scholarly journals A Cambrian Framework for the Oriented Cycle

10.37236/5387 ◽  
2015 ◽  
Vol 22 (4) ◽  
Author(s):  
Nathan Reading ◽  
David E Speyer

This paper completes the project of constructing combinatorial models (called frameworks) for the exchange graph and $\mathbf{g}$-vector fan associated to any exchange matrix $B$ whose Cartan companion is of finite or affine type, using the combinatorics and geometry of Coxeter-sortable elements and Cambrian lattices/fans. Specifically, we construct a framework in the unique non-acyclic affine case, the cyclically oriented $n$-cycle. In the acyclic affine case, a framework was constructed by combining a copy of the Cambrian fan for $B$ with an antipodal copy of the Cambrian fan for $-B$. In this paper, we extend this "doubled Cambrian fan'' construction to the oriented $n$-cycle, using a more general notion of sortable elements for quivers with cycles.


2020 ◽  
Vol 2 (5) ◽  
pp. 325-331
Author(s):  
I. D. Strilets ◽  
M. M. Kardash ◽  
D. V. Terin ◽  
T. V. Druzhinina ◽  
S. V. Tsyplyayev


Author(s):  
Barry Stroud

This chapter challenges the notion that the colours we believe to belong to the objects we see are ‘secondary’ qualities of those objects. Such a notion is endorsed by John McDowell, who has explained why he thinks the author is wrong to resist it. McDowell recognizes that the author’s focus on the conditions of successfully unmasking the metaphysical status of the colours of things is a way of trying to make sense of whatever notion of reality is involved in it. However, the author argues that the notion of reality he is concerned with is ‘independent reality’, not simply the general notion of reality. He also contends that an exclusively dispositional conception of an object’s being a certain colour cannot account for the perceptions we have of the colours of things.



2021 ◽  
Vol 9 (1) ◽  
pp. 118
Author(s):  
Ziqiang Liu ◽  
Hui Wei ◽  
Jiaen Zhang ◽  
Muhammad Saleem ◽  
Yanan He ◽  
...  

Acid rain (AR), as a global environmental threat, has profoundly adverse effects on natural soil ecosystems. Microorganisms involved in the nitrogen (N) cycle regulate the global N balance and climate stabilization, but little is known whether and how AR influences the structure and complexity of these microbial communities. Herein, we conducted an intact soil core experiment by manipulating the acidity of simulated rain (pH 7.5 (control, CK) vs. pH 4.0 (AR)) in subtropical agricultural soil, to reveal the differences in the structure and complexity of soil nitrifying and denitrifying microbiota using Illumina amplicon sequencing of functional genes (amoA, nirS, and nosZ). Networks of ammonia-oxidizing archaea (AOA) and nirS-carrying denitrifiers in AR treatment were less complex with fewer nodes and lower connectivity, while network of nosZ-carrying denitrifiers in AR treatment had higher complexity and connectivity relative to CK. Supporting this, AR reduced the abundance of keystone taxa in networks of AOA and nirS-carrying denitrifiers, but increased the abundance of keystone taxa in nosZ-carrying denitrifiers network. However, AR did not alter the community structure of AOA, ammonia-oxidizing bacteria (AOB), nirS-, and nosZ-carrying denitrifiers. Moreover, AR did not change soil N2O emissions during the experimental period. AOB community structure significantly correlated with content of soil available phosphorus (P), while the community structures of nirS- and nosZ-carrying denitrifiers both correlated with soil pH and available P content. Soil N2O emission was mainly driven by the nirS-carrying denitrifiers. Our results present new perspective on the impacts of AR on soil N-cycle microbial network complexity and keystone taxa in the context of global changes.



1978 ◽  
Vol 43 (1) ◽  
pp. 23-44 ◽  
Author(s):  
Nicolas D. Goodman

In this paper we introduce a new notion of realizability for intuitionistic arithmetic in all finite types. The notion seems to us to capture some of the intuition underlying both the recursive realizability of Kjeene [5] and the semantics of Kripke [7]. After some preliminaries of a syntactic and recursion-theoretic character in §1, we motivate and define our notion of realizability in §2. In §3 we prove a soundness theorem, and in §4 we apply that theorem to obtain new information about provability in some extensions of intuitionistic arithmetic in all finite types. In §5 we consider a special case of our general notion and prove a kind of reflection theorem for it. Finally, in §6, we consider a formalized version of our realizability notion and use it to give a new proof of the conservative extension theorem discussed in Goodman and Myhill [4] and proved in our [3]. (Apparently, a form of this result is also proved in Mine [13]. We have not seen this paper, but are relying on [12].) As a corollary, we obtain the following somewhat strengthened result: Let Σ be any extension of first-order intuitionistic arithmetic (HA) formalized in the language of HA. Let Σω be the theory obtained from Σ by adding functionals of finite type with intuitionistic logic, intensional identity, and axioms of choice and dependent choice at all types. Then Σω is a conservative extension of Σ. An interesting example of this theorem is obtained by taking Σ to be classical first-order arithmetic.



Water ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2012
Author(s):  
Vitória Régia do Nascimento Lima ◽  
Álvaro Gustavo Ferreira da Silva ◽  
Renata Ranielly Pedroza Cruz ◽  
Luana da Silva Barbosa ◽  
Neilier Rodrigues da Silva Junior ◽  
...  

Contaminated water consumption is one of the greatest risks to human health, especially in underdeveloped and developing countries. Water is a universal right, but millions of people worldwide consume untreated surface water. The objective in this study is to evaluate water purification with Nopalea cochenillifera var. Miúda biomass. Fragments (1, 2, and 3 g) of N. cochenillifera were added to the aqueous solution containing red-yellow Chromic and Podzolic Luvisol simulating turbid water sources in Northeastern Brazil. The total, non-structural (i.e., reducing and non-reducing sugars, alcohol insoluble solids), and structural (i.e., pectin) carbohydrates, adsorption kinetics, turbidity, electrical conductivity, pH, zeta potential, and total coliforms presence were evaluated. Findings show that the Nopalea cochenillifera biomass adsorbed the suspended particles in the aqueous solution, making it more translucent due to the complex and heterogeneous adsorbents’ ion exchange matrix, but the biomass addition did not eliminate total coliforms from the aqueous solution. We concluded that the Nopalea cochenillifera biomass water treatment reduces suspended dissolved particles and turbidity, but it needs to be associated with other treatments to eliminate total coliforms and ensure water safety for human consumption.



1997 ◽  
Vol 08 (03) ◽  
pp. 289-304 ◽  
Author(s):  
Marc Baumslag ◽  
Bojana Obrenić

Index-shuffle graphs are introduced as candidate interconnection networks for parallel computers. The comparative advantages of index-shuffle graphs over the standard bounded-degree "approximations" of the hypercube, namely butterfly-like and shuffle-like graphs, are demonstrated in the theoretical framework of graph embedding and network emulations. An N-node index-shuffle graph emulates: • an N-node shuffle-exchange graph with no slowdown, which the currently best emulations of shuffle-like graphs by hypercubes and butterflies incur a slowdown of Ω( log N). • its like-sized butterfly graph with a slowdown O( log log log N), while the currently best emulations of butterfly-like graphs by shuffle-like graphs incur a slowdown of Ω( log log N). • an N-node hypercube that executes an on-line leveled algorithm with a slowdown O( log log N), while the slowdown of currently best such emulations of the hypercube by its bounded-degree shuffle-like and butterfly-like derivatives remains Ω( log N). Our emulation is based on an embedding of an N-node hypercube into an N-node index-shuffle graph with dilation O( log log N), while the currently best embeddings of the hypercube into its bounded-degree shuffle-like and butterfly-like derivatives incur a dilation of Ω( log N).



2006 ◽  
Vol 75 (3) ◽  
pp. 1493-1501 ◽  
Author(s):  
Chantal Fradin ◽  
Abigail L. Mavor ◽  
Günther Weindl ◽  
Martin Schaller ◽  
Karin Hanke ◽  
...  

ABSTRACT Candida albicans is a polymorphic opportunistic fungus that can cause life-threatening systemic infections following hematogenous dissemination in patients susceptible to nosocomial infection. Neutrophils form part of the innate immune response, which is the first line of defense against microbes and is particularly important in C. albicans infections. To compare the transcriptional response of leukocytes exposed to C. albicans, we investigated the expression of key cytokine genes in polymorphonuclear and mononuclear leukocytes after incubation with C. albicans for 1 h. Isolated mononuclear cells expressed high levels of genes encoding proinflammatory signaling molecules, whereas neutrophils exhibited much lower levels, similar to those observed in whole blood. The global transcriptional profile of neutrophils was examined by using an immunology-biased human microarray to determine whether different morphological forms or the viability of C. albicans altered the transcriptome. Hyphal cells appeared to have the broadest effect, although the most strongly induced genes were regulated independently of morphology or viability. These genes were involved in proinflammatory cell-cell signaling, cell signal transduction, and cell growth. Generally, genes encoding known components of neutrophil granules showed no upregulation at this time point; however, lactoferrin, a well-known candidacidal peptide, was secreted by neutrophils. Addition to inhibitors of RNA or protein de novo synthesis did not influence the killing activity within 30 min. These results support the general notion that neutrophils do not require gene transcription to mount an immediate and direct attack against microbes. However, neutrophils exposed to C. albicans express genes involved in communication with other immune cells.



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