scholarly journals Evolution of the patellar sesamoid bone in mammals

2016 ◽  
Author(s):  
Mark E Samuels ◽  
Sophie Regnault ◽  
John R Hutchinson
Keyword(s):  
Knee Joint ◽  
Meta Analysis ◽  
Large Body ◽  
Extensor Tendon ◽  
Initial Step ◽  
Sesamoid Bone ◽  
Crown Group ◽  
Evolutionary Origins ◽  
Lever System ◽  
Almost All

The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of the patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that patellae most likely evolved between four to six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals, and up to three times in therian mammals. Furthermore, a patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition), and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa). Where a patella is present it plays an important role in hindlimb function; especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats -- from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds -- remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across mammalian evolution. This meta-analysis takes an initial step toward such a synthesis by collating available data and elucidating areas of promising future inquiry.

scholarly journals Evolution of the patellar sesamoid bone in mammals

2017 ◽  
Author(s):  
Mark E Samuels ◽  
Sophie Regnault ◽  
John R Hutchinson
Keyword(s):  
Knee Joint ◽  
Meta Analysis ◽  
Large Body ◽  
Extensor Tendon ◽  
Initial Step ◽  
Sesamoid Bone ◽  
Crown Group ◽  
Evolutionary Origins ◽  
Lever System ◽  
Almost All

The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of the patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that patellae most likely evolved between four to six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals, and up to three times in therian mammals. Furthermore, a patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition), and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa). Where a patella is present it plays an important role in hindlimb function; especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats -- from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds -- remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across mammalian evolution. This meta-analysis takes an initial step toward such a synthesis by collating available data and elucidating areas of promising future inquiry.

scholarly journals Evolution of the patellar sesamoid bone in mammals

2017 ◽  
Author(s):  
Mark E Samuels ◽  
Sophie Regnault ◽  
John R Hutchinson
Keyword(s):  
Knee Joint ◽  
Meta Analysis ◽  
Large Body ◽  
Extensor Tendon ◽  
Initial Step ◽  
Sesamoid Bone ◽  
Crown Group ◽  
Evolutionary Origins ◽  
Lever System ◽  
Almost All

The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of the patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that patellae most likely evolved between four to six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals, and up to three times in therian mammals. Furthermore, a patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition), and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa). Where a patella is present it plays an important role in hindlimb function; especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats -- from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds -- remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across mammalian evolution. This meta-analysis takes an initial step toward such a synthesis by collating available data and elucidating areas of promising future inquiry.

scholarly journals Evolution of the patellar sesamoid bone in mammals

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3103 ◽  
Author(s):  
Mark E. Samuels ◽  
Sophie Regnault ◽  
John R. Hutchinson
Keyword(s):  
Knee Joint ◽  
Meta Analysis ◽  
Large Body ◽  
Extensor Tendon ◽  
Initial Step ◽  
Sesamoid Bone ◽  
Crown Group ◽  
Evolutionary Origins ◽  
Lever System ◽  
Almost All

The patella is a sesamoid bone located in the major extensor tendon of the knee joint, in the hindlimb of many tetrapods. Although numerous aspects of knee morphology are ancient and conserved among most tetrapods, the evolutionary occurrence of an ossified patella is highly variable. Among extant (crown clade) groups it is found in most birds, most lizards, the monotreme mammals and almost all placental mammals, but it is absent in most marsupial mammals as well as many reptiles. Here, we integrate data from the literature and first-hand studies of fossil and recent skeletal remains to reconstruct the evolution of the mammalian patella. We infer that bony patellae most likely evolved between four and six times in crown group Mammalia: in monotremes, in the extinct multituberculates, in one or more stem-mammal genera outside of therian or eutherian mammals and up to three times in therian mammals. Furthermore, an ossified patella was lost several times in mammals, not including those with absent hindlimbs: once or more in marsupials (with some re-acquisition) and at least once in bats. Our inferences about patellar evolution in mammals are reciprocally informed by the existence of several human genetic conditions in which the patella is either absent or severely reduced. Clearly, development of the patella is under close genomic control, although its responsiveness to its mechanical environment is also important (and perhaps variable among taxa). Where a bony patella is present it plays an important role in hindlimb function, especially in resisting gravity by providing an enhanced lever system for the knee joint. Yet the evolutionary origins, persistence and modifications of a patella in diverse groups with widely varying habits and habitats—from digging to running to aquatic, small or large body sizes, bipeds or quadrupeds—remain complex and perplexing, impeding a conclusive synthesis of form, function, development and genetics across mammalian evolution. This meta-analysis takes an initial step toward such a synthesis by collating available data and elucidating areas of promising future inquiry.

scholarly journals Independent evolution towards larger body size in the distinctive Faroe Island mice

2021 ◽  
Author(s):  
Ricardo Wilches ◽  
William H Beluch ◽  
Ellen McConnell ◽  
Diethard Tautz ◽  
Yingguang Frank Chan
Keyword(s):  
Body Size ◽  
Meta Analysis ◽  
Small Body ◽  
Laboratory Mouse ◽  
Large Body ◽  
Natural Populations ◽  
Size Variation ◽  
Phenotypic Traits ◽  
Island Population ◽  
Multiple Loci

Abstract Most phenotypic traits in nature involve the collective action of many genes. Traits that evolve repeatedly are particularly useful for understanding how selection may act on changing trait values. In mice, large body size has evolved repeatedly on islands and under artificial selection in the laboratory. Identifying the loci and genes involved in this process may shed light on the evolution of complex, polygenic traits. Here, we have mapped the genetic basis of body size variation by making a genetic cross between mice from the Faroe Islands, which are among the largest and most distinctive natural populations of mice in the world, and a laboratory mouse strain selected for small body size, SM/J. Using this F2 intercross of 841 animals, we have identified 111 loci controlling various aspects of body size, weight and growth hormone levels. By comparing against other studies, including the use of a joint meta-analysis, we found that the loci involved in the evolution of large size in the Faroese mice were largely independent from those of a different island population or other laboratory strains. We hypothesize that colonization bottleneck, historical hybridization, or the redundancy between multiple loci have resulted in the Faroese mice achieving an outwardly similar phenotype through a distinct evolutionary path.

scholarly journals A living WHO guideline on drugs to prevent covid-19

BMJ ◽  
2021 ◽  
pp. n526
Author(s):  
François Lamontagne ◽  
Thomas Agoritsas ◽  
Reed Siemieniuk ◽  
Bram Rochwerg ◽  
Jessica Bartoszko ◽  
...  
Keyword(s):  
Systematic Review ◽  
Guideline Development ◽  
Meta Analysis ◽  
World Health ◽  
Policy And Practice ◽  
Assessment Development ◽  
Research Priority ◽  
Health Organization ◽  
Almost All ◽  
Drug Interventions

Abstract Clinical question What is the role of drugs in preventing covid-19? Why does this matter? There is widespread interest in whether drug interventions can be used for the prevention of covid-19, but there is uncertainty about which drugs, if any, are effective. The first version of this living guideline focuses on the evidence for hydroxychloroquine. Subsequent updates will cover other drugs being investigated for their role in the prevention of covid-19. Recommendation The guideline development panel made a strong recommendation against the use of hydroxychloroquine for individuals who do not have covid-19 (high certainty). How this guideline was created This living guideline is from the World Health Organization (WHO) and provides up to date covid-19 guidance to inform policy and practice worldwide. Magic Evidence Ecosystem Foundation (MAGIC) provided methodological support. A living systematic review with network analysis informed the recommendations. An international guideline development panel of content experts, clinicians, patients, an ethicist and methodologists produced recommendations following standards for trustworthy guideline development using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Understanding the new recommendation The linked systematic review and network meta-analysis (6 trials and 6059 participants) found that hydroxychloroquine had a small or no effect on mortality and admission to hospital (high certainty evidence). There was a small or no effect on laboratory confirmed SARS-CoV-2 infection (moderate certainty evidence) but probably increased adverse events leading to discontinuation (moderate certainty evidence). The panel judged that almost all people would not consider this drug worthwhile. In addition, the panel decided that contextual factors such as resources, feasibility, acceptability, and equity for countries and healthcare systems were unlikely to alter the recommendation. The panel considers that this drug is no longer a research priority and that resources should rather be oriented to evaluate other more promising drugs to prevent covid-19. Updates This is a living guideline. New recommendations will be published in this article and signposted by update notices to this guideline. Readers note This is the first version of the living guideline for drugs to prevent covid-19. It complements the WHO living guideline on drugs to treat covid-19. When citing this article, please consider adding the update number and date of access for clarity.

Statistical and measurement pitfalls in the use of meta-regression in meta-analysis

2017 ◽  
Vol 22 (5) ◽  
pp. 469-476 ◽  
Author(s):  
Frank L. Schmidt
Keyword(s):  
Social Sciences ◽  
Organizational Behavior ◽  
Meta Analysis ◽  
Social Science Research ◽  
Science Research ◽  
Content Type ◽  
Marketing Social ◽  
Meta Regression ◽  
Meta Analyses ◽  
Almost All

Purpose Meta-regression is widely used and misused today in meta-analyses in psychology, organizational behavior, marketing, management, and other social sciences, as an approach to the identification and calibration of moderators, with most users being unaware of serious problems in its use. The purpose of this paper is to describe nine serious methodological problems that plague applications of meta-regression. Design/methodology/approach This paper is methodological in nature and is based on well-established principles of measurement and statistics. These principles are used to illuminate the potential pitfalls in typical applications of meta-regression. Findings The analysis in this paper demonstrates that many of the nine statistical and measurement pitfalls in the use of meta-regression are nearly universal in applications in the literature, leading to the conclusion that few meta-regressions in the literature today are trustworthy. A second conclusion is that in almost all cases, hierarchical subgrouping of studies is superior to meta-regression as a method of identifying and calibrating moderators. Finally, a third conclusion is that, contrary to popular belief among researchers, the process of accurately identifying and calibrating moderators, even with the best available methods, is complex, difficult, and data demanding. Practical implications This paper provides useful guidance to meta-analytic researchers that will improve the practice of moderator identification and calibration in social science research literatures. Social implications Today, many important decisions are made on the basis of the results of meta-analyses. These include decisions in medicine, pharmacology, applied psychology, management, marketing, social policy, and other social sciences. The guidance provided in this paper will improve the quality of such decisions by improving the accuracy and trustworthiness of meta-analytic results. Originality/value This paper is original and valuable in that there is no similar listing and discussion of the pitfalls in the use of meta-regression in the literature, and there is currently a widespread lack of knowledge of these problems among meta-analytic researchers in all disciplines.

scholarly journals Investigation of moderator factors in e-business adoption: A quantitative meta-analysis of moderating effects on the drivers of intention and behavior

2017 ◽  
Vol 14 (1) ◽  
pp. 75-102 ◽  
Author(s):  
Bostjan Sumak ◽  
Marjan Hericko ◽  
Zoran Budimac ◽  
Maja Pusnik
Keyword(s):  
Technology Acceptance ◽  
New Technologies ◽  
Causal Effect ◽  
Meta Analysis ◽  
Moderating Effect ◽  
Factors Affecting ◽  
Adoption Research ◽  
Acceptance Model ◽  
Almost All ◽  
Business Technology

E-business technology is becoming one of the most important global markets where e-business solutions will have to adapt to new technologies. The main objective in this study was to synthesize existing knowledge in the field of e-business technology acceptance and to understand differences in Technology Acceptance Model (TAM) related causal effect sizes for different e-business contexts. A quantitative meta-analysis of existing empirical research about factors affecting e-business adoption was conducted using 89 published papers that provided empirical data about causal relationships. A moderator analysis was carried out to investigate the moderating effect of four factors: consumer type, device type, continent and respondent type. The results of the study showed a moderating effect for all four proposed factors in almost all TAM-related causal paths. The study also showed that TAM is the most common theory being applied in e-business adoption research.

scholarly journals Cerebrospinal Fluid IgM and Oligoclonal IgG Bands in Multiple Sclerosis: A Meta-Analysis of Prevalence and Prognosis

2021 ◽  
Vol 11 (11) ◽  
pp. 1444
Author(s):  
Mattia Fonderico ◽  
Emilio Portaccio ◽  
Lorenzo Razzolini ◽  
Luisa Pastò ◽  
Angelo Bellinvia ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Systematic Review ◽  
Clinical Course ◽  
Meta Analysis ◽  
Clinically Isolated Syndrome ◽  
Relapsing Remitting ◽  
Oligoclonal Igg ◽  
Almost All ◽  
Present Systematic Review ◽  
Oligoclonal Igg Bands

The presence of intrathecal IgM synthesis (ITMS) has been associated with an aggressive multiple sclerosis (MS) clinical course. In the present systematic review, we aimed at assessing the prevalence of ITMS among different MS phenotypes. Moreover, we aimed at quantifying the risk of a second relapse in ITMS positive and oligoclonal IgG bands (OCGBs)-positive patients. We selected clinical studies reporting the ITMS prevalence assessed as oligoclonal IgM Bands (OCMBs), lipid-specific OCMBs (LS-OCMBs), and/or as an intrathecal IgM production > 0% (IgMLoc, Reiber formula). The overall prevalence of ITMS was higher in relapsing-remitting (RR) than clinically isolated syndrome (CIS) patients (40.1% versus 23.8%, p < 0.00001), while was in line with that detected in primary progressive MS (PPMS, 26.7%). Almost all patients (98%) with ITMS had also OCGBs. The risk of having a second relapse was higher in OCGBs positive patients (HR = 2.18, p = 0.007) but much higher in ITMS positive patients (HR = 3.62, p = 0.0005). This study revealed that the prevalence of ITMS is higher in RRMS patients. It suggests that the risk of having a second relapse, previously ascribed to OCGBs, may, to a certain extent, be related to the presence of intrathecal IgM.

Freshwater Perkinsea: diversity, ecology and genomic information

2019 ◽  
Vol 42 (1) ◽  
pp. 3-17 ◽  
Author(s):  
M Jobard ◽  
I Wawrzyniak ◽  
G Bronner ◽  
D Marie ◽  
A Vellet ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Meta Analysis ◽  
Freshwater Ecosystems ◽  
Protein Coding ◽  
Lake Ecosystems ◽  
Operational Taxonomic Units ◽  
Clade 1 ◽  
Almost All ◽  
Parasitic Association

Abstract Studies on freshwater Perkinsea are scarce compared to their marine counterparts; they are therefore not well ecologically characterized. In this study, we investigated the diversity, distribution and ecological role of Perkinsea in freshwater ecosystems. Our approach included (1) the phylogenetic analyses of near full-length SSU and LSU sequences of freshwater Perkinsea, (2) a meta-analysis of public Perkinsea 18S ribosomal RNA gene sequences available from the freshwater environments (25 lakes, 4 rivers), (3) microscopic observations of Perkinsea associated with planktonic communities and (4) single amplified genome analysis. Whereas Perkinsea appear to be rare in river ecosystems (85 reads), they are found in almost all of the lakes studied. However, their diversity does vary considerably between lakes (from 0 to 2 463 Operational Taxonomic Units (OTUs)). Phylogenetic analysis showed that the Parvilucifera/Dinovorax/Snorkelia and Perkinsus/Xcellia/Gadixcellia clades resulted from an initial speciation event. This second clade is further split into well-supported, monophyletic groups, including a clade dominated by freshwater representatives, which is further structured into three distinct subclades: freshwater clade 1, freshwater clade 2 and a freshwater and brackish clade. The Perkinsea Single Amplified Genome (SAG) as well as most of the abundant Operational Taxonomic Units (OTUs) fall into freshwater clade 2. The tyramide signal amplification-fluorescent in situ hybridization method showed an internal association between Perkinsea and the colonial phytoplankton Sphaerocystis. The Single Amplified Genome (SAG) annotation contained 698 genes and gene ontology terms could be assigned to 486 protein-coding genes. Although the number of genes appears to be low (10.6% of the entire gene set assessed by BUSCO), the analysis of the proteome revealed some putative secreted virulence factors. This study showed a large distribution of Perkinsea across lake ecosystems and potential parasitic association with phytoplankton. However, further investigations are needed for a better knowledge on the role of these microorganisms in freshwater ecosystems.

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