654 research outputs found

    DSS File No.: 28SQ.23440-9-9140

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    Bogs and coal acid mine drainage are closely linked at the Victoria Junction Coal processing plant of DEVCO in Sydney, Cape Breton, Nova Scotia. This geographical setting facilitates the investigation of these bogs with respect to the effects of AMD on the ecosystem and determine their use in ameliorating the acidic conditions. The species assemblage is typical of that encountered in dwarf-shrub bogs of the Northeastern regions of the United States and Canada. These bogs are dominated by Chamaedaphne calyculata. This report describes the status of the vegetation in both bogs which have received AMD for varying times. It summarizes both onsite and laboratory investigations. Through the use of morphological-anatomical techniques, the death or growth of plant parts is determined. The old bog, exhibits significant acid stress, although it had only received aerial deposition of coal and a diffuse flow of AMD. A second bog, the new bog, located immediately above the stressed bog was healthy and unaffected by acid mine drainage until AMD seepage was diverted into the bog at the end of summer 1988. In the new bog the vegetation damage is much more severe than in the old bog and prognosis for continued survival is not good for many of the species that form the natural species assemblage of the bogs. The majority of shoot tips and lateral buds were found to be dead, suggesting little hope for recovery of the plants in subsequent years. Although damage was also observed in the same species of the old bog, the symptoms were not as severe as those seen in the new bog. Roots and rhizomes tended to show some damage but this was much reduced in comparison to that observed in the new bog. The most important species being able to survive is Typha latifolia. Other grasses, sedges, and rushes may however compete in the colonizing of the dying bogs. Thus, a change in species composition of the bogs can be expected. To promote the growth of cattails in AMD conditions foliar fertilizers were tested. Treatment with noticeable beneficial effects was the application of 4-18-16 at a dilution of 1O:l. Morphological investigations of cattail roots indicated large accumulation of metals on the epidermis and the hypodermal layers. In dead lateral roots, metal concentrations are highest and have penetrated the entire root cross section. Analysis of X-ray spectra of the metals by SEM of root cross sections, indicated that high concentrations of Fe are associated with high levels of S and greatly reduced concentrations of Ca. Crystal formation was noted in the iron-sulphate plaque accumulation in the roots. X-ray scans of cattail leaves growing in AMD conditions indicate the presence of glandular cell regions, called hyropoten with Fe levels three times that of the adjacent epidermal regions. These findings suggest, that the cattail rhizosphere may be active in ameliorating AMD and that adaptations to high iron concentrations through activation of particular cell regions of the leaves may occur

    Morphological/anatomical investigation of cattail transplants and bog vegetation

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    Report examines the effect of AMD on bog vegetation through on-site and laboratory investigation

    A study of algal establishment and growth in acid mine drainage (AMD) seeps and precipitation ponds : final report

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    Algae can frequently be found in acid mine drainage seeps. Their distribution in the waste water stream, however, is patchy. If present in high densities, and in the entire waste stream, algae could be utilized as polishing agents. In order to develop biological polishing systems, it is necessary to understand the factors controlling algal distributions

    Algal biopolishing of zinc : final report

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    Report examines the relationship between periphytic algae and the removal of zinc from waste water

    Micropedologia de um Argissolo amarelo com horizontes antrópicos (Terra Preta de Índio) na Amazînia Central.

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    Estudos micropedolĂłgicos foram carreados em Terra Preta de Índio (TPI) com o objetivo de elucidar os processos envolvidos em sua gĂȘnese, bem como suas formas de utilização prĂ©-colombiana. Blocos indeformados de solo foram coletados por horizonte e em suas respectivas transiçÔes em um perfil de Argissolo Amarelo A AntrĂłpico (TPI) localizado no municĂ­pio de Iranduba, AM. As lĂąminas delgadas confeccionadas a partir dos blocos foram descritas por meio de microscopia Ăłptica. Os resultados mostraram que os processos envolvidos na gĂȘnese desse solo envolveram: i) condiçÔes pedoambientais diferentes das atuais (pedorrelĂ­quias - nĂłdulos ferruginosos); ii) argiluviação, indicada por revestimentos de ferri-argilĂŁs orientados na parede de poros entre agregados e canais; iii) migração de ferro impregnando o fundo matricial (cutĂŁs de difusĂŁo); iv) bioturbação, atestada por preenchimento de poros por pelotas fecais e microagregação zoogenĂ©tica e v) antropismo, que contribuiu com a queima de resĂ­duos (partĂ­culas de carvĂ”es) e descarte de artefatos cerĂąmicos. A anĂĄlise dos fragmentos cerĂąmicos corroborou a utilização de cauixi (Tubella reticulata e Parnula betesil) e cariapĂ© (Bignoniacea) como antiplĂĄstico para o seu fabrico

    Inhibiting the coregulator CoREST impairs Foxp3+ Treg function and promotes antitumor immunity

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    Foxp3+ Tregs are key to immune homeostasis, but the contributions of various large, multiprotein complexes that regulate gene expression remain unexplored. We analyzed the role in Tregs of the evolutionarily conserved CoREST complex, consisting of a scaffolding protein, Rcor1 or Rcor2, plus Hdac1 or Hdac2 and Lsd1 enzymes. Rcor1, Rcor2, and Lsd1 were physically associated with Foxp3, and mice with conditional deletion of Rcor1 in Foxp3+ Tregs had decreased proportions of Tregs in peripheral lymphoid tissues and increased Treg expression of IL-2 and IFN-\u3b3 compared with what was found in WT cells. Mice with conditional deletion of the gene encoding Rcor1 in their Tregs had reduced suppression of homeostatic proliferation, inability to maintain long-term allograft survival despite costimulation blockade, and enhanced antitumor immunity in syngeneic models. Comparable findings were seen in WT mice treated with CoREST complex bivalent inhibitors, which also altered the phenotype of human Tregs and impaired their suppressive function. Our data point to the potential for therapeutic modulation of Treg functions by pharmacologic targeting of enzymatic components of the CoREST complex and contribute to an understanding of the biochemical and molecular mechanisms by which Foxp3 represses large gene sets and maintains the unique properties of this key immune cell

    Investigation into the use of histone deacetylase inhibitor MS-275 as a topical agent for the prevention and treatment of cutaneous squamous cell carcinoma in an SKH-1 hairless mouse model

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    <div><p>Cutaneous squamous cell carcinomas are a common form of highly mutated keratinocyte skin cancers that are of particular concern in immunocompromised patients. Here we report on the efficacy of topically applied MS-275, a clinically used histone deacetylase inhibitor, for the treatment and management of this disease. At 2 mg/kg, MS-275 significantly decreased tumor burden in an SKH-1 hairless mouse model of UVB radiation-induced skin carcinogenesis. MS-275 was cell permeable as a topical formulation and induced histone acetylation changes in mouse tumor tissue. MS-275 was also effective at inhibiting the proliferation of patient derived cutaneous squamous cell carcinoma lines and was particularly potent toward cells isolated from a regional metastasis on an immunocompromised individual. Our findings support the use of alternative routes of administration for histone deacetylase inhibitors in the treatment of high-risk squamous cell carcinoma which may ultimately lead to more precise delivery and reduced systemic toxicity.</p></div

    High-Grade Copper and Gold Deposited During Postpotassic Chlorite-White Mica-Albite Stage in the Far Southeast Porphyry Deposit, Philippines

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    Ninety-eight underground diamond holes (~102 km) drilled by Far Southeast Gold Resources Inc. at the Far Southeast porphyry Cu-Au deposit, Philippines, from 2011 to mid-2013, provide a three-dimensional exposure of the deposit between 700- and –750-m elevation, with surface at ~1,400-m elevation. Far Southeast contains an inferred resource of 891.7 million tonnes (Mt) averaging 0.7 g/t Au and 0.5 wt % Cu, equivalent to 19.8 Moz Au and 4.5 Mt Cu. This contribution reports the spatial and temporal distribution of alteration and mineralization at Far Southeast, notably a white-mica–chlorite-albite assemblage that formed after early secondary biotite and before late quartz–white-mica–pyrite alteration and that is associated with the highest copper and gold grades. Alteration assemblages were determined by drill core logging, short-wavelength infrared (SWIR) spectral analysis, petrographic examination, and a quantitative evaluation of materials by scanning electron microscopy (QEMSCAN) study. Alteration is limited around sparse veins or pervasive where vein density is high and the alteration halos coalesce. The alteration and mineralization zones with increasing depth are as follows: (1) the lithocap of quartz-alunite–dominated advanced argillic-silicic alteration that hosts part of the Lepanto high-sulfidation Cu-Au epithermal deposit (mostly above ~700-m elevation), (2) an aluminosilicate-dominated zone with coexisting pyrophyllite-diaspore ± kandite ± alunite and white mica (~700- to ~100-m elevation), (3) porphyry-style assemblages characterized by stockwork veins (below ~500-m elevation), (4) the 1 wt % Cu equivalent ore shell (~400- to –300-m elevation), and (5) an underlying subeconomic zone (about –300- to –750-m elevation, the base of drilling). The ore shells have a typical bell shape centered on a dioritic intrusive complex. The paragenetic sequence of the porphyry deposit includes stage 1 granular gray to white quartz-rich (± anhydrite ± magnetite ± biotite) veins with biotite-magnetite alteration. These were cut by stage 2 lavender-colored euhedral quartz-rich (± anhydrite ± sulfides) veins, with halos of greenish white-mica–chlorite-albite alteration. The white mica is largely illite, with an average 2,203-nm Al-OH wavelength position. The albite may reflect the mafic nature of the diorite magmatism. The quartz veins of this stage are associated with the bulk of copper deposited as chalcopyrite and bornite, as well as gold. Thin Cu sulfide (chalcopyrite, minor bornite) veins with minor quartz and/or anhydrite (paint veins), with or without a white-mica halo, also occur. These veins were followed by stage 3 anhydrite-rich pyrite-quartz veins with white-mica (avg 2,197 nm, illite)–pyrite alteration halos. Combined with previous studies, we conclude that this porphyry system, including the Far Southeast porphyry and Lepanto high-sulfidation Cu-Au deposits, evolved over a period of 0.1–0.2 m.y. Three diorite porphyry stocks were emplaced, and by ~1.4 Ma biotite-magnetite–style alteration formed with quartz-anhydrite veins and deposition of ≀0.5% Cu and ≀0.5 g/t Au (stage 1); coupled with this alteration style, a barren lithocap of residual quartz with quartz-alunite halo plus kandite ± pyrophyllite and/or diaspore formed at shallower depth (>700-m elevation). Subsequently, lavender quartz and anhydrite veins with bornite and chalcopyrite (high-grade stage, avg ~1 wt % Cu and ~1 g/t Au) and white-mica–chlorite-albite halos formed below ~400-m elevation (stage 2). They were accompanied by local pyrite replacement, the formation of hydrothermal breccias and Cu sulfide (paint) veins. Stage 2 was followed at ~1.3 Ma by the formation of igneous breccias largely along the margins of the high-grade zones and stage 3 pyrite-quartz-anhydrite ± chalcopyrite veins with white-mica (mostly illitic) halos. At shallower depths in the transition to the base of the lithocap, cooling led to the formation of aluminosilicate minerals (mainly pyrophyllite ± diaspore ± dickite) with anhydrite plus high-sulfidation-state sulfides and pyrite veinlets. Consistent with previous studies, it is likely that the lithocap-hosted enargite-Au mineralization formed during this later period

    Depth concentrations of deuterium ions implanted into some pure metals and alloys

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    Pure metals (Cu, Ti, Zr, V, Pd) and diluted Pd-alloys (Pd-Ag, Pd-Pt, Pd-Ru, Pd-Rh) were implanted by 25 keV deuterium ions at fluences in the range (1.2{\div}2.3)x1022 D+/m2. The post-treatment depth distributions of deuterium ions were measured 10 days and three months after the implantation using Elastic Recoil Detection Analysis (ERDA) and Rutherford Backscattering (RBS). Comparison of the obtained results allowed to make conclusions about relative stability of deuterium and hydrogen gases in pure metals and diluted Pd alloys. Very high diffusion rates of implanted deuterium ions from V and Pd pure metals and Pd alloys were observed. Small-angle X-ray scattering revealed formation of nanosized defects in implanted corundum and titanium.Comment: 12 pages, 9 figure

    Combining stable isotopes with contamination indicators: A method for improved investigation of nitrate sources and dynamics in aquifers with mixed nitrogen inputs.

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    Excessive nitrate (NO3−) concentration in groundwater raises health and environmental issues that must be addressed by all European Union (EU) member states under the Nitrates Directive and the Water Framework Directive. The identification of NO3− sources is critical to efficiently control or reverse NO3− contamination that affects many aquifers. In that respect, the use of stable isotope ratios 15N/14N and 18O/16O in NO3− (expressed as ÎŽ15N-NO3− and ÎŽ18O-NO3−, respectively) has long shown its value. However, limitations exist in complex environments where multiple nitrogen (N) sources coexist. This two-year study explores a method for improved NO3− source investigation in a shallow unconfined aquifer with mixed N inputs and a long established NO3− problem. In this tillage-dominated area of free-draining soil and subsoil, suspected NO3− sources were diffuse applications of artificial fertiliser and organic point sources (septic tanks and farmyards). Bearing in mind that artificial diffuse sources were ubiquitous, groundwater samples were first classified according to a combination of two indicators relevant of point source contamination: presence/absence of organic point sources (i.e. septic tank and/or farmyard) near sampling wells and exceedance/non-exceedance of a contamination threshold value for sodium (Na+) in groundwater. This classification identified three contamination groups: agricultural diffuse source but no point source (D+P−), agricultural diffuse and point source (D+P+) and agricultural diffuse but point source occurrence ambiguous (D+P±). Thereafter ÎŽ15N-NO3− and ÎŽ18O-NO3− data were superimposed on the classification. As ÎŽ15N-NO3− was plotted against ÎŽ18O-NO3−, comparisons were made between the different contamination groups. Overall, both ÎŽ variables were significantly and positively correlated (p 0.6, 0.53 ≀ slope ≀ 0.76), i.e. where point source contamination was characterised or suspected. These lines originated from the 2–6‰ range for ÎŽ15N-NO3−, which suggests that i) NO3− contamination was dominated by an agricultural diffuse N source (most likely the large organic matter pool that has incorporated 15N-depleted nitrogen from artificial fertiliser in agricultural soils and whose nitrification is stimulated by ploughing and fertilisation) rather than point sources and ii) denitrification was possibly favoured by high dissolved organic content (DOC) from point sources. Combining contamination indicators and a large stable isotope dataset collected over a large study area could therefore improve our understanding of the NO3− contamination processes in groundwater for better land use management. We hypothesise that in future research, additional contamination indicators (e.g. pharmaceutical molecules) could also be combined to disentangle NO3− contamination from animal and human wastes
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