Manganoan fayalite and products of its alteration from the Strzegom pegmatites, Poland

1989 ◽  
Vol 53 (371) ◽  
pp. 315-325 ◽  
Author(s):  
J. Janeczek
Keyword(s):  
Hydrothermal Alteration ◽  
Fluid Inclusions ◽  
Iron Hydroxide ◽  
Silicate Phase ◽  
Second Stage ◽  
Multi Stage ◽  
Composite Mixture ◽  
Quartz Aggregates ◽  
Lower Silesia

AbstractNodules of manganoan fayalite occur in schlieren pegmatities in the vicinity of Strzegom, Lower Silesia. The fayalite, Na0.02(Fe1.812+Mn0.16Mg 0.03)Si0.99O4, is unzoned and non pleochroic. 2Va = 42° a 4.826(3), b 10.500(2), c 6.102(2) A, d130obs. = 2.83 Å, d130calc. = 2.833 Å, D = 4.35 g cm-3, Dcalc. = 4.353 g cm-3. The role of Na+ ions in the fayalite chemistry is discussed. The fayalite underwent multi-stage hydrothermal alteration beginning at the highest temperature (440°C) of homogenization of gaseous-fluid inclusions in quartz adjacent to the fayalite grains. Increase in fO2 and then in PH2O resulted in the formation of magnetite-quartz and Mn-grunerite-magnetite-quartz aggregates within the fayalite grains. The fayalite is mantled by a Mn-greenalite-magnetite rim, Mn-grunerite-magnetite-Mn-minnesotaite zone in a stilpnomelane or greenalite-rich groundmass. The minnesotaite is believed to have formed at the expense of grunerite. Stilpnomelane, the most abundant silicate phase in the rim, is the product of biotite and presumably greenalite alteration at the second stage of increasing Na activity (the crystallization of cleavelandite) in the pegmatites. The fayalite is also heavily altered to iddingsite—a composite mixture of amorphous FeOOH and silica. The iron-hydroxide recrystallized partially to poorly-crystalline goethite.

Regulation of microRNAs in Inflammation-Associated Colorectal Cancer: A Mechanistic Approach

2020 ◽  
Vol 20 ◽  
Author(s):  
Sridhar Muthusami ◽  
Ilangovan Ramachandran ◽  
Sneha Krishnamoorthy ◽  
Yuvaraj Sambandam ◽  
Satish Ramalingam ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Molecular Mechanisms ◽  
Colorectal Carcinogenesis ◽  
Model Systems ◽  
Necrosis Factor Alpha ◽  
Multi Stage ◽  
Mechanistic Approach ◽  
Tnf Α ◽  
Factor Alpha

: The development of colorectal cancer (CRC) is a multi-stage process. The inflammation of the colon as in inflammatory bowel disease (IBD) such as ulcerative colitis (UC) or Crohn’s disease (CD) is often regarded as the initial trigger for the development of CRC. Many cytokines such as tumor necrosis factor alpha (TNF-α) and several interleukins (ILs) are known to exert proinflammatory actions, and inflammation initiates or promotes tumorigenesis of various cancers, including CRC through differential regulation of microRNAs (miRNAs/miRs). miRNAs can be oncogenic miRNAs (oncomiRs) or anti-oncomiRs/tumor suppressor miRNAs, and they play key roles during colorectal carcinogenesis. However, the functions and molecular mechanisms of regulation of miRNAs involved in inflammation-associated CRC are still anecdotal and largely unknown. Consolidating the published results and offering perspective solutions to circumvent CRC, the current review is focused on the role of miRNAs and their regulation in the development of CRC. We have also discussed the model systems adapted by researchers to delineate the role of miRNAs in inflammation-associated CRC.

The Role of Dimensional Distinctiveness in Children's and Adults' Artifact Categorization

2005 ◽  
Vol 16 (2) ◽  
pp. 137-144 ◽  
Author(s):  
Rubi Hammer ◽  
Gil Diesendruck
Keyword(s):  
Preschool Children ◽  
Contextual Factors ◽  
A Priori ◽  
Functional Similarity ◽  
Second Stage ◽  
Functional Dimension

There are conflicting results as to whether preschool children categorize artifacts on the basis of physical or functional similarity. The present study investigated the effect of the relative distinctiveness of these dimensions in children's categorization. In a physical-distinctive condition, preschool children and adults were initially asked to categorize computer-animated artifacts whose physical appearances were more distinctive than their functions. In a function-distinctive condition, the functional dimension of objects was more distinctive than their physical appearances. Both conditions included a second stage of categorization in which both dimensions were equally distinctive. Participants in a control condition performed only this stage of categorization. Adults in all conditions and stages consistently categorized by functional similarity. In contrast, children's categorization was affected by the relative distinctiveness of the dimensions. Children may not have a priori specific beliefs about how to categorize novel artifacts, and thus may be more susceptible to contextual factors.

Role of the silicate phase of an enclosing rock in the prereduction of disseminated chromium ores

2007 ◽  
Vol 2007 (4) ◽  
pp. 261-267 ◽  
Author(s):  
A. V. Roshin ◽  
V. E. Roshin ◽  
A. G. Ryabukhin ◽  
Yu. N. Goikhenberg
Keyword(s):  
Silicate Phase

The role of fluid inclusions in mineral exploration—An attempt on the Bihar Mica Belt of India

1993 ◽  
Vol 2 (2) ◽  
pp. 156-166 ◽  
Author(s):  
G. N. Jadhav ◽  
V. Panchapakesan ◽  
K. C. Sahu
Keyword(s):  
Fluid Inclusions ◽  
Mineral Exploration

scholarly journals Entrepreneurial decisions: Insights into the use of support services for new business creation

2014 ◽  
Vol 45 (4) ◽  
pp. 11-20 ◽  
Author(s):  
G. Ammetller ◽  
I. Rodriguez-Ardurab ◽  
J. Llados-Masllorens
Keyword(s):  
Decision Making ◽  
Support Services ◽  
Local Development ◽  
Integrative Model ◽  
Resource Based View ◽  
Utilization Of Services ◽  
Multi Stage ◽  
Business Creation ◽  
New Business

This research presents an integrative model about the use of those services that have been specifically designed to support entrepreneurial initiative. By contrast with conventional perspectives from the entrepreneurship field, mainly drawn from a resource-based view, we propose a two-fold approach to explain the utilization of services that are oriented to new business creation: by considering the role of resources within the start-up's reach (internal and external); by incorporating a behavioral and decision-making approach. On the basis of the suggested decision-making framework, a multi-stage decision model is developed and tested by means of a representative sample of entrepreneurs linked to a local development agency. The results show that the adoption and use of support services for new business creation is a complex and reflexive process, triggered by the entrepreneur's internal forces.The entrepreneur searches for information throughout the process and, with assistance from internal teams and external networks, evaluates the choices of businesssupport services. Our findings offer relevant implications and recommendations for business incubators and institutions.

scholarly journals Mineralogical and Fluid Inclusions Study of Epithermal Type Veins Intruding the Volcanic Rocks of the Kornofolia Area, Evros, NE Greece.

2019 ◽  
Vol 55 (1) ◽  
pp. 202
Author(s):  
Foteini Aravani ◽  
Lambrini Papadopoulou ◽  
Vasileios Melfos ◽  
Triantafillos Soldatos ◽  
Triantafillia Zorba ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Fluid Inclusion ◽  
Hydrothermal Alteration ◽  
Fluid Inclusions ◽  
Volcanic Rocks ◽  
The Other ◽  
Calc Alkaline ◽  
Ft Ir ◽  
Host Rocks

The volcanic rocks of Kornofolia area, Evros, host a number of epithermal-type veins. The host rocks are Oligocene calc-alkaline andesites to rhyo-dacites. The andesites form hydrothermal breccias and show hydrothermal alteration. The veins comprise mainly silica polymorphs such as quartz, chalcedony and three types of opal (milky white, transparent and green). Amethyst also forms in veins at the same area. Apart from the silica polymorphs, the veins are accompanied by calcite and zeolites. The main aim of this study is the characterization of the silica polymorphs. Using FT-IR analyses, variations in the crystal structure of the three opals were recognized. The green opal is found to be more amorphous than the other two types. Fluid-inclusion measurements were performed in calcite and were compared with amethyst from previous studies. The Th is between 121-175 °C and the Te between -22.9 and -22.4 °C. The salinities range from 0.9 to 4.5 wt % NaCl equiv.

scholarly journals Contrasting Mathematical Phenomena and Concepts in Ethnomathematics through Etic and Emic Approaches: A Study of Dhikr Jahar Practices in Tariqa Qodiriyah Naqsyabandiyah Ma’had Suryalaya

2021 ◽  
Vol 12 (1) ◽  
pp. 193-218
Author(s):  
Eko Yulianto ◽  
Wahyudin Wahyudin ◽  
Ahmad Tafsir ◽  
Sufyani Prabawanto
Keyword(s):  
Data Processing ◽  
Cultural Diversity ◽  
Qualitative Methods ◽  
Mathematical Concept ◽  
Research Trends ◽  
Mathematical Research ◽  
Mathematical Concepts ◽  
Second Stage ◽  
Emic And Etic

Ethno-mathematical research trends pioneered by D'Ambrosio are on the rise, especially in Indonesia as a nation with high cultural diversity which has a lot of potential researches to be explored. This paper has two major objectives, first to explore the importance of the role of mathematics in the practice of Dhikr Jahar in Tariqa Qodiriyyah Naqsyabandiyyah and second to contrast the differences between mathematical phenomena and mathematical concepts in ethnomathematics research. Attempts to contrast the mathematical phenomena and mathematical concepts in ethnomathematics was expected to provide a sharper highlight in the writing of ethnomathematics research. This research used qualitative methods with two approaches, namely ethnography and phenomenology. The locations of the research are at Pondok Pesantren Suryalaya-Sirnarasa and Padepokan Talangraga Tasikmalaya with observations for 9 months in the first stage and then 6 months in the second stage. The number of respondents interviewed in this research were 48 people. Data processing was performed using the Nvivo 12 Plus. The results showed that there are many mathematical phenomena in the practice of Dhikr Jahar Ikhwan TQN. In carrying out the practice of dhikr, the Ikhwan used a mathematical concept with two events, fingers and prayer beads aids. The concept of counting in dhikr was used strictly by the Ikhwan. They believe that numbers have an important role in the quantity of dhikr. Contrasting mathematical phenomena and mathematical concepts can be done with an emic and etic approach and is expected to become an alternative style in ethnomathematics research. 

scholarly journals The Role of Explicit and Implicit Confidence in Multi Stage Decisions

2020 ◽  
Vol 22 (3) ◽  
pp. 37-47
Author(s):  
Fatemeh Majdabadi ◽  
Reza Ebrahimpour ◽  
◽  
Keyword(s):  
Multi Stage
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