Mutation Rate and Spectrum

2021 ◽  
Author(s):  
Charles F. Baer
Keyword(s):  
Population Genetics ◽  
Mutation Rate ◽  
State Of The Art ◽  
Empirical Studies ◽  
Parent Cell ◽  
Higher Taxa ◽  
Theoretical Investigations ◽  
Sources Of Variation ◽  
Many Sources ◽  
Mutational Process

Many an introductory or general overview of the biology of mutation begins with the phrase “mutation is the ultimate source of genetic variation.” In the absence of mutation, one genome sequence would eventually become fixed in every species, recombination would become irrelevant, and evolution would grind to a halt. Thus, metaphorically, mutation is the fuel of evolution. To begin, it is important to define what is meant by “mutation.” For the purposes of this article, mutation is defined as the condition in which homologous DNA sequence differs between the parent cell at its origin and the daughter cell at its origin. Of primary interest are those mutations that are heritable across generations. Mutations result either from errors during replication that are not repaired, or damage to nonreplicating DNA that is not repaired prior to the next round of replication. Both of those points of control admit many sources of variation. In this article, mutation is considered in two contexts. First, papers that investigate causes of variation in the mutational process, and second, papers that investigate consequences of variation in the mutational process. The former includes theoretical investigations of the evolution of the mutation rate, as well as empirical studies of variation in the rate and molecular spectrum of mutation within genomes and between individuals and higher taxa. The latter category includes both theoretical and empirical studies of how variation in either the rate or spectrum of mutation affects the phenotype, and especially fitness. The focus is broad, including classical one- and two-locus population genetics, modern sequence-based population genetics, molecular genetics, and quantitative genetics. Theoretical studies are overrepresented, and empirical studies are bimodally distributed, with modes at the old (“classical”) and very recent (“state of the art”).

scholarly journals Beyond Mindfulness

Open Theology ◽  
2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Thomas G. Plante
Keyword(s):  
Research Evidence ◽  
State Of The Art ◽  
Empirical Studies ◽  
Religion And Spirituality ◽  
Spiritual Values ◽  
Quality Research ◽  
The Past ◽  
Enormous Amount ◽  
Consulting Psychology ◽  
Areas Of Interest

AbstractSince the publication of Bergin’s classic 1980 paper “Psychotherapy and Religious Values” in the Journal of Clinical and Consulting Psychology, an enormous amount of quality research has been conducted on the integration of religious and spiritual values and perspectives into the psychotherapy endeavor. Numerous empirical studies, chapters, books, blogs, and specialty organizations have emerged in the past 35 years that have helped researchers and clinicians alike come to appreciate the value of religion and spirituality in the psychotherapeutic process. While so much has been accomplished in this area of integration, so much more needs to occur in order for the psychotherapeutic world to benefit from the wisdom of the great religious and spiritual traditions and values. While state-of-the-art quality research has and continues to demonstrate how religious and spiritual practices and values can be used effectively to enhance the benefits of behavioral and psychological interventions, too often the field either gets overly focused on particular and perhaps trendy areas of interest (e.g., mindfulness) or fails to appreciate and incorporate the research evidence supporting (or not supporting) the use of certain religiously or spiritually informed assessments and interventions. The purpose of this article is to reflect on where the field integrating religion, spirituality and psychotherapy has evolved through the present and where it still needs to go in the future. In doing so I hope to reflect on the call for integration that Bergin highlights in his classic 1980 paper.

scholarly journals Students' engagement in school and family variables: A literature review

2016 ◽  
Vol 33 (2) ◽  
pp. 187-197 ◽  
Author(s):  
Feliciano Henriques VEIGA ◽  
Viorel ROBU ◽  
Joseph CONBOY ◽  
Adriana ORTIZ ◽  
Carolina CARVALHO ◽  
...  
Keyword(s):  
Parental Support ◽  
State Of The Art ◽  
Empirical Studies ◽  
Dropping Out ◽  
School Variables ◽  
Family Contexts ◽  
Perceived Parental Support ◽  
Family Variables ◽  
A Current

"Students' engagement in school" is regarded in the literature as a current and valued construct despite the lack of empirical studies on its relationship with specific family variables. The present research aimed to survey studies on the correlation between students' engagement in school and family contexts, specifically in terms of the following variables: perceived parental support, socioeconomic and sociocultural levels, perceived rights, and parental educational styles. In order to describe the state of the art of student's "engagement in school" and "family variables", a narrative review was conducted. The studies reviewed highlight the role of family as a context with significance in student's engagement in school. However, further research is needed to deepen the knowledge of this topic considering potential mediator variables, either personal or school variables. It was also found the need for a psychosocial intervention aimed at providing support for the students coming from adverse family contexts who exhibit low level of engagement associated with poor academic achievement and a higher probability of dropping out.

THE ASPECT HYPOTHESIS AND THE ACQUISITION OF L2 PAST MORPHOLOGY IN THE LAST 20 YEARS

2020 ◽  
Vol 42 (5) ◽  
pp. 1137-1167
Author(s):  
Kathleen Bardovi-Harlig ◽  
Llorenç Comajoan-Colomé
Keyword(s):  
Second Language ◽  
Second Language Acquisition ◽  
Language Acquisition ◽  
State Of The Art ◽  
Coming Of Age ◽  
Empirical Studies ◽  
Future Research ◽  
Aspect Hypothesis ◽  
Tense And Aspect ◽  
The Third

AbstractTwenty years ago, a state-of-the-art review in SSLA marked the coming of age of the study of temporality in second language acquisition. This was followed by three monographs on tense and aspect the next year. This article presents a state-of-the-scholarship review of the last 20 years of research addressing the aspect hypothesis (AH) (Andersen, 1991, 2002; Andersen & Shirai, 1994, 1996), the most tested hypothesis in L2 temporality research. The first section of the article gives an overview of the AH and examines its central tenets, and then explores the results of empirical studies that test the hypothesis. The second section considers studies that have investigated four crucial variables in the acquisition of temporality and the testing of the AH. The third section discusses theoretically motivated areas of future research within the framework of the hypothesis.

Bacitracin Determination in Feeds: Evaluation of Methods

1981 ◽  
Vol 64 (4) ◽  
pp. 980-990
Author(s):  
Hussein S Ragheb
Keyword(s):  
Contributing Factors ◽  
Plate Method ◽  
Large Variability ◽  
Collaborative Studies ◽  
Different Types ◽  
Test Organisms ◽  
Sources Of Variation ◽  
Zinc Bacitracin ◽  
Many Sources ◽  
Evaluation Of Methods

Abstract Assay of bacitracin activity in feeds is subject to many sources of variation. Bacitracin standards are complex mixtures and may contain various amounts of less active forms of bacitracin. Test organisms may respond differently to these mixtures. Collaborative studies should involve the use of one standard, perhaps USP zinc bacitracin. The use of different types of bacitracin standards (regular or zinc) in a laboratory may contribute to variation in sample potency. The pyridine extraction method is subject to serious operational difficulties. Among the contributing factors are incomplete evaporation of pyridine (causing positive bias), allowing the temperature to increase too much during evaporation (causing negative bias), and the numerous manipulative steps in the technique (causing large variability). Because of these factors and the toxic properties of pyridine, the method finds little use. Methanol extraction offers a better substitute for determining zinc or methylene disalicylate bacitracin in premixes and complete feeds by the plate method.

Early intervention systems for police: a state-of-the-art review

2020 ◽  
Vol 43 (4) ◽  
pp. 643-658 ◽  
Author(s):  
Christi L. Gullion ◽  
William R. King
Keyword(s):  
Systematic Review ◽  
Early Intervention ◽  
State Of The Art ◽  
Empirical Studies ◽  
Health And Wellness ◽  
Content Type ◽  
Individual Agency ◽  
Police Agencies ◽  
Reference Service ◽  
Systems Effectiveness

PurposeThe purpose of this paper is to provide a comprehensive literature review of prior empirical studies that have examined early intervention (EI) systems or programs in policing.Design/methodology/approachA systematic literature search of various government and academic databases (e.g. Emerald, Google Scholar, National Criminal Justice Reference Service (NCJRS), Sage, Taylor & Francis and Wiley) was conducted.FindingsThis systematic review identified eight EI studies that matched the selection criteria. Of these, two are multiagency studies and six are individual agency studies. Findings across studies are generally positive but overall relatively inconsistent with regard to EI systems' effectiveness.Practical implicationsPolice agencies benefit in identifying and addressing at-risk officers to ensure police accountability and officer safety, health and wellness. This research is invaluable for optimizing how EI systems can use agency data for such predictions.Originality/valueThis state-of-the-art review on EI systems in policing is the first of its kind. EI systems have been implemented by many police agencies, yet a limited number of empirical studies have been conducted. This systematic review will be useful for researchers who wish to further explore how EI systems are utilized and whether EI systems are successful/effective.

Death and Progress: How Evolvability is Influenced by Intrinsic Mortality

2020 ◽  
Vol 26 (1) ◽  
pp. 90-111 ◽  
Author(s):  
Frank Veenstra ◽  
Pablo González de Prado Salas ◽  
Kasper Stoy ◽  
Josh Bongard ◽  
Sebastian Risi
Keyword(s):  
Mortality Rate ◽  
Mutation Rate ◽  
Spatial Model ◽  
Fitness Landscape ◽  
State Of The Art ◽  
Global Maximum ◽  
Random Genetic Drift ◽  
Internal Factors ◽  
Programmed Death ◽  
Intrinsic Mortality

Many factors influence the evolvability of populations, and this article illustrates how intrinsic mortality (death induced through internal factors) in an evolving population contributes favorably to evolvability on a fixed deceptive fitness landscape. We test for evolvability using the hierarchical if-and-only-if (h-iff) function as a deceptive fitness landscape together with a steady state genetic algorithm (SSGA) with a variable mutation rate and indiscriminate intrinsic mortality rate. The mutation rate and the intrinsic mortality rate display a relationship for finding the global maximum. This relationship was also found when implementing the same deceptive fitness landscape in a spatial model consisting of an evolving population. We also compared the performance of the optimal mutation and mortality rate with a state-of-the-art evolutionary algorithm called age-fitness Pareto optimization (AFPO) and show how the two approaches traverse the h-iff landscape differently. Our results indicate that the intrinsic mortality rate and mutation rate induce random genetic drift that allows a population to efficiently traverse a deceptive fitness landscape. This article gives an overview of how intrinsic mortality influences the evolvability of a population. It thereby supports the premise that programmed death of individuals could have a beneficial effect on the evolvability of the entire population.

scholarly journals Missed opportunities: two case studies of digitalization of FM in hospitals

Facilities ◽  
2019 ◽  
Vol 37 (7/8) ◽  
pp. 381-394 ◽  
Author(s):  
Christian Koch ◽  
Geir Karsten Hansen ◽  
Kim Jacobsen
Keyword(s):  
Case Studies ◽  
State Of The Art ◽  
Empirical Studies ◽  
Facility Management ◽  
Missed Opportunities ◽  
Building Projects ◽  
Content Type ◽  
Organization And Management ◽  
Building Information ◽  
Complex Building

Purpose Digital practices of facility management (FM) are undergoing transformation. Several Nordic countries have ambitious hospital-building projects, driven by large public clients with long-term experience of operating complex building campuses. There is thus an opportunity for creating state-of-the-art digital FM. This paper aims to investigate the role of digital FM in new hospital projects in Scandinavia. Design/methodology/approach Based on a literature review, a framework of understanding of digital FM in hospital operation is established. Two longitudinal cases are presented and analysed, one for a greenfield hospital and the other for an extension of an existing hospital. Findings The literature highlights the importance of integration between technical digitalization, competences, organization and management of digital FM. The projects are in different phases and represent quite advanced preparations for digital FM. State-of-the-art computer-aided FM systems are prepared before operation. External consultants are involved, posing a dilemma of in-house/outsourced human resources in the future digital FM operation. Research limitations/implications Two case studies provide insights, but they have limited generalizability. Practical implications The study underscores the importance of preparation of management, organization and competences for digitalization. Originality/value Documented research on building information modelling (BIM) integrations in FM is still scarce. This article adds to the few empirical studies in the area. The findings illustrate that real estate administrators investing in FM software for new hospital buildings face challenges of aligning BIM models from design and construction to the FM system.

INTEGRATING STATE-OF-THE-ART SHORELINE INTERACTION KNOWLEDGE INTO SPILL MODELING

2008 ◽  
Vol 2008 (1) ◽  
pp. 915-922 ◽  
Author(s):  
Dagmar Schmidt Etkin ◽  
Jacqueline Michel ◽  
Deborah French McCay ◽  
Michel Boufadel ◽  
Hailong Li
Keyword(s):  
Literature Review ◽  
Oil Spill ◽  
Risk Model ◽  
State Of The Art ◽  
Empirical Studies ◽  
Practical Method ◽  
Complex Interaction ◽  
Laboratory Research ◽  
It Impacts ◽  
Comprehensive Literature Review

ABSTRACT An understanding of the complex interaction between oil and shoreline sediments in nearshore areas after an oil spill is essential for more accurate oil spill risk analysis modeling. In particular, an estimation of the degree to which shoreline sediments hold and retain oil during the 10–30 days after a spill is required for modeling the fate and trajectory of oil as it impacts a shoreline and either strands on or penetrates into the sediment or refloats to be deposited elsewhere. A comprehensive literature review of empirical studies, laboratory research, and oil-shoreline modeling was conducted. For a spill risk model to be applied in a stochastic manner, a relatively simple and practical method to estimate the oil holding capacity of shoreline sediments based on shoreline type and oil properties was derived from empirical shoreline cleanup assessment team (SCAT) data and a theoretical hydraulics model. The suggested methodology can be applied by spill modelers needing a way to estimate the amount of oil held by a shoreline upon impact to allow a trajectory model to more accurately project the total spread of oil.

Federal intervention of police under section 14141 – a state-of-the-art literature review

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jason W. Ostrowe
Keyword(s):  
Scoping Review ◽  
State Of The Art ◽  
Empirical Studies ◽  
Empirical Literature ◽  
Future Research ◽  
Content Type ◽  
Gray Literature ◽  
Federal Intervention ◽  
Trade Offs ◽  
National Police

PurposeThe purpose of this state-of-the-art review is to explore the empirical literature on federal intervention of police under 42 USC Section 14141.Design/methodology/approachA five-stage scoping review of the empirical literature related to 14141 was conducted through searches of scholarly databases and gray literature.FindingsThis scoping review revealed 21 empirical studies of 14141 published between 2002 and 2020 in criminal justice, criminology, legal and gray literature. Researchers employed various methodologies and designs to study 14141 reflecting the complexity of evaluating a multistage and multi-outcome federal intervention of police. The success of 14141 to reform police agencies is mixed. The empirical evidence suggests that application of this law is fraught with trade-offs and uncertainties including de-policing, increased crime and organizational difficulties in sustaining reform. Overall, more research would assist in understanding the efficacy of this federal mechanism of police accountability and reform.Originality/valueThis review is the first synthesis of the empirical literature on 14141. In consideration of the current national police crisis, findings help illuminate both what is known about federal intervention and areas for future research.

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