Predicting The Structure And Selectivity Of Coiled-Coil Proteins

A coiled-coil protein structure consists of two (in coiled-coil dimers) or more interacting α-helical strands that together form a left-handed supercoil structure. Many coiled-coil proteins are involved in significant biological functions such as the regulation of gene expression, known as transcription factors. Also coiled-coil structures entail unique mechanical properties critical to the function and integrity of various motor proteins, cytoskeletal filaments and extra-cellular matrix proteins. Engineering these transcription factors is also expected to create more efficient and practical solutions to treat neurodegenerative diseases such as Alzheimer\u27s disease (AD), Parkinson\u27s disease (PD), Huntington\u27s disease (HD), amyotrophic lateral sclerosis (ALS) and prion diseases, which are increasingly being realized to have common cellular and molecular mechanisms including protein aggregation. The main objectives of our work are: a) to develop a model to predict the propensity of a protein sequence to form an isolated coiled-coil structure, and b) to investigate the selectivity of coiled-coils by studying protein-protein interactions. Control over protein-protein interaction specificity has a wide range of applications in synthetic biology such as protein labeling and purification (as high-specificity affinity tags or cognate pairs), drugs and toxin delivery and disease modulation. In naturally occurring proteins, specificity is achieved via a complex balance of various molecular-level energetic and entropic interactions. Such complexity makes any specificity prediction from the primary sequence data an extremely complicated task. Possibly, one of the simplest and most studied protein-protein interactions exists in coiled-coil structures

On kk-layered numbers

A positive integer $n$ is said to be $k$-layered if its divisors can be partitioned into $k$ sets with equal sum. In this paper, we start the systematic study of these class of numbers. In particular, we state some algorithms to find some even $k$-layered numbers $n$ such that $2^{\alpha}n$ is a $k$-layered number for every positive integer $\alpha$. We also find the smallest $k$-layered number for $1\leq k\leq 8$. Furthermore, we study when $n!$ is a $3$-layered and when is a $4$-layered number. Moreover, we classify all $4$-layered numbers of the form $n=p^{\alpha}q^{\beta}rt$, where $\alpha$, $1\leq \beta\leq 3$, $p$, $q$, $r$, and $t$ are two positive integers and four primes, respectively. In addition, in this paper, some other results concerning these numbers and their relationship with $k$-multiperfect numbers, near-perfect numbers, and superabundant numbers are discussed. Also, we find an upper bound for the differences of two consecutive $k$-layered numbers for every positive integer $1\leq k\leq 5$. Finally, by assuming the smallest $k$-layered number, we find an upper bound for the difference of two consecutive $k$-layered numbers.Comment: 25 pages, 2 tables, comments are welcom

Sparse solutions to underdetermined Kronecker product systems

AbstractThree properties of matrices: the spark, the mutual incoherence and the restricted isometry property have recently been introduced in the context of compressed sensing. We study these properties for matrices that are Kronecker products and show how these properties relate to those of the factors. For the mutual incoherence we also discuss results for sums of Kronecker products

Identification and classification of open book accounting dimensions by considering inter-organizational cost management: A case study of petrochemical companies listed in Tehran Stock Exchange

This study aims to identify and to classify Open book accounting (OBA) dimensions according to inter-organizational cost management (IOCM) in petrochemical companies listed in Tehran Stock Exchange. In this research, there are 18 statistical society financial and accounting experts listed in Tehran Stock Exchange. By studying the theoretical literature and conducted investigations inside and outside of the country and also the experts’ comments, the OBA dimensions were identified and then classified by analytical hierarchy process technique. According to the studies and experts’ ideas, four dimensions including nature of data and accounting data disclosure practices, uses of disclosed accounting data, conditions of OBA, cost implementation of OBA were identified as OBA dimensions. The results of examinations were shown that, considering the comments on dimensions of nature of data and accounting data disclosure practices, the form of data disclosure plays a more important role. In uses of disclosed accounting data dimension, coordination and planning among team members play the most important role. According to conditions of OBA dimension, trust is the most important one and in cost implementation of OBA dimension, the cost of the other party plays the most important role

Identification and classification of open book accounting dimensions

This study aims to identify and to classify Open book accounting (OBA) dimensions according to inter-organizational cost management (IOCM). The study selects six university professors in the field of accounting and by studying the theoretical literature and conducted investigations inside and outside of the country, the OBA dimensions were identified and then they were classified by analytical hierarchy process technique. According to the studies and experts’ ideas, four dimensions including nature of data and accounting data disclosure practices, uses of disclosed accounting data, conditions of OBA, cost implementation of OBA were identified as OBA dimensions. The results of our survey indicate that the form of data disclosure as well as coordination and planning among team members played essential role for OBA development. In addition, trust and the cost of the second party were other important factors, which must be considered when OBA is applied in any industry