Major and trace element and multiple sulfur isotope composition of sulfides from the Paleoproterozoic Surda copper deposit, Singhbhum Shear Zone, India: Implications for the mineralization processes

The present study combines major and trace element composition, and sulfur (S) isotope data of pyrite and chacopyrite from the Surda copper sulfide deposit in the Singhbhum Shear Zone, the most important copper and uranium producing belt (Singhbhum Cu-U Belt) in India. Three textural and compositional types of both pyrite and chalcopyrite were distinguished; unzoned to partially zoned Pyrite IA with high Co (up to 54900 ppm) and low Ni content is earliest, followed by oscillatory zoned Pyrite IB with high As (up to 25600 ppm) and Co (up to 46800 ppm), bothoccurring in pyrite I + chalcopyrite I + pyrrhotite + magnetite + apatite vein; Cobaltite-type substitution (Fe1-xCox)(S1-xAsx)2 is suggested for Pyrite IB. Gold occurs in Pyrite I as minor “invisible” gold and as electrum inclusions. It also occurs along with Cu, Mn, Ni, Hg, Ag, Pb, Sb, Zn, Ce, Y, U, and Th in micro-fractures that transgress the primary zoning pattern defined by As, Co, and Ni in Pyrite IB. The early inclusion-rich chalcopyrite generation (Chalcopyrite I) contains high concentration of Zn and Se, and minor to trace amounts of Co, Ni, Hg, Pb, Sb, Te, and Bi, appeared in between Pyrite I and II.Low Co, high Ni (up to 37700 ppm) content Pyrite II, and inclusion-free Chalcopyrite II enriched in Co, Ni, Hg, Bi, Mn, Ag, Sb, V, and Pb are cogenetic, and occurring in pyrite II + pyrrhotite + pentlandite + chalcopyrite II ± violarite vein. Low Co and Ni containing Pyrite III + Chalcopyrite III occur mainly as disseminated grains. The relative timing of formation of Pyrite II + Chalcopyrite II with PyriteIII + Chalcopyrite III remains uncertain. Pyrite + chalcopyrite textures indicate that all pyrite + chalcopyrite formed at some time prior to the end of deformation and metamorphism. Both in situ and mineral separates of all pyrite types and associated chalcopyrite yield a narrow range of positive δ34S values (between +3.8 to +6.9 ‰) suggesting sulfur being derived from a similar source. Consistent positive δ34S values and other circumstantial evidence indicate that most sulfur was derived from seawater sulfate or modified seawater (brine/evaporite). Δ33S values revealed mass dependent fractionation (MDF) signature. It is proposed that incorporation of MDF sulfur of the mineralization event in Paleoproterozoic Singhbhum Cu-U Belt took place after the great oxidation event. The high Se concentrations (260 to 400 ppm) and ∑Se/∑S ratios for both Pyrite I and II from Surda deposit (4.4 to 5.7 x10-4) suggest a low temperature of the Cu–rich ores (250°-350°C), and precipitation from a metalliferous fluid with a high ∑Se/∑S ratio (10-4 to 10-3) consistent with igneous input of these elements

Calcium Homeostasis in Myogenic Differentiation Factor 1 (MyoD)-Transformed, Virally-Transduced, Skin-Derived Equine Myotubes

Dysfunctional skeletal muscle calcium homeostasis plays a central role in the pathophysiology of several human and animal skeletal muscle disorders, in particular, genetic disorders associated with ryanodine receptor 1 (RYR1) mutations, such as malignant hyperthermia, central core disease, multiminicore disease and certain centronuclear myopathies. In addition, aberrant skeletal muscle calcium handling is believed to play a pivotal role in the highly prevalent disorder of Thoroughbred racehorses, known as Recurrent Exertional Rhabdomyolysis. Traditionally, such defects were studied in human and equine subjects by examining the contractile responses of biopsied muscle strips exposed to caffeine, a potent RYR1 agonist. However, this test is not widely available and, due to its invasive nature, is potentially less suitable for valuable animals in training or in the human paediatric setting. Furthermore, increasingly, RYR1 gene polymorphisms (of unknown pathogenicity and significance) are being identified through next generation sequencing projects. Consequently, we have investigated a less invasive test that can be used to study calcium homeostasis in cultured, skin-derived fibroblasts that are converted to the muscle lineage by viral transduction with a MyoD (myogenic differentiation 1) transgene. Similar models have been utilised to examine calcium homeostasis in human patient cells, however, to date, there has been no detailed assessment of the cells’ calcium homeostasis, and in particular, the responses to agonists and antagonists of RYR1. Here we describe experiments conducted to assess calcium handling of the cells and examine responses to treatment with dantrolene, a drug commonly used for prophylaxis of recurrent exertional rhabdomyolysis in horses and malignant hyperthermia in humans

The Evolution of Compact Binary Star Systems

We review the formation and evolution of compact binary stars consisting of white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and BHs are thought to be the primary astrophysical sources of gravitational waves (GWs) within the frequency band of ground-based detectors, while compact binaries of WDs are important sources of GWs at lower frequencies to be covered by space interferometers (LISA). Major uncertainties in the current understanding of properties of NSs and BHs most relevant to the GW studies are discussed, including the treatment of the natal kicks which compact stellar remnants acquire during the core collapse of massive stars and the common envelope phase of binary evolution. We discuss the coalescence rates of binary NSs and BHs and prospects for their detections, the formation and evolution of binary WDs and their observational manifestations. Special attention is given to AM CVn-stars -- compact binaries in which the Roche lobe is filled by another WD or a low-mass partially degenerate helium-star, as these stars are thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure

The expression of HSP60 and HSP10 in large bowel carcinomas with lymph node metastase

BACKGROUND: The involvement of Heat Shock Proteins (HSP) in cancer development and progression is a widely debated topic. The objective of the present study was to evaluate the presence and expression of HSP60 and HSP10 in a series of large bowel carcinomas and locoregional lymph nodes with and without metastases. METHODS: 82 Astler and Coller's stage C2 colorectal cancers, of which 48 well-differentiated and 34 poorly-differentiated, were selected along with 661 lymph nodes, including 372 with metastases and 289 with reactive hyperplasia only, from the same tumours. Primitive tumours and both metastatic and reactive lymph nodes were studied; specifically, three different compartments of the lymph nodes, secondary follicle, paracortex and medullary sinus, were also analysed. An immunohistochemical research for HSP60 and HSP10 was performed and the semiquantitative results were analysed by statistical analysis to determine the correlation between HSPs expression and 1) tumour grading; 2) degree of inflammation; 3) number of lymph nodes involved; 4) lymph node compartment hyperplasia. Moreover, western blotting was performed on a smaller group of samples to confirm the immunohistochemical results. RESULTS: Our data show that the expression of HSP60, in both primary tumour and lymph node metastasis, is correlated with the tumoral grade, while the HSP10 expression is not. Nevertheless, the levels of HSP10 are commonly higher than the levels of HSP60. In addition, statistical analyses do not show any correlation between the degree of inflammation and the immunopositivity for both HSP60 and HSP10. Moreover, we find a significant correlation between the presence of lymph node metastases and the positivity for both HSP60 and HSP10. In particular, metastatic lymph nodes show a higher percentage of cells positive for both HSP60 and HSP10 in the secondary follicles, and for HSP10 in the medullary sinuses, when compared with hyperplastic lymph nodes. CONCLUSION: HSP60 and HSP10 may have diagnostic and prognostic significance in the management of this tumour and their overexpression in tumoral cells may be functionally related to tumoral progression. We hypothesise that their expression in follicular and medullary cells of lymph nodes may be induced by formation of metastases. Further studies based on these observations could lead to a better understanding of the HSPs involvement in colorectal cancer progression, as well as other neoplasms

Islet Endothelial Activation and Oxidative Stress Gene Expression Is Reduced by IL-1Ra Treatment in the Type 2 Diabetic GK Rat

Inflammation followed by fibrosis is a component of islet dysfunction in both rodent and human type 2 diabetes. Because islet inflammation may originate from endothelial cells, we assessed the expression of selected genes involved in endothelial cell activation in islets from a spontaneous model of type 2 diabetes, the Goto-Kakizaki (GK) rat. We also examined islet endotheliuml/oxidative stress (OS)/inflammation-related gene expression, islet vascularization and fibrosis after treatment with the interleukin-1 (IL-1) receptor antagonist (IL-1Ra)

One thousand plant transcriptomes and the phylogenomics of green plants

Abstract: Green plants (Viridiplantae) include around 450,000–500,000 species1, 2 of great diversity and have important roles in terrestrial and aquatic ecosystems. Here, as part of the One Thousand Plant Transcriptomes Initiative, we sequenced the vegetative transcriptomes of 1,124 species that span the diversity of plants in a broad sense (Archaeplastida), including green plants (Viridiplantae), glaucophytes (Glaucophyta) and red algae (Rhodophyta). Our analysis provides a robust phylogenomic framework for examining the evolution of green plants. Most inferred species relationships are well supported across multiple species tree and supermatrix analyses, but discordance among plastid and nuclear gene trees at a few important nodes highlights the complexity of plant genome evolution, including polyploidy, periods of rapid speciation, and extinction. Incomplete sorting of ancestral variation, polyploidization and massive expansions of gene families punctuate the evolutionary history of green plants. Notably, we find that large expansions of gene families preceded the origins of green plants, land plants and vascular plants, whereas whole-genome duplications are inferred to have occurred repeatedly throughout the evolution of flowering plants and ferns. The increasing availability of high-quality plant genome sequences and advances in functional genomics are enabling research on genome evolution across the green tree of life

Werkstofftechnische Charakterisierung untereutektischer Legierungen im System Fe-C-B-X

Zielsetzung der Arbeit war es einen Grundstein zur Entwicklung B-legierter Werkzeugstähle zu schaffen. Dazu wurde die Wirkung der Elemente B und Cr auf die Gefügeentstehung, die Stabilität und die mikromechanischen Eigenschaften von Hartphasen in untereutektischen Fe-C-B und Fe-C-B-Cr Legierungen analysiert. Zusätzlich wurden Wechselwirkungen der Elemente B und Cr mit Mn, Mo, V oder Nb berücksichtigt. Es wurden Laborlegierungen der Systeme Fe-C-B und Fe-C-B-Cr mit Zugaben der Elemente Mn, Mo, V oder Nb erschmolzen und experimentell charakterisiert. Basierend auf diesen Ergebnissen wurden zwei B-legierte Kaltarbeitsstähle (KAS) entwickelt und mittels schmelz-, sowie pulvermetallurgischer Urformung verarbeitet. Die neuartigen B-legierten KAS erreichen im Vergleich zu konventionellen KAS der Systeme Fe-Cr-C und Fe-Cr-V-C, eine gleiche oder höhere Zähigkeit, Festigkeit und Verschleißbeständigkeit, während die Materialkosten für B-legierten KAS deutlich geringer sind.The aim of the work was to provide a basis for the development of B-alloyed tool steels. To this end, the effect of the elements B and Cr on the microstructure formation, the stability and the micromechanical properties of hard phases in hypoeutectic Fe-C-B and Fe-C-B-Cr alloys was analyzed. Additionally, interactions of the elements B and Cr with Mn, Mo, V or Nb were investigated. Laboratory alloys of the systems Fe-C-B and Fe-C-B-Cr with additions of the elements Mn, Mo, V or Nb were casted and characterized experimentally. Based on these results, two B-alloyed cold-work steels (CWS) were developed and processed by means of melt and powder metallurgical manufacturing. The novel B-alloyed CWS achieve the same or higher toughness, strength and wear resistance compared to conventional CWS of the Fe-Cr-C and Fe-Cr-V-C systems, while material cost for the B-alloyed CWS are significantly lower

Microstructures, heat treatment and properties of boron alloyed tool steels

To enable the development of novel Fe–C–B–Cr and Fe–C–B–Cr–Mo cold work tool steels, the microstructures and hardness‐tempering behaviors of hypoeutectic laboratory melts are investigated. The results show that increasing Cr content enhances the thermodynamic stability of the ultrahard M$_2$B borides. The formation of carboborides is suppressed by adjusting the B/(C + B) ratio, Cr content, and austenitization temperature. A secondary hardenability at 500 °C is achieved by Mo addition. In addition, Mo stabilizes the M$_23$(C,B)$_6$ phase and at higher contents the M3B2 boride. Based on these investigations, Fe0.4C1B–Cr alloys are designed which, inspired by the microstructure of the steel X153CrMoV12‐1, feature a $\alpha$′‐Fe hardenable matrix but 15 vol% of eutectic M$_2$B borides instead of M$_7$C$_3$ for wear protection. The Fe0.4C1B–Cr steels are produced by casting and hot rolling as well as powder metallurgy and hot isostatic pressing. The (tribo‐) mechanical properties are investigated and compared with X153CrMoV12‐1. Fracture toughness, bending strength, wear resistance, and hardness of the novel Fe0.4C1B–Cr alloys are found to be similar or superior to the steel X153CrMoV12‐1, at decreased material cost