative coal dust and respiratory symptoms

    High through-put sequencing of the Parhyale hawaiensis mRNAs and microRNAs to aid comparative developmental studies

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    Understanding the genetic and evolutionary basis of animal morphological diversity will require comparative developmental studies that use new model organisms. This necessitates development of tools for the study of genetics and also the generation of sequence information of the organism to be studied. The development of next generation sequencing technology has enabled quick and cost effective generation of sequence information. Parhyale hawaiensis has emerged as a model organism of choice due to the development of advanced molecular tools, thus P. hawaiensis genetic information will help drive functional studies in this organism. Here we present a transcriptome and miRNA collection generated using next generation sequencing platforms. We generated approximately 1.7 million reads from a P. hawaiensis cDNA library constructed from embryos up to the germ band stage. These reads were assembled into a dataset comprising 163,501 transcripts. Using the combined annotation of Annot8r and pfam2go, Gene Ontology classifications was assigned to 20,597 transcripts. Annot8r was used to provide KEGG orthology to our transcript dataset. A total of 25,292 KEGG pathway assignments were defined and further confirmed with reciprocal blast against the NCBI nr protein database. This has identified many P. hawaiensis gene orthologs of key conserved signalling pathways involved in development. We also generated small RNA sequences from P. hawaiensis, identifying 55 conserved miRNAs. Sequenced small RNAs that were not annotated by stringent comparison to mirBase were used to search the Daphnia pulex for possible novel miRNAs. Using a conservative approach, we have identified 51 possible miRNA candidates conserved in the Daphnia pulex genome, which could be potential crustacean/arthropod specific miRNAs. Our study presents gene and miRNA discovery in a new model organism that does not have a sequenced genome. The data provided by our work will be valuable for the P. hawaiensis community as well as the wider evolutionary developmental biology community

    De novo assembly and characterization of a maternal and developmental transcriptome for the emerging model crustacean Parhyale hawaiensis

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    <p>Abstract</p> <p>Background</p> <p>Arthropods are the most diverse animal phylum, but their genomic resources are relatively few. While the genome of the branchiopod <it>Daphnia pulex </it>is now available, no other large-scale crustacean genomic resources are available for comparison. In particular, genomic resources are lacking for the most tractable laboratory model of crustacean development, the amphipod <it>Parhyale hawaiensis</it>. Insight into shared and divergent characters of crustacean genomes will facilitate interpretation of future developmental, biomedical, and ecological research using crustacean models.</p> <p>Results</p> <p>To generate a transcriptome enriched for maternally provided and zygotically transcribed developmental genes, we created cDNA from ovaries and embryos of <it>P. hawaiensis</it>. Using 454 pyrosequencing, we sequenced over 1.1 billion bases of this cDNA, and assembled them <it>de novo </it>to create, to our knowledge, the second largest crustacean genomic resource to date. We found an unusually high proportion of C2H2 zinc finger-containing transcripts, as has also been reported for the genome of the pea aphid <it>Acyrthosiphon pisum</it>. Consistent with previous reports, we detected trans-spliced transcripts, but found that they did not noticeably impact transcriptome assembly. Our assembly products yielded 19,067 unique BLAST hits against <b>nr </b>(E-value cutoff e-10). These included over 400 predicted transcripts with significant similarity to <it>D. pulex </it>sequences but not to sequences of any other animal. Annotation of several hundred genes revealed <it>P. hawaiensis </it>homologues of genes involved in development, gametogenesis, and a majority of the members of six major conserved metazoan signaling pathways.</p> <p>Conclusions</p> <p>The amphipod <it>P. hawaiensis </it>has higher transcript complexity than known insect transcriptomes, and trans-splicing does not appear to be a major contributor to this complexity. We discuss the importance of a reliable comparative genomic framework within which to consider findings from new crustacean models such as <it>D. pulex </it>and <it>P. hawaiensis</it>, as well as the need for development of further substantial crustacean genomic resources.</p

    A virtual reality collaborative planning simulator and its method for three machines in a fully mechanized coal mining face

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    The existing automatic control program and its parameters for three machines in a fully mechanized Coal Mining face are static and simplex and are therefore inadequate for satisfying the complex and dynamic environment of underground coal mines. To overcome this problem, a collaborative mathematical model is established that includes the effects of a dynamic environment. A virtual reality collaborative planning simulator with methods for the three machines is also proposed based on a multi-agent system. According to the dynamic characteristics of the environment, equipment, and technologies, a fully mechanized Unity3D simulator (FMUnitySim) is designed in terms of multiple factors and multiple dimensions. The factors affecting the coordinated operation of the three machines are analyzed and modeled. The communication modes, coordination, and redundant sensing process among multiple agents, which include the shearer agent and the scraper conveyor agent, are also investigated in detail. Using this system, the key parameters of the three machines can be planned and adjusted online to design and distinctly observe the corresponding collaborative simulations of coordinated operation with multiple perspectives and in real time. Tests of different maximum shearer haulage speeds for regular or reverse transporting coal are designed; their key parameters, including the average shearer haulage speed, average follower distance, and average scraper conveyor load, are planned and simulated using FMUnitySim. The optimal parameter combination is obtained by analyzing and comparing the simulation results. The proposed FMUnitySim offers an effective means and theoretical basis for the rapid planning and safe automatic production of a fully mechanized Coal Mining face

    Oral azacitidine maintenance therapy for acute myeloid leukemia in first remission

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    Background: Although induction chemotherapy results in remission in many older patients with acute myeloid leukemia (AML), relapse is common and overall survival is poor. Methods: We conducted a phase 3, randomized, double-blind, placebo-controlled trial of the oral formulation of azacitidine (CC-486, a hypomethylating agent that is not bioequivalent to injectable azacitidine), as maintenance therapy in patients with AML who were in first remission after intensive chemotherapy. Patients who were 55 years of age or older, were in complete remission with or without complete blood count recovery, and were not candidates for hematopoietic stem-cell transplantation were randomly assigned to receive CC-486 (300 mg) or placebo once daily for 14 days per 28-day cycle. The primary end point was overall survival. Secondary end points included relapse-free survival and health-related quality of life. Results: A total of 472 patients underwent randomization; 238 were assigned to the CC-486 group and 234 were assigned to the placebo group. The median age was 68 years (range, 55 to 86). Median overall survival from the time of randomization was significantly longer with CC-486 than with placebo (24.7 months and 14.8 months, respectively; P<0.001). Median relapse-free survival was also significantly longer with CC-486 than with placebo (10.2 months and 4.8 months, respectively; P<0.001). Benefits of CC-486 with respect to overall and relapse-free survival were shown in most subgroups defined according to baseline characteristics. The most common adverse events in both groups were grade 1 or 2 gastrointestinal events. Common grade 3 or 4 adverse events were neutropenia (in 41% of patients in the CC-486 group and 24% of patients in the placebo group) and thrombocytopenia (in 22% and 21%, respectively). Overall health-related quality of life was preserved during CC-486 treatment. Conclusions: CC-486 maintenance therapy was associated with significantly longer overall and relapse-free survival than placebo among older patients with AML who were in remission after chemotherapy. Side effects were mainly gastrointestinal symptoms and neutropenia. Quality-of-life measures were maintained throughout treatment

    Cold-inducible proteins CIRP and RBM3, a unique couple with activities far beyond the cold

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