Silver-base metal epithermal vein and listwaenite types of deposit Crnac, Rogozna Mts., Kosovo. Part I: Ore mineral geochemistry and sulfur isotope study

Pb-Zn-Ag vein and listwaenite types of mineralization in Crnac deposit, Western Vardar zone, were deposited within several stages: (i) the pre-ore stage comprises pyrite, arsenopyrite, pyrrhotite, quartz, kaolinite and is followed by magnetite-pyrite; (ii) the syn-ore stage is composed of galena, sphalerite, tetrahedrite and stefanite; and (iii) the post-ore stage is composed of carbonates, pyrite, arsenopyrite and minor galena. The vein type mineralization is hosted by Jurassic amphibolites and veins terminate within overlying serpentinites. Mineralized listwaenites are developed along the serpentinite-amphibolite interface. The reserves are estimated to 1.7 Mt of ore containing in average 7.6% lead, 2.9% zinc, and 102 g/t silver. Sulfides from the pre- and syn-mineralization assemblage of the vein- and listwaenite-types of mineralization from the Crnac Pb-Zn-Ag deposit have been analyzed using microprobe, crush-leachates and sulfur isotopes. The pre-ore assemblage precipitated under high sulfur fugacities (f(S(2)) = 10(-8)-10(-6) bar) from temperatures ranging between 350 degrees C and 380 degrees C. Most likely water-rock reactions, boiling and/or increase of pH caused an increase of delta(34)S of pyrite toward upper levels within the deposit. The decomposition of pre-ore pyrrhotite to a pyrite-magnetite mixture occurred at a fugacity of sulfur from f(S(2)) = 8.7 x 10(-10) to 9.6 x 10(-9) bar and fugacity of oxygen from f(O(2)) = 2.4 x 10(-30) to 3.1 x 10(-28) bars, indicating a contribution of an oxidizing fluid, i.e. meteoric water during pre-ore stages of hydrothermal activity. The crystallization temperatures obtained by the sphalerite-galena isotope geothermometer range from 230 to 310 degrees C. The delta(34)S values of pre- and syn-ore sulfides (pyrite, galena, sphalerite, delta(34)S = 0.3-5.9 parts per thousand) point to magmatic sulfur. Values of delta(34)S of galena and sphalerite are decreasing upwards due to precipitation of early formed sulfide minerals. Post-ore assemblage precipitated at temperature below 190 degrees C. Based on data presented above, we assume two fluid sources: (i) a magmatic source, supported by sulfur isotopic compositions within pre- and syn-ore minerals and a high mol% of fluorine found within pre- and syn-ore leachates, and (ii) a meteoric source, deduced by coincident pyrite-magnetite intergrowth, sulfur isotopic trends within syn-ore minerals and decrease of crystallization temperatures from the pre-ore stage (380-350 degrees C), towards the syn-ore (310-215 degrees C) and post-ore stages (<190 degrees C). Post-ore fluids are Na-Ca-Mg-K-Li chlorine rich and were modified via water-rock reactions. Simple mineral assemblage and sphalerite composition range from 1.5 to 10.1 mol% of FeS catalog Crnac to a group of intermediate sulfidation epithermal deposit. (C) 2011 Elsevier B.V. All rights reserved.

Dynamic Modelling of Material Flows and Sustainable Resource Use: Case Studies in Regional Metabolism and Space Life Support Systems

Sustainable resource use is one of the most important environmental issues of our times. It is closely related to discussions on the 'peaking' of various natural resources serving as energy sources, agricultural nutrients, or metals indispensable in high-technology applications. Although the peaking theory remains controversial, it is commonly recognized that a more sustainable use of resources would alleviate negative environmental impacts related to resource use. In this thesis, sustainable resource use is analysed from a practical standpoint, through several different case studies. Four of these case studies relate to resource metabolism in the Canton of Geneva in Switzerland: the aim was to model the evolution of chosen resource stocks and flows in the coming decades. The studied resources were copper (a bulk metal), phosphorus (a vital agricultural nutrient), and wood (a renewable resource). In addition, the case of lithium (a critical metal) was analysed briefly in a qualitative manner and in an electric mobility perspective. In addition to the Geneva case studies, this thesis includes a case study on the sustainability of space life support systems. Space life support systems are systems whose aim is to provide the crew of a spacecraft with the necessary metabolic consumables over the course of a mission. Sustainability was again analysed from a resource use perspective. In this case study, the functioning of two different types of life support systems, ARES and BIORAT, were evaluated and compared; these systems represent, respectively, physico-chemical and biological life support systems. Space life support systems could in fact be used as a kind of 'laboratory of sustainability' given that they represent closed and relatively simple systems compared to complex and open terrestrial systems such as the Canton of Geneva. The chosen analysis method used in the Geneva case studies was dynamic material flow analysis: dynamic material flow models were constructed for the resources copper, phosphorus, and wood. Besides a baseline scenario, various alternative scenarios (notably involving increased recycling) were also examined. In the case of space life support systems, the methodology of material flow analysis was also employed, but as the data available on the dynamic behaviour of the systems was insufficient, only static simulations could be performed. The results of the case studies in the Canton of Geneva show the following: were resource use to follow population growth, resource consumption would be multiplied by nearly 1.2 by 2030 and by 1.5 by 2080. A complete transition to electric mobility would be expected to only slightly (+5%) increase the copper consumption per capita while the lithium demand in cars would increase 350 fold. For example, phosphorus imports could be decreased by recycling sewage sludge or human urine; however, the health and environmental impacts of these options have yet to be studied. Increasing the wood production in the Canton would not significantly decrease the dependence on wood imports as the Canton's production represents only 5% of total consumption. In the comparison of space life support systems ARES and BIORAT, BIORAT outperforms ARES in resource use but not in energy use. However, as the systems are dimensioned very differently, it remains questionable whether they can be compared outright. In conclusion, the use of dynamic material flow analysis can provide useful information for policy makers and strategic decision-making; however, uncertainty in reference data greatly influences the precision of the results. Space life support systems constitute an extreme case of resource-using systems; nevertheless, it is not clear how their example could be of immediate use to terrestrial systems.

Estabilidade de agregados e distribuição de carbono e nutrientes em Argissolo sob adubação orgânica e mineral

O objetivo deste trabalho foi avaliar o impacto da adubação orgânica e mineral sobre a estabilidade de agregados e a distribuição de C, N e P, em classes de agregados de um Argissolo Vermelho-Amarelo. Os tratamentos consistiram de 0 e 40 m³ ha-1 por ano de adubação orgânica e de 0, 250 e 500 kg ha-1 de adubação mineral N-P-K da fórmula 4-14-8. Uma área sob floresta atlântica foi utilizada como referência. Amostras foram coletadas nas camadas de 0-10 e 10-20 cm. Houve predomínio da classe de agregados entre 4 e 2 mm, que correspondeu a 39,7% do total de agregados separados por via seca no tratamento com composto orgânico. Os teores de C orgânico total para adubação orgânica foram 17,5 e 36,7% maiores para as classes 4-2 e 0,105-0,25 mm. A adubação orgânica contribuiu para teores de N e P totais de 43 e 38,7% (0-10 cm) e 35,4 e 36,8% (10-20 cm), maiores que os dos tratamentos sem adubo orgânico. A relação carbono/nitrogênio se manteve constante entre as classes de agregados de um mesmo tratamento, enquanto a de carbono/fósforo reduziu com o uso de adubo orgânico ou mineral, em relação à mata nativa. Os índices de estabilidade de agregados se correlacionaram positivamente aos teores de carbono orgânico total da classe 4-2 mm.

Fertilidade do solo, nutrição mineral e produtividade da bananeira irrigada por dez anos

O objetivo deste trabalho foi avaliar as alterações na fertilidade do solo, na nutrição mineral e na produtividade de bananeira irrigada por dez anos. O experimento foi conduzido em Latossolo Vermelho eutrófico, de 1997 a 2007, no Município de Janaúba, MG, em um plantio comercial de banana 'Prata-Anã', onde se utilizam, para irrigação por gotejamento, água calcária de poço tubular com salinidade alta e concentração média de sódio. Observou-se que a aplicação da irrigação, por dez anos, promove forte elevação no pH e na condutividade elétrica do solo e desequilíbrios nutricionais, o que limita a produtividade da bananeira. Os teores foliares de macro e micronutrientes permanecem acima dos valores de referência para a cultura.

Effects of mental stress on insulin-mediated glucose metabolism and energy expenditure in lean and obese women.

The effects of the sympathetic activation elicited by a mental stress on insulin sensitivity and energy expenditure (VO(2)) were studied in 11 lean and 8 obese women during a hyperinsulinemic-euglycemic clamp. Six lean women were restudied under nonselective beta-adrenergic blockade with propranolol to determine the role of beta-adrenoceptors in the metabolic response to mental stress. In lean women, mental stress increased VO(2) by 20%, whole body glucose utilization ([6,6-(2)H(2)]glucose) by 34%, and cardiac index (thoracic bioimpedance) by 25%, whereas systemic vascular resistance decreased by 24%. In obese women, mental stress increased energy expenditure as in lean subjects, but it neither stimulated glucose uptake nor decreased systemic vascular resistance. In the six lean women who were restudied under propranolol, the rise in VO(2), glucose uptake, and cardiac output and the decrease in systemic vascular resistance during mental stress were all abolished. It is concluded that 1) in lean subjects, mental stress stimulates glucose uptake and energy expenditure and produces vasodilation; activation of beta-adrenoceptors is involved in these responses; and 2) in obese patients, the effects of mental stress on glucose uptake and systemic vascular resistance, but not on energy expenditure, are blunted.

Modulation of plant HMG-CoA reductase by protein phosphatase 2A: Positive and negative control at a key node of metabolism

The enzyme HMG-CoA reductase (HMGR) has a key regulatory role in the mevalonate pathway for isoprenoid biosynthesis, critical not only for normal plant development, but also for the adaptation to demanding environmental conditions. Consistent with this notion, plant HMGR is modulated by many diverse endogenous signals and external stimuli. Protein phosphatase 2A (PP2A) is involved in auxin, abscisic acid, ethylene and brassinosteroid signaling and now emerges as a positive and negative multilevel regulator of plant HMGR, both during normal growth and in response to a variety of stress conditions. The interaction with HMGR is mediated by B" regulatory subunits of PP2A, which are also calcium binding proteins. The new discoveries uncover the potential of PP2A to integrate developmental and calcium-mediated environmental signals in the control of plant HMGR.

Determinants of the essential one-carbon metabolism metabolites, homocysteine, S-adenosylmethionine, S-adenosylhomocysteine and folate, in cerebrospinal fluid.

BACKGROUND: Disturbances in the levels of one-carbon (1C) metabolism metabolites have been associated with a wide variety of neuropsychiatric diseases. Cerebrospinal fluid (CSF) levels of homocysteine (Hcy) and the other 1C metabolites, nor their interrelatedness and putative determinants, have been studied extensively in a healthy population. METHODS: Plasma and CSF samples from 100 individuals free from neuropsychiatric diseases were analyzed (55 male, 45 female; age 50±17 years). In blood, we measured plasma Hcy, serum folate and serum vitamin B12. In CSF, we measured total Hcy, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH) and 5-methyltetrahydrofolate (5-methylTHF). Highly selective analytical methods like liquid chromatography combined with either mass spectrometry or fluorescence detection were used. RESULTS: CSF Hcy was inversely correlated with CSF 5-methylTHF and positively with plasma Hcy, independent of serum folate status. CSF SAH correlated with age, lower CSF 5-methylTHF and higher CSF Hcy. CSF 5-methylTHF showed independent negative correlations with age and positive correlations with serum folate. CSF SAM did not correlate with any of the 1C metabolites. CONCLUSIONS: Aging is characterized by a reduction in CSF 5-methylTHF levels and increased CSF levels of the potentially neurotoxic transmethylation inhibitor SAH. CSF 5-methylTHF, which is itself determined in part by systemic folate status, is a powerful independent determinant of CSF levels of Hcy and SAH.

Fusaric acid-producing strains of Fusarium oxysporum alter 2,4-diacetylphloroglucinol biosynthetic gene expression in Pseudomonas fluorescens CHA0 in vitro and in the rhizosphere of wheat.

The phytotoxic pathogenicity factor fusaric acid (FA) represses the production of 2,4-diacetylphloroglucinol (DAPG), a key factor in the antimicrobial activity of the biocontrol strain Pseudomonas fluorescens CHA0. FA production by 12 Fusarium oxysporum strains varied substantially. We measured the effect of FA production on expression of the phlACBDE biosynthetic operon of strain CHA0 in culture media and in the wheat rhizosphere by using a translational phlA'-'lacZ fusion. Only FA-producing F. oxysporum strains could suppress DAPG production in strain CHA0, and the FA concentration was strongly correlated with the degree of phlA repression. The repressing effect of FA on phlA'-'lacZ expression was abolished in a mutant that lacked the DAPG pathway-specific repressor PhlF. One FA-producing strain (798) and one nonproducing strain (242) of F. oxysporum were tested for their influence on phlA expression in CHA0 in the rhizosphere of wheat in a gnotobiotic system containing a sand and clay mineral-based artificial soil. F. oxysporum strain 798 (FA(+)) repressed phlA expression in CHA0 significantly, whereas strain 242 (FA(-)) did not. In the phlF mutant CHA638, phlA expression was not altered by the presence of either F. oxysporum strain 242 or 798. phlA expression levels were seven to eight times higher in strain CHA638 than in the wild-type CHA0, indicating that PhlF limits phlA expression in the wheat rhizosphere.

Nitrogen metabolism in Zucker rats is affected by moderate reduction, but not by moderate incerase in dietary protein

Marked changes in the content of protein in the diet affects the rat"s pattern of growth, but there is not any data on the effects to moderate changes. Here we used a genetically obese rat strain (Zucker) to examine the metabolic modifications induced to moderate changes in the content of protein of diets, doubling (high-protein (HP): 30%) or halving (low-protein (LP): 8%) the content of protein of reference diet (RD: 16%). Nitrogen, energy balances, and amino acid levels were determined in lean (L) and obese (O) animals after 30 days on each diet. Lean HP (LHP) animals showed higher energy efficiency and amino acid catabolism but maintained similar amino acid accrual rates to the lean RD (LRD) group. Conversely, the lean LP (LLP) group showed a lower growth rate, which was compensated by a relative increase in fat mass. Furthermore, these animals showed greater efficiency accruing amino acids. Obesity increased amino acid catabolism as a result of massive amino acid intake; however, obese rats maintained protein accretion rates, which, in the OHP group, implied a normalization of energy efficiency. Nonetheless, the obese OLP group showed the same protein accretion pattern as in lean animals (LLP). In the base of our data, concluded that the Zucker rats accommodate their metabolism to support moderates increases in the content of protein in the diet, but do not adjust in the same way to a 50% decrease in content of protein, as shown by an index of growth reduced, both in lean and obese rats.

Effects of zoledronate versus placebo on spine bone mineral density and microarchitecture assessed by the trabecular bone score in postmenopausal women with osteoporosis: A three-year study.

The trabecular bone score (TBS) is an index of bone microarchitectural texture calculated from anteroposterior dual-energy X-ray absorptiometry (DXA) scans of the lumbar spine (LS) that predicts fracture risk, independent of bone mineral density (BMD). The aim of this study was to compare the effects of yearly intravenous zoledronate (ZOL) versus placebo (PLB) on LS BMD and TBS in postmenopausal women with osteoporosis. Changes in TBS were assessed in the subset of 107 patients recruited at the Department of Osteoporosis of the University Hospital of Berne, Switzerland, who were included in the HORIZON trial. All subjects received adequate calcium and vitamin D3. In these patients randomly assigned to either ZOL (n = 54) or PLB (n = 53) for 3 years, BMD was measured by DXA and TBS assessed by TBS iNsight (v1.9) at baseline and 6, 12, 24, and 36 months after treatment initiation. Baseline characteristics (mean ± SD) were similar between groups in terms of age, 76.8 ± 5.0 years; body mass index (BMI), 24.5 ± 3.6 kg/m(2) ; TBS, 1.178 ± 0.1 but for LS T-score (ZOL-2.9 ± 1.5 versus PLB-2.1 ± 1.5). Changes in LS BMD were significantly greater with ZOL than with PLB at all time points (p < 0.0001 for all), reaching +9.58% versus +1.38% at month 36. Change in TBS was significantly greater with ZOL than with PLB as of month 24, reaching +1.41 versus-0.49% at month 36; p = 0.031, respectively. LS BMD and TBS were weakly correlated (r = 0.20) and there were no correlations between changes in BMD and TBS from baseline at any visit. In postmenopausal women with osteoporosis, once-yearly intravenous ZOL therapy significantly increased LS BMD relative to PLB over 3 years and TBS as of 2 years. © 2013 American Society for Bone and Mineral Research.

Occurrence of a new sulphate mineral: Ca7Na3K(SO4)9 in the Emet borate deposits, western Anatolia (Turkey)

This paper is a preliminary report on the petrographic and geochemical characteristics of a new sulphate mineral associated with lacustrine glauberite layers. This mineral is present in two boreholes recently drilled in the Emet borate district (Mio-cene; western Anatolia , Turkey). The evaporitic succession in these boreholes is mainly formed of a glauber ite-probertiteal-ternation. We suggest the name"emetite", after the town of Emet, for the new sulphate mineral, although the fine crystal size hinders the appropriate chemical and crystallographic characterization required to propose it as a new mineral to the International Mineralogical Association. .

Occurrence of a new sulphate mineral: Ca7Na3K(SO4)9 in the Emet borate deposits, western Anatolia (Turkey)

This paper is a preliminary report on the petrographic and geochemical characteristics of a new sulphate mineral associated with lacustrine glauberite layers. This mineral is present in two boreholes recently drilled in the Emet borate district (Mio-cene; western Anatolia , Turkey). The evaporitic succession in these boreholes is mainly formed of a glauber ite-probertiteal-ternation. We suggest the name"emetite", after the town of Emet, for the new sulphate mineral, although the fine crystal size hinders the appropriate chemical and crystallographic characterization required to propose it as a new mineral to the International Mineralogical Association. .

Feasibility of direct mapping of cerebral fluorodeoxy-D-glucose metabolism in situ at subcellular resolution using soft X-ray fluorescence.

Glucose metabolism is difficult to image with cellular resolution in mammalian brain tissue, particularly with (18) fluorodeoxy-D-glucose (FDG) positron emission tomography (PET). To this end, we explored the potential of synchrotron-based low-energy X-ray fluorescence (LEXRF) to image the stable isotope of fluorine (F) in phosphorylated FDG (DG-6P) at 1 μm(2) spatial resolution in 3-μm-thick brain slices. The excitation-dependent fluorescence F signal at 676 eV varied linearly with FDG concentration between 0.5 and 10 mM, whereas the endogenous background F signal was undetectable in brain. To validate LEXRF mapping of fluorine, FDG was administered in vitro and in vivo, and the fluorine LEXRF signal from intracellular trapped FDG-6P over selected brain areas rich in radial glia was spectrally quantitated at 1 μm(2) resolution. The subsequent generation of spatial LEXRF maps of F reproduced the expected localization and gradients of glucose metabolism in retinal Müller glia. In addition, FDG uptake was localized to periventricular hypothalamic tanycytes, whose morphological features were imaged simultaneously by X-ray absorption. We conclude that the high specificity of photon emission from F and its spatial mapping at ≤1 μm resolution demonstrates the ability to identify glucose uptake at subcellular resolution and holds remarkable potential for imaging glucose metabolism in biological tissue. © 2012 Wiley Periodicals, Inc.

Leaf mineral composition of grafted eggplant grown in soil infested with Verticillium and root-knot nematodes

The objective of this work was to determine differences in leaf mineral composition between ungrafted and grafted onto (Solanum torvum) eggplant (Solanum melongena), cultivars 'Faselis' and 'Pala', grown in a soil infested with Verticillium dahliae and Meloidogyne incognita, or in a noninfested soil. Grafting increased leaf P and Mn concentrations, and decreased N concentrations, in both soils. Grafting also enhanced leaf Ca concentration of 'Pala', but it did not affect that of 'Faselis' depending on the cropping year. Leaf Mg concentration of grafted plants in infested soil was lower than that of ungrafted ones in noninfested soil. Results showed that, under the same fertilization program, the grafted 'Faselis' plants used the nutrients more efficiently than the 'Pala' ones. Use of S. torvum as a rootstock for 'Faselis' resulted in an effective protection against multiple pathogen infestation. Fertilization may be necessary when grafted 'Faselis' plants are grown in a soil infested with the pathogens, since grafting and infestation generally decrease leaf N, Mg, Ca and Fe concentrations, either by reducing the nutrient concentrations directly or by increasing leaf Mn concentration.

Carbohydrate and nitrogen stores in Festuca paniculata under mowing explain dominance in subalpine grasslands

Cessation of traditional management threatens semi-natural grassland diversity through the colonisation or increase of competitive species adapted to nutrient-poor conditions. Regular mowing is one practice that controls their abundance. This study evaluated the ecophysiological mechanisms limiting short- and long-term recovery after mowing for Festuca paniculata, a competitive grass that takes over subalpine grasslands in the Alps following cessation of mowing. We quantified temporal variations in carbon (C) and nitrogen (N) content, starch, fructan and total soluble sugars in leaves, stem bases and roots of F. paniculata during one growth cycle in mown and unmown fields and related them to the dynamics of soil mineral N concentration and soil moisture. Short-term results suggest that the regrowth of F. paniculata following mowing might be N-limited, first because of N dilution by C increments in the plant tissue, and second, due to low soil mineral N and soil moisture at this time of year. However, despite short-term effects of mowing on plant growth, C and N content and concentration at the beginning of the following growing season were not affected. Nevertheless, total biomass accumulation at peak standing biomass was largely reduced compared to unmown fields. Moreover, lower C storage capacity at the end of the growing season impacted C allocation to vegetative reproduction during winter, thereby dramatically limiting the horizontal growth of F. paniculata tussocks in the long term. We conclude that mowing reduces the growth of F. paniculata tussocks through both C and N limitation. Such results will help understanding how plant responses to defoliation regulate competitive interactions within plant communities.