Oxidation of sulphides and rapid weathering in recent landslides

Abstract. Linking together the processes of rapid physical erosion to the resultant chemical dissolution of rock is a crucial step in building an overall deterministic understanding of weathering in mountain belts. Landslides, which are the most volumetrically important geomorphic process at these high rates of erosion, can generate extremely high rates of very localised weathering. To elucidate how this process works we have taken advantage of uniquely intense landsliding, resulting from Typhoon Morakot, in the Taimali river and surrounds in Southern Taiwan. Combining detailed analysis of seepage chemistry with estimates of catchment-by-catchment landslide volumes, we demonstrate that in this setting the primary role of landslides is to introduce fresh, highly labile mineral phases into the surface weathering environment. There, rapid weathering is driven by the oxidation of pyrite and the resultant sulphuric acid-driven dissolution of primarily carbonate rock. The total dissolved load correlates well with dissolved sulphate – the chief product of this style of weathering – in both landslides and streams draining the area (R2 = 0.841 and 0.929 respectively, p < 0.001 in both cases), with solute chemistry in seepage from landslides and catchments affected by significant landsliding governed by the same weathering reactions. Bedrock landslides create conditions for weathering where all mineral phase in a lithology are initially unweathered within landslide deposits, and therefore the most labile phases dominate the weathering at the outset and during a transient period of depletion. This mode of dissolution can strongly alter the overall output of solutes from catchments and their contribution to global chemical cycles if landslide-derived material is retained in catchments for extended periods after mass wasting.

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Oxidation of sulfides and rapid weathering in recent landslides

Earth Surface Dynamics ◽

10.5194/esurf-4-727-2016 ◽

2016 ◽

Vol 4 (3) ◽

pp. 727-742 ◽

Cited By ~ 10

Author(s):

Robert Emberson ◽

Niels Hovius ◽

Albert Galy ◽

Odin Marc

Keyword(s):

Sulfuric Acid ◽

Primary Role ◽

Mass Wasting ◽

Mineral Phases ◽

Physical Erosion ◽

Solute Chemistry ◽

Southern Taiwan ◽

Mountain Belts ◽

Dissolved Load

Abstract. Linking together the processes of rapid physical erosion and the resultant chemical dissolution of rock is a crucial step in building an overall deterministic understanding of weathering in mountain belts. Landslides, which are the most volumetrically important geomorphic process at these high rates of erosion, can generate extremely high rates of very localised weathering. To elucidate how this process works we have taken advantage of uniquely intense landsliding, resulting from Typhoon Morakot, in the T'aimali River and surrounds in southern Taiwan. Combining detailed analysis of landslide seepage chemistry with estimates of catchment-by-catchment landslide volumes, we demonstrate that in this setting the primary role of landslides is to introduce fresh, highly labile mineral phases into the surface weathering environment. There, rapid weathering is driven by the oxidation of pyrite and the resultant sulfuric-acid-driven dissolution of primarily carbonate rock. The total dissolved load correlates well with dissolved sulfate – the chief product of this style of weathering – in both landslides and streams draining the area (R2 =  0.841 and 0.929 respectively; p < 0.001 in both cases), with solute chemistry in seepage from landslides and catchments affected by significant landsliding governed by the same weathering reactions. The predominance of coupled carbonate–sulfuric-acid-driven weathering is the key difference between these sites and previously studied landslides in New Zealand (Emberson et al., 2016), but in both settings increasing volumes of landslides drive greater overall solute concentrations in streams. Bedrock landslides, by excavating deep below saprolite–rock interfaces, create conditions for weathering in which all mineral phases in a lithology are initially unweathered within landslide deposits. As a result, the most labile phases dominate the weathering immediately after mobilisation and during a transient period of depletion. This mode of dissolution can strongly alter the overall output of solutes from catchments and their contribution to global chemical cycles if landslide-derived material is retained in catchments for extended periods after mass wasting.

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Upper gastrointestinal tract bleeding in institutionalized mentally retarded adults. Primary role of esophagitis

Archives of Family Medicine ◽

10.1001/archfami.4.1.30 ◽

1995 ◽

Vol 4 (1) ◽

pp. 30-33 ◽

Cited By ~ 8

Author(s):

J. L. Orchard

Keyword(s):

Gastrointestinal Tract ◽

Mentally Retarded ◽

Upper Gastrointestinal Tract ◽

Primary Role ◽

Gastrointestinal Tract Bleeding ◽

Upper Gastrointestinal

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Sports Photography and Historical Development

Physical Education and Sport Through the Centuries ◽

10.2478/spes-2018-0008 ◽

2018 ◽

Vol 5 (1) ◽

pp. 93-115

Author(s):

Miloš Stamenković

Keyword(s):

Historical Development ◽

Emotional Reaction ◽

Main Role ◽

Primary Role

SummarySports photography undoubtedly has a significant place in sports press and publicism. It’s main and primary role is to present sports to the readers as art, which it is. Sport is characterized by dynamic and varied movements, and the main role of sports photography is reflected in the fact that it is in this way that sport shows its essence. Having in mind that photography tells more than a thousand words it sends a clear message to the reader as well to people who are informed about events via sports portals. Sports photography is a multidimensional art for many reasons. When we say “multi”, it primarily refers to a wider range that sports photography has to offer, which means sports photography is not only directed at presenting athletes on the move and the main actors who contribute to achieving the results by their engagement – it also has the role of sports “psychophotography” which is an analysis and capture of the emotional reaction of an athlete after winning or losing from the opposing team.

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OBOLESCENCE AND THE DIFFUSION OF INNOVATIONS

Izvestiâ Timirâzevskoj selʹskohozâjstvennoj akademii ◽

10.26897/0021-342x-2020-4-113-130 ◽

2020 ◽

pp. 113-130

Author(s):

A.V. GOLUBEV ◽

Keyword(s):

Diffusion Of Innovations ◽

Time Lag ◽

Practical Implementation ◽

Primary Role ◽

Innovation Development ◽

Scientific Hypothesis ◽

Scientific Papers ◽

The Moment ◽

Sociological Studies

The diffusion of innovations is described as a process in a number of scientific papers. At the same time, the causes of this process have not been sufficiently studied. The author’s goal is to consider the main regularities, under which the life cycle of innovations begins, and propose measures to enhance diffusion in modern conditions. As a scientific hypothesis, the author accepts the postulate about the primary role of the obolescence of attracted innovations in this process. The analysis revealed not only the economic proportions that initiate the start of innovation promotion, but also the influence on the diffusion rate of the obsolescence degree of innovations and the market share occupied by the new product. Methodological approaches have been developed to determine economic efficiency depending on the moment of technological change-over, as well as to determine the absolute and relative speed of innovation diffusion. Sociological studies were conducted to determine the state of innovation development and the time lag between obtaining information about an innovation and its practical implementation. The author presents his “Agroopyt” information system developed to disseminate knowledge in the agricultural sphere and ensure technology transfer in agriculture. Digital methods provide for significant accelerateion of the diffusion of innovations and expand its scope.

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Four Mutant Alleles Elucidate the Role of the G2 Protein in the Development of C4 and C3 Photosynthesizing Maize Tissues

Genetics ◽

10.1093/genetics/159.2.787 ◽

2001 ◽

Vol 159 (2) ◽

pp. 787-797

Author(s):

Lizzie Cribb ◽

Lisa N Hall ◽

Jane A Langdale

Keyword(s):

Cell Types ◽

Bundle Sheath ◽

Primary Role ◽

Ribulose Bisphosphate Carboxylase ◽

Sheath Cell ◽

Mesophyll Cells ◽

Phenotypic Data ◽

Bisphosphate Carboxylase ◽

Bundle Sheath Cell

Abstract Maize leaf blades differentiate dimorphic photosynthetic cell types, the bundle sheath and mesophyll, between which the reactions of C4 photosynthesis are partitioned. Leaf-like organs of maize such as husk leaves, however, develop a C3 pattern of differentiation whereby ribulose bisphosphate carboxylase (RuBPCase) accumulates in all photosynthetic cell types. The Golden2 (G2) gene has previously been shown to play a role in bundle sheath cell differentiation in C4 leaf blades and to play a less well-defined role in C3 maize tissues. To further analyze G2 gene function in maize, four g2 mutations have been characterized. Three of these mutations were induced by the transposable element Spm. In g2-bsd1-m1 and g2-bsd1-s1, the element is inserted in the second intron and in g2-pg14 the element is inserted in the promoter. In the fourth case, g2-R, four amino acid changes and premature polyadenylation of the G2 transcript are observed. The phenotypes conditioned by these four mutations demonstrate that the primary role of G2 in C4 leaf blades is to promote bundle sheath cell chloroplast development. C4 photosynthetic enzymes can accumulate in both bundle sheath and mesophyll cells in the absence of G2. In C3 tissue, however, G2 influences both chloroplast differentiation and photosynthetic enzyme accumulation patterns. On the basis of the phenotypic data obtained, a model that postulates how G2 acts to facilitate C4 and C3 patterns of tissue development is proposed.

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Primary role of increasing urea-N concentration in a novel Microcystis densa bloom: Evidence from ten years of field investigations and laboratory experiments

Ecotoxicology and Environmental Safety ◽

10.1016/j.ecoenv.2020.111713 ◽

2021 ◽

Vol 208 ◽

pp. 111713

Author(s):

Yangyang Cai ◽

Xiaowen Luo ◽

Xiaoyuan He ◽

Changyuan Tang

Keyword(s):

Laboratory Experiments ◽

Primary Role ◽

N Concentration ◽

Field Investigations

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The Only Function of Grauzone Required for Drosophila Oocyte Meiosis Is Transcriptional Activation of the cortex Gene

Genetics ◽

10.1093/genetics/155.4.1831 ◽

2000 ◽

Vol 155 (4) ◽

pp. 1831-1839

Author(s):

Emily Harms ◽

Tehyen Chu ◽

Gwénola Henrion ◽

Sidney Strickland

Keyword(s):

Zinc Finger ◽

Transcriptional Activation ◽

Single Amino Acid ◽

Primary Role ◽

Extra Copy ◽

Oocyte Meiosis ◽

Zinc Finger Motifs ◽

High Level ◽

Transcriptional Pathway

Abstract The grauzone and cortex genes are required for the completion of meiosis in Drosophila oocytes. The grauzone gene encodes a C2H2-type zinc-finger transcription factor that binds to the cortex promoter and is necessary for high-level activation of cortex transcription. Here we define the region of the cortex promoter to which Grauzone binds and show that the binding occurs through the C-terminal, zinc-finger-rich region of the protein. Mutations in two out of the five grauzone alleles result in single amino acid changes within different zinc-finger motifs. Both of these mutations result in the inability of Grauzone to bind DNA effectively. To determine the mechanism by which Grauzone regulates meiosis, transgenic flies were produced with an extra copy of the cortex gene in homozygous grauzone females. This transgene rescued the meiosis arrest of embryos from these mutants and allowed their complete development, indicating that activation of cortex transcription is the primary role of Grauzone during Drosophila oogenesis. These experiments further define a new transcriptional pathway that controls the meiotic cell cycle in Drosophila oocytes.

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A Note on Teaching and Learning Linear Algebra in Tribhuvan University

Journal of the Institute of Engineering ◽

10.3126/jie.v15i2.27673 ◽

2019 ◽

Vol 15 (2) ◽

pp. 242-245

Author(s):

Tulasi Prasad Nepal

Keyword(s):

Linear Algebra ◽

Teaching Methods ◽

Teaching And Learning ◽

Active Part ◽

Primary Role ◽

Group Discussions ◽

Mathematical System ◽

Traditional Lectures ◽

Individual Opinion

The teaching of linear algebra has always been a challenge for teachers of mathematics, because it is extremely important that students become introduced into complex and abstract mathematical system of linear algebra and learn concepts which can be successfully applied later in other mathematical topics. It is necessary that teachers better understand how students learn, and recognize and allow that the appropriate content, methods and context could be different in different environments. As mathematicians, we are aware of the significant interconnections of different ideas and concepts, which is difficult to recognize and understand. We should not forget that understanding of these kinds of interconnections develops through active and hard exploration of mathematical topics through permanent discovering of new interconnections and relations. Thus, primary role of a teacher is to try to move students to take an active part during the class concerning important and difficult concepts, either through the form of individual opinion or through the form of group discussions. It is not easy to suggest teaching methods, especially in comparison to traditional lectures, which would be effective and would actively, engage students and generate stimulating learning.

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Depletion of Centromeric MCAK Leads to Chromosome Congression and Segregation Defects Due to Improper Kinetochore Attachments

Molecular Biology of the Cell ◽

10.1091/mbc.e03-08-0581 ◽

2004 ◽

Vol 15 (3) ◽

pp. 1146-1159 ◽

Cited By ~ 192

Author(s):

Susan L. Kline-Smith ◽

Alexey Khodjakov ◽

Polla Hergert ◽

Claire E. Walczak

Keyword(s):

Essential Role ◽

Dominant Negative ◽

Primary Role ◽

Complex Behavior ◽

Chromosome Movement ◽

Immunofluorescence Localization ◽

Microtubule Attachment ◽

Chromosome Congression

The complex behavior of chromosomes during mitosis is accomplished by precise binding and highly regulated polymerization dynamics of kinetochore microtubules. Previous studies have implicated Kin Is, unique kinesins that depolymerize microtubules, in regulating chromosome positioning. We have characterized the immunofluorescence localization of centromere-bound MCAK and found that MCAK localized to inner kinetochores during prophase but was predominantly centromeric by metaphase. Interestingly, MCAK accumulated at leading kinetochores during congression but not during segregation. We tested the consequences of MCAK disruption by injecting a centromere dominant-negative protein into prophase cells. Depletion of centromeric MCAK led to reduced centromere stretch, delayed chromosome congression, alignment defects, and severe missegregation of chromosomes. Rates of chromosome movement were unchanged, suggesting that the primary role of MCAK is not to move chromosomes. Furthermore, we found that disruption of MCAK leads to multiple kinetochore–microtubule attachment defects, including merotelic, syntelic, and combined merotelic-syntelic attachments. These findings reveal an essential role for Kin Is in prevention and/or correction of improper kinetochore–microtubule attachments.

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