Iron Mountain Research Articles

Trace-element partitioning in perovskite: Implications for the geochemistry of kimberlites and other mantle-derived undersaturated rocks

Perovskite is a common groundmass phase in many mantle-derived undersaturated rocks (e.g., kimberlites), serving as an important repository for rare-earth elements (REE), high-field-strength elements (especially, Ti, Nb and Ta), Th and U. Perovskite-groundmass partition coefficients, calculated for samples of hypabyssal kimberlite from the Chicken Park (Colorado), Iron Mountain (Wyoming) and Udachnaya East (Russia) are largely consistent with those calculated for perovskite from katungite (potassic olivine melilitite) lava from Bunyaruguru, Uganda. The major and trace elements, analyzed by electron-microprobe and laser-probe techniques, can be grouped into strongly incompatible (DX≪0.1: K, Rb, Zn, Ba, Al), moderately incompatible (DX=0.1–0.5: Mn, Ga, Sc, V, Fe), compatible (DX=1.0–5.0: Ca, Sr, Hf, heavy REE), and strongly compatible (DX>5.0: Y, light- to mid-range REE, Th, U, Ti, Nb, Ta). Sodium gives a wide range of partitioning values in the kimberlitic perovskite, all of which are higher than the Na value for the katungite (DNa=0.19). This discrepancy is interpreted to indicate loss of Na from the kimberlitic magma during its emplacement, resulting in low Na levels in the groundmass and overestimated partition coefficients. The calculated Pb values corrected for UTh decay are also many times higher in the kimberlitic perovskite relative to the katungite (DPb=0.3); the latter value is considered a better estimate because it was not affected by UTh decay and is in better accord with the partitioning data for other divalent cations. Notably, perovskite has a higher affinity for light REE (LREE), Ho, Ta, Hf and Th relative to heavy REE (HREE), Y, Nb, Zr and U, respectively. Decoupling is particularly strong in the LREE-HREE, Th-U and Nb-Ta pairs, and will produce a noticeable effect on the composition of magma precipitating perovskite even at small degrees of fractionation. Such effects are not observed in kimberlites, even though fractionation of other minerals (notably, olivine) probably does play an important role in the evolution of kimberlites, as demonstrated in the present work on the basis of published data. Perovskite in kimberlites commonly develops a zoning pattern involving a rim-ward decrease in Th/U ratio, Na, REE, Th and Ta contents, and an increase in Nb/Ta value, which can be explained by gradual depletion of the host magma in these elements due to their early sequestration in the core of perovskite crystals and, possibly, Na loss (see above). There are also cases (e.g., Lac de Gras kimberlites) where perovskite develops a discontinuous NbFeZr-rich rim. These evolved compositions plot away from the normal zoning trend described above owing to their low Na content for the given level of REE enrichment, indicating that a significant proportion of the latter elements is incorporated in this perovskite as REE(Fe,Al)O3. Petrographic observations, combined with the published data and lack of any spectroscopic evidence for the presence of water in this perovskite, indicate that this type of zoning formed due to the loss of a volatile phase from the kimberlitic magma, accompanied by perovskite fragmentation and followed by reaction of perovskite fragments with an evolved trace-element-rich melt.

Using In-Slag Charcoal as an Indicator of “Terminal” Iron Production within the Angkorian Period (10th–13th Centuries AD) Center of Preah Khan of Kompong Svay, Cambodia

Recent fieldwork by the Industries of Angkor Project (INDAP) has identified the first extensive evidence of iron production within an Angkorian Khmer (9th to 15th centuries AD) center at Preah Khan of Kompong Svay (Preah Khan) in Preah Vihear province, Cambodia. This immense 22-km2temple complex appears to be an outpost of Khmer settlement situated in close proximity to Phnom Dek ("Iron Mountain"), the richest known source of iron oxide in Cambodia. Combined with the fact that Preah Khan's temple architecture dates between the late 10th to early 13th centuries, the period that the Khmer greatly expanded their territorial influence, our primary hypothesis is that this complex was established to gain access to and monitor production of iron for the capital of Angkor. The vast number and size of these iron slag concentrations, some up to 5 m in height by 35 m in length, precludes the use of traditional excavation and dating methods. Instead, this paper employs14C dating of “in-slag” charcoal from surface slag cakes to produce a spatial chronology of late or “terminal” industrial activities. The results indicate that metallurgy was “last” practiced at various locations within Preah Khan in the mid-13th to late 17th centuries, with 3 distinct clusters between the late 13th and late 15th centuries. Based on this initial survey of surface collections, it appears that iron production at Preah Khan occurred after the final phase of masonry construction. More significantly, this work provides the first robust set of dates for late Angkorian and Middle period industrial activities in Cambodia.

Using In-Slag Charcoal as an Indicator of “Terminal” Iron Production within the Angkorian Period (10th–13th Centuries AD) Center of Preah Khan of Kompong Svay, Cambodia

Recent fieldwork by the Industries of Angkor Project (INDAP) has identified the first extensive evidence of iron production within an Angkorian Khmer (9th to 15th centuries AD) center at Preah Khan of Kompong Svay (Preah Khan) in Preah Vihear province, Cambodia. This immense 22-km2 temple complex appears to be an outpost of Khmer settlement situated in close proximity to Phnom Dek (“Iron Mountain”), the richest known source of iron oxide in Cambodia. Combined with the fact that Preah Khan's temple architecture dates between the late 10th to early 13th centuries, the period that the Khmer greatly expanded their territorial influence, our primary hypothesis is that this complex was established to gain access to and monitor production of iron for the capital of Angkor. The vast number and size of these iron slag concentrations, some up to 5 m in height by 35 m in length, precludes the use of traditional excavation and dating methods. Instead, this paper employs 14C dating of “in-slag” charcoal from surface slag cakes to produce a spatial chronology of late or “terminal” industrial activities. The results indicate that metallurgy was “last” practiced at various locations within Preah Khan in the mid-13th to late 17th centuries, with 3 distinct clusters between the late 13th and late 15th centuries. Based on this initial survey of surface collections, it appears that iron production at Preah Khan occurred after the final phase of masonry construction. More significantly, this work provides the first robust set of dates for late Angkorian and Middle period industrial activities in Cambodia.

In Situ Evolutionary Rate Measurements Show Ecological Success of Recently Emerged Bacterial Hybrids

Few data are available on how quickly free-living microorganisms evolve. We analyzed biofilms collected from a well-defined acid mine drainage system over 9 years to investigate the processes and determine rates of bacterial evolution directly in the environment. Population metagenomic analyses of the dominant primary producer yielded the nucleotide substitution rate, which we used to show that proliferation of a series of recombinant bacterial strains occurred over the past few decades. The ecological success of hybrid bacterial types highlights the role of evolutionary processes in rapid adaptation within natural microbial communities.

Geomicrobiology of extremely acidic subsurface environments

Extreme acidophiles (microorganisms with pH optima of <3) can colonize and exploit subterranean environments, such as abandoned metal sulfide mines, that have the potential for developing widespread or isolated pockets of acidity. Although acidophiles can utilize a wide range of electron donors, inorganic materials (reduced sulfur, ferrous iron, and possibly hydrogen) are often the most abundant sources of energy for acidophiles in the subsurface. The diversity and interactions of acidophilic microbial communities in two abandoned sulfide mineral mines (in Iron Mountain, California, and the Harz mountains in Germany) and a sulfidic cave (Frasissi, Italy) are reviewed. In addition, the contrasting geomicrobiology of two abandoned sulfide mineral mines in north Wales is described. Both are extremely acidic (pH~2) and low-temperature (8-9°C) sites, but one (Cae Coch) is essentially a dry mine with isolated pockets of water, while the other (Mynydd Parys) contains a vast underground lake that was partially drained several years ago. The microbial communities in these two mines exhibit different relative abundances and often different species of archaea and bacteria. Wooden pit props, submerged in the underground lake, act as a slow-release source of organic carbon in the subterranean Mynydd Parys lake, supporting a microbial community that is more enriched with heterotrophic microorganisms.

Distribution and geochemistry of selected trace elements in the Sacramento River near Keswick Reservoir

The effect of heavy metals from the Iron Mountain Mines (IMM) Superfund site on the upper Sacramento River is examined using data from water and bed sediment samples collected during 1996–97. Relative to surrounding waters, aluminum, cadmium, cobalt, copper, iron, lead, manganese, thallium, zinc and the rare-earth elements (REE) were all present in high concentrations in effluent from Spring Creek Reservoir (SCR), which enters into the Sacramento River in the Spring Creek Arm of Keswick Reservoir. SCR was constructed in part to regulate the flow of acidic, metal-rich waters draining the IMM Superfund site. Although virtually all of these metals exist in SCR in the dissolved form, upon entering Keswick Reservoir they at least partially converted via precipitation and/or adsorption to the particulate phase. In spite of this, few of the metals settled out; instead the vast majority was transported colloidally down the Sacramento River at least to Bend Bridge, 67km from Keswick Dam.The geochemical influence of IMM on the upper Sacramento River was variable, chiefly dependent on the flow of Spring Creek. Although the average flow of the Sacramento River at Keswick Dam is 250m3/s (cubic meters per second), even flows as low as 0.3m3/s from Spring Creek were sufficient to account for more than 15% of the metals loading at Bend Bridge, and these proportions increased with increasing Spring Creek flow.The dissolved proportion of the total bioavailable load was dependent on the element but steadily decreased for all metals, from near 100% in Spring Creek to values (for some elements) of less than 1% at Bend Bridge; failure to account for the suspended sediment load in assessments of the effect of metals transport in the Sacramento River can result in estimates which are low by as much as a factor of 100.

Selected Trace Elements in the Sacramento River, California: Occurrence and Distribution

The impact of trace elements from the Iron Mountain Superfund site on the Sacramento River and selected tributaries is examined. The concentration and distribution of many trace elements-including aluminum, arsenic, boron, barium, beryllium, bismuth, cadmium, cerium, cobalt, chromium, cesium, copper, dysprosium, erbium, europium, iron, gadolinium, holmium, potassium, lanthanum, lithium, lutetium, manganese, molybdenum, neodymium, nickel, lead, praseodymium, rubidium, rhenium, antimony, selenium, samarium, strontium, terbium, thallium, thulium, uranium, vanadium, tungsten, yttrium, ytterbium, zinc, and zirconium-were measured using a combination of inductively coupled plasma-mass spectrometry and inductively coupled plasma-atomic emission spectrometry. Samples were collected using ultraclean techniques at selected sites in tributaries and the Sacramento River from below Shasta Dam to Freeport, California, at six separate time periods from mid-1996 to mid-1997. Trace-element concentrations in dissolved (ultrafiltered [0.005-μm pore size]) and colloidal material, isolated at each site from large volume samples, are reported. For example, dissolved Zn ranged from 900μg/L at Spring Creek (Iron Mountain acid mine drainage into Keswick Reservoir) to 0.65μg/L at the Freeport site on the Sacramento River. Zn associated with colloidal material ranged from 4.3μg/L (colloid-equivalent concentration) in Spring Creek to 21.8μg/L at the Colusa site on the Sacramento River. Virtually all of the trace elements exist in Spring Creek in the dissolved form. On entering Keswick Reservoir, the metals are at least partially converted by precipitation or adsorption to the particulate phase. Despite this observation, few of the elements are removed by settling; instead the majority is transported, associated with colloids, downriver, at least to the Bend Bridge site, which is 67km from Keswick Dam. Most trace elements are strongly associated with the colloid phase going downriver under both low- and high-flow conditions.

Untidy Borders: Eamonn Wall’s Negotiation of the American West

Eamonn Wall’s developing oeuvre has won acclaim on both sides of the Atlantic, making his poetic explorations of Diaspora and dual home countries of interest to scholars of the American West. As Irish scholar Charles Fanning notes, in Wall “[t]here is no more perceptive and sensitive chronicler of the experience of migration” (“Review” 155). In a series of volumes, starting with Iron Mountain Road (1997), Wall has investigated the complications of passage, the tensions of boundaries, and the difficulties of adaptation to new landscapes in the American West, among other places. Wall’s alternating positions as émigré, traveler, dweller, and native son provide him with a unique perspective on the acts of leaving, becoming, and imagining. His is not a double but a multiple consciousness, and the spirit that animates his poems and prose is restive and unsettled. Patrick Hicks defines Wall’s cartographic imagination this way: “He has an intimate understanding of what it means to be neither here nor there, and his words pull us toward new places” (306). In his accumulated work, Wall rejects easy dichotomies and forced symmetries, embracing instead the untidy borders of a life unassimilated and partially translated.

Vibrational, X-ray absorption, and Mössbauer spectra of sulfate minerals from the weathered massive sulfide deposit at Iron Mountain, California

The Iron Mountain Mine Superfund site in California is a prime example of an acid mine drainage (AMD) system with well developed assemblages of sulfate minerals typical for such settings. Here we present and discuss the vibrational (infrared), X-ray absorption, and Mössbauer spectra of a number of these phases, augmented by spectra of a few synthetic sulfates related to the AMD phases. The minerals and related phases studied in this work are (in order of increasing Fe 2O 3/FeO): szomolnokite, rozenite, siderotil, halotrichite, römerite, voltaite, copiapite, monoclinic Fe 2(SO 4) 3, Fe 2(SO 4) 3·5H 2O, kornelite, coquimbite, Fe(SO 4)(OH), jarosite and rhomboclase. Fourier transform infrared spectra in the region 750–4000 cm −1 are presented for all studied phases. Position of the FTIR bands is discussed in terms of the vibrations of sulfate ions, hydroxyl groups, and water molecules. Sulfur K-edge X-ray absorption near-edge structure (XANES) spectra were collected for selected samples. The feature of greatest interest is a series of weak pre-edge peaks whose position is determined by the number of bridging oxygen atoms between Fe 3+ octahedra and sulfate tetrahedra. Mössbauer spectra of selected samples were obtained at room temperature and 80 K for ferric minerals jarosite and rhomboclase and mixed ferric–ferrous minerals römerite, voltaite, and copiapite. Values of Fe 2+/[Fe 2+ + Fe 3+] determined by Mössbauer spectroscopy agree well with those determined by wet chemical analysis. The data presented here can be used as standards in spectroscopic work where spectra of well-characterized compounds are required to identify complex mixtures of minerals and related phases.

A secure data protection strategy

Information is the lifeblood of your business. Do you know what information you are holding, who's holding it and whether it's safe? Information is the lifeblood of your business. Do you know what information you're holding, who's holding it and whether or not it's safe? Failing to manage physical and digital information can result in potentially catastrophic financial and reputational damage. Implementing only minimal information security processes can lead to damaging headlines, unwelcome public scrutiny and customer relation nightmares. Furthermore, government regulations, evolving legislation and new audit requirements put in place to protect personal and confidential data make it imperative that organisations adapt quickly to the latest compliance guidelines. But information security breaches and backup tape theft have been undesirable ramifications of business computing since its very inception. Organisations need to pay more attention to the physical and digital data they are generating and think about how they are going to organise, store and protect it, says Russell Sanderson of Iron Mountain UK.

Biofilm development in the extremely acidophilic archaeon ‘Ferroplasma acidarmanus’ Fer1

'Ferroplasma acidarmanus' Fer1 is an iron-oxidizing extreme acidophile isolated from the Iron Mountain mine, California, USA. This archaeon is predominantly found in biofilm-associated structures in the environment, and produces two distinct biofilm morphologies. Bioinformatic analysis of the 'F. acidarmanus' Fer1 genome identified genes annotated as involved in attachment and biofilm formation. No putative quorum sensing signaling genes were identified and no N-acyl homoserine lactone-like compounds were found in 'F. acidarmanus' Fer1 biofilm supernatant. Scanning confocal microscopy analysis of biofilm development on the surface of pyrite demonstrated the temporal and spatial development of biofilm growth. Furthermore, two-dimensional polyacrylamide gel electrophoresis was used to examine differential protein expression patterns between biofilm and planktonic populations. Ten up-regulated proteins were identified that included six enzymes associated with anaerobic growth, suggesting that the dominating phenotype in the mature biofilm was associated with anaerobic modes of growth. This report increases our knowledge of the genetic and proteomic basis of biofilm formation in an extreme acidophilic archaeon.

Microbial production of isotopically light iron(II) in a modern chemically precipitated sediment and implications for isotopic variations in ancient rocks

The inventories and Fe isotope composition of aqueous Fe(II) and solid-phase Fe compounds were quantified in neutral-pH, chemically precipitated sediments downstream of the Iron Mountain acid mine drainage site in northern California, USA. The sediments contain high concentrations of amorphous Fe(III) oxyhydroxides [Fe(III)(am)] that allow dissimilatory iron reduction (DIR) to predominate over Fe-S interactions in Fe redox transformation, as indicated by the very low abundance of Cr(II)-extractable reduced inorganic sulfur compared with dilute HCl-extractable Fe. delta(56)Fe values for bulk HCl- and HF-extractable Fe were approximately 0. These near-zero bulk delta(56)Fe values, together with the very low abundance of dissolved Fe in the overlying water column, suggest that the pyrite Fe source had near-zero delta(56)Fe values, and that complete oxidation of Fe(II) took place prior to deposition of the Fe(III) oxide-rich sediment. Sediment core analyses and incubation experiments demonstrated the production of millimolar quantities of isotopically light (delta(56)Fe approximately -1.5 to -0.5 per thousand) aqueous Fe(II) coupled to partial reduction of Fe(III)(am) by DIR. Trends in the Fe isotope composition of solid-associated Fe(II) and residual Fe(III)(am) are consistent with experiments with synthetic Fe(III) oxides, and collectively suggest an equilibrium Fe isotope fractionation between aqueous Fe(II) and Fe(III)(am) of approximately -2 per thousand. These Fe(III) oxide-rich sediments provide a model for early diagenetic processes that are likely to have taken place in Archean and Paleoproterozoic marine sediments that served as precursors for banded iron formations. Our results suggest pathways whereby DIR could have led to the formation of large quantities of low-delta(56)Fe minerals during BIF genesis.

In vitro antimicrobial activity of less-utilized spice and herb extracts against selected food-borne bacteria

In this study we compared the antimicrobial activities of extracts from four under-utilized spices and herbs including goraka ( Garcinia quaesita), galangal ( Alpinia galanga), lemon iron bark ( Eucalyptus staigerana) and mountain pepper ( Tasmannia lanceolata) to the three common spices and herbs pepper ( Piper nigrum) , rosemary ( Rosmarinus officinalis), and oregano ( Oreganum vulgare). Different extraction solvents were used (water, ethanol and hexane) and extracts were tested against four food-borne bacteria ( Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes and Staphylococcus aureus) using agar disc diffusion and broth dilution assays. Solvent type greatly influenced the antimicrobial activity of the spice and herb extracts except for those of P. nigrum, which had little or no activity. In general the spice and herb extracts with antimicrobial activity were more effective against Gram-positive than Gram-negative bacteria. Extracts from the under-utilized herbs and spices had significant activity. In particular, A. galanga hexane and ethanol extracts and E. staigerana ethanol and water extracts had strong antimicrobial activity against S. aureus and/or L. monocytogenes. Interestingly the minimal inhibitory concentrations determined using the broth dilution method and the diameter of inhibition zones using the disc diffusion assay were not strongly correlated ( r 2 ranged from 0.10 to 0.70) in most extracts, suggesting that choosing just one method for antimicrobial testing may lead to indefinite conclusions. The total phenolic content of two extracts from each spice and herb was assayed to establish any relationship between antimicrobial activity and phenolic compound levels, however this was found to poorly correlated ( r 2 < 0.30). This study has demonstrated that simple extracts of novel under-utilized herbs and spices have potential antimicrobial activity against food-borne bacterial species. Further it is indicated that the antimicrobial activity in some herbs and spices may be due to the presence of substances other than phenolic compounds.

C Day-Lewis: A Life by Peter Stanford

MLR, 105.3, 2010 859 zation of the fiction in thematerial and economic history of the Depression-era South will be of interest to scholars of environmental literary criticism. University of Kansas Doreen Fowler C Day-Lewis: A Life. By Peter Stanford. London: Continuum. 2007. x+368pp. ?25. ISBN 978-0-8264-8603-5. Writing to Day-Lewis in 1963,W. H. Auden congratulates his old friend on his recent Selected Poems: 'The critics [. . .] think all our lot stopped writing 25 years ago. How silly they are going to look presently' (p. 283). Peter Stanford agrees. In a passionate epilogue, he argues that because Day-Lewis's work is unusually auto biographical', a biography is a necessary 'spur to read more of it', while putting his money on poems written after the 1930s, in particular his narrative verse (p. 325). Despite his former celebrity,Day-Lewis has become amarginal figure inaccounts of twentieth-century poetry. The general view has followed the vituperations of his bete noire Geoffrey Grigson that he was an Audenesque also-ran, whose most characteristic work?the sequences From Feathers to Iron (1931) and TheMagnetic Mountain (1933)?refract Auden's influence, vocabulary, and politics without suf ficient creative independence. In contrast with MacNeice and Spender, Day-Lewis has come to seem a poet whose work was conditioned bywriting inAuden's over bearing shadow. As Stanford shows, such views are unfair. He exposes Grigson as motivated more bymalice and jealousy (pp. 133-34). Similarly, the account of the friendship between Auden and Day-Lewis suggests that thiswas initially a more equal relationship, inwhich the older Day-Lewis often disregarded Auden's cat egorical advice. But when reading Auden's strictures on Transitional Poem (1929), it ishard to disagree with his criticism ('you are not taking enough trouble about your medium, your technique of expression') of lines such as 'From him rise up the litanies of leaves | From the tormented wood, and semi-breves |Of birds accompany the simple dawn' (p. 81). One of Stanford's great strengths is that he quotes copiously from the ceuvre. Yet as the last quotation suggests, this becomes a double-edged virtue. On the one hand, Stanford gives a real sense of the range ofDay-Lewis's poetry; on the other, the reader is inevitably prodded into asking questions about the value of thework. Stanford is rightlywary of the biographer's 'temptation [...] of reading autobio graphy into every line in [the subject's] published work' (p. 13).With Day-Lewis, however, 'refined' autobiography is never far away and became a cornerstone of his poetic. In a lecture as Oxford Professor of Poetry, he argued 'Wemust love the poet, in his work, before we find critical reasons for approving thatwork' (p. 249). Stanford suggests that this position repudiates Leavisite orthodoxy and aligns Day Lewis with his heroes, Hardy and Wordsworth. Yet it also poses the question of how lovable Day-Lewis's poetic persona is.His personal lifewas troubled: he had a difficult relationship with his clergyman father after the early death of his mother. His two marriages were punctuated by a series of affairs, including a 86o Reviews long, ultimately unhappy relationship with Rosamund Lehmann. Though Stanford seeks to exculpate Day-Lewis from the charge of having affairs to get poetic copy (p. 287), his poetry is less reticent. In 'TheWidow Interviewed', thewidow of a poet justifies his extra-marital sallies on the grounds that 'One place he might find [...] a poem's crude and filthy ore, was |Between a woman's legs' (Day-Lewis, The Complete Poems (Stanford: Stanford University Press, 1992), p. 631). The critical issue is not somuch whether Day-Lewis should have behaved better, but whether his behaviour led him towrite good poems: the evidence from this biography, as from the Complete Poems, ismixed. Though the affairwith Lehmann provoked strong individual poems during the 1940s, too often the reader gets the sense that Day-Lewis uses poetry as ameans ofmoral self-justification. In this respect, though this sympathetic and detailed portraitmakes a thoughtful case forDay-Lewis's poetry, it also suggests some of the reasons why ithas been eclipsed in recent years. If the 'ideological' poems of the 1930s...

Precise U–Pb and Th–Pb age determination of kimberlitic perovskites by secondary ion mass spectrometry

Perovskite, a common Th- and U-enriched accessory mineral crystallised from kimberlitic magmas, has long been thought to be an important geochronometer for dating the emplacement of kimberlite. However, it also contains variably high levels of common Pb, which makes it difficult to obtain a precise measurement of radiogenic Pb/U and Pb/Th isotopic compositions using microbeam techniques such as SIMS and LA-ICP-MS. We present calibration protocols for in situ U–Pb and Th–Pb age determination of kimberlitic perovskite using the large double-focusing Cameca IMS 1280. Linear relationships are found between ln( 206Pb⁎ +/U +) and ln(UO 2 +/U +), and between ln( 208Pb⁎ +/Th +) and ln(ThO +/Th +), based on which the inter-element fractionation in unknown samples during SIMS analyses can be precisely calibrated against a perovskite standard. The well-characterized Ice River perovskite is chosen as the U–Pb and Th–Pb age standard in this study. The 204Pb-correction method was used to estimate the fraction of common Pb, which is consistent with the results obtained using the 207Pb-based correction method for the dated perovskites of Phanerozoic age. A Tazheran perovskite with unusually high U but rather low Th yielded a Concordia U–Pb age of 462.8 ± 2.5 Ma and a Th–Pb age of 462 ± 4 Ma. Two perovskite samples from the Iron Mountain kimberlite have identical Concordia U–Pb ages of 410.8 ± 3.4 Ma and 411.0 ± 2.6 Ma, which are consistent within errors with their corresponding Th–Pb ages of 409.2 ± 7.2 Ma and 412.3 ± 3.3 Ma, respectively. Two perovskite samples from the Wesselton Mine of South Africa yielded indistinguishable 206Pb/ 238U ages of 91.5 ± 2.2 Ma and 90.3 ± 2.9 Ma, and Th–Pb ages of 90.5 ± 0.8 Ma and 88.4 ± 1.6 Ma, respectively. Accuracy and precision of 1–2% (95% confidence level) for these measurements have been demonstrated by the consistency of their U–Pb and Th–Pb ages with the recommended U–Pb ages of previous works.

Robotic surgical telepathology between the Iron Mountain and Milwaukee Department of Veterans Affairs Medical Centers: a twelve year experience

Since mid-1996 we have operated a diagnostic robotic telepathology (TP) system at the Iron Mountain, Michigan, Department of Veterans Affairs Medical Center (VAMC) from the Milwaukee, Wisconsin VAMC, located some 220 miles away. No on-site pathologist is present in Iron Mountain. Instead, an experienced, well-trained pathologist assistant, under direction of pathologists located in Milwaukee, is responsible for tissue grossing and sectioning. The pathologist assistant places slides onto the stage of the robotic microscope, which is then controlled by pathologists in Milwaukee. Each case read by TP is subsequently read by light microscopy (LM) by the same pathologist. Three distinct phases of TP have been recognized. Our experience during Phase I (mid-1996 through early 1999) has been published previously. During Phase II (early 1999 through mid-2004), one of the two senior telepathologists in Phase I retired and three junior pathologists were hired. During Phase III (mid-2004 though June 2008), two new junior pathologists were hired and ASAP Imaging (Apollo Telemedicine, Inc., Falls Church, VA) was implemented. The number of TP case opportunities in Phases I, II and III was 2,200; 5,841 and 3,512; respectively resulting in a total of 11,553. A total of 1,834 cases were deferred to LM for a variety of reasons. The number of TP diagnoses rendered in Phases I, II and III was 2,144; 4,636 and 2,939; respectively, for a total of 9,719. The major discordance rates in Phases I, II and III were 0.33%, 0.45% and 0.20%, respectively with an overall rate of 0.35%. Pathologist-specific discordance rates were not significantly different and ranged from a low of 0.12% to a high of 0.77%, while case deferral rates were significantly different (P < 0.0001) and ranged from 2.5% to 28.7%. In general, no relationship between deferral rate and discordance rate was noted. Iron Mountain clinicians have expressed great satisfaction with the services provided by their off-site pathologist colleagues.

An Evaluation of Patient-Physician Communication Style During Telemedicine Consultations

Background The quality of physician-patient communication is a critical factor influencing treatment outcomes and patient satisfaction with care. To date, there is little research to document the effect of telemedicine (TM) on physician-patient communication.Objective The objectives of this study are to measure and describe verbal and nonverbal communication during clinical TM consultations and to compare TM with in-person (IP) consultations in terms of the quality of physician-patient communication.Methods Veteran patients (n = 19) requiring pulmonary medicine consultations were enrolled into the study. The study group included 11 patients from the Iron Mountain Veterans Affairs Hospital (VAMC) remote site. Patients had individual TM consultations with a pulmonary physician at the Milwaukee VAMC hub site. A control group of 8 patients had IP consultations with a pulmonary physician at the Milwaukee VAMC. Video recordings of medical consultations were coded for patient-physician verbal and nonverbal communication patterns using the Roter Interaction Analysis System (RIAS).Results There were no differences in the length of TM consultations (22.2 minutes) and IP consultations (21.9 minutes). Analysis of visit dialogue indicated that the ratio of physician to patient talk was 1.45 for TM and 1.13 for IP consultations, indicating physician verbal dominance. Physicians were more likely to use orientation statements during IP consultations (P = .047). There were greater requests for repetition from patients during TM consultations (P = .034), indicating perceptual difficulties.Conclusions The study findings indicate differences between TM and IP consultations in terms of physician-patient communication style. Results suggest that, when comparing TM and IP consultations in terms of physician-patient communication, TM visits are more physician centered, with the physician controlling the dialogue and the patient taking a relatively passive role. Further research is needed to determine whether these differences are significant and whether they have relevance in terms of health outcomes and patient satisfaction with care.

Iron speciation in natural hyperacid water investigated by Mössbauer spectroscopy

We have demonstrated the usefulness of the archetypical solid state-technique of Mössbauer spectroscopy to non-invasive studies of the redox and coordination chemistry of iron in a natural hyperacid solution from Iron Mountain, CA. Suitable fast cooling conditions were used to prepare a glass from the natural solution. Measurements of spectra at low temperatures (6 and 15 K) and in large external magnetic fields (6 T) of the glassy, frozen solution revealed a behaviour characteristic of slow paramagnetic relaxation of ferric ions. Analyses of the spectral components are in good agreement with dominance of hexaaquairon(III) ions.

Robotic surgical telepathology between the Iron Mountain and Milwaukee Department of Veterans Affairs Medical Centers: a 12-year experience

Since mid-1996, we have operated a diagnostic robotic telepathology (TP) system at the Iron Mountain, MI, Department of Veterans Affairs Medical Center (VAMC) from the Milwaukee, WI, VAMC, located some 220 miles away. No on-site pathologist is present in Iron Mountain. Instead, an experienced, well-trained pathologist assistant, under direction of pathologists located in Milwaukee, is responsible for tissue grossing and sectioning. The pathologist assistant places slides onto the stage of the robotic microscope, which is then controlled by pathologists in Milwaukee. Each case read by TP is subsequently read by light microscopy (LM) by the same pathologist. Three distinct phases of TP have been recognized. Our experience during phase I (mid-1996 to early 1999) has been published previously. During phase II (early 1999 to mid-2004), 1 of the 2 senior telepathologists in phase I retired, and 3 junior pathologists were hired. During phase III (mid-2004 to June 2008), 2 new junior pathologists were hired, and ASAP Imaging (Apollo Telemedicine, Inc., Falls Church, VA) was implemented. The number of TP case opportunities in phases I, II, and III was 2200, 5841, and 3512, respectively, resulting in a total of 11 553. A total of 1834 cases were deferred to LM for a variety of reasons. The number of TP diagnoses rendered in phases I, II, and III was 2144, 4636, and 2939, respectively, resulting in a total of 9719. The major discordance rates in phases I, II, and III were 0.33%, 0.45%, and 0.20%, respectively, with an overall rate of 0.35%. Pathologist-specific discordance rates were not significantly different and ranged from a low of 0.12% to a high of 0.77%, whereas case deferral rates were significantly different (P < .0001) and ranged from 2.5% to 28.7%. In general, no relationship between deferral rate and discordance rate was noted. Iron Mountain clinicians have expressed great satisfaction with the services provided by their off-site pathologist colleagues.

Community Genomic and Proteomic Analyses of Chemoautotrophic Iron-Oxidizing “ Leptospirillum rubarum ” (Group II) and “ Leptospirillum ferrodiazotrophum ” (Group III) Bacteria in Acid Mine Drainage Biofilms

We analyzed near-complete population (composite) genomic sequences for coexisting acidophilic iron-oxidizing Leptospirillum group II and III bacteria (phylum Nitrospirae) and an extrachromosomal plasmid from a Richmond Mine, Iron Mountain, CA, acid mine drainage biofilm. Community proteomic analysis of the genomically characterized sample and two other biofilms identified 64.6% and 44.9% of the predicted proteins of Leptospirillum groups II and III, respectively, and 20% of the predicted plasmid proteins. The bacteria share 92% 16S rRNA gene sequence identity and >60% of their genes, including integrated plasmid-like regions. The extrachromosomal plasmid carries conjugation genes with detectable sequence similarity to genes in the integrated conjugative plasmid, but only those on the extrachromosomal element were identified by proteomics. Both bacterial groups have genes for community-essential functions, including carbon fixation and biosynthesis of vitamins, fatty acids, and biopolymers (including cellulose); proteomic analyses reveal these activities. Both Leptospirillum types have multiple pathways for osmotic protection. Although both are motile, signal transduction and methyl-accepting chemotaxis proteins are more abundant in Leptospirillum group III, consistent with its distribution in gradients within biofilms. Interestingly, Leptospirillum group II uses a methyl-dependent and Leptospirillum group III a methyl-independent response pathway. Although only Leptospirillum group III can fix nitrogen, these proteins were not identified by proteomics. The abundances of core proteins are similar in all communities, but the abundance levels of unique and shared proteins of unknown function vary. Some proteins unique to one organism were highly expressed and may be key to the functional and ecological differentiation of Leptospirillum groups II and III.