scholarly journals Variation and Evolution of Human Centromeres: A Field Guide and Perspective

2021 ◽  
Vol 55 (1) ◽  
pp. 583-602
Author(s):  
Karen H. Miga ◽  
Ivan A. Alexandrov
Keyword(s):  
Genome Instability ◽  
Artificial Chromosome ◽  
Human Artificial Chromosome ◽  
Epigenetic Variation ◽  
Data Sets ◽  
Satellite Repeat ◽  
New Era ◽  
Sequence Organization ◽  
Repeat Structure ◽  
Definition Of

We are entering a new era in genomics where entire centromeric regions are accurately represented in human reference assemblies. Access to these high-resolution maps will enable new surveys of sequence and epigenetic variation in the population and offer new insight into satellite array genomics and centromere function. Here, we focus on the sequence organization and evolution of alpha satellites, which are credited as the genetic and genomic definition of human centromeres due to their interaction with inner kinetochore proteins and their importance in the development of human artificial chromosome assays. We provide an overview of alpha satellite repeat structure and array organization in the context of these high-quality reference data sets; discuss the emergence of variation-based surveys; and provide perspective on the role of this new source of genetic and epigenetic variation in the context of chromosome biology, genome instability, and human disease.

Molecular and Cytological Analyses of Large Tracks of Centromeric DNA Reveal the Structure and Evolutionary Dynamics of Maize Centromeres

Genetics ◽  
2003 ◽  
Vol 163 (2) ◽  
pp. 759-770 ◽  
Author(s):  
Kiyotaka Nagaki ◽  
Junqi Song ◽  
Robert M Stupar ◽  
Alexander S Parokonny ◽  
Qiaoping Yuan ◽  
...  
Keyword(s):  
Evolutionary Dynamics ◽  
Artificial Chromosome ◽  
Grass Species ◽  
Sequence Motifs ◽  
Long Terminal Repeats ◽  
Satellite Repeat ◽  
Sequence Comparisons ◽  
Centromeric Dna ◽  
Conserved Sequence ◽  
Satellite Sequences

Abstract We sequenced two maize bacterial artificial chromosome (BAC) clones anchored by the centromere-specific satellite repeat CentC. The two BACs, consisting of ∼200 kb of cytologically defined centromeric DNA, are composed exclusively of satellite sequences and retrotransposons that can be classified as centromere specific or noncentromere specific on the basis of their distribution in the maize genome. Sequence analysis suggests that the original maize sequences were composed of CentC arrays that were expanded by retrotransposon invasions. Seven centromere-specific retrotransposons of maize (CRM) were found in BAC 16H10. The CRM elements inserted randomly into either CentC monomers or other retrotransposons. Sequence comparisons of the long terminal repeats (LTRs) of individual CRM elements indicated that these elements transposed within the last 1.22 million years. We observed that all of the previously reported centromere-specific retrotransposons in rice and barley, which belong to the same family as the CRM elements, also recently transposed with the oldest element having transposed ∼3.8 million years ago. Highly conserved sequence motifs were found in the LTRs of the centromere-specific retrotransposons in the grass species, suggesting that the LTRs may be important for the centromere specificity of this retrotransposon family.

scholarly journals Quantification of Ligand PET Studies using a Reference Region with a Displaceable Fraction: Application to Occupancy Studies with [11C]-DASB as an Example

2011 ◽  
Vol 32 (1) ◽  
pp. 70-80 ◽  
Author(s):  
Federico E Turkheimer ◽  
Sudhakar Selvaraj ◽  
Rainer Hinz ◽  
Venkatesha Murthy ◽  
Zubin Bhagwagar ◽  
...  
Keyword(s):  
Specific Binding ◽  
Normal Subjects ◽  
Volume Of Distribution ◽  
Binding Potential ◽  
Accurate Estimation ◽  
Data Sets ◽  
Reference Region ◽  
Reference Tissue ◽  
Positron Emission ◽  
Definition Of

This paper aims to build novel methodology for the use of a reference region with specific binding for the quantification of brain studies with radioligands and positron emission tomography (PET). In particular: (1) we introduce a definition of binding potential BPD = DVR–1 where DVR is the volume of distribution relative to a reference tissue that contains ligand in specifically bound form, (2) we validate a numerical methodology, rank-shaping regularization of exponential spectral analysis (RS-ESA), for the calculation of BPD that can cope with a reference region with specific bound ligand, (3) we demonstrate the use of RS-ESA for the accurate estimation of drug occupancies with the use of correction factors to account for the specific binding in the reference. [11C]-DASB with cerebellum as a reference was chosen as an example to validate the methodology. Two data sets were used; four normal subjects scanned after infusion of citalopram or placebo and further six test—retest data sets. In the drug occupancy study, the use of RS-ESA with cerebellar input plus corrections produced estimates of occupancy very close the ones obtained with plasma input. Test-retest results demonstrated a tight linear relationship between BPD calculated either with plasma or with a reference input and high reproducibility.

Chinese Intellectuals as Represented in ‘New Era’ Fictional Dialogues

2017 ◽  
Author(s):  
Hui Lai
Keyword(s):  
Key Words ◽  
Stylistic Analysis ◽  
Dual Model ◽  
New Era ◽  
Qualitative Approaches ◽  
Diachronic Change ◽  
The Status ◽  
Diachronic Study ◽  
Chinese Intellectuals ◽  
Definition Of

This book explores the status of Chinese intellectuals from 1980 to 2005 and its diachronic change in this period, as represented by dialogues between intellectuals and their leaders in fiction. June 1989 serves as a historical dividing line on which to base this diachronic study. In order to carry out the study, first, the direct speech of intellectuals and their leaders is extracted and compiled into corpora for a ‘key key-words’ analysis (see section 3.3.2 for a definition of key key-words). Second, a stylistic analysis is undertaken with the aim of conducting a more detailed qualitative investigation of the dialogues. Three dialogues in each of the two periods are selected for the stylistic analysis. The key-words derived from this analysis describe features of the speech of intellectuals, the speech of intellectuals as compared to the speech of leaders and the speech of leaders as compared to that of intellectuals. The study shows that the key key-words indicating topics of the speech and those characterising the style of the speech represent the social identity of intellectuals. A comparison of these key keywords between the two periods uncovers the diachronic change in the status of intellectuals. The corpus approach is complemented by a stylistic analysis, which explores dialogues selected from different years to emphasise the diachronic change. A dual model is formulated to incorporate dialogue analysis into a larger structure of goal development analysis. The study shows how speakers use discursive strategies to manage relationships and have their situational goals achieved in interaction. Negotiation of goals invokes the institutional and social identities of speakers, bringing out their status. The research shows that the corpus approach and the stylistic analysis can be combined to present a more comprehensive description of data. It is hoped that this will shed some light on studies of post-Cultural Revolution Chinese intellectuals and on how quantitative and qualitative approaches merge in the investigation of interaction between superiors and subordinates.

scholarly journals Market factors related to hospitals’ patient satisfaction ratings

2015 ◽  
Vol 4 (4) ◽  
pp. 40 ◽  
Author(s):  
Abby Swanson Kazley ◽  
Eric W. Ford ◽  
Mark Diana ◽  
Nir Menachemi
Keyword(s):  
Patient Satisfaction ◽  
Pay For Performance ◽  
Data Sets ◽  
New Era ◽  
Scarce Resources ◽  
Patient Protection ◽  
Market Factors ◽  
External Forces ◽  
The Relationship ◽  
Improve Patient

Patient satisfaction is an important dimension of care that has been linked to improved clinical outcomes and increased compliance as well as organizational success. The passage of the Patient Protection and Affordable Care Act included rules that incentivize hospitals to improve patient satisfaction by offering increased reimbursements. In this analysis, three data sets are used to retrospectively examine the relationship between environmental market factors and patient satisfaction. We find that per capita income within the hospital’s catchment area, competition, metro status, and availability of general and specialty practitioners are significantly associated with hospitals’ patient satisfaction levels. In a new era of pay-for-performance and increased competition for scarce resources, hospitals must closely monitor and respond to external forces. One strategy for overcoming a turbulent external environment may be to focus on patient satisfaction.

scholarly journals Indicators of AEI Applied to the Delaware Estuary

2002 ◽  
Vol 2 ◽  
pp. 169-189 ◽  
Author(s):  
Lawrence W. Barnthouse ◽  
Douglas G. Heimbuch ◽  
Vaughn C. Anthony ◽  
Ray W. Hilborn ◽  
Ransom A. Myers
Keyword(s):  
Meta Analysis ◽  
Juvenile Fish ◽  
Fish Populations ◽  
Weight Of Evidence ◽  
Data Sets ◽  
Delaware Estuary ◽  
Fish Stocks ◽  
Trends Analysis ◽  
Definition Of

We evaluated the impacts of entrainment and impingement at the Salem Generating Station on fish populations and communities in the Delaware Estuary. In the absence of an agreed-upon regulatory definition of “adverse environmental impact” (AEI), we developed three independent benchmarks of AEI based on observed or predicted changes that could threaten the sustainability of a population or the integrity of a community.Our benchmarks of AEI included: (1) disruption of the balanced indigenous community of fish in the vicinity of Salem (the “BIC” analysis); (2) a continued downward trend in the abundance of one or more susceptible fish species (the “Trends” analysis); and (3) occurrence of entrainment/impingement mortality sufficient, in combination with fishing mortality, to jeopardize the future sustainability of one or more populations (the “Stock Jeopardy” analysis).The BIC analysis utilized nearly 30 years of species presence/absence data collected in the immediate vicinity of Salem. The Trends analysis examined three independent data sets that document trends in the abundance of juvenile fish throughout the estuary over the past 20 years. The Stock Jeopardy analysis used two different assessment models to quantify potential long-term impacts of entrainment and impingement on susceptible fish populations. For one of these models, the compensatory capacities of the modeled species were quantified through meta-analysis of spawner-recruit data available for several hundred fish stocks.All three analyses indicated that the fish populations and communities of the Delaware Estuary are healthy and show no evidence of an adverse impact due to Salem. Although the specific models and analyses used at Salem are not applicable to every facility, we believe that a weight of evidence approach that evaluates multiple benchmarks of AEI using both retrospective and predictive methods is the best approach for assessing entrainment and impingement impacts at existing facilities.

scholarly journals Markers of hikikomori in young people dur

2021 ◽  
pp. 70-74
Author(s):  
Inna Chuhueva ◽  
Viktoriia Sakovska
Keyword(s):  
Fast Food ◽  
Educational Activity ◽  
Psychological State ◽  
Defence Mechanism ◽  
High Susceptibility ◽  
New Era ◽  
Long Time ◽  
Definition Of ◽  
The Impact ◽  
Very High

The article summarizes the definition of the term “hikikomori”, analyzes the situation of quarantine restriction: its essence and features of the impact on adolescence. Peculiarities of manifestation of hikikomori markers at adolescence are determined. We consider the studied phenomenon in the system of approaches like a way to meet needs, as a set of manifestations of syndromes of a new era, as a psychological defence mechanism, as a psychological state and process. Depending on the intensity of markers, we divide hikikomori into counter-dependent, poorly adaptable and interdependent, super dependent. The parameters that determine the level of manifestations of hikikomori include antisocial solitude at home, antisocially with leaving the house, selective society. The levels of manifestation of hikikomori include physical, emotional, social. Quarantine restrictions, as unusual living conditions that require forced solitude, selfisolation can be a factor that encourages the emergence of markers of hikikomori in adolescents. Such people have a shift in activity in cyberspace and at night, inseparable stay with the gadget (during meals, in the bathroom, in the toilet, etc.). Neglect of the organization of life (do not clean the bed after sleep, do not clean the room for a long time, do not change clothes during the day and wear night pyjamas around the clock, neglect a healthy diet, eat outside the regime, mostly fast food, etc.). In communication with others, they show irritability with the desire to avoid contact and solitude in their room. Also, at such a person, disorganization of educational activity hastily is observed. It is difficult for them to organize the learning process; they show procrastination (postponement of tasks). If the classes are as videoconferencing, they do not include video and microphone. They are away from contact with the group and the teacher, even if they need contact for feedback, they ignore it. An empirical study of the susceptibility to hikikomori markers in adolescents revealed that about 40% of subjects have a high susceptibility to hikikomori markers, and almost 11% of young men – very high.

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