26 research outputs found

    Integration of advanced remote sensing and geospatial methodologies to enhance mineral exploration: An example from the southern Gawler Ranges, South Australia

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    The world’s demand for metals is increasing and there is a growing need for mineral explorers to locate new ore deposits. Globally, discovery of economic mineral deposits is becoming more challenging due to the increasing depths where exploration is being conducted to discover mineral deposits. Most surficial deposits have been discovered, driving exploration into terrains with substantial weathered regolith cover, and requiring new exploration methods. Current traditional exploration methods including geophysics, high density soil sampling and geochemical analysis can be expensive, time consuming and limited in geographic extent. Although remote sensing methods have been applied to regional-scale mineral exploration, there is potential for them to be used more fully in regions where regolith is a continuing challenge. The overarching aim of this multidisciplinary thesis is to develop methods that integrate forms of remote sensing and geospatial information to reduce the risk and cost of exploration in weathered terrains by identifying and mapping surface alteration related to buried mineralisation. The study area used to develop and test these methodologies was the southern Gawler Ranges, South Australia, a region prospective for gold, porphyry-copper and epithermal-silver mineralisation. This semi-arid environment is moderately vegetated with limited geological exposures. Most basement rocks are overlain by approximately 100 m of weathered cover materials presenting challenges for both exploration and remote sensing methods. The broad research aim was addressed through three more specific objectives: 1. Development of an objective regolith-landform map using geospatial data and a repeatable methodology that can be used to guide the early stages of exploration potential assessment; 2. Characterisation of surface expressions of alteration mineralogy and interpretation of landscape processes using airborne hyperspectral imagery and mineralogical data; and 3. Integration of surface geochemistry, mineralogy and regolith-landform mapping to understand and map surface signatures of potential buried mineralisation. An unsupervised classification was applied to geospatial data layers including a Digital Elevation Model, Topographic Position Index and potassium, thorium and uranium gamma-ray radiometrics. This was clustered to generate an objective regolith-landform map representing the main regolith-landform types. This map captured many of the features typically mapped by traditional regolith-landform mapping as assessed by a statistical goodness of fit measure. While not a replacement for the resource-intensive traditional regolith maps derived from extensive field work, this method used freely available geospatial data an objective, repeatable methodology to produce a map that has potential to increase understanding of the landscape and assist targeting of areas of alteration and mineralisation for more detailed exploration. Airborne hyperspectral imagery was analysed by Spectral Feature Fitting, matching image spectra to reference spectra to identify alteration mineralogy. X-ray diffraction was used to independently validate mineralogy present in the landscape providing insight into unclear spatial distributions of some minerals and confirming the presence of key alteration minerals. Landscape processes were interpreted by integrating the spatial distribution of minerals with the objective regolith-landform map. Advanced argillic and argillic alteration were identified in the study area, focused around an exposed alunite breccia at Nankivel Hill. The results placed the central topographic feature, Nankivel Hill, proximal to potential porphyry mineralisation, with Peterlumbo Hill distal to mineralisation as possible chloritic alteration expressed at the surface in this region. Definition of lithologies from major element geochemistry identified ten rock and cover sequence types within the study area. A region-specific pathfinder element suite was defined using interpretation and thresholds of the Nankivel and Peterlumbo Hill rock exposures. The mineral hosts of these pathfinder elements were proposed from interpretation of semi-quantitative X-ray diffraction to determine the influence of weathering on dispersion of pathfinder elements from rock exposure to cover sequence materials. This suggested that most pathfinder elements were hosted in a variety of minerals including alunite, jarosite, microcline, muscovite, orthoclase and hematite in rock exposures and a broader range of feldspars, clays, micas, carbonates and iron oxides associated with cover sequence materials. Definitions of proximal and distal geochemical and mineralogical footprints of a porphyry deposit were delineated using the surface geochemistry, X-ray diffraction and hyperspectral mineralogical data. The landscape position of pathfinder elements was interpreted to recommend sample media with the most potential for identification of pathfinders at higher concentrations. The outcomes of this research demonstrate several encouraging approaches for use of land surface remote sensing and geospatial analysis in the context of mineral exploration in highly weathered and covered terrains. These methods can be integrated easily with more traditional methods and data to improve mineral exploration outcomes for the industry. The increasing need to explore terrains with extensive depths of cover in order to discover new ore deposits suggests that the industry would benefit from integrating these tools to enhance future exploration.Thesis (Ph.D.) -- University of Adelaide, School of Biological Sciences, 202

    Women's views and postpartum follow-up in the CHIPS Trial (Control of Hypertension in Pregnancy Study).

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    OBJECTIVE: To compare women's views about blood pressure (BP) control in CHIPS (Control of Hypertension In Pregnancy Study) (NCT01192412). DESIGN: Quantitative and qualitative analysis of questionnaire responses. SETTING: International randomised trial (94 sites, 15 countries). POPULATION/SAMPLE: 911 (92.9%) women randomised to 'tight' (target diastolic blood pressure, 85mmHg) or 'less tight' (target diastolic blood pressure, 100mmHg) who completed questionnaires. METHODS: A questionnaire was administered at ∌6-12 weeks postpartum regarding post-discharge morbidity and views about trial participation. Questionnaires were administered by the site co-ordinator, and contact was made by phone, home or clinic visit; rarely, data was collected from medical records. Quantitative analyses were Chi-square or Fisher's exact test for categorical variables, mixed effects multinomial logistic regression to adjust for confounders, and p<0.001 for statistical significance. NVivo software was used for thematic analysis of women's views. MAIN OUTCOME MEASURES: Satisfaction, measured as willingness to have the same treatment in another pregnancy or recommend that treatment to a friend. RESULTS: Among the 533 women in 'tight' (N=265) vs. 'less tight' (N=268) control who provided comments for qualitative analysis, women in 'tight' (vs. 'less tight') control made fewer positive comments about the amount of medication taken (5 vs. 28 women, respectively) and intensity of BP monitoring (7 vs. 17, respectively). However, this did not translate into less willingness to either have the same treatment in another pregnancy (434, 95.8% vs. 423, 92.4%, respectively; p=0.14) or recommend that treatment to a friend (435, 96.0% and 428, 93.4%, respectively; p=0.17). Importantly, although satisfaction remained high among women with an adverse outcome, those in 'tight' control who suffered an adverse outcome (vs. those who did not) were not consistently less satisfied, whereas this was not the case among women in 'less tight' control among whom satisfaction was consistently lower for the CHIPS primary outcome (p<0.001), severe hypertension (p≀0.01), and pre-eclampsia (p<0.001). CONCLUSIONS: Women in 'tight' (vs. 'less tight') control were equally satisfied with their care, and more so in the face of adverse perinatal or maternal outcomes

    Influence of gestational age at initiation of antihypertensive therapy: Secondary analysis of CHIPS trial data (control of hypertension in pregnancy study).

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    For hypertensive women in CHIPS (Control of Hypertension in Pregnancy Study), we assessed whether the maternal benefits of tight control could be achieved, while minimizing any potentially negative effect on fetal growth, by delaying initiation of antihypertensive therapy until later in pregnancy. For the 981 women with nonsevere, chronic or gestational hypertension randomized to less-tight (target diastolic blood pressure, 100 mm Hg), or tight (target, 85 mm Hg) control, we used mixed-effects logistic regression to examine whether the effect of less-tight (versus tight) control on major outcomes was dependent on gestational age at randomization, adjusting for baseline factors as in the primary analysis and including an interaction term between gestational age at randomization and treatment allocation. Gestational age was considered categorically (quartiles) and continuously (linear or quadratic form), and the optimal functional form selected to provide the best fit to the data based on the Akaike information criterion. Randomization before (but not after) 24 weeks to less-tight (versus tight) control was associated with fewer babies with birth weight 48 hours (Pinteraction=0.354). For the mother, less-tight (versus tight) control was associated with more severe hypertension at all gestational ages but particularly so before 28 weeks (Pinteraction=0.076). In women with nonsevere, chronic, or gestational hypertension, there seems to be no gestational age at which less-tight (versus tight) control is the preferred management strategy to optimize maternal or perinatal outcomes

    A greve, o carnaval e os comícios: O mundo do trabalho portuårio em Buenos Aires e a configuração de uma comunidade obreira, verão de 1904

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    Objetivo/contexto: El presente trabajo indaga sobre el proceso de configuraciĂłn de una comunidad obrera en el puerto de Buenos Aires, resultado de la acciĂłn de los trabajadores y habitantes del barrio obrero a inicios del siglo XX. Originalidad: En el cruce de diversas historiografĂ­as (historia social, cultural y polĂ­tica), aquĂ­ se propone mirar de manera conjunta la dimensiĂłn laboral, la conflictividad obrera, el tiempo de la fiesta o carnaval y la participaciĂłn electoral, para pensar, desde esta multiplicidad de eventos y experiencias, la apariciĂłn de una comunidad obrera radicalizada y con una particular identificaciĂłn gestada en la movilizaciĂłn durante una Ă©poca especĂ­fica a comienzos del siglo XX. MetodologĂ­a: A partir de una coyuntura significativa, como fueron los meses de fines de 1903 e inicios de 1904 en el barrio portuario, y basado en un variado conjunto de documentos (periĂłdicos comerciales, barriales, gremiales, de las izquierdas, revistas de actualidad, informes policiales, fotografĂ­as, entre otros), el artĂ­culo reconstruye la experiencia obrera en los escenarios de la protesta, el carnaval y la votaciĂłn para diputados celebrada durante ese verano. Al mismo tiempo, se ponderan aquĂ­ la dimensiĂłn territorial de la configuraciĂłn comunitaria y los lugares centrales de la trama conformada por la protesta, la fiesta y las elecciones. Conclusiones: El anĂĄlisis permite identificar que las sociabilidades obreras en el puerto consolidaron una comunidad, afincada en solidaridades familiares, corporativas, partidistas y vecinales obreras, en tiempos de movilizaciĂłn gremial, polĂ­tica y festiva, y de confrontaciĂłn radicalizada con el Estado y las empresas.Objective/context: This paper inquires about the process of emergence of a working-class community in the port of Buenos Aires, resulting from actions by workers and inhabitants of the working-class neighborhood at the beginning of the 20th century. Originality: At the crossroads of diverse historiographies (social, cultural and political history), this paper proposes a joint regard at the labor dimension, worker disputes, carnival celebrations and electoral participation, and to use this multiplicity of events and experiences to think about the emergence of a radicalized worker community, with a particular identity gestated in the mobilization during a specific time at the beginning of the 20th century. Methodology: The months from late 1903 to early 1904 were an important juncture in the port district, and based on a diverse set of documents (commercial, neighborhood, trade and left-wing newspapers, news magazines, police reports, photographs, among others), this paper reconstructs the worker experience in three settings converging in the summer months: protest, carnival and legislative polls. At the same time, it ponders the territorial dimension of community configuration and the key places that formed the backdrop to a story of protest, celebration, and elections. Conclusions: This analysis shows us that worker sociabilities around the port consolidated a community based on family, corporate, partisan, neighborhood and worker solidarities, in times of labor, political and festive mobilization, and of radicalized confrontation with the State and with corporations.Objetivo/contexto: O presente trabalho indaga sobre o processo de configuração de uma comunidade obreira no porto de Buenos Aires, resultado da ação dos trabalhadores e habitantes do bairro obreiro no inĂ­cio do sĂ©culo XX. Originalidade: No cruzamento de diversas historiografias (histĂłria social, cultural e polĂ­tica), propĂ”e-se aqui observar, de maneira conjunta, a dimensĂŁo laboral, a conflituosidade obreira, o tempo da festa ou carnaval e a participação eleitoral para pensar, a partir dessa multiplicidade de eventos e experiĂȘncias, a aparição de uma comunidade obreira radicalizada e com uma identificação particular gestada na mobilização durante uma Ă©poca especĂ­fica no começo do sĂ©culo XX. Metodologia: A partir de uma conjuntura significativa, como foi o final de 1903 e inĂ­cio de 1904 no bairro portuĂĄrio e baseado em um variado conjunto de documentos (jornais comerciais, de bairros, de grĂȘmios, das esquerdas, revistas de atualidades, relatĂłrios policiais, fotografias, entre outros), o artigo reconstrĂłi a experiĂȘncia obreira nos cenĂĄrios do protesto, do carnaval e da votação para deputados celebrada nesse verĂŁo. Ao mesmo tempo, ponderam-se aqui a dimensĂŁo territorial da configuração comunitĂĄria e os lugares centrais da trama formada pelo protesto, pela festa e pelas eleiçÔes. ConclusĂ”es: A anĂĄlise permite identificar que as sociabilidades obreiras no porto consolidaram uma comunidade, estabelecida em solidariedades familiares, corporativas, partidaristas e de vizinhanças obreiras, em tempos de mobilização gremial, polĂ­tica e festiva, e de confronto radicalizado com o Estado e com as empresas.Fil: Caruso, Laura Gabriela. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad Nacional de San Martin. Instituto de Altos Estudios Sociales. Centro de Estudios de Historia E Historia del Arte.; Argentin

    Influence of gestational age at initiation of antihypertensive therapy: secondary analysis of CHIPS trial data (control of hypertension in pregnancy study)

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    For hypertensive women in CHIPS (Control of Hypertension in Pregnancy Study), we assessed whether the maternal benefits of tight control could be achieved, while minimizing any potentially negative effect on fetal growth, by delaying initiation of antihypertensive therapy until later in pregnancy. For the 981 women with nonsevere, chronic or gestational hypertension randomized to less-tight (target diastolic blood pressure, 100 mm Hg), or tight (target, 85 mm Hg) control, we used mixed-effects logistic regression to examine whether the effect of less-tight (versus tight) control on major outcomes was dependent on gestational age at randomization, adjusting for baseline factors as in the primary analysis and including an interaction term between gestational age at randomization and treatment allocation. Gestational age was considered categorically (quartiles) and continuously (linear or quadratic form), and the optimal functional form selected to provide the best fit to the data based on the Akaike information criterion. Randomization before (but not after) 24 weeks to less-tight (versus tight) control was associated with fewer babies with birth weight 48 hours (Pinteraction=0.354). For the mother, less-tight (versus tight) control was associated with more severe hypertension at all gestational ages but particularly so before 28 weeks (Pinteraction=0.076). In women with nonsevere, chronic, or gestational hypertension, there seems to be no gestational age at which less-tight (versus tight) control is the preferred management strategy to optimize maternal or perinatal outcomes

    Minimal information for studies of extracellular vesicles 2018 (MISEV2018):a position statement of the International Society for Extracellular Vesicles and update of the MISEV2014 guidelines

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    The last decade has seen a sharp increase in the number of scientific publications describing physiological and pathological functions of extracellular vesicles (EVs), a collective term covering various subtypes of cell-released, membranous structures, called exosomes, microvesicles, microparticles, ectosomes, oncosomes, apoptotic bodies, and many other names. However, specific issues arise when working with these entities, whose size and amount often make them difficult to obtain as relatively pure preparations, and to characterize properly. The International Society for Extracellular Vesicles (ISEV) proposed Minimal Information for Studies of Extracellular Vesicles (“MISEV”) guidelines for the field in 2014. We now update these “MISEV2014” guidelines based on evolution of the collective knowledge in the last four years. An important point to consider is that ascribing a specific function to EVs in general, or to subtypes of EVs, requires reporting of specific information beyond mere description of function in a crude, potentially contaminated, and heterogeneous preparation. For example, claims that exosomes are endowed with exquisite and specific activities remain difficult to support experimentally, given our still limited knowledge of their specific molecular machineries of biogenesis and release, as compared with other biophysically similar EVs. The MISEV2018 guidelines include tables and outlines of suggested protocols and steps to follow to document specific EV-associated functional activities. Finally, a checklist is provided with summaries of key points

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∌99% of the euchromatic genome and is accurate to an error rate of ∌1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Hyperspectral characterisation of alteration zones in the southern Gawler Range Volcanics margin

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    Poster presented at the 10th International Mining Geology Conference, 20-22 September 2017 in Hobart, Australia, run by the Australasian Institute of Mining and Metallurgy (AusIMM).<br

    High-frequency lake data benefits society through broader engagement with stakeholders: a synthesis of GLEON data use survey and member experiences

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    The Global Lake Ecological Observatory Network (GLEON) has a tremendous opportunity to facilitate greater publicunderstanding of lakes and enable evidence-based decision making for freshwater ecosystems with high frequencydata. To investigate this potential as well as the scope of outreach activities currently underway, we surveyed the 46GLEON sites active as of 2013 about the uses of the high-frequency lake data (HFD). Of the 26 who responded, 69%engaged in or were aware of the use of GLEON HFD beyond academics. To highlight some of the outreach activitiesconducted in collaboration with GLEON scientists, we elaborate on 3 categories of data use: (1) engaging with citizens, (2) educating students and teachers, and (3) aiding in decision making. When synthesized with a discussion of examples of broader engagement activities across the network from the perspective of participants, the results suggest GLEON?s network science approach enables the diffusion of ideas and tools for conducting effective outreach. Results also point to opportunities for GLEON to build on existing experience to encourage greater engagement of member scientists in lake conservation, restoration, and management. In light of the growing challenges in managing water quality and quantity, our findings will help determine best practices and provide guidance to scientists on how to engage a broader range of stakeholders in lake research and management.Fil: Smyth, Robyn L.. Bard College; Estados UnidosFil: Caruso, Alicia. Bard College; Estados UnidosFil: Borre, Lisa. Cary Institute Of Ecosystem Studies; Estados UnidosFil: Zhu, Guangwei. Chinese Academy Of Sciences; RepĂșblica de ChinaFil: Zhu, Mengyuan. Chinese Academy Of Sciences; RepĂșblica de ChinaFil: Hetherington, Amy. Cornell University; Estados UnidosFil: Jennings, Eleanor. Dundalk Institute Of Technology; IrlandaFil: Klug, Jennifer. Fairfield University; Estados UnidosFil: Piccolo, Maria Cintia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - BahĂ­a Blanca. Instituto Argentino de OceanografĂ­a. Universidad Nacional del Sur. Instituto Argentino de OceanografĂ­a; ArgentinaFil: Rusak, James. Ontario Ministry Of The Environment And Climate Change; CanadĂĄ. Queen’s University; CanadĂĄFil: Weathers, Kathleen.. Cary Institute of Ecosystem Studies,; Estados UnidosFil: Wigdahl Perry, Courtney. State University of New York; Estados Unido
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