Evolution of Length Variation in the Primate Mhc DR Subregion

On the Crystal Chemistry of Inorganic Nitrides: Crystal-Chemical Parameters and Opportunities in the Exploration of Their Compositional Space

10.26434/chemrxiv.11626974.v2 ◽

2020 ◽

Author(s):

Olivier Charles Gagné

Keyword(s):

Functional Properties ◽

A Priori ◽

Lone Pair ◽

Length Variation ◽

Electronic Effects ◽

Statistical Knowledge ◽

Redox Active ◽

Multiply Bonded ◽

Jahn Teller ◽

Compositional Space

The scarcity of nitrogen in Earth’s crust, combined with challenging synthesis, have made inorganic nitrides a relatively-unexplored class of compounds compared to their naturally-abundant oxide counterparts. To facilitate exploration of their compositional space via a priori modeling, and to help a posteriori structure verification not limited to inferring the oxidation state of redox-active cations, we derive a suite of bond-valence parameters and Lewis-acid strength values for 76 cations observed bonding to N3-, and further outline a baseline statistical knowledge of bond lengths for these compounds. We examine structural and electronic effects responsible for the functional properties and anomalous bonding behavior of inorganic nitrides, and identify promising venues for exploring uncharted compositional spaces beyond the reach of high-throughput computational methods. We find that many mechanisms of bond-length variation ubiquitous to oxide and oxysalt compounds (e.g., lone-pair stereoactivity, the Jahn-Teller and pseudo Jahn-Teller effects) are similarly pervasive in inorganic nitrides, and are occasionally observed to result in greater distortion magnitude than their oxide counterparts. We identify inorganic nitrides with multiply-bonded metal ions as a promising venue in heterogeneous catalysis, e.g. in the development of a post-Haber-Bosch process proceeding at milder reaction conditions, thus representing further opportunity in the thriving exploration of the functional properties of this emerging class of materials.

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Performance enhancement of Echo Cancellation Using a Combination of Partial Update ( PU) Methods and New Variable Length LMS (NVLLMS) Algorithm

Journal of Engineering ◽

10.31026/j.eng.2018.05.05 ◽

2018 ◽

Vol 24 (5) ◽

pp. 66

Author(s):

Thamer M. Jamel ◽

Faez Fawzi Hammood

Keyword(s):

Mean Square Error ◽

Return Loss ◽

Performance Enhancement ◽

Variable Length ◽

Echo Cancellation ◽

Convergence Time ◽

Length Variation ◽

Mean Square ◽

Step Size ◽

Echo Return Loss Enhancement

In this paper, several combination algorithms between Partial Update LMS (PU LMS) methods and previously proposed algorithm (New Variable Length LMS (NVLLMS)) have been developed. Then, the new sets of proposed algorithms were applied to an Acoustic Echo Cancellation system (AEC) in order to decrease the filter coefficients, decrease the convergence time, and enhance its performance in terms of Mean Square Error (MSE) and Echo Return Loss Enhancement (ERLE). These proposed algorithms will use the Echo Return Loss Enhancement (ERLE) to control the operation of filter's coefficient length variation. In addition, the time-varying step size is used.The total number of coefficients required was reduced by about 18% , 10% , 6%, and 16% using Periodic, Sequential, Stochastic, and M-max PU NVLLMS algorithms respectively, compared to that used by a full update method which is very important, especially in the application of mobile communication since the power consumption must be considered. In addition, the average ERLE and average Mean Square Error (MSE) for M-max PU NVLLMS are better than other proposed algorithms.

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FGF5 missense mutation is associated with dromedary hair length variation

Animal Genetics ◽

10.1111/age.13132 ◽

2021 ◽

Author(s):

T. Maraqa ◽

B. H. Alhajeri ◽

H. Alhaddad

Keyword(s):

Missense Mutation ◽

Length Variation ◽

Hair Length

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Natural variation in plant telomere length is associated with flowering time

The Plant Cell ◽

10.1093/plcell/koab022 ◽

2021 ◽

Author(s):

Jae Young Choi ◽

Liliia R Abdulkina ◽

Jun Yin ◽

Inna B Chastukhina ◽

John T Lovell ◽

...

Keyword(s):

Life History ◽

Telomere Length ◽

Flowering Time ◽

Dna Sequences ◽

Genome Wide Association Study ◽

Genomic Analysis ◽

Life History Strategies ◽

Length Variation ◽

Chromosomal Structure ◽

Chromosome Integrity

Abstract Telomeres are highly repetitive DNA sequences found at the ends of chromosomes that protect the chromosomes from deterioration during cell division. Here, using whole genome re-sequencing and terminal restriction fragment assays, we found substantial natural intraspecific variation in telomere length in Arabidopsis thaliana, rice (Oryza sativa), and maize (Zea mays). Genome-wide association study (GWAS) mapping in A. thaliana identified 13 regions with GWAS-significant associations underlying telomere length variation, including a region that harbors the telomerase reverse transcriptase (TERT) gene. Population genomic analysis provided evidence for a selective sweep at the TERT region associated with longer telomeres. We found that telomere length is negatively correlated with flowering time variation not only in A. thaliana, but also in maize and rice, indicating a link between life history traits and chromosome integrity. Our results point to several possible reasons for this correlation, including the possibility that longer telomeres may be more adaptive in plants that have faster developmental rates (and therefore flower earlier). Our work suggests that chromosomal structure itself might be an adaptive trait associated with plant life history strategies.

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Predicting the Impact of Describing New Species on Phylogenetic Patterns

Integrative Organismal Biology ◽

10.1093/iob/obz028 ◽

2019 ◽

Vol 1 (1) ◽

Cited By ~ 1

Author(s):

D C Blackburn ◽

G Giribet ◽

D E Soltis ◽

E L Stanley

Keyword(s):

New Species ◽

Phylogenetic Trees ◽

Branch Length ◽

Length Variation ◽

Tree Shape ◽

Branch Lengths ◽

Taxonomic History ◽

Ecological Patterns ◽

The Impact ◽

Incomplete Sampling

Abstract Although our inventory of Earth’s biodiversity remains incomplete, we still require analyses using the Tree of Life to understand evolutionary and ecological patterns. Because incomplete sampling may bias our inferences, we must evaluate how future additions of newly discovered species might impact analyses performed today. We describe an approach that uses taxonomic history and phylogenetic trees to characterize the impact of past species discoveries on phylogenetic knowledge using patterns of branch-length variation, tree shape, and phylogenetic diversity. This provides a framework for assessing the relative completeness of taxonomic knowledge of lineages within a phylogeny. To demonstrate this approach, we use recent large phylogenies for amphibians, reptiles, flowering plants, and invertebrates. Well-known clades exhibit a decline in the mean and range of branch lengths that are added each year as new species are described. With increased taxonomic knowledge over time, deep lineages of well-known clades become known such that most recently described new species are added close to the tips of the tree, reflecting changing tree shape over the course of taxonomic history. The same analyses reveal other clades to be candidates for future discoveries that could dramatically impact our phylogenetic knowledge. Our work reveals that species are often added non-randomly to the phylogeny over multiyear time-scales in a predictable pattern of taxonomic maturation. Our results suggest that we can make informed predictions about how new species will be added across the phylogeny of a given clade, thus providing a framework for accommodating unsampled undescribed species in evolutionary analyses.

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Length Variation in Age-0 Westslope Cutthroat Trout at Multiple Spatial Scales

North American Journal of Fisheries Management ◽

10.1577/m07-120.1 ◽

2008 ◽

Vol 28 (5) ◽

pp. 1529-1540 ◽

Cited By ~ 5

Author(s):

Kathleen E. McGrath ◽

J. Michael Scott ◽

Bruce E. Rieman

Keyword(s):

Spatial Scales ◽

Cutthroat Trout ◽

Length Variation ◽

Westslope Cutthroat Trout ◽

Multiple Spatial Scales

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Load Distribution of Parallel Springs With Random Length and Stiffness

Journal of Vibration and Acoustics ◽

10.1115/1.3269460 ◽

1987 ◽

Vol 109 (4) ◽

pp. 402-406 ◽

Cited By ~ 1

Author(s):

Go¨ran Gerbert ◽

Jacques de Mare´

Keyword(s):

Uniform Distribution ◽

Load Distribution ◽

Simple Formula ◽

Mechanical Design ◽

Numerical Results ◽

Maximal Length ◽

Major Influence ◽

Length Variation ◽

Spring Stiffness ◽

Failure Risk

There are many applications in mechanical design where load distribution is modelled with parallel springs. Here random variation in spring length and spring stiffness is considered. Length variation is assumed to be the major influence and the case with uniform distribution is analyzed in detail. Small variations in spring stiffness are included. Numerical results are given. A simple formula is presented which gives the maximal length deviation as a function of the number of springs. The formula is based on a 10 percent failure risk which is a common number in practical mechanical design.

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