scholarly journals Representations of constant socle rank for the Kronecker algebra

2020 ◽  
Vol 32 (1) ◽  
pp. 23-43 ◽  
Author(s):  
Daniel Bissinger
Keyword(s):  
Recent Work ◽  
Abelian Groups ◽  
Wild Type ◽  
Kronecker Algebra ◽  
Radical Property

AbstractInspired by recent work of Carlson, Friedlander and Pevtsova concerning modules for p-elementary abelian groups {E_{r}} of rank r over a field of characteristic {p>0}, we introduce the notions of modules with constant d-radical rank and modules with constant d-socle rank for the generalized Kronecker algebra {\mathcal{K}_{r}=k\Gamma_{r}} with {r\geq 2} arrows and {1\leq d\leq r-1}. We study subcategories given by modules with the equal d-radical property and the equal d-socle property. Utilizing the simplification method due to Ringel, we prove that these subcategories in {\operatorname{mod}\mathcal{K}_{r}} are of wild type. Then we use a natural functor {\operatorname{\mathfrak{F}}\colon{\operatorname{mod}\mathcal{K}_{r}}\to% \operatorname{mod}kE_{r}} to transfer our results to {\operatorname{mod}kE_{r}}.

scholarly journals Mutant p53 Sequestration of the MDM2 Acidic Domain Inhibits E3 Ligase Activity

2018 ◽  
Vol 39 (4) ◽  
Author(s):  
Leixiang Yang ◽  
Tanjing Song ◽  
Qian Cheng ◽  
Lihong Chen ◽  
Jiandong Chen
Keyword(s):  
Tumor Cells ◽  
Recent Work ◽  
Intramolecular Interaction ◽  
E3 Ligase ◽  
Mutant P53 ◽  
Wild Type ◽  
Gain Of Function ◽  
Core Domain ◽  
Acidic Domain ◽  
Wild Type P53

ABSTRACT Missense p53 mutants often accumulate in tumors and drive progression through gain of function. MDM2 efficiently degrades wild-type p53 but fails to degrade mutant p53 in tumor cells. Previous studies revealed that mutant p53 inhibits MDM2 autoubiquitination, suggesting that the interaction inhibits MDM2 E3 activity. Recent work showed that MDM2 E3 activity is stimulated by intramolecular interaction between the RING and acidic domains. Here, we show that in the mutant p53-MDM2 complex, the mutant p53 core domain binds to the MDM2 acidic domain with significantly higher avidity than wild-type p53. The mutant p53-MDM2 complex is deficient in catalyzing ubiquitin release from the activated E2 conjugating enzyme. An MDM2 construct with extra copies of the acidic domain is resistant to inhibition by mutant p53 and efficiently promotes mutant p53 ubiquitination and degradation. The results suggest that mutant p53 interferes with the intramolecular autoactivation mechanism of MDM2, contributing to reduced ubiquitination and increased accumulation in tumor cells.

scholarly journals Functional Organization of Single and Paired V(D)J Cleavage Complexes

2001 ◽  
Vol 21 (13) ◽  
pp. 4256-4264 ◽  
Author(s):  
Mark A. Landree ◽  
Sam B. Kale ◽  
David B. Roth
Keyword(s):  
Recent Work ◽  
Active Site ◽  
Functional Organization ◽  
Wild Type ◽  
Synaptic Complex ◽  
Specific Recognition ◽  
Nucleoprotein Complex ◽  
Rag 1 ◽  
Hairpin Formation

ABSTRACT RAG-1 and RAG-2 initiate V(D)J recombination by binding to specific recognition sequences (RSS) and then cleave the DNA in two steps: nicking and hairpin formation. Recent work has established that a dimer of RAG-1 and either one or two monomers of RAG-2 bind to a single RSS, but the enzymatic contributions of the RAG molecules within this nucleoprotein complex and its functional organization have not been elucidated. Using heterodimeric protein preparations containing both wild-type and catalytically deficient RAG-1 molecules, we found that one active monomer is sufficient for both nicking and hairpin formation at a single RSS, demonstrating that a single active site can carry out both cleavage steps. Furthermore, the mutant heterodimers efficiently cleaved both RSS in a synaptic complex. These results strongly suggest that two RAG-1 dimers are responsible for RSS cleavage in a synaptic complex, with one monomer of each dimer catalyzing both nicking and hairpin formation at each RSS.

scholarly journals Reduced Infectivity of a Leishmania donovani Biopterin Transporter Genetic Mutant and Its Use as an Attenuated Strain for Vaccination

2002 ◽  
Vol 70 (1) ◽  
pp. 62-68 ◽  
Author(s):  
Barbara Papadopoulou ◽  
Gaétan Roy ◽  
Marie Breton ◽  
Christoph Kündig ◽  
Carole Dumas ◽  
...  
Keyword(s):  
Homologous Recombination ◽  
Recent Work ◽  
Interferon Gamma ◽  
Protective Immunity ◽  
Gene Disruption ◽  
Leishmania Donovani ◽  
Vaccination Strategy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Null Mutant ◽  
Wild Type

ABSTRACT Pterins are essential for the growth of Leishmania species, and recent work has led to the isolation of the biopterin transporter BT1. In this study, we inactivated the Leishmania donovani biopterin transporter BT1 by gene disruption mediated by homologous recombination. No transport of biopterin was detected in this mutant. The L. donovani BT1 null mutant showed a much lesser capacity for inducing infection in mice than wild-type parasites and could elicit protective immunity in mice susceptible to infection against a L. donovani challenge. Splenocytes isolated from mice immunized with the BT1 null mutant parasites produced significant amounts of interferon gamma following stimulation with L. donovani promastigotes as measured by enzyme-linked immunosorbent assay and enzyme-linked immunospot assays. Overall, these results show that by genetically manipulating the pterin transport in L. donovani, it is possible to generate an attenuated organism that could be part of a vaccination strategy.

scholarly journals Plünnecke inequalities for measure graphs with applications

2015 ◽  
Vol 37 (2) ◽  
pp. 418-439
Author(s):  
KAMIL BULINSKI ◽  
ALEXANDER FISH
Keyword(s):  
Recent Work ◽  
Measure Space ◽  
Correspondence Principle ◽  
Abelian Groups ◽  
Density Estimates ◽  
Vertex Set ◽  
Banach Density ◽  
Measure Preserving Actions

We generalize Petridis’s new proof of Plünnecke’s graph inequality to graphs whose vertex set is a measure space. Consequently, by a recent work of Björklund and Fish, this gives new Plünnecke inequalities for measure-preserving actions which enable us to deduce, via a Furstenberg correspondence principle, Banach density estimates in countable abelian groups that extend those given by Jin.

scholarly journals The Sharp Threshold for Maximum-Size Sum-Free Subsets in Even-Order Abelian Groups

2015 ◽  
Vol 24 (4) ◽  
pp. 609-640 ◽  
Author(s):  
NEAL BUSHAW ◽  
MAURÍCIO COLLARES NETO ◽  
ROBERT MORRIS ◽  
PAUL SMITH
Keyword(s):  
Recent Work ◽  
Abelian Groups ◽  
Maximum Size ◽  
Constant Factor ◽  
Sharp Threshold ◽  
Even Order ◽  
Free Subset ◽  
Free Sets

We study sum-free sets in sparse random subsets of even-order abelian groups. In particular, we determine the sharp threshold for the following property: the largest such set is contained in some maximum-size sum-free subset of the group. This theorem extends recent work of Balogh, Morris and Samotij, who resolved the caseG= ℤ2n, and who obtained a weaker threshold (up to a constant factor) in general.

What sentimentalists should say about emotion

2019 ◽  
Vol 42 ◽  
Author(s):  
Charlie Kurth
Keyword(s):  
Moral Judgment ◽  
Recent Work ◽  
Relevant Information ◽  
Moral Cognition ◽  
Multilevel Structure

Abstract Recent work by emotion researchers indicates that emotions have a multilevel structure. Sophisticated sentimentalists should take note of this work – for it better enables them to defend a substantive role for emotion in moral cognition. Contra May's rationalist criticisms, emotions are not only able to carry morally relevant information, but can also substantially influence moral judgment and reasoning.

The Sun as a Magnetic Star

1976 ◽  
Vol 32 ◽  
pp. 457-463
Author(s):  
John M. Wilcox ◽  
Leif Svalgaard
Keyword(s):  
Recent Work ◽  
Rotation Axis ◽  
Polar Field ◽  
Magnetic Star ◽  
Rotational Axis ◽  
Field Variation ◽  
The Sun ◽  
Arbitrary Angle ◽  
Solar Magnetism ◽  
Oblique Rotator

SummaryThe sun as a magnetic star is described on the basis of recent work on solar magnetism. Observations at an arbitrary angle to the rotation axis would show a 22-year polar field variation and a 25-day equatorial sector variation. The sector variation would be similar to an oblique rotator with an angle of 90° between the magnetic and rotational axis.

Ultrastructure of Melanin Formation in Curvularia sp., Alternaria sp., and Drechslera Sorokiniana

1977 ◽  
Vol 35 ◽  
pp. 398-399
Author(s):  
M. H. Wheeler ◽  
W. J. Tolmsoff ◽  
A. A. Bell
Keyword(s):  
Potassium Phosphate ◽  
Thielaviopsis Basicola ◽  
Wild Type ◽  
Potassium Phosphate Buffer ◽  
Transmission Microscopy ◽  
Electron Transmission ◽  
Melanin Formation ◽  
Before And After ◽  
Alternaria Sp ◽  
Electron Transmission Microscopy

(+)-Scytalone [3,4-dihydro-3,6,8-trihydroxy-l-(2Hj-naphthalenone] and 1,8-di- hydroxynaphthalene (DHN) have been proposed as intermediates of melanin synthesis in the fungi Verticillium dahliae (1, 2, 3, 4) and Thielaviopsis basicola (4, 5). Scytalone is enzymatically dehydrated by V. dahliae to 1,3,8-trihydroxynaphthalene which is then reduced to (-)-vermelone [(-)-3,4- dihydro-3,8-dihydroxy-1(2H)-naphthalenone]. Vermelone is subsequently dehydrated to DHN which is enzymatically polymerized to melanin.Melanin formation in Curvularia sp., Alternaria sp., and Drechslera soro- kiniana was examined by light and electron-transmission microscopy. Wild-type isolates of each fungus were compared with albino mutants before and after treatment with 1 mM scytalone or 0.1 mM DHN in 50 mM potassium phosphate buffer, pH 7.0. Both chemicals were converted to dark pigments in the walls of hyphae and conidia of the albino mutants. The darkened cells were similar in appearance to corresponding cells of the wild types under the light microscope.

Microstructural comparison of synthetic bioceramics with natural bioceramics

1991 ◽  
Vol 49 ◽  
pp. 38-39
Author(s):  
Shulin Wen ◽  
Jingwei Feng ◽  
A. Krajewski ◽  
A. Ravaglioli
Keyword(s):  
Recent Work ◽  
Human Body ◽  
Human Tissues ◽  
Main Constituent ◽  
Laboratory Furnace ◽  
Chinese Adult ◽  
Human Enamel ◽  
Biological Compatibility ◽  
Synthetic Hydroxyapatite ◽  
Synthetic Work

Hydroxyapatite bioceramics has attracted many material scientists as it is the main constituent of the bone and the teeth in human body. The synthesis of the bioceramics has been performed for years. Nowadays, the synthetic work is not only focused on the hydroapatite but also on the fluorapatite and chlorapatite bioceramics since later materials have also biological compatibility with human tissues; and they may also be very promising for clinic purpose. However, in comparison of the synthetic bioceramics with natural one on microstructure, a great differences were observed according to our previous results. We have investigated these differences further in this work since they are very important to appraise the synthetic bioceramics for their clinic application.The synthetic hydroxyapatite and chlorapatite were prepared according to A. Krajewski and A. Ravaglioli and their recent work. The briquettes from different hydroxyapatite or chlorapatite powders were fired in a laboratory furnace at the temperature of 900-1300°C. The samples of human enamel selected for the comparison with synthetic bioceramics were from Chinese adult teeth.

Ultrastructure and Morphology of the Neurospora Crassa Cell Wall Mutants, Slime And Slime X, Using Tem and Sem

1976 ◽  
Vol 34 ◽  
pp. 54-55
Author(s):  
Karen S. Howard ◽  
H. D. Braymer ◽  
M. D. Socolofsky ◽  
S. A. Milligan
Keyword(s):  
Cell Wall ◽  
Neurospora Crassa ◽  
Wild Type ◽  
Morphological Comparison ◽  
Small Areas ◽  
Solid Media ◽  
Thin Sectioning ◽  
X Cells ◽  
Mutant Cells ◽  
Isolated Cell

The recently isolated cell wall mutant slime X of Neurospora crassa was prepared for ultrastructural and morphological comparison with the cell wall mutant slime. The purpose of this article is to discuss the methods of preparation for TEM and SEM observations, as well as to make a preliminary comparison of the two mutants.TEM: Cells of the slime mutant were prepared for thin sectioning by the method of Bigger, et al. Slime X cells were prepared in the same manner with the following two exceptions: the cells were embedded in 3% agar prior to fixation and the buffered solutions contained 5% sucrose throughout the procedure.SEM: Two methods were used to prepare mutant and wild type Neurospora for the SEM. First, single colonies of mutant cells and small areas of wild type hyphae were cut from solid media and fixed with OSO4 vapors similar to the procedure used by Harris, et al. with one alteration. The cell-containing agar blocks were dehydrated by immersion in 2,2-dimethoxypropane (DMP).

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