bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mid–Cretaceous Episodic Magmatism and Tin Mineralization in Khingan‐Okhotsk Volcano–Plutonic Belt, Far East Russia
Authors: SATO Kohei , VRUBLEVSKY Anatoly A. , RODIONOV Sergei M. , ROMANOVSKY Nikolai P. , NEDACHI Munetomo 
Published: November 2008

Abstract: Age of magmatism and tin mineralization in the Khingan‐Okhotsk volcano–plutonic belt, including the Khingan, Badzhal and Komsomolsk tin fields, were reviewed in terms of tectonic history of the continental margin of East Asia. This belt consists mainly of felsic volcanic rocks and granitoids of the reduced type, being free of remarkable geomagnetic anomaly, in contrast with the northern Sikhote‐Alin volcano–plutonic belt dominated by oxidized‐type rocks and gold mineralization. The northern end of the Khingan‐Okhotsk belt near the Sea of Okhotsk, accompanied by positive geomagnetic anomalies, may have been overprinted by magmatism of the Sikhote‐Alin belt.Tin–associated magmatism in the Khingan‐Okhotsk belt extending over 400 km occurred episodically in a short period (9510 Ma) in the middle Cretaceous time, which is coeval with the accretion of the Kiselevka‐Manoma complex, the youngest accretionary wedge in the eastern margin of the Khingan‐Okhotsk accretionary terranes. The episodic magmatism is in contrast with the Cretaceous‐Paleogene long–lasted magmatism in Sikhote–Alin, indicating the two belts are essentially different arcs, rather than juxtaposed arcs derived from a single arc. The tin‐associated magmatism may have been caused by the subduction of a young and hot back‐arc basin, which is inferred from oceanic plate stratigraphy of the coeval accre‐tionary complex and its heavy mineral assemblage of immature volcanic arc provenance. The subduction of the young basin may have resulted in dominance of the reduced‐type felsic magmas due to incorporation of carbonaceous sediments within the accretionary complex near the trench. Subsequently, the back‐arc basin may have been closed by the oblique collision of the accretionary terranes in Sikhote–Alin, which was subjected to the Late Cretaceous to Paleogene magmatism related to another younger subduction system. These processes could have proceeded under transpressional tectonic regime due to oblique subduction of the paleo‐Pacific plates under Eurasian continent.
Sulfur Content and Isotopic Ratio of Cambro‐Ordovician Carbonate Rocks from South Korea: A Possible Source for Mesozoic Magmatic‐hydrothermal Ore Sulfur
Authors: ISHIHARA Shunso , JIN Myung–Shik , KAJIWARA Yoshimichi 
Published: November 2008

Abstract: Carbonate rocks of Cambrian (18 samples) and lower‐middle Ordovician (11 samples) ages from South Korea were analyzed for sulfur contents of structurally substituted sulfate (SSS) and sulfides and their δ34S values. The δ34S values of SSS ranging from +25.9 to +45.2 permil, are averaged as +33.6 and +33.5 permil for the Cambrian and Ordovician rocks, respectively, which indicate high δ34S values of the Cambro‐Ordovician seawater. The SSS contents in the carbonate rocks are low being 2.9 to 17.3 ppm S (averaged as 7.0 ppm S). Sulfide sulfur, on the contrary, is much abundant containing 3 to 1,880 ppm S and the δ34S values range widely between –17.6 and +31.1 permil. Sulfide sulfur of the studied rocks excluding impure carbonates has an average content of 187 ppm S and δ34S value of +12.8 permil (n=24). The estimated δ34S (sulfate–sulfide) values, which range from 13.8 to 25.4 permil in general with a few exceptions from 36.5 up to 52.3 permil for some impure carbonates, may provide evidence for the persistent oceanic anoxia with its temporary recovery during the Cambro‐Ordovician time.The SSS and sulfide sulfurs have often higher δ34S values than the Mesozoic‐Cenozoic ore sulfur (Ishihara et al., 2000). Since carbonate rocks are very reactive with circulating hydrothermal ore solution, high δ34S values of the Korean ore deposits might be caused to some extent by 34S enrichment from the host carbonates, resulting in the low SSS contents observed.
Role of Iron(III) and Aluminum Hydroxides in Concentration/reduction of Au(III) Complexes
Authors: UCHIDA Akiko , YOKOYAMA Takushi , MOTOMURA Yoshinobu , MIYAZAKI Akane , OKAUE Yoshihiro , WATANABE Koichiro , IZAWA Eiji 
Published: November 2008

Abstract: The adsorption of gold on iron(III) and aluminum hydroxides from solutions containing Au(III) complexes has been studied as a function of pH and chloride concentration at 30C. Iron(III) hydroxide was more effective in adsorbing gold from solution than aluminum hydroxide. However, both hydroxides controlled the behavior of Au(III) complex with very similar manner. The most effective gold adsorption occurred in aqueous solution with near neutral pH and low Cl concentration. In this solution condition, Au(III) complexes were mainly dissolved as AuCl2(OH)2‐ and AuCl(OH)3‐, and the surface charge for both hydroxides was positive. In addition, the adsorbed Au(III) complexes were spontaneously reduced to elemental gold in spite of the absence of a specific reducing agent.The results of this study suggest that adsorption and spontaneous reduction of gold complexes on the surface of hydrous metal oxides with positive charge play an important role in gold precipitation in subsurface environment.
Geology and Genesis of the Ta'ergou Skarn ‐ Quartz Vein Tungsten Deposit in the North Qilian Caledonian Orogenic Belt, Northwest China
Authors: Zhang Zuoheng , Mao Jingwen , Yang Jianmin , Wang Zhiliang , Zhang Zhaochong 
Published: November 2008

Abstract. The Ta'ergou tungsten deposit in Gansu province, northwestern China, is located in the western part of the North Qilian Caledonian orogen, and consists of scheelite skarn bodies and wolframite quartz veins. The tungsten‐bearing skarn developed by the replacement of carbonate layers intercalated in the Precambrian schist and amphibolite whereas wolframite‐quartz ore veins developed along a group of fractures that cut through horizontal skarns. The Ta'ergou tungsten deposit is genetically related to the Caledonian Yeniutan granodiorite intrusion and occurs ca. 500 m wide in the exo‐contact zone 300 ∼ 500 m apart from the intrusion. The granodiorite displays a lower grade of differentiation, low content of SiO2 and high contents of mafic components.There are three types of fluid inclusions in the wolframite‐quartz vein systems, i. e. aqueous, CO2‐H2O and CO2‐rich. The homogenization temperature of aqueous inclusion ranges from 140 to 380d̀C and their salinities from 6.4 to 17.4 equivalent wt% NaCl. Laser Raman spectroscopy shows that the inclusions contain a relatively high content of CO2. The δ34S values of skarn type sulfides range from +8.1 to +12.7 per mil and those of quartz vein sulfides from +9.3 to +14.9 per mil, similar to sulfides of the granodiorite with from +6.0 to +11.7 per mil. The δ18O values of quartz are between +10.5 and +13.3 per mil and those of wolframite between +3.4 and +5.1 per mil. The δ18O water values of ore forming fluids range from +0.6 to +6.4 per mil and suggest the mixture of magmatic fluids with meteoric water formed the ore‐forming fluids.It has been proved that Precambrian strata in the west sector of North Qilian region are enriched in tungsten. We propose the strata were remelted to be tungsten‐granitoid during subduction. The polymetallic tungsten was gradually accumulated into the roof pendants of the granite intrusion by fractional crystallization and then was deposited by hydrothermal fluids during metasomatism and infilling along fractures. On the other hand, the granite intrusion also acted as “heating machine” to make hydrothermal fluids leach out the metals from Precambrian strata and these metals joined the ore‐forming hydrothermal system.
Chemical Composition of Ores from the Takara Volcanogenic Massive Sulfide Deposit, Central Japan
Authors: Yakushi Daigoro , Enjoji Mamoru 
Published: November 2008

Abstract. The Takara volcanogenic massive sulfide (VMS) deposit occurs in Miocene formation of the Misaka Mountain, the South Fossa Magna region, central Japan. The tectonic setting of the Misaka Mountain is reconstructed to be a part of the paleo Izu‐Ogasawara arc which collided with the Honshu arc and to form accreted body in the present position. The Takara deposit, therefore, is considered to have formed in the paleo Izu‐Ogasawara arc.The ores from the Takara deposit are classified into pyrite‐type ore, chalcopyrite‐type ore, and sphalerite‐type ore on the basis of chemical composition and their mineral assemblages. Some pyrite‐type ores are characterized by their high Au content. The Au content is hardly recognized in the chalcopyrite‐type and sphalerite‐type ores.The ores from the Takara deposit have intermediate bulk chemical composition between those from the Besshi‐type deposits and the Kuroko‐type deposits that are two representative VMS deposits. However, the bulk chemical composition is closer to that from the Kuroko‐type deposits. And moreover, chemical composition of tetrahedrite‐tennantite series minerals (tetrahedrite) is similar to that from the Kuroko‐type deposits. The bulk chemical composition (Cu, Zn, Co, Pb, and As contents) of ores is affected by the chemical composition of volcanic rocks associated with VMS deposits.
Gpnmb is a melanoblast‐expressed, MITF‐dependent gene
Authors: Loftus Stacie K. , Antonellis Anthony , Matera Ivana , Renaud Gabriel , Baxter Laura L. , Reid Duncan , Wolfsberg Tyra G. , Chen Yidong , Wang ChenWei ,   NISC Comparative Sequencing Program, Prasad Megana K. , Bessling Seneca L. , McCallion Andrew S. , Green Eric D. , Bennett Dorothy C. , Pavan William J. 
Published: November 2008

SummaryExpression profile analysis clusters Gpnmb with known pigment genes, Tyrp1, Dct, and Si. During development, Gpnmb is expressed in a pattern similar to Mitf, Dct and Si with expression vastly reduced in Mitf mutant animals. Unlike Dct and Si, Gpnmb remains expressed in a discrete population of caudal melanoblasts in Sox10‐deficient embryos. To understand the transcriptional regulation of Gpnmb we performed a whole genome annotation of 2,460,048 consensus MITF binding sites, and cross‐referenced this with evolutionarily conserved genomic sequences at the GPNMB locus. One conserved element, GPNMB‐MCS3, contained two MITF consensus sites, significantly increased luciferase activity in melanocytes and was sufficient to drive expression in melanoblasts in vivo. Deletion of the 5′‐most MITF consensus site dramatically reduced enhancer activity indicating a significant role for this site in Gpnmb transcriptional regulation. Future analysis of the Gpnmb locus will provide insight into the transcriptional regulation of melanocytes, and Gpnmb expression can be used as a marker for analyzing melanocyte development and disease progression.
Stem cell factor induces ERM proteins phosphorylation through PI3K activation to mediate melanocyte proliferation and migration
Authors: Jeon Songhee , Kim Nan‐Hyung , Kim Ji‐Young , Lee Ai‐Young 
Published: November 2008

SummaryStem cell factor (SCF) activates a variety of signals associated with stimulation of proliferation, differentiation, migration, and survival in melanocytes. However, the molecular mechanisms by which SCF and its receptor Kit activates these signaling pathways simultaneously and independently are still poorly defined. Here, we examined whether SCF induces ezrin/radixin/moesin (ERM) proteins phosphorylation as a downstream target of PI3K in melanocytes. ERM proteins are cross‐linkers between the plasma membrane and the actin cytoskeleton and are activated by phosphorylation of a C‐terminal threonine residue. Our results demonstrated that SCF‐induced ERM proteins phosphorylation on threonine residue and Rac1 activation in cultured normal human melanocytes through the activation of PI3K. The functional role of phosphorylated‐ERM proteins was examined using melanocytes infected with adenovirus carrying a dominant negative mutant (Ala‐558, TA) or wild type of moesin. In the TA moesin‐overexpressing melanocytes, SCF‐induced cell proliferation and migration were inhibited. Thus, our results indicate that phosphorylation of ERM proteins plays an important role in the regulation of SCF‐induced melanocyte proliferation and migration.
Positive crosstalk between ERK and p38 in melanoma stimulates migration and in vivo proliferation
Authors: Estrada Yeriel , Dong Jianli , Ossowski Liliana 
Published: November 2008

SummaryMelanoma is one of the most therapy‐resistant cancers. Activating mutations in BRAF and NRAS are the source of extracellular signal regulated protein kinase (ERK) pathway activation. We show that melanoma cell lines, originating in different metastatic sites, with BRAF or NRAS mutations, in addition to active mitogen activated protein kinase (MAPK)–ERK, also have highly activated stress activated protein kinase (SAPK)‐p38. This is in direct contrast to carcinoma cells in which the activity of the two kinases appears to be mutually exclusive; high level of p38 activity inhibits, through a negative feedback, ERK activity and prevents tumorigenesis. Melanomas are insensitive to ERK inhibition by p38 and utilize p38‐signaling pathway for migration and growth in vivo. We found a positive functional loop linking the high ERK activity to surface expression of αVβ3‐integrin. This integrin, by interacting with vitronectin, induces p38 activity and increases IL‐8 production, enhancing cell migration. Because the negative loop from p38 to ERK is lost, the two kinases can remain simultaneously activated. Inhibition of ERK and p38 activities is more effective in blocking in vivo growth than inhibition of each kinase individually. Future therapies might have to consider targeting of both pathways.
Specific Detection of Viable
Legionella
Cells by Combined Use of Photoactivated Ethidium Monoazide and PCR/Real-Time PCR
Authors: Chang Bin , Sugiyama Kanji , Taguri Toshitsugu , Amemura-Maekawa Junko , Kura Fumiaki , Watanabe Haruo 
Published: November 2008

ABSTRACT

Legionella
organisms are prevalent in manmade water systems and cause legionellosis in humans. A rapid detection method for viable
Legionella
cells combining ethidium monoazide (EMA) and PCR/real-time PCR was assessed. EMA could specifically intercalate and cleave the genomic DNA of heat- and chlorine-treated dead
Legionella
cells. The EMA-PCR assay clearly showed an amplified fragment specific for
Legionella
DNA from viable cells, but it could not do so for DNA from dead cells. The number of EMA-treated dead
Legionella
cells estimated by real-time PCR exhibited a 10
4
- to 10
5
-fold decrease compared to the number of dead
Legionella
cells without EMA treatment. Conversely, no significant difference in the numbers of EMA-treated and untreated viable
Legionella
cells was detected by the real-time PCR assay. The combined assay was also confirmed to be useful for specific detection of culturable
Legionella
cells from water samples obtained from spas. Therefore, the combined use of EMA and PCR/real-time PCR detects viable
Legionella
cells rapidly and specifically and may be useful in environmental surveillance for
Legionella
.
Biodiversity of Thermophilic Prokaryotes with Hydrolytic Activities in Hot Springs of Uzon Caldera, Kamchatka (Russia)
Authors: Kublanov Ilya V. , Perevalova Anna A. , Slobodkina Galina B. , Lebedinsky Aleksander V. , Bidzhieva Salima K. , Kolganova Tatyana V. , Kaliberda Elena N. , Rumsh Lev D. , Haertlé Thomas , Bonch-Osmolovskaya Elizaveta A. 
Published: November 2008

ABSTRACTSamples of water from the hot springs of Uzon Caldera with temperatures from 68 to 87°C and pHs of 4.1 to 7.0, supplemented with proteinaceous (albumin, casein, or α- or β-keratin) or carbohydrate (cellulose, carboxymethyl cellulose, chitin, or agarose) biological polymers, were filled with thermal water and incubated at the same sites, with the contents of the tubes freely accessible to the hydrothermal fluid. As a result, several enrichment cultures growing in situ on different polymeric substrates were obtained. Denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA gene fragments obtained after PCR withBacteria-specific primers showed that the bacterial communities developing on carbohydrates included the generaCaldicellulosiruptorandDictyoglomusand that those developing on proteins contained members of theThermotogalesorder. DGGE analysis performed after PCR withArchaea- andCrenarchaeota-specific primers showed that archaea related to uncultured environmental clones, particularly those of theCrenarchaeotaphylum, were present in both carbohydrate- and protein-degrading communities. Five isolates obtained from in situ enrichments or corresponding natural samples of water and sediments represented the bacterial generaDictyoglomusandCaldanaerobacteras well as new archaea of theCrenarchaeotaphylum. Thus, in situ enrichment and consequent isolation showed the diversity of thermophilic prokaryotes competing for biopolymers in microbial communities of terrestrial hot springs.
Improved Thermostability and Acetic Acid Tolerance of
Escherichia coli
via Directed Evolution of Homoserine
o
-Succinyltransferase
Authors: Mordukhova Elena A. , Lee Hee-Soon , Pan Jae-Gu 
Published: November 2008

ABSTRACT

In
Escherichia coli
, growth is limited at elevated temperatures mainly because of the instability of a single enzyme, homoserine
o
-succinyltransferase (MetA), the first enzyme in the methionine biosynthesis pathway. The
metA
gene from the thermophile
Geobacillus kaustophilus
cloned into the
E. coli
chromosome was found to enhance the growth of the host strain at elevated temperature (44°C), thus confirming the limited growth of
E. coli
due to MetA instability. In order to improve
E. coli
growth at higher temperatures, we used random mutagenesis to obtain a thermostable MetA

E. coli

protein. Sequencing of the thermotolerant mutant showed five amino acid substitutions: S61T, E213V, I229T, N267D, and N271K. An
E. coli
strain with the mutated
metA
gene chromosomally inserted showed accelerated growth over a temperature range of 34 to 44°C. We used the site-directed
metA
mutants to identify two amino acid residues responsible for the sensitivity of MetA

E. coli

to both heat and acids. Replacement of isoleucine 229 with threonine and asparagine 267 with aspartic acid stabilized the protein. The thermostable MetA

E. coli

enzymes showed less aggregation in vivo at higher temperature, as well as upon acetic acid treatment. The data presented here are the first to show improved
E. coli
growth at higher temperatures solely due to MetA stabilization and provide new knowledge for designing
E. coli
strains that grow at higher temperatures, thus reducing the cooling cost of bioprocesses.
Binding Specificity of the Lantibiotic-Binding Immunity Protein NukH
Authors: Okuda Ken-ichi , Yanagihara Sae , Shioya Kouki , Harada Yoshitaka , Nagao Jun-ichi , Aso Yuji , Zendo Takeshi , Nakayama Jiro , Sonomoto Kenji 
Published: November 2008

ABSTRACT

NukH is a lantibiotic-binding immunity protein that shows strong binding activity against type A(II) lantibiotics. In this study, the binding specificity of NukH was analyzed by using derivatives of nukacin ISK-1, which is a type A(II) lantibiotic produced by
Staphylococcus warneri
ISK-1. Interactions between cells of
Lactococcus lactis
transformants expressing
nukH
and nukacin ISK-1 derivatives were analyzed by using a quantitative peptide-binding assay. Differences in the cell-binding rates of each nukacin ISK-1 derivative suggested that three lysine residues at positions 1 to 3 of nukacin ISK-1 contribute to the effective binding of nukacin ISK-1 to
nukH
-expressing cells. The binding levels of mutants with lanthionine and dehydrobutyrine substitutions (S11A nukacin
4-27
and T24A nukacin
4-27
, respectively) to
nukH
-expressing cells were considerably lower than those of nukacin
4-27
, suggesting that unusual amino acids play a decisive role in NukH recognition. Additionally, it was suggested that T9A nukacin
4-27
, a mutant with a 3-methyllanthionine substitution, binds to NukH via an intermolecular disulfide bond after it is weakly recognized by NukH. We succeeded in the detection of specific type A(II) lantibiotics from the culture supernatants of various bacteriocin producers by using the binding specificity of
nukH
-expressing cells.
Novel Family of Carbohydrate Esterases, Based on Identification of the
Hypocrea jecorina
Acetyl Esterase Gene
Authors: Li Xin-Liang , Skory Christopher D. , Cotta Michael A. , Puchart Vladimir , Biely Peter 
Published: November 2008

ABSTRACT

Plant cell walls have been shown to contain acetyl groups in hemicelluloses and pectin. The gene
aes1
, encoding the acetyl esterase (Aes1) of
Hypocrea jecorina
, was identified by amino-terminal sequencing, peptide mass spectrometry, and genomic sequence analyses. The coded polypeptide had 348 amino acid residues with the first 19 serving as a secretion signal peptide. The calculated molecular mass and isoelectric point of the secreted enzyme were 37,088 Da and pH 5.89, respectively. No significant homology was found between the predicated Aes1 and carbohydrate esterases of known families, but putative
aes1
orthologs were found in genomes of many fungi and bacteria that produce cell wall-degrading enzymes. The
aes1
transcript levels were high when the fungal cells were induced with sophorose, cellulose, oat spelt xylan, lactose, and arabinose. The recombinant Aes1 produced by
H. jecorina
transformed with
aes1
under the cellobiohydrolase I promoter displayed properties similar to those reported for the native enzyme. The enzyme hydrolyzed acetate ester bond specifically. Using 4-nitrophenyl acetate as substrate, the activity of the recombinant enzyme was enhanced by
d
-xylose,
d
-glucose, cellobiose,
d
-galactose, and xylooligosaccharides but not by arabinose, mannose, or lactose. With the use of 4-nitrophenyl-β-
d
-xylopyranoside monoacetate as substrate in a β-xylosidase-coupled assay, Aes1 hydrolyzed positions 3 and 4 with the same efficiency while the
H. jecorina
acetylxylan esterase 1 exclusively deacetylated the position 2 acetyl group. Aes1 was capable of transacetylating methylxyloside in aqueous solution. The data presented demonstrate that Aes1 and other homologous microbial proteins may represent a new family of esterases for lignocellulose biodegradation.
Isolation and Characterization of Methicillin-Resistant
Staphylococcus aureus
Strains from Louisiana Retail Meats
Authors: Pu Shuaihua , Han Feifei , Ge Beilei 
Published: November 2008

ABSTRACT

We investigated the prevalence of
Staphylococcus aureus
and methicillin-resistant
S. aureus
(MRSA) in 120 retail meat samples from 30 grocery stores in Baton Rouge, LA.
S. aureus
strains were recovered from 45.6% of pork samples and 20% of beef samples, whereas MRSA strains were isolated from six meat samples (five pork samples and one beef sample). The MRSA isolates were of two strain types (clones), one harboring Panton-Valentine leucocidin and belonging to pulsed-field gel electrophoresis type USA300 and the other one belonging to USA100.