scholarly journals Ancient DNA reveals that few GWAS loci have been strongly selected during recent human history

2021 ◽  
Author(s):  
Corinne N. Simonti ◽  
Joseph Lachance
Keyword(s):  
Hereditary Disease ◽  
Neutral Evolution ◽  
Mhc Genes ◽  
Signature Of Selection ◽  
Bayesian Inference Method ◽  
Disease Risks ◽  
New Evidence ◽  
Ancient Individual ◽  
Over Time ◽  
Selection Of

AbstractGenetic data from ancient humans has provided new evidence in the study of loci thought to be under historic selection, and thus is a powerful tool for identifying instances of selection that might be missed by methods that use present-day samples alone. Using a curated set of disease-associated variants from the NHGRI-EBI GWAS Catalog, we provide an analysis to identify disease-associated variants that bear signatures of selection over time. After accounting for the fact that not every ancient individual contributed equally to modern genomes, a Bayesian inference method was used to infer allele frequency trajectories over time and determine which disease-associated loci exhibit signatures of natural selection. Of the 2,709 variants analyzed in this study, 895 show at least a weak signature of selection (|s| > 0.001), including multiple variants that are introgressed from Neanderthals. However, only nine disease-associated variants show a signature of strong selection (|s| > 0.01). Additionally, we find that many risk-associated alleles have increased in frequency during the past 10,000 years. Overall, we find that disease-associated variants from GWAS are governed by nearly neutral evolution. Exceptions to this broad pattern include GWAS loci that protect against asthma and variants in MHC genes. Ancient samples allow us an unprecedented look at how our species has changed over time, and our results represent an important early step in using this new source of data to better understand the evolution of hereditary disease risks.

scholarly journals Response to Fuson, Clements, and Sarama Commentary on Litkowski, Duncan, Logan, and Purpura (2020)

AERA Open ◽  
2021 ◽  
Vol 7 ◽  
pp. 233285842110271
Author(s):  
David J. Purpura ◽  
Ellen C. Litkowski ◽  
Robert J. Duncan ◽  
Jessica A. R. Logan
Keyword(s):  
Young Children ◽  
Grade Level ◽  
High Quality ◽  
Equity Issues ◽  
Quality Instruction ◽  
New Evidence ◽  
Over Time

In response to Fuson et al.’s commentary on Litkowski et al. (2020), we clarify and expand on three areas: (1) the need for prekindergarten standards, (2) the value in developmental survey work, and (3) the importance of understanding curriculum translation and uptake. Specifically, we note that standards need to be appropriate for grade-level and it is time for more aligned prekindergarten standards. Developmental survey work is critical for ensuring that standards and expectations are accurate and adjusted to meet current needs and can be used address equity issues in instruction. Furthermore, we agree that intervention and curriculum work are needed, but there should be explicit emphasis on enhancing uptake and use of high-quality instruction. Ultimately, we need a system of assessment and instruction that is continually updated and improved, that integrates and modifies new evidence over time to ensure that we are striving for—and attaining—the best results for young children.

scholarly journals Acceleration in the bilingual acquisition of phonological structure: Evidence from Polish–English bilingual children

2014 ◽  
Vol 18 (4) ◽  
pp. 713-725 ◽  
Author(s):  
MARCO TAMBURELLI ◽  
EIRINI SANOUDAKI ◽  
GARY JONES ◽  
MICHELLE SOWINSKA
Keyword(s):  
Nonword Repetition ◽  
Bilingual Children ◽  
Consonant Clusters ◽  
Phonological Structure ◽  
English Bilingual ◽  
Two Factors ◽  
New Evidence ◽  
Phonological Complexity ◽  
Repetition Task ◽  
Selection Of

This study examines the production of consonant clusters in simultaneous Polish–English bilingual children and in language-matched English monolinguals (aged 7;01–8;11). Selection of the language pair was based on the fact that Polish allows a greater range of consonant clusters than English. A nonword repetition task was devised in order to examine clusters of different types (obstruent-liquid vs. s + obstruent) and in different word positions (initial vs. medial), two factors that play a significant role in repetition accuracy in monolingual acquisition (e.g., Kirk & Demuth, 2005). Our findings show that bilingual children outperformed monolingual controls in the word initial s + obstruent condition. These results indicate that exposure to complex word initial clusters (in Polish) can accelerate the development of less phonologically complex clusters (in English). This constitutes significant new evidence that the facilitatory effects of bilingual acquisition extend to structural phonological domains. The implications that these results have on competing views of phonological organisation and phonological complexity are also discussed.

scholarly journals Three Evidence Based Methods to Compensate for a Lack of Subject Background when Ordering Chemistry Monographs

2008 ◽  
Vol 3 (3) ◽  
pp. 3
Author(s):  
Robert A. Wright
Keyword(s):  
Statistical Analysis ◽  
Statistical Significance ◽  
Evidence Base ◽  
Circulation Rate ◽  
Evidence Based ◽  
Practical Application ◽  
Present Evidence ◽  
Library System ◽  
Over Time ◽  
Selection Of

Objective – The aim of this article is to present evidence based methods for the selection of chemistry monographs, particularly for librarians lacking a background in chemistry. These methods will be described in detail, their practical application illustrated, and their efficacy tested by analyzing circulation data. Methods – Two hundred and ninety-five chemistry monographs were selected between 2005 and 2007 using rigorously-applied evidence based methods involving the Library's integrated library system (ILS), Google, and SciFinder Scholar. The average circulation rate of this group of monographs was compared to the average circulation rate of 254 chemistry monographs selected between 2002 and 2004 when the methods were not used or were in an incomplete state of development. Results – Circulations/month were on average 9% greater in the cohort of monographs selected with the rigorously-applied evidence based methods. Further statistical analysis, however, finds that this result can not be attributed to the different application of these methods. Conclusion – The methods discussed in this article appear to provide an evidence base for the selection of chemistry monographs, but their application does not change circulation rates in a statistically significant way. Further research is needed to determine if this lack of statistical significance is real or a product of the organic development and application of these methods over time, making definitive comparisons difficult.

scholarly journals Kilburn High Road Revisited

2016 ◽  
Vol 1 (2) ◽  
pp. 128-140 ◽  
Author(s):  
Cristina Capineri
Keyword(s):  
Sense Of Place ◽  
Service Management ◽  
Street Life ◽  
The Many ◽  
High Road ◽  
Simple Narrative ◽  
Unique Relationship ◽  
Over Time ◽  
Selection Of

Drawing on John Agnew’s (1987) theoretical framework for the analysis of place (location, locale and sense of place) and on Doreen Massey’s (1991) interpretation of Kilburn High Road (London), the contribution develops an analysis of the notion of place in the case study of Kilburn High Road by comparing the semantics emerging from Doreen Massey’s interpretation of Kilburn High Road in the late Nineties with those from a selection of noisy and unstructured volunteered geographic information collected from Flickr photos and Tweets harvested in 2014–2015. The comparison shows how sense of place is dynamic and changing over time and explores Kilburn High Road through the categories of location, locale and sense of place derived from the qualitative analysis of VGI content and annotations. The contribution shows how VGI can contribute to discovering the unique relationship between people and place which takes the form given by Doreen Massey to Kilburn High Road and then moves on to the many forms given by people experiencing Kilburn High Road through a photo, a Tweet or a simple narrative. Finally, the paper suggests that the analysis of VGI content can contribute to detect the relevant features of street life, from infrastructure to citizens’ perceptions, which should be taken into account for a more human-centered approach in planning or service management.

scholarly journals Supporting the development of scientific understanding when constructing an evolving explanation

2022 ◽  
Vol 4 (1) ◽  
Author(s):  
Ann M. Novak ◽  
David F. Treagust
Keyword(s):  
Scientific Explanation ◽  
Project Based Learning ◽  
Incremental Development ◽  
Freshwater Organisms ◽  
Freshwater System ◽  
New Evidence ◽  
Scientific Ideas ◽  
Over Time

AbstractWe explore how students developed an integrated understanding of scientific ideas and how they applied their understandings in new situations. We examine the incremental development of 7th grade students’ scientific ideas across four iterations of a scientific explanation related to a freshwater system. We demonstrate that knowing how to make use of scientific ideas to explain phenomena needs to be learned just as developing integrated understanding of scientific ideas needs to be learned. Students participated in an open-ended, long-term project-based learning unit, constructing one explanation over time to address, “How healthy is our stream for freshwater organisms and how do our actions on land potentially impact the water quality of the stream?” The explanation developed over several weeks as new data were collected and analyzed. Students discussed evidence by revisiting scientific ideas and including new scientific ideas. This research investigates two questions: (1) As students engage in writing a scientific explanation over time, to what extent do they develop integrated understanding of appropriate scientific ideas? and (2) When writing about new evidence, do these earlier experiences of writing explanations enable students to make use of new scientific ideas in more sophisticated ways? In other words, do earlier experiences allow students to know how to make use of their ideas in these new situations? The results indicated statistically significant effects. Through various iterations of the explanation students included richer discussion using appropriate scientific ideas. Students were also able to make better use of new knowledge in new situations.

scholarly journals Modeling neutral viral mutations in the spread of SARS-CoV-2 epidemics

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255438
Author(s):  
Vitor M. Marquioni ◽  
Marcus A. M. de Aguiar
Keyword(s):  
Population Genetics ◽  
Analytical Solution ◽  
Genetic Distance ◽  
Mean Field ◽  
Neutral Evolution ◽  
Genetic Evolution ◽  
Epidemic Spreading ◽  
Different Strains ◽  
Over Time ◽  
Good Agreement

Although traditional models of epidemic spreading focus on the number of infected, susceptible and recovered individuals, a lot of attention has been devoted to integrate epidemic models with population genetics. Here we develop an individual-based model for epidemic spreading on networks in which viruses are explicitly represented by finite chains of nucleotides that can mutate inside the host. Under the hypothesis of neutral evolution we compute analytically the average pairwise genetic distance between all infecting viruses over time. We also derive a mean-field version of this equation that can be added directly to compartmental models such as SIR or SEIR to estimate the genetic evolution. We compare our results with the inferred genetic evolution of SARS-CoV-2 at the beginning of the epidemic in China and found good agreement with the analytical solution of our model. Finally, using genetic distance as a proxy for different strains, we use numerical simulations to show that the lower the connectivity between communities, e.g., cities, the higher the probability of reinfection.

scholarly journals Authoring the Strange: The Evolving Notions of Authorship in Prefaces to Classical Chinese Supernatural Fiction

2018 ◽  
Vol 8 (1) ◽  
pp. 34-55 ◽  
Author(s):  
Frances Weightman
Keyword(s):  
Classical Chinese ◽  
Authorial Persona ◽  
Over Time ◽  
Selection Of ◽  
Supernatural Fiction

Abstract This article considers the ways in which ideas of authorship have been portrayed in the authorial prefaces (zixu) to a selection of classical Chinese tales of the supernatural (zhiguai). It posits that the authorial preface is a unique forum for exploring the interplay between the author, reader and text. Within the controversial and contested tradition of writings about strange and otherworldly phenomena, it argues that over time the zixu provided a platform for the emergence of an increasingly individualised authorial persona.

Substitution of Synthetic Fibers by Bio-Based Fibers in a Structural Mortar

2022 ◽  
Author(s):  
Marie Audouin ◽  
Nicolas Philippe ◽  
Fabien Bernardeau ◽  
Mariann Chaussy ◽  
Sergio Pons Ribera ◽  
...  
Keyword(s):  
Carbon Capture ◽  
Natural Fibers ◽  
Second Step ◽  
Synthetic Fibers ◽  
Chemical Treatments ◽  
Formulation Parameters ◽  
Metallic Fibers ◽  
Important Objective ◽  
Over Time ◽  
Selection Of

The use of bio-based material is now widespread in insulation concrete, for example hemp concrete. The bio-based materials in concrete provide many advantages: lightness, sound and thermal insulation, hydrothermal regulation while contributing to a reduction in the environmental impact due to the carbon capture during the plant growth. The development of materials incorporating plant is therefore an important objective for the construction. The next step will be to introduce bio-based materials in structural mortars and concretes. The project FIBRABETON proposes to substitute synthetic or metallic fibers by natural fibers in screed and slab. After a selection of biomass on the resources availability, separation and fractionation are the key step in processing to obtain technical natural fibers. Bulk fiber shaping and packaging methods for easy handling and transportation are tested. Then, functionalization of technical natural fibers by physical & chemical treatments to improve the durability with cement paste is carried out. The second step concerns the introduction of treated or not treated fibers in mortar and concrete formulations. The variation of the nature of the biomass, fibers shape and dosage in concrete are studied. The workability, the compressive strength and withdrawal resistance are measured in order to obtain the best formulation parameters. The evolution of properties over time is also evaluated. The project FIBRABETON is carried out with ESTP, FRD and Vicat and is subsidized by ADEME, Grand Est region and FEDER.

scholarly journals Multi-Component Antioxidative System and Robust Carbohydrate Status, the Essence of Plant Arsenic Tolerance

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 283 ◽  
Author(s):  
Monika Kofroňová ◽  
Aneta Hrdinová ◽  
Petra Mašková ◽  
Jana Tremlová ◽  
Petr Soudek ◽  
...  
Keyword(s):  
Net Photosynthesis ◽  
Nicotiana Sylvestris ◽  
Arsenic Tolerance ◽  
Total Antioxidant ◽  
As Stress ◽  
First Time ◽  
Carbohydrate Status ◽  
New Evidence ◽  
Tolerant Genotype ◽  
Selection Of

Arsenic (As) contaminates the food chain and decreases agricultural production through impairing plants, particularly due to oxidative stress. To better understand the As tolerance mechanisms, two contrasting tobacco genotypes: As-sensitive Nicotiana sylvestris and As-tolerant N.tabacum, cv. ‘Wisconsin’ were analyzed. The most meaningful differences were found in the carbohydrate status, neglected so far in the As context. In the tolerant genotype, contrary to the sensitive one, net photosynthesis rates and saccharide levels were unaffected by As exposure. Importantly, the total antioxidant capacity was far stronger in the As-tolerant genotype, based on higher antioxidants levels (e.g., phenolics, ascorbate, glutathione) and activities and/or appropriate localizations of antioxidative enzymes, manifested as reverse root/shoot activities in the selected genotypes. Accordingly, malondialdehyde levels, a lipid peroxidation marker, increased only in sensitive tobacco, indicating efficient membrane protection in As-tolerant species. We bring new evidence of the orchestrated action of a broad spectrum of both antioxidant enzymes and molecules essential for As stress coping. For the first time, we propose robust carbohydrate metabolism based on undisturbed photosynthesis to be crucial not only for subsidizing C and energy for defense but also for participating in direct reactive oxygen species (ROS) quenching. The collected data and suggestions can serve as a basis for the selection of plant As phytoremediators or for targeted breeding of tolerant crops.

scholarly journals Multicriteria comparative analysis of pillars strengthening of the historic building

2019 ◽  
Vol 9 (1) ◽  
pp. 18-25 ◽  
Author(s):  
Katarzyna Kafel ◽  
Agnieszka Leśniak ◽  
Krzysztof Zima
Keyword(s):  
Comparative Analysis ◽  
Carrying Capacity ◽  
Evaluation Criteria ◽  
Historic Buildings ◽  
Historic Building ◽  
Wide Range ◽  
Over Time ◽  
Selection Of

AbstractOver time, historic buildings are exposed to various destructive mechanisms brought about by a wide range of damaging factors. Costs and methods of reinforcing their individual components are, among others, an important issue. The term "reinforcement" is linked with the concept of conservation, which stands for the actions taken with the aim of preserving a building. It provides a well-articulated system consisting of activities that lead to the reinforcement of the structure, usability enhancement or to the improvement of its carrying capacity. This article analyses the selection of an appropriate brick pillar reinforcement method, taking into account accepted evaluation criteria.

Sign in / Sign up

Export Citation Format

Share Document