bluuebunny/crossref_metadata_2025 huggingface dataset:
Matrix Metalloproteinase Polymorphisms and Bladder Cancer Risk
Authors: Kader A. Karim , Shao Lina , Dinney Colin P. , Schabath Matthew B. , Wang Yunfei , Liu Jun , Gu Jian , Grossman H. Barton , Wu Xifeng
Published: December 2006

Matrix metalloproteinases (MMP) contribute to tumor microenvironment and are associated with bladder cancer. A study examining the association between MMP polymorphisms and bladder cancer risk has never been published. We analyzed the association of 11 single nucleotide polymorphisms (SNPs) and one microsatellite polymorphism in MMP genes MMP-1, MMP-2, MMP-3, MMP-8, MMP-9, and MMP-12 with bladder cancer risk in 560 Caucasian patients and 560 controls matched on age, gender, and ethnicity. Individual, combination, haplotype, and diplotype analyses were done. No associations between individual MMP polymorphisms and overall bladder cancer risk were seen. The MMP-9 microsatellite ≥24 CA repeat allele and the MMP-12-82 GG polymorphisms were associated with invasive bladder cancer risk [odds ratio (OR), 2.60; 95% confidence interval (95% CI), 1.07–6.26; and OR, 4.59; 95% CI, 1.21–17.32, respectively]. Smoke-stratified analyses revealed several associations between MMP polymorphisms, alone and in combination, with bladder cancer risk, particularly in light smokers. Linkage disequilibrium was seen in all of the MMP-1, MMP-3, MMP-8, and MMP-12 SNPs and in four of five MMP-9 polymorphisms tested. Several MMP-9 haplotype and diplotypes were associated with overall and invasive bladder cancer risk. Our study suggests that genetic variations in the MMP family are associated with bladder cancer risk. Heavy carcinogen exposure may overwhelm some of the genetic effects of MMP polymorphisms. Our study confirms the importance of taking a multigenic pathway–based approach to risk assessment. (Cancer Res 2006; 66(24): 11644-8)
Endothelins Induce CCR7 Expression by Breast Tumor Cells via Endothelin Receptor A and Hypoxia-Inducible Factor-1
Authors: Wilson Julia L. , Burchell Joy , Grimshaw Matthew J.
Published: December 2006

Endothelin expression is increased in breast tumors and is associated with invasion and metastasis, whereas CCR7 expression by breast tumor cells may have a role in the organ specificity of breast cancer spread. In this article, we have analyzed whether endothelins influence breast tumor cell expression of the chemokine receptor CCR7. Stimulation of human breast tumor cell lines with endothelins increased cell surface expression of CCR7 via endothelin receptor A. The iron chelators desferrioxamine and cobalt chloride, which induce hypoxia-inducible factor (HIF)-mediated transcription, also increased CCR7 expression; transfection of a dominant-negative version of the HIF regulatory subunit, HIF-1α, into MCF-7 cells abolished CCR7 induction by endothelins, indicating that increased expression is due to HIF-1 stabilization. Endothelin stimulation promoted invasion toward the CCR7 ligands CCL19 and CCL21. Endothelin-mediated chemokine-independent invasion itself is dependent on CCR7 activity and could be abolished using a CCR7-neutralizing monoclonal antibody. In human breast carcinomas, mRNA expression of endothelins correlated with the level of CCR7 expression, both of which were associated with the presence of lymph node metastases. Expression of the CCR7 ligands CCL19 and CCL21 was also higher in breast cancer patients with lymph node involvement compared with those without, but expression of these chemokines did not correlate with endothelin expression. These data show that CCR7 may be regulated by the breast tumor microenvironment and further support the use of endothelin receptor antagonists in the treatment of invasive and metastatic breast cancer. (Cancer Res 2006; 66(24): 11802-7)
Quantitating Therapeutic Disruption of Tumor Blood Flow with Intravital Video Microscopy
Authors: Iga Arthur M. , Sarkar Sandip , Sales Kevin M. , Winslet Marc C. , Seifalian Alexander M.
Published: December 2006

Vascular-disrupting agents (VDA) kill tumor cells by selectively disrupting blood circulation in tumors. In vivo analysis of this intensely studied class of anticancer agents is invaluable for preclinical assessment of pharmacodynamic end points and effective therapeutic windows. In this review, we consider the role of intravital video microscopy in measuring tumor vascular response to VDAs, the potential of which lies in the opportunity to quantitate specific variables and to obtain real-time information on how VDAs affect tumor microcirculation. (Cancer Res 2006; 66(24): 11517-9)
Ataxia Telangiectasia Mutated Down-regulates Phospho-Extracellular Signal-Regulated Kinase 1/2 via Activation of MKP-1 in Response to Radiation
Authors: Nyati Mukesh K. , Feng Felix Y. , Maheshwari Divya , Varambally Sooryanarayana , Zielske Steven P. , Ahsan Aarif , Chun Patrick Y. , Arora Vinay A. , Davis Mary A. , Jung Mira , Ljungman Mats , Canman Christine E. , Chinnaiyan Arul M. , Lawrence Theodore S.
Published: December 2006

Ataxia telangiectasia mutated (ATM) kinase plays a crucial role in the cellular response to DNA damage and in radiation resistance. Although much effort has focused on the relationship between ATM and other nuclear signal transducers, little is known about interactions between ATM and mitogenic signaling pathways. In this study, we show a novel relationship between ATM kinase and extracellular signal-regulated kinase 1/2 (ERK1/2), a key mitogenic stimulator. Activation of ATM by radiation down-regulates phospho-ERK1/2 and its downstream signaling via increased expression of mitogen-activated protein kinase phosphatase MKP-1 in both cell culture and tumor models. This dephosphorylation of ERK1/2 is independent of epidermal growth factor receptor (EGFR) activity and is associated with radioresistance. These findings show a new function for ATM in the control of mitogenic pathways affecting cell signaling and emphasize the key role of ATM in coordinating the cellular response to DNA damage. (Cancer Res 2006; 66(24): 11554-9)
SLC5A8 Triggers Tumor Cell Apoptosis through Pyruvate-Dependent Inhibition of Histone Deacetylases
Authors: Thangaraju Muthusamy , Gopal Elangovan , Martin Pamela M. , Ananth Sudha , Smith Sylvia B. , Prasad Puttur D. , Sterneck Esta , Ganapathy Vadivel
Published: December 2006

Tumor cells up-regulate glycolysis but convert pyruvate into lactate instead of oxidizing it. Here, we show that pyruvate, but not lactate, is an inhibitor of histone deacetylases (HDAC) and an inducer of apoptosis in tumor cells and that SLC5A8, a Na+/monocarboxylate cotransporter, is obligatory for this process. We found that SLC5A8 is expressed in nontransformed breast epithelial cell lines but silenced by DNA methylation in tumor cell lines. The down-regulation of the gene is also evident in primary breast tumors. When MCF7 breast tumor cells are transfected with SLC5A8 cDNA, the cells undergo pyruvate-dependent apoptosis. Butyrate and propionate also induce apoptosis in SLC5A8-expressing cells, whereas lactate does not. The differential ability of these monocarboxylates to cause apoptosis in SLC5A8-expressing MCF7 cells correlates with their ability to inhibit HDACs. Apoptosis induced by SLC5A8/pyruvate in MCF7 cells is associated with up-regulation of p53, Bax, tumor necrosis factor–related apoptosis-inducing ligand (TRAIL), TRAIL receptor (TRAILR) 1, and TRAILR2 and down-regulation of Bcl2 and survivin. Lactate dehydrogenase isozymes are differentially expressed in nontransformed cells and tumor cells such that the latter convert pyruvate into lactate. Silencing of SLC5A8 coupled with conversion of pyruvate into lactate in tumor cells correlates with increased HDAC activity in these cells compared with nontransformed cells. Our studies thus identify pyruvate as a HDAC inhibitor and indicate that the Na+-coupled pyruvate transport underlies the tumor-suppressive role of SLC5A8. We propose that tumor cells silence SLC5A8 and convert pyruvate into lactate as complementary mechanisms to avoid pyruvate-induced cell death. (Cancer Res 2006; 66(24): 11560-4)
Collagen I Promotes Metastasis in Pancreatic Cancer by Activating c-Jun NH2-Terminal Kinase 1 and Up-regulating N-Cadherin Expression
Authors: Shintani Yasushi , Hollingsworth Michael A. , Wheelock Margaret J. , Johnson Keith R.
Published: December 2006

We have previously shown that N-cadherin expression is associated with tumor invasion, and that some cancer cells respond to specific extracellular matrix molecules by up-regulating N-cadherin. Pancreatic cancer is characterized by excessive deposition of type I collagen. Here, we show that human pancreatic cancer cells respond to collagen I, but not other matrices, by increasing motility and up-regulating mesenchymal markers, including N-cadherin. Both collagen I–mediated motility and metastasis in a mouse model for pancreatic cancer were inhibited by N-cadherin knockdown. Furthermore, inhibiting c-Jun NH2-terminal kinase (JNK) with chemical inhibitors or short hairpin RNA abrogated all collagen I–induced changes. We show that JNK1 is activated in response to collagen I, which increases tumorigenesis by up-regulating N-cadherin expression and by increasing motility. (Cancer Res 2006; 66(24): 11745-53)
Activated Checkpoint Kinase 2 Provides a Survival Signal for Tumor Cells
Authors: Ghosh Jagadish C. , Dohi Takehiko , Raskett Christopher M. , Kowalik Timothy F. , Altieri Dario C.
Published: December 2006

Tumor cells often become resistant to DNA damage–based therapy; however, the underlying mechanisms are not yet understood. Here, we show that tumor cells exposed to DNA damage counteract cell death by releasing the antiapoptotic protein, survivin, from mitochondria. This is independent of p53, and requires activated checkpoint kinase 2 (Chk2), a putative tumor suppressor. Molecular or genetic targeting of Chk2 prevents the release of survivin from mitochondria, enhances DNA damage–induced tumor cell apoptosis, and inhibits the growth of resistant in vivo tumors. Therefore, activated Chk2 circumvents its own tumor-suppressive functions by promoting tumor cell survival. Inhibiting Chk2 in combination with DNA-damaging agents may provide a rational approach for treating resistant tumors. (Cancer Res 2006; 66(24): 11576-9)
DNA Damage by Benzo(a)pyrene in Human Cells Is Increased by Cigarette Smoke and Decreased by a Filter Containing Rosemary Extract, Which Lowers Free Radicals
Authors: Alexandrov Kroum , Rojas Margarita , Rolando Christian
Published: December 2006

We found previously that the human lung benzo(a)pyrene (BP)-7,8-diol-9,10-epoxide-N2-deoxyguanosine (BPDE-dG) adduct concentrate in the target bronchial cells. This adduct is now considered to be critical event in tumorigenesis by BP. In this study, we investigate the contribution of cigarette smoke on the BPDE-dG formation. In a cell-free system, the amount of (−)-anti-BPDE-dG adduct increased linearly with concentration of cigarette smoke in the presence of (+)-BP-7,8-diol. Catalase and superoxide dismutase inhibited its formation by >80%. When MCF-7 cells were treated for 2 hours with the (+)-BP-7,8-diol, cigarette smoke increased dose dependently the formation of (−)-anti-BPDE-dG and decreased the cytochrome P450 (CYP)–dependent formation of (+)-r-7,t-8-dihydroxy-c-9,10-oxy-7,8,9,10-tetrahydro-BP the adduct. Then, cells were treated for up to 1 day with BP and then exposed for 2 hours with cigarette smoke. During these 2 hours, there are twice the increase in the adduct formation in cells treated with cigarette smoke compared with levels in nontreated cells due to CYP activity. Thus, cigarette smoke containing reactive oxygen species may activate the second step of BP metabolic way, leading to the formation of BPDE-dG adduct. Cigarette smoke thus seems may be in part responsible for the formation of the critical lung tumorigenic adduct. Finally, modified cigarette filter containing rosemary extract decreases by >70% of the BPDE-dG adducts level due to the cigarette smoke in MCF-7 cells. This approach may lead to decreasing lung cancer risk in addicted smokers. (Cancer Res 2006; 66(24): 11938-45)
Tcl1 Expression in Chronic Lymphocytic Leukemia Is Regulated by miR-29 and miR-181
Authors: Pekarsky Yuri , Santanam Urmila , Cimmino Amelia , Palamarchuk Alexey , Efanov Alexey , Maximov Vadim , Volinia Stefano , Alder Hansjuerg , Liu Chang-Gong , Rassenti Laura , Calin George A. , Hagan John P. , Kipps Thomas , Croce Carlo M.
Published: December 2006

B-cell chronic lymphocytic leukemia (B-CLL) is the most common human leukemia in the world. Deregulation of the TCL1 oncogene is a causal event in the pathogenesis of the aggressive form of this disease as was verified by using animal models. To study the mechanism of Tcl1 regulation in CLL, we carried out microRNA expression profiling of three types of CLL: indolent CLL, aggressive CLL, and aggressive CLL showing 11q deletion. We identified distinct microRNA signatures corresponding to each group of CLL. We further determined that Tcl1 expression is regulated by miR-29 and miR-181, two microRNAs differentially expressed in CLL. Expression levels of miR-29 and miR-181 generally inversely correlated with Tcl1 expression in the CLL samples we examined. Our results suggest that Tcl1 expression in CLL is, at least in part, regulated by miR-29 and miR-181 and that these microRNAs may be candidates for therapeutic agents in CLLs overexpressing Tcl1. (Cancer Res 2006; 66(24): 11590-3)
Tropical Atlantic SST Prediction with Coupled Ocean–Atmosphere GCMs
Authors: Stockdale Timothy N. , Balmaseda Magdalena A. , Vidard Arthur
Published: December 2006

Variations in tropical Atlantic SST are an important factor in seasonal forecasts in the region and beyond. An analysis is given of the capabilities of the latest generation of coupled GCM seasonal forecast systems to predict tropical Atlantic SST anomalies. Skill above that of persistence is demonstrated in both the northern tropical and equatorial Atlantic, but not farther south. The inability of the coupled models to correctly represent the mean seasonal cycle is a major problem in attempts to forecast equatorial SST anomalies in the boreal summer. Even when forced with observed SST, atmosphere models have significant failings in this area. The quality of ocean initial conditions for coupled model forecasts is also a cause for concern, and the adequacy of the near-equatorial ocean observing system is in doubt. A multimodel approach improves forecast skill only modestly, and large errors remain in the southern tropical Atlantic. There is still much scope for improving forecasts of tropical Atlantic SST.
Climate Forcings and Climate Sensitivities Diagnosed from Coupled Climate Model Integrations
Authors: Forster Piers Mde F. , Taylor Karl E.
Published: December 2006

A simple technique is proposed for calculating global mean climate forcing from transient integrations of coupled atmosphere–ocean general circulation models (AOGCMs). This “climate forcing” differs from the conventionally defined radiative forcing as it includes semidirect effects that account for certain short time scale responses in the troposphere. First, a climate feedback term is calculated from reported values of 2 × CO2 radiative forcing and surface temperature time series from 70-yr simulations by 20 AOGCMs. In these simulations carbon dioxide is increased by 1% yr−1. The derived climate feedback agrees well with values that are diagnosed from equilibrium climate change experiments of slab-ocean versions of the same models. These climate feedback terms are associated with the fast, quasi-linear response of lapse rate, clouds, water vapor, and albedo to global surface temperature changes. The importance of the feedbacks is gauged by their impact on the radiative fluxes at the top of the atmosphere. Partial compensation is found between longwave and shortwave feedback terms that lessens the intermodel differences in the equilibrium climate sensitivity. There is also some indication that the AOGCMs overestimate the strength of the positive longwave feedback.

These feedback terms are then used to infer the shortwave and longwave time series of climate forcing in twentieth- and twenty-first-century simulations in the AOGCMs. The technique is validated using conventionally calculated forcing time series from four AOGCMs. In these AOGCMs the shortwave and longwave climate forcings that are diagnosed agree with the conventional forcing time series within ∼10%. The shortwave forcing time series exhibit order of magnitude variations between the AOGCMs, differences likely related to how both natural forcings and/or anthropogenic aerosol effects are included. There are also factor of 2 differences in the longwave climate forcing time series, which may indicate problems with the modeling of well-mixed greenhouse gas changes. The simple diagnoses presented provides an important and useful first step for understanding differences in AOGCM integrations, indicating that some of the differences in model projections can be attributed to different prescribed climate forcing, even for so-called standard climate change scenarios.
Some additional localities for Idocrase in Cornwall
Authors: Barrow G. , Thomas H. H.
Published: December 2006

The continuation of the mapping of the aureole of metamorphism round the Bodmin Moor granite has led to the discovery of fresh occurrences of idocrase, developed in the altered, impure limestones. The failure to find this mineral hitherto is now clearly due to the former absence of artificial openings in suitable localities, for the mineral has so far not been found in recognizable form in natural exposures, owing to the rapidity with which these calcareous rocks decompose.

Altered calcareous rocks containing idocrase in considerable abundance have recently been laid open in a small quarry on the west side of the stream at Tvenuth Mill, which is about 400 yards south of the granite margin in the well-known Caradon area.
Different habits of fluorite crystals
Authors: Drugman Julien
Published: December 2006

Although a considerable amount of work has been published On the occurrence and crystallography of fluorite, comparatively little has been done on the variations in habit of the crystal s. V. Goldschmidt's 'Atlas der Krystallformen' (vol. 4, 1913) gives 160 drawings with references for different forms and combinations of fluorite, but very few attempts have been made to explain the different habits observed. Experiments on the artificial growth of crystals by different methods; under varying conditions of temperature and pressure, and in the presence of foreign substances in the solution do not appear to have been made.
Determination of minerals in platinum concentrates from the Transvaal by X-ray methods
Authors: Bannister F. A.
Published: December 2006

Concentrates from the platiniferous norites of the Bushveld, Transvaal, are not completely soluble in aqua regia. The insoluble portion consists of steel-grey fragments first analysed chemically by R. A. Cooper and considered by him to be a new platinum mineral represented by the formula Pt(As,S)2. The name cooperite was proposed for the new mineral by F. Wartenweiller, and after further work Cooper decided that the arsenic found in the early analysis was due to the presence of sperrylite, and he changed the formula to PtS2. H. Schneiderhöhn observed simple twinning and, less frequently, polysynthetie lamellae on polished sections of mineral grains from the same deposits, and he suggested that cooperite is probably orthorhombic and isomorphous with marcasite. The latest account of the new mineral has been published by H. R. Adam who gave several analyses of cooperite from the Rustenburg and Potgietersrust districts and concluded that the ‘mineral is PtS2with a small amount of excess metal (platinum, palladium, and nickel) present in solid solution’.
On stichtite from Cunningsburgh, Shetland Islands
Authors: Read H. H. , Dixon B. E.
Published: December 2006

The rare mineral stichtite, a complex hydroxy-carbonate of magnesium, chromium, and iron, was defined in 1910 by W. F. Petterd on material from the Adelaide silver-lead mine, Dundas, Tasmania. Petterd's description, together with detailed optical and chemical studies by A. S. Wesley, L. K. Ward, L. Hezner, and A. Himmelbauer, were collected by W. H. Twelvetrees and issued by the Tasmanian Department of Mines in 1914. A new analysis of the Tasmanian material is included by W. F. Foshag in his investigation of the hydrotalcite group.

The mineral was next recorded by E. Poitevin and R. P. D. Graham from the Megantic mine, Black Lake area, Quebec; no chemical data of this occurrence are available.
Meteoric iron and silica-glass from the meteorite craters of Henbury (Central Australia) and Wabar (Arabia)
Authors: Spencer L. J.
Published: December 2006

The study of the materials from these two recently discovered occurrences has added much to the knowledge of meteorite craters. The two present many points in common and they supplement one another. At Henbury there is a much better development of the meteoric iron, while at Wabar the silica-glass predominates.
Silica-glass from the Libyan Desert
Authors: Clayton P. A. , Spencer L. J.
Published: December 2006

An occurrence of silica-glass in lumps up to 10 lb. in weight, smaller fragments being scattered over an area at least 80 by 25 kilometres, has been discovered in the course of the work of the Egyptian Desert Surveys. A Survey expedition under Mr. P. A. Clayton was sent out in December 1932 to work in the unexplored area of the Sand Sea and Gill Kebir, west of Major R. A. Bagnold's 1930 route, and found the glass on December 29, 1932.
Hydrocalumite (4CaO.Al2O3.12H2O), a new mineral from Scawt Hill, Co. Antrim
Authors: Tilley C. E.
Published: December 2006

In a further search for portlandite amongst the vug minerals of the Scawt Hill contact-zone, attention was drawn to some infillings containing a mineral which had not previously been observed. These infillings, which occur in a larnite-rock carrying melilitewollastonite aggregates of the hybrid zone of the contact, consist of afwillite, portlandite, ettringite, and aggregates of a mineral, the light-greenish colour of which was conspicuous.
On the occurrence of neptunite and eudialyte in quartzbearing syenites from Barnavave, Carlingford, Ireland
Authors: Nockolds S. R.
Published: December 2006

Some years ago the author gave a short description of a quartz-bearing syenite and its xenoliths occurring on the eastern side of Barnavave. The locality was revisited recently and more material wascollected, while another outcrop of syenite was discovered farther tothe north at locality 5.

The new material collected at the original locality is not very differentfrom that previously described. The syenite occurs as veins in lime-stone and, whereas all the previously described material was quartz-bearing, some of the syenite in very narrow veins is virtually free fromquartz. Again, certain specimens carry a fair amount of late-crystallizing wollastonite which may be replaced to a varying degree by pecto-lite.
An X-Ray examination of a sample of pure calcite and of solid-solution effects in some natural calcites
Authors: Andrews K. W.
Published: December 2006

In the course of the routine X-ray examination of a number of lowgrade iron ores in order to determine their constitution, it was observed that the calcite phase had varying interplanar spacings. Since these variations could have been due to differing solid-solution contents of other carbonates, further consideration was given to this point. The existence of these generally small amounts of solid solution is of some technological interest.

A sample of 'specpure' calcite, supplied by Messrs. Johnson, Matthey & Co. Ltd., was used to provide accurate lattice parameters and interplanar spacings for pure calcite.
Mineralogical applications of a two-crystal Weissenberg X-ray goniometer
Authors: Wooster W. A.
Published: December 2006

The study of minerals, using X-ray goniomcters in place of optical I instruments, has proceeded far in recent years. It is now a common practice among mineralogists and petrologists to confirm the nature of a given specimen by X-ray methods when there is some doubt about the identification by the older methods. The occurrence of pseudomorphs sometimes leads to misidentifications even in crystals of large size. If the material is cryptoerystalline it may be almost impossible to make an identification by optical methods. In such cases X-ray photographs may be of great assistance.
The aegirine-granulites of Glen Lui, Braemar, Aberdeenshire
Authors: McLachlan G. R.
Published: December 2006

In the explanation of sheet 65 of the Geological Survey of Scotland an outcrop of aegirine-granulites was described from Glen Lui, 1¼ miles SSE. of Derry Lodge. Brief descriptions of some of the rocks were given and it was suggested that they might be metamorphosed igneous rocks having distinct affinities with the borolanites of Assynt. Such a correlation, it was felt, would be of importance in assessing the age of metamorphism in the Central Highlands. Harker (1932) made the further suggestion that these rocks might originally have been a tuff which had subsequently become metamorphosed.
A serpentine mineral from Kennack Cove, Lizard, Cornwall
Authors: Midgley H. G.
Published: December 2006

A white soapy mineral which could not easily be identified in the hand-specimen was collected from a vein in the serpentine rock at Kennack Cove, Lizard, in April 1949. From a preliminary optical examination the mineral was thought to be saponite, and therefore of interest to clay mineralogists. Chemical analysis, X-ray, thermal, and optical investigations were carried out at the Building Research Station.
Some physical properties of raw and calcined flint
Authors: Weymouth J. H. , Williamson W. O.
Published: December 2006

Flint from the chalk of north-western Europe has long been an ingredient of ceramic 'bodies'. It is still widely used by British pottery manufacturers in glazed tries and in certain types of tableware. Continental manufacturers also have made some use of it.

Flint is more readily converted to cristobalite than are the coarsergrained varieties of quartzose silica. The presence of an adequate amount of cristobalite in the 'body' ensures that, at room-temperature, the glaze-film on the ware shall be under a compressive stress. Thus the development of 'crazing', i.e. of minute tension-fissures in the glaze, tends to be avoided.
A new occurrence of uvarovite from northern Karelia in Finland (with plate XV)
Authors: von Knorring Oleg
Published: December 2006

In 1929 Väiyrynen discovered a chalcopyrite-bearing pyrrhotine deposit at the village of Luikonlahti, 30 km. NW. of the Outokumpu mine. This occurrence is associated with a complex of serpentine, quartzites, phyllites, dolomites, and diopside-tremolite-roeks, together with penetrating granites, aplites, and pegmatites. The rock association thus closely resembles that of the Outokumpu ore-field.
New occurrences of duftite
Authors: Claringbull G. F.
Published: December 2006

During an examination of the mineral bayldonite, (Pb,Cu)7(AsO4)4(OH)2.H2O, for the purpose of obtaining standard X-ray powder data to compare with supposed single crystals of this species, it was found that a specimen purchased in 1948 as bayldonite from Ojuela mine, Mapimi, Durango, Mexico (B.M. 1948,267) gave a powder pattern related to those of members of the descloizite group and fairly close to but not identical with conichalcite, CuCaAsO4OH. It chanced that about the same time a specimen of a green botryoidal mineral from Brandy Gill, Caldbeek Fells, Cumberland, sent in by Mr. W. F. Davidson for determination was photographed and showed similar variations from the conichalcite pattern. Qualitative spectrographic comparison of the Mapimi and Brandy Gill materials with several conichalcites suggested that the differences in the powder photographs might be due to the presence of lead in the former.
On collophane in Thames gravel
Authors: Ellis S. E. , Claringbull G. F.
Published: December 2006

In mid-1949 the London Natural History Society set up a committee to investigate and record temporary geological sections in the London area. Among the earliest to be dealt with was the excavation in flood-plain gravel for the foundations of the Concert Hall for the Festival of Britain (1951). Samples of 100-200 grams were taken from two sandlentieles for heavy mineral investigation, and material from one of these, passing 60 mesh and washed by laevigation, yielded, on separation by means of a bromoform-benzene mixture of density about 2"73, an assemblage with abundant garnet, tourmaline, zircon, and kyanite, very occasional staurolite, cassiterite, and fluorite, and moderately abundant collophane.
The ‘superposition error’ in the micrometric analysis of rocks
Authors: Elliott R. B.
Published: December 2006

It is a well-known method in the measurement of birefringence to utilize a crystal's 'bevelled edge', on which appears a sequence of polarization colours, from that colour representing small relative retardation where the edge is thin, to a higher colour corresponding to the full thickness of the mineral in the microsection. In dolerites these bevelled edges on augites are extremely common and are very apparent between crossed nicols. In ordinary light, however, the majority of them are undiscernible and a grain appears to have uniform thickness over its entire area. The reason for the non-appearance of the bevelled edge in ordinary light is straightforward: the augites have excellent relief, that of the adjacent felspars is low; relief is a surface phenomena and independent of thickness, so that a thin edge of augite overlying felspar has the relief of augite, and the felspar is unnoticed.
X-ray investigation of bredigite
Authors: Douglas Audrey M. B.
Published: December 2006

The X-ray work described below has been done on crystals of bredigite obtained from two different sources, the natural mineral from Scawt Hill, County Antrim, and the synthetic mineral from spiegeleisen slags. Both types of material have been fully deseribed by Tilley and Vincent (1948). Their analysis shows that the slag mineral is a calcium orthosilicate in which Ca is partly replaced by Mg, Mn, and Ba, the extent of the replacement being represented by the formula (Cal.59Ba0.08Mg0.31Mn0.09)SiO4. Tilley and Vincent conclude that this orthorhombic (pseudo-hexagonal) phase is identical with the high-temperature form α' of pure Ca2SiO4, the existence of which was suggested by Bredig (1943a), and confirmed by TrSmel (1949) using a high-temperature powder camera. Bredig (1943a) also suggests, on the basis of a comparison of X-ray powder patterns, that the crystal structure of α'-Ca2SiO4 is similar to that of β-K2SO4. The present single-crystal work was originally undertaken in order to investigate the structure of α'-Ca2SiO4 more fully.
Hydrous micas
Authors: Brown George , Norrish Keith
Published: December 2006

Hydrous micas differ from normal micas in that they contain less potassium and more water. In the calculation of structural formulae from their chemical analyses, two methods have been used which rely on the following different assumptions:

1. As these minerals are often fine-grained and may contain adsorbed water, no reliance is placed on the value of H2O+ (water lost above 105° C.) as a measure of structural water. The water content is ignored and the structural formula is calculated on the basis of 20 oxygens plus 4 hydroxyls per structural unit. This method has been used by Hendricks and Ross and by Grim and Bradley.

2. The water which is recorded as H2O+ in the chemical analysis is assumed to represent hydroxyl groups in the aluminosilicate layers of the minerals. Thus, instead of having 20 oxygens and 4 hydroxyl ions per structural unit as in normal micas, formulae are derived which show less than 20 oxygens and more than 4 hydroxyls, the total oxygen plus hydroxyl remaining 24. This method has been used by Brammall, Leech, and Bannister.
A phase-contrast microscopic study of the surface structure of blende crystals (With Plates III and IV.)
Authors: Verma Ajit Ram
Published: December 2006

The surface structure of blende crystals from Joplin, Jasper County, Missouri, U.S.A., has been explored by the application of phase-contrast microscopy and light-profile microscopy. Attention has been specially directed to the small-scale features with thicknesses (or depths) of molecular dimensions.

Some growth features of special interest were observed. A large number of beautifully developed growth spirals were observed on the tetrahedral face of a blende crystal. These are in accord with the dislocation theory of Burton, Cabrera, and Frank. The high visibility of these growth spirals is possibly due to the preferential deposition of some impurity, or etching, which also gives a mottled appearance to the entire surface. In addition, an extensive microscopic structure has been observed on some crystal faces. Triangular growth terraces and markings are seen, both orientated parallel to the edges of the crystal. Some triangles, inverted with respect to the latter, have been explained on similar lines to the well-known ‘growth trigons’ on the octahedral faces of diamond as arising from imperfect dislocations.

An attempt has been made to explain the growth features in the light of known theories of crystal growth.
Determination of the composition of kalsilites by an X-ray method
Authors: Sahama Th. G. , Neuvonen K. J. , Hytönen Kai
Published: December 2006

Three new analyses of kalsilite are given, with optical and X-ray data; two (K/(K + Na) = 0·95. 0·98) are from rocks where it is closely associated with nepheline. An analysis of one of the nephelines is also given (K/(K + Na) = 0·31). The cell dimensions vary appreciably with sodium content, and the composition of kalsilite may be determined from the equation:

100 K/(K + Na) = 100−227·27(Δ 6·264),

where Δ is the difference, in degrees, between the diffraction angles 2ϑ for 102 and 101, using Cu-Kα radiation.
Manganese silicate minerals from Chikla, Bhandara District, India
Authors: Bilgrami S. A.
Published: December 2006

Blanfordite (a manganiferous aegirine), rhodonite, alurgite, manganophyllite, and piemontite are deseribed from a pegmatite that cuts a manganese ore band in the Sitasaongi mine, Chikla, Bhandara district, India. In addition, rhodonite and piemontite are described from gneiss and schist areas. Chemical analyses and optical properties of all these minerals are given and their possible origin suggested.
Cosalite and other lead sulpho-salts at Grainsgill, Carrock Fell, Caldbeck, Cumberland
Authors: Kingsbury Arthur W. G. , Hartley J.
Published: December 2006

Cosalite, aikinite, zinckenite, jamesonite, and boulangerite occur at Grainsgill; the first three minerals have not hitherto been recorded from Britain. The specimens probably come from a series of low-temperature quartz-carbonate veins, later than the original mineralization and also distinet from the east west copper-lead veins.
Pyrosmalite in the Broken Hill lode, New South Wales
Authors: Stillwell F. L. , McAndrew John
Published: December 2006

Pyrosmalite is a widespread, though very limited, constituent of the Broken Hill lode, and is formed by the hydration and chlorination of the manganeseiron silicates. It is altered in contact with galena and eventually disintegrates into a mat of very fine fibres. The pyrosmalite varies substantially in ratio of Mn/Fe, and two specimens from the rare vughs and fractures gave on analysis ratios of 1·96 and 0·71. The refractive indices decrease slightly with increasing amounts of manganese and water, with a simultaneous small increase in the unit-cell dimensions. The name pyrosmalite is retained for the mineral species in accord with its earlier usage and its recent limitation to the iron-rich variety of an isomorphous series is not endorsed.
Dickite from sandstones in northern England and North Wales
Authors: Smithson Frank , Brown George
Published: December 2006

The occurrence of dickite as a rock-forming mineral in sandstones of the Lower Carboniferous Series, the Millstone Grit, and the Middle Jurassic has been reported previously by the authors. In view of the paucity of data on this mineral, six samples were purified and examined optically, by staining tests, and by the X-ray powder method. In addition, a chemical analysis, a differential thermal analysis, and a thermal weight-loss curve were made on the purest sample. The investigations confirm the identity of the material.
The morphology of the Unter-Rupsroth montmorillonite
Authors: Nixon H. L. , Weir A. H.
Published: December 2006

Electron micrographs of Na-saturated Unter-Rupsroth montmorillonite show that many of the individual flakes, which are probably 10 Å. thick, have straight edges meeting in 120° angles. This is evidence in support of the pseudohexagonal structure of montmorillonite. Similar pictures were obtained with Lisaturated clay and with ‘Calgon’-dispersed material. The usefulness of electron microscopy for the study of clay mineral morphology depends upon the efficiency of dispersion and the details of the mounting techniques rather than the nature of the exchange cation or the particular dispersing agent employed.
Saponite from Allt Ribhein, Fiskavaig Bay, Skye
Authors: Mackenzie R. C.
Published: December 2006

This saponite, which is closely associated with zeolites such as stillbirth, heulandite, thomsonite, and gonnardite, occurs in vesicles in basalt. It has the composition: 1·02M+ (Mg5·84Mn0·01Al0·03Fe0·08) (Si6·99Al1·01)O20(OH)4, according to a new method for calculating the ionic formulae of smectites: this method also enables determination of the temperature at which all sorbed moisture is removed—in this instance about 800°C. The exchangeable cations are largely Ca2+. The chemical, thermal, and X-ray data are discussed with reference to other saponite samples. Electron-microscope examination showed a tendency to elongation in the direction of the α-axis. It is concluded that the saponite is of excellent purity and free from interstratification.
Further consideration of the crystal structure of kaolinite
Authors: Brindley G. W. , Nakahra M.
Published: December 2006

The layer structure of the kaolin mineral dickite has been shown to differ significantly from the idealized arrangement of regular tetrahedra and octahedra. Since the structure of kaolinite can be studied only by X-ray powder methods, it cannot be refined beyond the idealized arrangement. By applying the dickite type of layer structure to the ease of kaolinite, an explanation for the triclinic symmetry of kaolinite has been obtained, and also an improved agreement with the observed X-ray intensities.
The alteration of pyrochlore to columbite in carbonatites in Tanganyika (With Plates XX and XXI.)
Authors: James T. C. , McKie Duncan
Published: December 2006

The formation of columbite has been observed in two carbonatites in south-west Tanganyika where it is due to autometasomatism following the emplacement of the bodies. Disoriented aggregates of columbite crystallites are formed as pseudomorphs after eubo-octahedra of pyrochlore in sövite. This alteration is accompanied by the addition of Fe, conversion of amphibole and biotite in the sövite to a ferruginous tale. the formation of an iron-bearing carbonate, and the introduction of colloform silica: Ca and Na are lost in part. The general alteration of the sövite can be ascribed to the influx of iron-bearing solutions at relatively low temperature and high pressure.
Minium from Broken Hill, New South Wales
Authors: Skinner Brian J. , McBriar E. Maud
Published: December 2006

Minium occurs at Broken Hill, New South Wales, as pseudomorphs after cerussite, formed during fires in the mine. It is tetragonal with a = 8·824 Å. and c = 6·564 Å.; sp. gr. 8·2 + 0·2. The Broken Hill minium appears identical in physical properties with synthetic Pb3O4 described by other workers.
A thermal and X-ray investigation of scarbroite
Authors: Duffin W. J. , Goodyear J.
Published: December 2006

Scarbroite, a fine-grained but compact deposit obtained from fissures in the sandstone on the north Yorkshire coast, is shown by chemical analysis to have an idealized formula Al2(CO3)3·12Al(OH)3. X-ray and electron diffraction data indicate a triclinic cell with a 9·94 Å., b 14·88 Å., c 26·47 Å., α 98·7°, β 96·5°, and γ 89·0°. A layer structure consisting of gibbsite-type sheets of Al(OH)3 and sheets of Al2(CO3)3 is proposed. The structure is stable from room temperature to about 125° C.
Vaterite from Ballycraigy, Larne, Northern Ireland
Authors: McConnell J. D. C.
Published: December 2006

Vaterite, the third unstable polymorph of CaCO3, is recognized by optical and X-ray powder techniques as a major constituent in a carbonated calcium silicate hydrogel complex formed from larnite at Ballycraigy, Lame, Northern Ireland. Re-indexed X-ray powder data obtained on synthetic vaterite are provided indicating a hexagonal unit cell with dimensions a = 7·135 Å. and c = 8·524 Å., Z = 6CaCO3. The re-indexing is endorsed by the results of electron diffraction study of synthetic vaterite. Vaterite is shown to correspond to the hypothetical CaCO3 member of the bastnäsite-synchisite mineral series on the basis of extrapolated cell dimensions and optical properties. A structural scheme for vaterite is proposed in which Ca layers replace the CeF layers in bastnäsite, and near-vertical CO3 groups are present. The stability relations of natural vaterite are discussed and comment made on the recent observation of vaterite, in a like environment, in carbonated cements and mortars.
Tacharanite and other hydrated calcium silicates from Portree, Isle of Skye
Authors: Sweet Jessie M. , Bothwell D. I. , Williams D. L.
Published: December 2006

The vesicles of an olivine-dolerite that occurs as a small outcrop near Portree in the Isle of Skye contain zeolites and some hydrated calcium silicates. These latter include tobermorite, xonotlite, gyrolite, and what is presumed to be a new member of the tobermorite group. An attempt is made to account for the sequence of crystallization of the minerals.
Contribution to the study of ore minerals in some igneous rocks from Assynt
Authors: Stumpfl E. F.
Published: December 2006

The parageneses of opaque minerals in three Assynt rocks are described. A biotite-diorite dyke-rock of Lewisian age is characterized by a primary igneous assemblage of Fe-Ti oxides, pyrrhotine, and pentlandite. Effects of metamorphism are recognized, particularly in the oxidation of ilmenite in a Lewisian epidiorite dyke-rock. Cromaltite contains a primary assemblage of oxide minerals together with a later hydrothermal sulphide assemblage. Evidence from the opaque minerals cannot be reconciled with a theory of limestone assimilation. The correlation of the distribution of Co, Ni, and Cu in the rocks with the opaque minerals present is considered.
The Redfields meteorite—A unique iron from Western Australia
Authors: De Laeter J. R. , McCall G. J. H. , Reed S. J. B.
Published: December 2006

A metallic mass brought to the Western Australian Museum from the Wongan Hills district N.W. of Perth has been identified as an iron meteorite of unique type. It has graphite inclusions about I mm across distributed throughout the metal giving a ‘raisin bread’ appearance. Its nickel content (6·65 %) is comparable with that of coarse octahedrites but the kamacite grain structure is anomalous. Its gallium, germanium, and nickel contents place it close to, but outside, Wasson's chemical group IIb. Taenite is absent and troilite is rare. Neumann bands in the kamacite are distorted and the kamacite has flowed around large schreibersite inclusions. The latter have an exceptionally low nickel content (7·0 %) and probably formed at an unusually high temperature. The kamacite contains more phosphorus than normal iron meteorites, and small schreibersite grains in the kamacite are relatively nickel-poor (22 %). The unusual structure of this iron is thought to be due to one or more of the factors high carbon, high phosphorus, and relatively rapid cooling.
The crystal chemistry of the amphiboles. I: Refinement of the Crystal structure of ferrotschermakite
Authors: Hawthorne F. C. , Grundy H. D.
Published: December 2006

Three-dimensional counter-diffractometer data and a full-matrix least-squares method have been used to refine the crystal structure of a ferrotschermakite in the space group C2/m. The chemical composition of the amphibole is with cell parameters a 9·8179(7), b 18·1060(14), c 5·3314(5) Å, and β 105·00(I). Cation site-occupancies were initially assigned by ionic-radius criteria and refined with the constraint that the sum total of the site-occupancies be equal to the chemical analysis.

The A-site shows positional and substitutional disorder and can be better represented by two sites, one on the mirror plane and the other on the 2-fold axis.

Unit weights were used throughout the refinement and the final R-factor for 1207 observed nonequivalent reflections was 4·5 %.
A transmission electron microscope and X-ray diffraction study of muscovite and chlorite
Authors: Oertel G. , Curtis C. D. , Phakey P. P.
Published: December 2006

Single-crystal diffraction patterns produced by transmitted radiation, both X-rays and electrons, reveal varying degrees of disorder and long-range order in common phyllosilicates from several different rock types. The transmission electron micrographs and their selected-area diffraction patterns demonstrate the presence of numerous stacking faults parallel to (001) of muscovite and chlorite. Individual stacking faults can be recognized by the diffraction-contrast fringe patterns they cause, and partial dislocations can be seen where such faults terminate inside a crystal. Long-range order of muscovite explains what seemed to be spurious, high ‘background’ levels that are sometimes encountered in the analysis of rock fabrics by transmitted X-rays.
Irish osumilite
Authors: Chinner G. A. , Dixon P. D.
Published: December 2006

Osumilite of composition closely approaching that of the K,Mg end-member occurs as a significant constituent of tridymite-enstatite-feldspar-cordierite-hematite-magnetite buchites at the contact of the Tertiary dolerite plug of Tieveragh, Co. Antrim; it is proposed that the mineral be known as osumilite-(K,Mg). Despite laboratory demonstration of the metastability of osumilite-(K,Mg) over a wide pressure-temperature range, the unaltered character and apparently constant composition of the Tieveragh osumilites raises the possibility of an osumilite stability field within the system K2O-MgO-FeO-Al2O3-SiO2.
The Barea, Dyarrl Island, and Emery meteorites, and a review of the mesosiderites
Authors: Mason Brian , Jarosewich E.
Published: December 2006

Barea and Emery are typical mesosiderites, whereas Dyarrl Island is unique in having the lowest metal content and the highest FeO/(FeO + MgO) ratio of any meteorite of this class. Average pyroxene compositions have been determined for the individual mesosiderites, and show a sequential increase in FeSiO3 content, ranging from a mean of 21 mole % for Veramin to 45 mole % for Dyarrl Island. Steinbach may possibly be classed as a mesosiderite, since its mineralogy is identical except for the absence of plagioclase. Dalgaranga and Mt. Padbury may be a paired fall. The chemical and mineralogical composition of the silicate material of the mesosiderites is similar to, but not identical with the howardites; the overall range of composition is greater in the mesosiderites.