Lipid rafts are small, dynamic membrane areas characterized by the clustering of selected membrane lipids as the result of the spontaneous separation of glycolipids, sphingolipids, and cholesterol in a liquid-ordered phase. The exact dynamics underlying phase separation of membrane lipids in the complex biological membranes are still not fully understood. Nevertheless, alterations in the membrane lipid composition affect the lateral organization of molecules belonging to lipid rafts. Neural lipid rafts are found in brain cells, including neurons, astrocytes, and microglia, and are characterized by a high enrichment of specific lipids depending on the cell type. These lipid rafts seem to organize and determine the function of multiprotein complexes involved in several aspects of signal transduction, thus regulating the homeostasis of the brain. The progressive decline of brain performance along with physiological aging is at least in part associated with alterations in the composition and structure of neural lipid rafts. In addition, neurodegenerative conditions, such as lysosomal storage disorders, multiple sclerosis, and Parkinson’s, Huntington’s, and Alzheimer’s diseases, are frequently characterized by dysregulated lipid metabolism, which in turn affects the structure of lipid rafts. Several events underlying the pathogenesis of these diseases appear to depend on the altered composition of lipid rafts. Thus, the structure and function of lipid rafts play a central role in the pathogenesis of many common neurodegenerative diseases.

tRNAs universally carry a CCA nucleotide triplet at their 3'-ends. In eukaryotes, the CCA is added post-transcriptionally by the CCA-adding enzyme (CAE). The mitochondrion of the parasitic protozoan Trypanosoma brucei lacks tRNA genes and therefore imports all of its tRNAs from the cytosol. This has generated interest in the tRNA modifications and their distribution in this organism, including how CCA is added to tRNAs. Here, using a BLAST search for genes encoding putative CAE proteins in T. brucei, we identified a single ORF, Tb927.9.8780, as a potential candidate. Knockdown of this putative protein, termed TbCAE, resulted in the accumulation of truncated tRNAs, abolished translation, and inhibited both total and mitochondrial CCA-adding activities, indicating that TbCAE is located both in the cytosol and mitochondrion. However, mitochondrially localized tRNAs were much less affected by the TbCAE ablation than the other tRNAs. Complementation assays revealed that the N-terminal 10 amino acids of TbCAE are dispensable for its activity and mitochondrial localization and that deletion of 10 further amino acids abolishes both. A growth arrest caused by the TbCAE knockdown was rescued by the expression of the cytosolic isoform of yeast CAE, even though it was not imported into mitochondria. This finding indicated that the yeast enzyme complements the essential function of TbCAE by adding CCA to the primary tRNA transcripts. Of note, ablation of the mitochondrial TbCAE activity, which likely has a repair function, only marginally affected growth.

I. A. Sheipak and T. A. Garmanova
Trans. Moscow Math. Soc. 80 (2020), 189-210.
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Publication Date: Apr 10 2020 The SEC will withdraw the existing approval order and the fund will become subject to the requirements of Rule 6c-11 and Nasdaq Rule 5704....

Publication Date: Apr 10 2020 Yes. According to the SEC, once an ETF becomes eligible to operate under Rule 6c-11 and elects to list on Nasdaq under Nasdaq Rule 5704, the existing order related to that fund (and all other funds under that exemptive order) will be rescinded. Once a fund is listed under Nasdaq Rule 5704, it will not be able to relist under Nasdaq Rule 5705(b) (Index Fund Shares) or Nasdaq Rule 5735 (Managed Fund Shares) unless a new exemptive relief order is obtained from the SEC....

20 April 2020

Origami paper-folding may not seem like a subject for mathematical investigation or one with sophisticated applications, yet anyone who has tried to fold a road map or wrap a present knows that origami is no trivial matter. Mathematicians, computer scientists, and engineers have recently discovered that this centuries-old subject can be used to solve many modern problems.The methods of origami are now used to fold objects such as automobile air bags and huge space telescopes efficiently, and may be related to how proteins fold. Manufacturers often want to make a product out of a single piece of material. The manufacturing problem then becomes one of deciding whether a shape can be folded and if so, is there an efficient way to find a good fold? Thus, many origami research problems have to do with algorithm complexity and optimization theory. A testament to the diversity of origami, as well as the power of mathematics, is its applicability to problems at the molecular level, in manufacturing, and in outer space. For More Information: http://db.uwaterloo.ca/~eddemain/papers/MapFolding/

euromicron AG, a medium-sized technology group and specialist for networking business and production processes, has taken on Funkwerk AG, Kölleda, as a strategic anchor investor. Funkwerk AG is a leading provider of innovative communication, information and security systems and intends to acquire a total of up to around 28% of euromicron AG’s increased share capital following the implementation of the resolved capital measures.

With less than two months to go before the start of the World Youth Netball Championships (WYNC),

Kathrin Bringmann, Matthew Krauel and Michael Tuite
Trans. Amer. Math. Soc. 373 (2020), 3261-3293.
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Kamen G. Ivanov and Pencho Petrushev
Trans. Amer. Math. Soc. 373 (2020), 3117-3176.
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L. Bernal-González, H. J. Cabana-Méndez, G. A. Muñoz-Fernández and J. B. Seoane-Sepúlveda
Trans. Amer. Math. Soc. 373 (2020), 3063-3083.
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Hilaf Hasson and Jeffrey Yelton
Trans. Amer. Math. Soc. 373 (2020), 3009-3030.
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M. V. Pratsiovytyi and S. P. Ratushniak
Theor. Probability and Math. Statist. 99 (2020), 211-228.
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Yu. S. Mishura and H. S. Zhelezniak
Theor. Probability and Math. Statist. 99 (2020), 199-210.
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D. V. Gusak and E. V. Karnaukh
Theor. Probability and Math. Statist. 99 (2020), 77-89.
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