The Roles and Evolutionary Patterns of Intronless Genes in Deuterostomes

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Ming Zou

2011-01-01

Full Text Available Genes without introns are a characteristic feature of prokaryotes, but there are still a number of intronless genes in eukaryotes. To study these eukaryotic genes that have prokaryotic architecture could help to understand the evolutionary patterns of related genes and genomes. Our analyses revealed a number of intronless genes that reside in 6 deuterostomes (sea urchin, sea squirt, zebrafish, chicken, platypus, and human. We also determined the conservation for each intronless gene in archaea, bacteria, fungi, plants, metazoans, and other eukaryotes. Proportions of intronless genes that are inherited from the common ancestor of archaea, bacteria, and eukaryotes in these species were consistent with their phylogenetic positions, with more proportions of ancient intronless genes residing in more primitive species. In these species, intronless genes belong to different cellular roles and gene ontology (GO categories, and some of these functions are very basic. Part of intronless genes is derived from other intronless genes or multiexon genes in each species. In conclusion, we showed that a varying number and proportion of intronless genes reside in these 6 deuterostomes, and some of them function importantly. These genes are good candidates for subsequent functional and evolutionary analyses specifically.

Gang Youth, Substance Use Patterns, and Drug Normalization

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Sanders, Bill

2012-01-01

Gang membership is an indicator of chronic illicit substance use and such patterns of use may have a normalized character. Using epidemiological and qualitative data collected between 2006 and 2007, this manuscript examines the drug normalization thesis among a small sample (n=60) of gang youth aged 16-25 years from Los Angeles. Overall, while…

Connecting proximate mechanisms and evolutionary patterns: pituitary gland size and mammalian life history.

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Kamilar, J M; Tecot, S R

2015-11-01

At the proximate level, hormones are known to play a critical role in influencing the life history of mammals, including humans. The pituitary gland is directly responsible for producing several hormones, including those related to growth and reproduction. Although we have a basic understanding of how hormones affect life history characteristics, we still have little knowledge of this relationship in an evolutionary context. We used data from 129 mammal species representing 14 orders to investigate the relationship between pituitary gland size and life history variation. Because pituitary gland size should be related to hormone production and action, we predicted that species with relatively large pituitaries should be associated with fast life histories, especially increased foetal and post-natal growth rates. Phylogenetic analyses revealed that total pituitary size and the size of the anterior lobe of the pituitary significantly predicted a life history axis that was correlated with several traits including body mass, and foetal and post-natal growth rates. Additional models directly examining the association between relative pituitary size and growth rates produced concordant results. We also found that relative pituitary size variation across mammals was best explained by an Ornstein-Uhlenbeck model of evolution, suggesting an important role of stabilizing selection. Our results support the idea that the size of the pituitary is linked to life history variation through evolutionary time. This pattern is likely due to mediating hormone levels but additional work is needed. We suggest that future investigations incorporating endocrine gland size may be critical for understanding life history evolution. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

HIV-1 Evolutionary Patterns Associated with Metastatic Kaposi’s Sarcoma during AIDS

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Susanna L. Lamers

2016-01-01

Full Text Available Kaposi’s sarcoma (KS in HIV-infected individuals can have a wide range of clinical outcomes, from indolent skin tumors to a life-threatening visceral cancer. KS tumors contain endothelial-related cells and inflammatory cells that may be HIV-infected. In this study we tested if HIV evolutionary patterns distinguish KS tumor relatedness and progression. Multisite autopsies from participants who died from HIV-AIDS with KS prior to the availability of antiretroviral therapy were identified at the AIDS and Cancer Specimen Resource (ACSR. Two patients (KS1 and KS2 died predominantly from non-KS-associated disease and KS3 died due to aggressive and metastatic KS within one month of diagnosis. Skin and visceral tumor and nontumor autopsy tissues were obtained (n=12. Single genome sequencing was used to amplify HIV RNA and DNA, which was present in all tumors. Independent HIV tumor clades in phylogenies differentiated KS1 and KS2 from KS3, whose sequences were interrelated by both phylogeny and selection. HIV compartmentalization was confirmed in KS1 and KS2 tumors; however, in KS3, no compartmentalization was observed among sampled tissues. While the sample size is small, the HIV evolutionary patterns observed in all patients suggest an interplay between tumor cells and HIV-infected cells which provides a selective advantage and could promote KS progression.

Molecular evolutionary patterns of NAD+/Sirtuin aging signaling pathway across taxa.

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Uma Gaur

Full Text Available A deeper understanding of the conserved molecular mechanisms in different taxa have been made possible only because of the evolutionary conservation of crucial signaling pathways. In the present study, we explored the molecular evolutionary pattern of selection signatures in 51 species for 10 genes which are important components of NAD+/Sirtuin pathway and have already been directly linked to lifespan extension in worms and mice. Selection pressure analysis using PAML program revealed that MRPS5 and PPARGC1A were under significant constraints because of their functional significance. FOXO3a also displayed strong purifying selection. All three sirtuins, which were SIRT1, SIRT2 and SIRT6, displayed a great degree of conservation between taxa, which is consistent with the previous report. A significant evolutionary constraint is seen on the anti-oxidant gene, SOD3. As expected, TP53 gene was under significant selection pressure in mammals, owing to its major role in tumor progression. Poly-ADP-ribose polymerase (PARP genes displayed the most sites under positive selection. Further 3D structural analysis of PARP1 and PARP2 protein revealed that some of these positively selected sites caused a change in the electrostatic potential of the protein structure, which may allow a change in its interaction with other proteins and molecules ultimately leading to difference in the function. Although the functional significance of the positively selected sites could not be established in the variants databases, yet it will be interesting to see if these sites actually affect the function of PARP1 and PARP2.

Vocal fold contact patterns based on normal modes of vibration.

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Smith, Simeon L; Titze, Ingo R

2018-05-17

The fluid-structure interaction and energy transfer from respiratory airflow to self-sustained vocal fold oscillation continues to be a topic of interest in vocal fold research. Vocal fold vibration is driven by pressures on the vocal fold surface, which are determined by the shape of the glottis and the contact between vocal folds. Characterization of three-dimensional glottal shapes and contact patterns can lead to increased understanding of normal and abnormal physiology of the voice, as well as to development of improved vocal fold models, but a large inventory of shapes has not been directly studied previously. This study aimed to take an initial step toward characterizing vocal fold contact patterns systematically. Vocal fold motion and contact was modeled based on normal mode vibration, as it has been shown that vocal fold vibration can be almost entirely described by only the few lowest order vibrational modes. Symmetric and asymmetric combinations of the four lowest normal modes of vibration were superimposed on left and right vocal fold medial surfaces, for each of three prephonatory glottal configurations, according to a surface wave approach. Contact patterns were generated from the interaction of modal shapes at 16 normalized phases during the vibratory cycle. Eight major contact patterns were identified and characterized by the shape of the flow channel, with the following descriptors assigned: convergent, divergent, convergent-divergent, uniform, split, merged, island, and multichannel. Each of the contact patterns and its variation are described, and future work and applications are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

The evolutionary history of vertebrate cranial placodes II. Evolution of ectodermal patterning.

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Schlosser, Gerhard; Patthey, Cedric; Shimeld, Sebastian M

2014-05-01

Cranial placodes are evolutionary innovations of vertebrates. However, they most likely evolved by redeployment, rewiring and diversification of preexisting cell types and patterning mechanisms. In the second part of this review we compare vertebrates with other animal groups to elucidate the evolutionary history of ectodermal patterning. We show that several transcription factors have ancient bilaterian roles in dorsoventral and anteroposterior regionalisation of the ectoderm. Evidence from amphioxus suggests that ancestral chordates then concentrated neurosecretory cells in the anteriormost non-neural ectoderm. This anterior proto-placodal domain subsequently gave rise to the oral siphon primordia in tunicates (with neurosecretory cells being lost) and anterior (adenohypophyseal, olfactory, and lens) placodes of vertebrates. Likewise, tunicate atrial siphon primordia and posterior (otic, lateral line, and epibranchial) placodes of vertebrates probably evolved from a posterior proto-placodal region in the tunicate-vertebrate ancestor. Since both siphon primordia in tunicates give rise to sparse populations of sensory cells, both proto-placodal domains probably also gave rise to some sensory receptors in the tunicate-vertebrate ancestor. However, proper cranial placodes, which give rise to high density arrays of specialised sensory receptors and neurons, evolved from these domains only in the vertebrate lineage. We propose that this may have involved rewiring of the regulatory network upstream and downstream of Six1/2 and Six4/5 transcription factors and their Eya family cofactors. These proteins, which play ancient roles in neuronal differentiation were first recruited to the dorsal non-neural ectoderm in the tunicate-vertebrate ancestor but subsequently probably acquired new target genes in the vertebrate lineage, allowing them to adopt new functions in regulating proliferation and patterning of neuronal progenitors. Copyright © 2014 Elsevier Inc. All rights

Risk attitudes in a changing environment: An evolutionary model of the fourfold pattern of risk preferences.

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Mallpress, Dave E W; Fawcett, Tim W; Houston, Alasdair I; McNamara, John M

2015-04-01

A striking feature of human decision making is the fourfold pattern of risk attitudes, involving risk-averse behavior in situations of unlikely losses and likely gains, but risk-seeking behavior in response to likely losses and unlikely gains. Current theories to explain this pattern assume particular psychological processes to reproduce empirical observations, but do not address whether it is adaptive for the decision maker to respond to risk in this way. Here, drawing on insights from behavioral ecology, we build an evolutionary model of risk-sensitive behavior, to investigate whether particular types of environmental conditions could favor a fourfold pattern of risk attitudes. We consider an individual foraging in a changing environment, where energy is needed to prevent starvation and build up reserves for reproduction. The outcome, in terms of reproductive value (a rigorous measure of evolutionary success), of a one-off choice between a risky and a safe gain, or between a risky and a safe loss, determines the risk-sensitive behavior we should expect to see in this environment. Our results show that the fourfold pattern of risk attitudes may be adaptive in an environment in which conditions vary stochastically but are autocorrelated in time. In such an environment the current options provide information about the likely environmental conditions in the future, which affect the optimal pattern of risk sensitivity. Our model predicts that risk preferences should be both path dependent and affected by the decision maker's current state. (c) 2015 APA, all rights reserved).

Complex evolutionary patterns revealed by mitochondrial genomes of the domestic horse.

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Ning, T; Li, J; Lin, K; Xiao, H; Wylie, S; Hua, S; Li, H; Zhang, Y-P

2014-01-01

The domestic horse is the most widely used and important stock and recreational animal, valued for its strength and endurance. The energy required by the domestic horse is mainly supplied by mitochondria via oxidative phosphorylation. Thus, selection may have played an essential role in the evolution of the horse mitochondria. Besides, demographic events also affect the DNA polymorphic pattern on mitochondria. To understand the evolutionary patterns of the mitochondria of the domestic horse, we used a deep sequencing approach to obtain the complete sequences of 15 mitochondrial genomes, and four mitochondrial gene sequences, ND6, ATP8, ATP6 and CYTB, collected from 509, 363, 363 and 409 domestic horses, respectively. Evidence of strong substitution rate heterogeneity was found at nonsynonymous sites across the genomes. Signatures of recent positive selection on mtDNA of domestic horse were detected. Specifically, five amino acids in the four mitochondrial genes were identified as the targets of positive selection. Coalescentbased simulations imply that recent population expansion is the most probable explanation for the matrilineal population history for domestic horse. Our findings reveal a complex pattern of non-neutral evolution of the mitochondrial genome in the domestic horses.

Patterns and processes in the evolutionary history of parrotfishes (Family Labridae)

KAUST Repository

Choat, John. H.; klanten, Oya. S.; Van Herwerden, Lynne; Robertson, D. Ross; Clements, Kendall D.

2012-01-01

Phylogenetic reconstruction of the evolutionary relationships among 61 of the 70 species of the parrotfish genera Chlorurus and Scarus (Family Labridae) based on mitochondrial and nuclear gene sequences retrieved 15 well-supported clades with mid Pliocene/Pleistocene diversification. Twenty-two reciprocally monophyletic sister-species pairs were identified: 64% were allopatric, and the remainder were sympatric. Age of divergence was similar for allopatric and sympatric species pairs. Sympatric sister pairs displayed greater divergence in morphology, ecology, and sexually dimorphic colour patterns than did allopatric pairs, suggesting that both genetic drift in allopatric species pairs and ecologically adaptive divergence between members of sympatric pairs have played a role in diversification. Basal species typically have small geographical ranges and are restricted to geographically and ecologically peripheral reef habitats. We found little evidence that a single dominant process has driven diversification, nor did we detect a pattern of discrete, sequential stages of diversification in relation to habitat, ecology, and reproductive biology. The evolution of Chlorurus and Scarus has been complex, involving a number of speciation processes. © 2012 The Linnean Society of London.

Patterns and processes in the evolutionary history of parrotfishes (Family Labridae)

KAUST Repository

Choat, John. H.

2012-09-05

Phylogenetic reconstruction of the evolutionary relationships among 61 of the 70 species of the parrotfish genera Chlorurus and Scarus (Family Labridae) based on mitochondrial and nuclear gene sequences retrieved 15 well-supported clades with mid Pliocene/Pleistocene diversification. Twenty-two reciprocally monophyletic sister-species pairs were identified: 64% were allopatric, and the remainder were sympatric. Age of divergence was similar for allopatric and sympatric species pairs. Sympatric sister pairs displayed greater divergence in morphology, ecology, and sexually dimorphic colour patterns than did allopatric pairs, suggesting that both genetic drift in allopatric species pairs and ecologically adaptive divergence between members of sympatric pairs have played a role in diversification. Basal species typically have small geographical ranges and are restricted to geographically and ecologically peripheral reef habitats. We found little evidence that a single dominant process has driven diversification, nor did we detect a pattern of discrete, sequential stages of diversification in relation to habitat, ecology, and reproductive biology. The evolution of Chlorurus and Scarus has been complex, involving a number of speciation processes. © 2012 The Linnean Society of London.

Evaluation of corneal higher order aberrations in normal topographic patterns

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Ali Mirzajani

2016-06-01

Conclusions: Based on results in this study, there were a good correlation between corneal topographic pattern and corneal HOAs in normal eyes. These results indicate that the corneal HOAs values are largely determined by the topographic patterns. A larger sample size would perhaps have been beneficial to yield in more accurate outcomes.

Evolutionary patterns in the sequence and structure of transfer RNA: early origins of archaea and viruses.

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Feng-Jie Sun

2008-03-01

Full Text Available Transfer RNAs (tRNAs are ancient molecules that are central to translation. Since they probably carry evolutionary signatures that were left behind when the living world diversified, we reconstructed phylogenies directly from the sequence and structure of tRNA using well-established phylogenetic methods. The trees placed tRNAs with long variable arms charging Sec, Tyr, Ser, and Leu consistently at the base of the rooted phylogenies, but failed to reveal groupings that would indicate clear evolutionary links to organismal origin or molecular functions. In order to uncover evolutionary patterns in the trees, we forced tRNAs into monophyletic groups using constraint analyses to generate timelines of organismal diversification and test competing evolutionary hypotheses. Remarkably, organismal timelines showed Archaea was the most ancestral superkingdom, followed by viruses, then superkingdoms Eukarya and Bacteria, in that order, supporting conclusions from recent phylogenomic studies of protein architecture. Strikingly, constraint analyses showed that the origin of viruses was not only ancient, but was linked to Archaea. Our findings have important implications. They support the notion that the archaeal lineage was very ancient, resulted in the first organismal divide, and predated diversification of tRNA function and specificity. Results are also consistent with the concept that viruses contributed to the development of the DNA replication machinery during the early diversification of the living world.

Using Evolutionary Theory to Guide Mental Health Research.

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Durisko, Zachary; Mulsant, Benoit H; McKenzie, Kwame; Andrews, Paul W

2016-03-01

Evolutionary approaches to medicine can shed light on the origins and etiology of disease. Such an approach may be especially useful in psychiatry, which frequently addresses conditions with heterogeneous presentation and unknown causes. We review several previous applications of evolutionary theory that highlight the ways in which psychiatric conditions may persist despite and because of natural selection. One lesson from the evolutionary approach is that some conditions currently classified as disorders (because they cause distress and impairment) may actually be caused by functioning adaptations operating "normally" (as designed by natural selection). Such conditions suggest an alternative illness model that may generate alternative intervention strategies. Thus, the evolutionary approach suggests that psychiatry should sometimes think differently about distress and impairment. The complexity of the human brain, including normal functioning and potential for dysfunctions, has developed over evolutionary time and has been shaped by natural selection. Understanding the evolutionary origins of psychiatric conditions is therefore a crucial component to a complete understanding of etiology. © The Author(s) 2016.

Normal cranial bone marrow MR imaging pattern with age-related ADC value distribution

International Nuclear Information System (INIS)

Li Qi; Pan Shinong; Yin Yuming; Li Wei; Chen Zhian; Liu Yunhui; Wu Zhenhua; Guo Qiyong

2011-01-01

Objective: To determine MRI appearances of normal age-related cranial bone marrow and the relationship between MRI patterns and apparent diffusion coefficient (ADC) values. Methods: Five hundred subjects were divided into seven groups based on ages. Cranial bone marrow MRI patterns were performed based on different thickness of the diploe and signal intensity distribution characteristics. ADC values of the frontal, parietal, occipital and temporal bones on DWI were measured and calculated. Correlations between ages and ADC values, between patterns and ADC values, as well as the distribution of ADC values were analyzed. Results: Normal cranial bone marrow was divided into four types and six subtypes, Type I, II, III and IV, which had positive correlation with age increasing (χ 2 = 266.36, P 0.05). In addition, there was significant negative correlation between the ADC values and MRI patterns in the normal parietal and occipital bones (r = -0.691 and -0.750, P < 0.01). Conclusion: The combination of MRI features and ADC values changes in different cranial bones showed significant correlation with age increasing. Familiar with the MRI appearance of the normal bone marrow conversion pattern in different age group and their ADC value will aid the diagnosis and differential of the cranial bone pathology.

Patterns of brain structural connectivity differentiate normal weight from overweight subjects.

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Gupta, Arpana; Mayer, Emeran A; Sanmiguel, Claudia P; Van Horn, John D; Woodworth, Davis; Ellingson, Benjamin M; Fling, Connor; Love, Aubrey; Tillisch, Kirsten; Labus, Jennifer S

2015-01-01

Alterations in the hedonic component of ingestive behaviors have been implicated as a possible risk factor in the pathophysiology of overweight and obese individuals. Neuroimaging evidence from individuals with increasing body mass index suggests structural, functional, and neurochemical alterations in the extended reward network and associated networks. To apply a multivariate pattern analysis to distinguish normal weight and overweight subjects based on gray and white-matter measurements. Structural images (N = 120, overweight N = 63) and diffusion tensor images (DTI) (N = 60, overweight N = 30) were obtained from healthy control subjects. For the total sample the mean age for the overweight group (females = 32, males = 31) was 28.77 years (SD = 9.76) and for the normal weight group (females = 32, males = 25) was 27.13 years (SD = 9.62). Regional segmentation and parcellation of the brain images was performed using Freesurfer. Deterministic tractography was performed to measure the normalized fiber density between regions. A multivariate pattern analysis approach was used to examine whether brain measures can distinguish overweight from normal weight individuals. 1. White-matter classification: The classification algorithm, based on 2 signatures with 17 regional connections, achieved 97% accuracy in discriminating overweight individuals from normal weight individuals. For both brain signatures, greater connectivity as indexed by increased fiber density was observed in overweight compared to normal weight between the reward network regions and regions of the executive control, emotional arousal, and somatosensory networks. In contrast, the opposite pattern (decreased fiber density) was found between ventromedial prefrontal cortex and the anterior insula, and between thalamus and executive control network regions. 2. Gray-matter classification: The classification algorithm, based on 2 signatures with 42 morphological features, achieved 69

Patterns of brain structural connectivity differentiate normal weight from overweight subjects

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Gupta, Arpana; Mayer, Emeran A.; Sanmiguel, Claudia P.; Van Horn, John D.; Woodworth, Davis; Ellingson, Benjamin M.; Fling, Connor; Love, Aubrey; Tillisch, Kirsten; Labus, Jennifer S.

2015-01-01

Background Alterations in the hedonic component of ingestive behaviors have been implicated as a possible risk factor in the pathophysiology of overweight and obese individuals. Neuroimaging evidence from individuals with increasing body mass index suggests structural, functional, and neurochemical alterations in the extended reward network and associated networks. Aim To apply a multivariate pattern analysis to distinguish normal weight and overweight subjects based on gray and white-matter measurements. Methods Structural images (N = 120, overweight N = 63) and diffusion tensor images (DTI) (N = 60, overweight N = 30) were obtained from healthy control subjects. For the total sample the mean age for the overweight group (females = 32, males = 31) was 28.77 years (SD = 9.76) and for the normal weight group (females = 32, males = 25) was 27.13 years (SD = 9.62). Regional segmentation and parcellation of the brain images was performed using Freesurfer. Deterministic tractography was performed to measure the normalized fiber density between regions. A multivariate pattern analysis approach was used to examine whether brain measures can distinguish overweight from normal weight individuals. Results 1. White-matter classification: The classification algorithm, based on 2 signatures with 17 regional connections, achieved 97% accuracy in discriminating overweight individuals from normal weight individuals. For both brain signatures, greater connectivity as indexed by increased fiber density was observed in overweight compared to normal weight between the reward network regions and regions of the executive control, emotional arousal, and somatosensory networks. In contrast, the opposite pattern (decreased fiber density) was found between ventromedial prefrontal cortex and the anterior insula, and between thalamus and executive control network regions. 2. Gray-matter classification: The classification algorithm, based on 2 signatures with 42

Combining evolutionary game theory and network theory to analyze human cooperation patterns

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Scatà, Marialisa; Di Stefano, Alessandro; La Corte, Aurelio; Liò, Pietro; Catania, Emanuele; Guardo, Ermanno; Pagano, Salvatore

2016-01-01

Highlights: • We investigate the evolutionary dynamics of human cooperation in a social network. • We introduce the concepts of “Critical Mass”, centrality measure and homophily. • The emergence of cooperation is affected by the spatial choice of the “Critical Mass”. • Our findings show that homophily speeds up the convergence towards cooperation. • Centrality and “Critical Mass” spatial choice partially offset the impact of homophily. - Abstract: As natural systems continuously evolve, the human cooperation dilemma represents an increasingly more challenging question. Humans cooperate in natural and social systems, but how it happens and what are the mechanisms which rule the emergence of cooperation, represent an open and fascinating issue. In this work, we investigate the evolution of cooperation through the analysis of the evolutionary dynamics of behaviours within the social network, where nodes can choose to cooperate or defect following the classical social dilemmas represented by Prisoner’s Dilemma and Snowdrift games. To this aim, we introduce a sociological concept and statistical estimator, “Critical Mass”, to detect the minimum initial seed of cooperators able to trigger the diffusion process, and the centrality measure to select within the social network. Selecting different spatial configurations of the Critical Mass nodes, we highlight how the emergence of cooperation can be influenced by this spatial choice of the initial core in the network. Moreover, we target to shed light how the concept of homophily, a social shaping factor for which “birds of a feather flock together”, can affect the evolutionary process. Our findings show that homophily allows speeding up the diffusion process and make quicker the convergence towards human cooperation, while centrality measure and thus the Critical Mass selection, play a key role in the evolution showing how the spatial configurations can create some hidden patterns, partially

Mitochondrial DNA haplotype distribution patterns in Pinus ponderosa (Pinaceae): range-wide evolutionary history and implications for conservation.

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Potter, Kevin M; Hipkins, Valerie D; Mahalovich, Mary F; Means, Robert E

2013-08-01

Ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) exhibits complicated patterns of morphological and genetic variation across its range in western North America. This study aims to clarify P. ponderosa evolutionary history and phylogeography using a highly polymorphic mitochondrial DNA marker, with results offering insights into how geographical and climatological processes drove the modern evolutionary structure of tree species in the region. We amplified the mtDNA nad1 second intron minisatellite region for 3,100 trees representing 104 populations, and sequenced all length variants. We estimated population-level haplotypic diversity and determined diversity partitioning among varieties, races and populations. After aligning sequences of minisatellite repeat motifs, we evaluated evolutionary relationships among haplotypes. The geographical structuring of the 10 haplotypes corresponded with division between Pacific and Rocky Mountain varieties. Pacific haplotypes clustered with high bootstrap support, and appear to have descended from Rocky Mountain haplotypes. A greater proportion of diversity was partitioned between Rocky Mountain races than between Pacific races. Areas of highest haplotypic diversity were the southern Sierra Nevada mountain range in California, northwestern California, and southern Nevada. Pinus ponderosa haplotype distribution patterns suggest a complex phylogeographic history not revealed by other genetic and morphological data, or by the sparse paleoecological record. The results appear consistent with long-term divergence between the Pacific and Rocky Mountain varieties, along with more recent divergences not well-associated with race. Pleistocene refugia may have existed in areas of high haplotypic diversity, as well as the Great Basin, Southwestern United States/northern Mexico, and the High Plains.

Evolutionary Pattern and Regulation Analysis to Support Why Diversity Functions Existed within PPAR Gene Family Members

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Tianyu Zhou

2015-01-01

Full Text Available Peroxisome proliferators-activated receptor (PPAR gene family members exhibit distinct patterns of distribution in tissues and differ in functions. The purpose of this study is to investigate the evolutionary impacts on diversity functions of PPAR members and the regulatory differences on gene expression patterns. 63 homology sequences of PPAR genes from 31 species were collected and analyzed. The results showed that three isolated types of PPAR gene family may emerge from twice times of gene duplication events. The conserved domains of HOLI (ligand binding domain of hormone receptors domain and ZnF_C4 (C4 zinc finger in nuclear in hormone receptors are essential for keeping basic roles of PPAR gene family, and the variant domains of LCRs may be responsible for their divergence in functions. The positive selection sites in HOLI domain are benefit for PPARs to evolve towards diversity functions. The evolutionary variants in the promoter regions and 3′ UTR regions of PPARs result into differential transcription factors and miRNAs involved in regulating PPAR members, which may eventually affect their expressions and tissues distributions. These results indicate that gene duplication event, selection pressure on HOLI domain, and the variants on promoter and 3′ UTR are essential for PPARs evolution and diversity functions acquired.

Evolutionary Pattern and Regulation Analysis to Support Why Diversity Functions Existed within PPAR Gene Family Members.

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Zhou, Tianyu; Yan, Xiping; Wang, Guosong; Liu, Hehe; Gan, Xiang; Zhang, Tao; Wang, Jiwen; Li, Liang

2015-01-01

Peroxisome proliferators-activated receptor (PPAR) gene family members exhibit distinct patterns of distribution in tissues and differ in functions. The purpose of this study is to investigate the evolutionary impacts on diversity functions of PPAR members and the regulatory differences on gene expression patterns. 63 homology sequences of PPAR genes from 31 species were collected and analyzed. The results showed that three isolated types of PPAR gene family may emerge from twice times of gene duplication events. The conserved domains of HOLI (ligand binding domain of hormone receptors) domain and ZnF_C4 (C4 zinc finger in nuclear in hormone receptors) are essential for keeping basic roles of PPAR gene family, and the variant domains of LCRs may be responsible for their divergence in functions. The positive selection sites in HOLI domain are benefit for PPARs to evolve towards diversity functions. The evolutionary variants in the promoter regions and 3' UTR regions of PPARs result into differential transcription factors and miRNAs involved in regulating PPAR members, which may eventually affect their expressions and tissues distributions. These results indicate that gene duplication event, selection pressure on HOLI domain, and the variants on promoter and 3' UTR are essential for PPARs evolution and diversity functions acquired.

Patterns of pulmonary maturation in normal and abnormal pregnancy.

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Goldkrand, J W; Slattery, D S

1979-03-01

Fetal pulmonary maturation may be a variable event depending on various feto-maternal environmental and biochemical influences. The patterns of maturation were studied in 211 amniotic fluid samples from 123 patients (normal 55; diabetes 23; Rh sensitization 19; preeclampsia 26). The phenomenon of globule formation from the amniotic fluid lipid extract and is relation to pulmonary maturity was utilized for this analysis. Validation of this technique is presented. A normal curve was constructed from 22 to 42 weeks; gestation and compared to the abnormal pregnancies. Patients with class A, B, and C diabetes and Rh-sensitized pregnancies had delayed pulmonary maturation. Patients with class D diabetes and preclampsia paralleled the normal course of maturation. A discussion of these results and their possible cause is presented.

Physical activity patterns in morbidly obese and normal-weight women.

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Kwon, Soyang; Mohammad, Jamal; Samuel, Isaac

2011-01-01

To compare physical activity patterns between morbidly obese and normal-weight women. Daily physical activity of 18 morbidly obese and 7 normal-weight women aged 30-58 years was measured for 2 days using the Intelligent Device for Energy Expenditure and Activity (IDEEA) device. The obese group spent about 2 hr/day less standing and 30 min/day less walking than did the normal-weight group. Time spent standing (standing time) was positively associated with time spent walking (walking time). Age- and walking time-adjusted standing time did not differ according to weight status. Promoting standing may be a strategy to increase walking.

[Charles Darwin and the problem of evolutionary progress].

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Iordanskiĭ, N N

2010-01-01

According to Ch. Darwin's evolutionary theory, evolutionary progress (interpreted as morpho-physiological progress or arogenesis in recent terminology) is one of logical results of natural selection. At the same time, natural selection does not hold any factors especially promoting evolutionary progress. Darwin emphasized that the pattern of evolutionary changes depends on organism nature more than on the pattern of environment changes. Arogenesis specificity is determined by organization of rigorous biological systems - integral organisms. Onward progressive development is determined by fundamental features of living organisms: metabolism and homeostasis. The concept of social Darwinism differs fundamentally from Darwin's ideas about the most important role of social instincts in progress of mankind. Competition and selection play secondary role in socio-cultural progress of human society.

Differences in dietary patterns between overweight and normal-weight adolescents.

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Jodkowska, Maria; Oblacińska, Anna; Tabak, Izabela; Radiukiewicz, Katarzyna

2011-01-01

To investigate the differences in the dietary patterns of Polish overweight and normal weight adolescents. The study was carried out on a group of 1906 pupils from gymnasium (lower secondary school) aged 13-15 years, of whom 953 were overweight and 953 had normal body mass. The sample was taken from a representative group of 8386 pupils. Their height and body weight were measured, and their BMI was calculated. Overweight was defined as BMI ł85 percentile for gender and age. Using the method of "selection in pairs", each overweight pupil was paired with a pupil with normal body weight. The research tool was a self-reported questionnaire, containing questions regarding how often selected food products were usually consumed during the week, how regularly basic meals (breakfast, lunch, supper) were eaten, and data on snacking. Overweight adolescents consumed unhealthy products such as sweets and crisps significantly less often than their peers with appropriate body mass. Overweight girls ate dark bread significantly more often, and consumed soft drinks less often than their peers with normal weight. Overweight adolescents had more irregular meals than those with normal weight: only 44% overweight adolescents had breakfast every day, significantly less than adolescents with normal weight. Nevertheless, overweight teenagers snacked significantly less often than young people with normal body mass. The overweight teenagers also less often chose snacks with high fat content, sugar and salt, and more often vegetables, fruits, as well as yoghurt and kefir. 1. Our study shows that compliance of low energy diet alone does not ensure the maintenance of normal body weight. Irregularity of meals and breakfast skipping play an important role in developing overweight and obesity in adolescents. 2. In future studies on dietary patterns in a larger sample of adolescents, emphasis should be placed on adding questions about portion size, food preparation and meal time. Eating

Lymphoscintigraphy in paediatric patients for suspected lymphoedema: normal variants, abnormal and syndromic patterns

International Nuclear Information System (INIS)

Pascual, T.; Howman-Giles, R.; Martin, H.

2009-01-01

Full text: Background: Lymphoscintigraphy (LS) is the diagnostic test of choice differentiating lymphoedema from other causes of extremity swelling. The LS patterns in normal and congenital lymphoedema in the paediatric population are not well defined. The impact of LS on clinical decision making is also not well reported. Aims: 1. define normal LS patterns in the pediatric population 2. describe types of abnormality (aplasia, hypoplasia, hyperplasia/dilated system) 3. describe LS patterns in syndromic lymphatic vascular disease 4. correlate LS with clinical impact on patient management. Methods: Retrospective review of all paediatric patients who had LS from July 1996-April 2008 was undertaken. Indications, sites of abnormality, LS patterns and clinical outcome were reviewed. Results: 118 patients (3mths-21yrs, mean 6 yrs) underwent LS. Normal LS patterns and variations were identified in 57 pts (48%). Sixty-one scans (52%) were abnormal showing lymph node aplasia (11%), hypoplasia (17%), mixed-pattern (8%), hyperplasia/dilated system (4%) and other patterns ie intestinal/pulmonary lymphangiectasia and vascual lymphatic malformations (11%). Patients with no signs of lymphoedema may still have aplasia or hypoplasia on LS. Dermal back flow is not always seen in lymphoedema. Management impact related to diagnosis and potential for development of lymphoedema in other limbs, differentiation of lymphoedema in patients with other vascular anomalies, stratification for lymphoedema therapy or referral to the dysmorphology clinic. Conclusion: LS is a valuable tool in the evaluation of lymphoedema in pediatric patients. Recognition of scan patterns in patients with suspected lymphoedema or lymphatic vascular diseases is essential as it plays a major role in the clinical management.

Normal hepatic vein patterns on ultrasound

International Nuclear Information System (INIS)

Kim, Hae Jin; Chae, Yoo Soon; Park, Hea Yeoung; Park, Bok Hwan; Kim, Yang Sook

1987-01-01

Understanding of the anatomy of the hepatic vein is important in manipulation for transplantation of the liver, hepatectomy and the treatment of hepatic trauma with avulsion of the hepatic vein. Demonstrated of the inferior right hepatic vein (IRHV) is also important; in some cases of hepatocellular carcinoma, thrombus can be seen in the IRHV; in primary Budd-Chiari syndrome, the IRHV is main draining vein; during hepatectomy, the postero-inferior segment of the right lobe and draining IRHV can be preserved. For some 10 months ultrasound examination was done in a total of 124 patients with normal liver function with special emphasis on the hepatic vein, their branches, and the IRHV, and analysed in terms of branching pattern and relative size of the hepatic vein and the detection rate of the IRHV.

Applied evolutionary economics and economic geography

OpenAIRE

Peter Sunley

2008-01-01

Applied Evolutionary Economics and Economic Geography aims to further advance empirical methodologies in evolutionary economics, with a special emphasis on geography and firm location. It does so by bringing together a select group of leading scholars including economists, geographers and sociologists, all of whom share an interest in explaining the uneven distribution of economic activities in space and the historical processes that have produced these patterns.

Evolutionary and Ecological Consequences of Interspecific Hybridization in Cladocerans

NARCIS (Netherlands)

Schwenk, K.; Spaak, P.

1995-01-01

The evolutionary process of interspecific hybridization in cladocerans is reviewed based on ecological and population genetic data. The evolutionary consequences of hybridization, biogeographic patterns and fitness comparisons are analyzed within the conceptual framework of theories on

Can Evolutionary Principles Explain Patterns of Family Violence?

Science.gov (United States)

Archer, John

2013-01-01

The article's aim is to evaluate the application of the evolutionary principles of kin selection, reproductive value, and resource holding power to the understanding of family violence. The principles are described in relation to specific predictions and the mechanisms underlying these. Predictions are evaluated for physical violence perpetrated…

Are hotspots of evolutionary potential adequately protected in southern California?

Science.gov (United States)

Vandergast, A.G.; Bohonak, A.J.; Hathaway, S.A.; Boys, J.; Fisher, R.N.

2008-01-01

Reserves are often designed to protect rare habitats, or "typical" exemplars of ecoregions and geomorphic provinces. This approach focuses on current patterns of organismal and ecosystem-level biodiversity, but typically ignores the evolutionary processes that control the gain and loss of biodiversity at these and other levels (e.g., genetic, ecological). In order to include evolutionary processes in conservation planning efforts, their spatial components must first be identified and mapped. We describe a GIS-based approach for explicitly mapping patterns of genetic divergence and diversity for multiple species (a "multi-species genetic landscape"). Using this approach, we analyzed mitochondrial DNA datasets from 21 vertebrate and invertebrate species in southern California to identify areas with common phylogeographic breaks and high intrapopulation diversity. The result is an evolutionary framework for southern California within which patterns of genetic diversity can be analyzed in the context of historical processes, future evolutionary potential and current reserve design. Our multi-species genetic landscapes pinpoint six hotspots where interpopulation genetic divergence is consistently high, five evolutionary hotspots within which genetic connectivity is high, and three hotspots where intrapopulation genetic diversity is high. These 14 hotspots can be grouped into eight geographic areas, of which five largely are unprotected at this time. The multi-species genetic landscape approach may provide an avenue to readily incorporate measures of evolutionary process into GIS-based systematic conservation assessment and land-use planning.

Reproducible pattern of microRNA in normal human skin

DEFF Research Database (Denmark)

Holst, Line; Kaczkowski, Bogumil; Gniadecki, Robert

2010-01-01

RNA expression pattern in normal human skin. Here we investigated miRNA expression profiles from skin biopsies of 8 healthy volunteers taken from sun protected and mildly photo damaged skin using the modified protocol for miRNA extraction. We were able to show a constant pattern of miRNA expression between......MicroRNAs (miRNAs) regulate cell growth, differentiation and apoptosis via specific targeting of messenger RNA (mRNA). Aberrant mRNA expression contributes to pathological processes such as carcinogenesis. To take advantage of miRNA profiling in skin disease it is essential to investigate mi...... different individuals. We did not find any significant differences in miRNA expression between sun protected and mildly photodamaged skin. These results may be valuable for future design of studies on miRNA expression in skin disease....

Reproducible pattern of microRNA in normal human skin

DEFF Research Database (Denmark)

Holst, Line; Kaczkowski, Bogumil; Gniadecki, Robert

2010-01-01

RNA expression pattern in normal human skin. Here we investigated miRNA expression profiles from skin biopsies of 8 healthy volunteers taken from sun protected and mildly photo damaged skin using the modified protocol for miRNA extraction. We were able to show a constant pattern of miRNA expression between...... different individuals. We did not find any significant differences in miRNA expression between sun protected and mildly photodamaged skin. These results may be valuable for future design of studies on miRNA expression in skin disease.......MicroRNAs (miRNAs) regulate cell growth, differentiation and apoptosis via specific targeting of messenger RNA (mRNA). Aberrant mRNA expression contributes to pathological processes such as carcinogenesis. To take advantage of miRNA profiling in skin disease it is essential to investigate mi...

Age-related pattern of normal cranial bone marrow: MRI study

International Nuclear Information System (INIS)

Pan Shinong; Li Qi; Li Wei; Chen Zhian; Wu Zhenhua; Guo Qiyong; Liu Yunhui

2009-01-01

Objective: To investigate the age-related pattern of normal skull bone marrow with 3.0 T MR T 1 WI. Methods: Cranial MR T 1 WI images which were defined to be normal were retrospectively reviewed in 360 cases. Patients with known diffuse bone marrow disease, focal lesions, history of radiation treatment or steroid therapy were excluded, while patients whose cranial MRI and follow-up visits were all normal were included in this study. All the subjects were divided into 7 groups according to the age: 50 years group. Mid- and para- sagittal T 1 WI images were used to be analyzed and the type of cranial bone marrow was classified according to the thickness of diploe and the pattern of the signal characteristics. Statistical analysis was conducted to reveal the relationship between the age and the type. Results: The normal skull bone marrow could be divided into four types as follows: (1) Type-I: 115 cases, 47 of which appeared type- Ia and the mean thickness was (1.24±0.31) mm; 68 of which appeared type-Ib and the mean thickness was (1.76±0.37) mm. Type-II: 57 cases and the mean thickness was (2.78 ± 0.69) mm. Type-III: 148 cases, 18 of which appeared type-IIIa and the mean thickness was (2.33 ± 0.65) mm; 88 of which appeared type-IIIb and the mean thickness was (4.01± 0.86) mm; 42 of which appeared type-IIIc and the mean thickness was (4.31±0.73) mm. Type-IV: 40 cases, 25 of which appeared type-IVa and the mean thickness was (5.17±1.02) mm; 15 of which appeared type-IVb and the mean thickness was (5.85±1.45) mm. (2) 2 =266.36, P<0.01). Conclusion: There is characteristic in the distribution of normal skull bone marrow with age growing. And skull bone marrow transforms gradually from type-I to IV with aging. (authors)

Archaeogenetics in evolutionary medicine.

Science.gov (United States)

Bouwman, Abigail; Rühli, Frank

2016-09-01

Archaeogenetics is the study of exploration of ancient DNA (aDNA) of more than 70 years old. It is an important part of the wider studies of many different areas of our past, including animal, plant and pathogen evolution and domestication events. Hereby, we address specifically the impact of research in archaeogenetics in the broader field of evolutionary medicine. Studies on ancient hominid genomes help to understand even modern health patterns. Human genetic microevolution, e.g. related to abilities of post-weaning milk consumption, and specifically genetic adaptation in disease susceptibility, e.g. towards malaria and other infectious diseases, are of the upmost importance in contributions of archeogenetics on the evolutionary understanding of human health and disease. With the increase in both the understanding of modern medical genetics and the ability to deep sequence ancient genetic information, the field of archaeogenetic evolutionary medicine is blossoming.

SU-E-J-178: A Normalization Method Can Remove Discrepancy in Ventilation Function Due to Different Breathing Patterns

Energy Technology Data Exchange (ETDEWEB)

Qu, H; Yu, N; Stephans, K; Xia, P [Cleveland Clinic, Cleveland, OH (United States)

2014-06-01

Purpose: To develop a normalization method to remove discrepancy in ventilation function due to different breathing patterns. Methods: Twenty five early stage non-small cell lung cancer patients were included in this study. For each patient, a ten phase 4D-CT and the voluntarily maximum inhale and exhale CTs were acquired clinically and retrospectively used for this study. For each patient, two ventilation maps were calculated from voxel-to-voxel CT density variations from two phases of the quiet breathing and two phases of the extreme breathing. For the quiet breathing, 0% (inhale) and 50% (exhale) phases from 4D-CT were used. An in-house tool was developed to calculate and display the ventilation maps. To enable normalization, the whole lung of each patient was evenly divided into three parts in the longitude direction at a coronal image with a maximum lung cross section. The ratio of cumulated ventilation from the top one-third region to the middle one-third region of the lung was calculated for each breathing pattern. Pearson's correlation coefficient was calculated on the ratios of the two breathing patterns for the group. Results: For each patient, the ventilation map from the quiet breathing was different from that of the extreme breathing. When the cumulative ventilation was normalized to the middle one-third of the lung region for each patient, the normalized ventilation functions from the two breathing patterns were consistent. For this group of patients, the correlation coefficient of the normalized ventilations for the two breathing patterns was 0.76 (p < 0.01), indicating a strong correlation in the ventilation function measured from the two breathing patterns. Conclusion: For each patient, the ventilation map is dependent of the breathing pattern. Using a regional normalization method, the discrepancy in ventilation function induced by the different breathing patterns thus different tidal volumes can be removed.

SU-E-J-178: A Normalization Method Can Remove Discrepancy in Ventilation Function Due to Different Breathing Patterns

International Nuclear Information System (INIS)

Qu, H; Yu, N; Stephans, K; Xia, P

2014-01-01

Purpose: To develop a normalization method to remove discrepancy in ventilation function due to different breathing patterns. Methods: Twenty five early stage non-small cell lung cancer patients were included in this study. For each patient, a ten phase 4D-CT and the voluntarily maximum inhale and exhale CTs were acquired clinically and retrospectively used for this study. For each patient, two ventilation maps were calculated from voxel-to-voxel CT density variations from two phases of the quiet breathing and two phases of the extreme breathing. For the quiet breathing, 0% (inhale) and 50% (exhale) phases from 4D-CT were used. An in-house tool was developed to calculate and display the ventilation maps. To enable normalization, the whole lung of each patient was evenly divided into three parts in the longitude direction at a coronal image with a maximum lung cross section. The ratio of cumulated ventilation from the top one-third region to the middle one-third region of the lung was calculated for each breathing pattern. Pearson's correlation coefficient was calculated on the ratios of the two breathing patterns for the group. Results: For each patient, the ventilation map from the quiet breathing was different from that of the extreme breathing. When the cumulative ventilation was normalized to the middle one-third of the lung region for each patient, the normalized ventilation functions from the two breathing patterns were consistent. For this group of patients, the correlation coefficient of the normalized ventilations for the two breathing patterns was 0.76 (p < 0.01), indicating a strong correlation in the ventilation function measured from the two breathing patterns. Conclusion: For each patient, the ventilation map is dependent of the breathing pattern. Using a regional normalization method, the discrepancy in ventilation function induced by the different breathing patterns thus different tidal volumes can be removed

Evolutionary history of lagomorphs in response to global environmental change.

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Deyan Ge

Full Text Available Although species within Lagomorpha are derived from a common ancestor, the distribution range and body size of its two extant groups, ochotonids and leporids, are quite differentiated. It is unclear what has driven their disparate evolutionary history. In this study, we compile and update all fossil records of Lagomorpha for the first time, to trace the evolutionary processes and infer their evolutionary history using mitochondrial genes, body length and distribution of extant species. We also compare the forage selection of extant species, which offers an insight into their future prospects. The earliest lagomorphs originated in Asia and later diversified in different continents. Within ochotonids, more than 20 genera occupied the period from the early Miocene to middle Miocene, whereas most of them became extinct during the transition from the Miocene to Pliocene. The peak diversity of the leporids occurred during the Miocene to Pliocene transition, while their diversity dramatically decreased in the late Quaternary. Mantel tests identified a positive correlation between body length and phylogenetic distance of lagomorphs. The body length of extant ochotonids shows a normal distribution, while the body length of extant leporids displays a non-normal pattern. We also find that the forage selection of extant pikas features a strong preference for C(3 plants, while for the diet of leporids, more than 16% of plant species are identified as C(4 (31% species are from Poaceae. The ability of several leporid species to consume C(4 plants is likely to result in their size increase and range expansion, most notably in Lepus. Expansion of C(4 plants in the late Miocene, the so-called 'nature's green revolution', induced by global environmental change, is suggested to be one of the major 'ecological opportunities', which probably drove large-scale extinction and range contraction of ochotonids, but inversely promoted diversification and range expansion of

Evolutionary games on graphs

Science.gov (United States)

Szabó, György; Fáth, Gábor

2007-07-01

Game theory is one of the key paradigms behind many scientific disciplines from biology to behavioral sciences to economics. In its evolutionary form and especially when the interacting agents are linked in a specific social network the underlying solution concepts and methods are very similar to those applied in non-equilibrium statistical physics. This review gives a tutorial-type overview of the field for physicists. The first four sections introduce the necessary background in classical and evolutionary game theory from the basic definitions to the most important results. The fifth section surveys the topological complications implied by non-mean-field-type social network structures in general. The next three sections discuss in detail the dynamic behavior of three prominent classes of models: the Prisoner's Dilemma, the Rock-Scissors-Paper game, and Competing Associations. The major theme of the review is in what sense and how the graph structure of interactions can modify and enrich the picture of long term behavioral patterns emerging in evolutionary games.

Evolutionary Patterns of Renewable Energy Technology Development in East Asia (1990–2010

Directory of Open Access Journals (Sweden)

Yoonhwan Oh

2016-07-01

Full Text Available This study investigates the evolutionary patterns of renewable energy technology in East Asian countries—Japan, Korea, and China—as an emerging technology where the catch-up strategy is actively taking place. To reflect the quality of technology development activities, we assess each country’s research and development (R&D activities using patent citation analysis. The goal of this study is to overcome the limitations of prior research that uses quantitative information, such as R&D expenditures and number of patents. This study observes the process of technological catch-up and leapfrogging in the East Asian renewable energy sector. Furthermore, we find that each nation’s technology development portfolio differs depending on the composition share of technologies. Policymakers in emerging economies can use the findings to shape R&D strategies to develop the renewable energy sector and provide an alternative method of evaluating the qualitative development of technology.

Perception of Gait Patterns that Deviate from Normal and Symmetric Biped Locomotion

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Ismet eHandzic

2015-02-01

Full Text Available This study examines the range of gait patterns that are perceived as healthy and human-like with the goal of understanding how much asymmetry is allowable in a gait pattern before other people start to notice a gait impairment. Specifically, this study explores if certain abnormal walking patterns can be dismissed as unimpaired or not uncanny. Altering gait biomechanics is generally done in the fields of prosthetics and rehabilitation, however the perception of gait is often neglected. Although a certain gait can be functional, it may not be considered as normal by observers. On the other hand, an abnormally perceived gait may be more practical or necessary in some situations, such as limping after an injury or stroke and when wearing a prosthesis. This research will help to find the balance between the form and function of gait. Gait patterns are synthetically created using a passive dynamic walker (PDW model that allows gait patterns to be systematically changed without the confounding influence from human sensorimotor feedback during walking. This standardized method allows the perception of specific changes in gait to be studied. The PDW model was used to produce walking patterns that showed a degree of abnormality in gait cadence, knee height, step length, and swing time created by changing the foot roll-over-shape, knee damping, knee location, and leg masses. The gait patterns were shown to participants who rated them according to separate scales of impairment and uncanniness. The results indicate that some pathological and asymmetric gait patterns are perceived as unimpaired and normal. Step time and step length asymmetries less than 5%, small knee location differences, and gait cadence changes of 25% do not result in a change in perception. The results also show that the parameters of a pathologically or uncanny perceived gait can be beneficially altered by increasing other independent parameters, in some sense masking the initial

Pressure-flow characteristics of normal and disordered esophageal motor patterns.

Science.gov (United States)

Singendonk, Maartje M J; Kritas, Stamatiki; Cock, Charles; Ferris, Lara F; McCall, Lisa; Rommel, Nathalie; van Wijk, Michiel P; Benninga, Marc A; Moore, David; Omari, Taher I

2015-03-01

To perform pressure-flow analysis (PFA) in a cohort of pediatric patients who were referred for diagnostic manometric investigation. PFA was performed using purpose designed Matlab-based software. The pressure-flow index (PFI), a composite measure of bolus pressurization relative to flow and the impedance ratio, a measure of the extent of bolus clearance failure were calculated. Tracings of 76 pediatric patients (32 males; 9.1 ± 0.7 years) and 25 healthy adult controls (7 males; 36.1 ± 2.2 years) were analyzed. Patients mostly had normal motility (50%) or a category 4 disorder and usually weak peristalsis (31.5%) according to the Chicago Classification. PFA of healthy controls defined reference ranges for PFI ≤142 and impedance ratio ≤0.49. Pediatric patients with pressure-flow (PF) characteristics within these limits had normal motility (62%), most patients with PF characteristics outside these limits also had an abnormal Chicago Classification (61%). Patients with high PFI and disordered motor patterns all had esophagogastric junction outflow obstruction. Disordered PF characteristics are associated with disordered esophageal motor patterns. By defining the degree of over-pressurization and/or extent of clearance failure, PFA may be a useful adjunct to esophageal pressure topography-based classification. Copyright © 2015 Elsevier Inc. All rights reserved.

Quantification of differences between nailfold capillaroscopy images with a scleroderma pattern and normal pattern using measures of geometric and algorithmic complexity.

Science.gov (United States)

Urwin, Samuel George; Griffiths, Bridget; Allen, John

2017-02-01

This study aimed to quantify and investigate differences in the geometric and algorithmic complexity of the microvasculature in nailfold capillaroscopy (NFC) images displaying a scleroderma pattern and those displaying a 'normal' pattern. 11 NFC images were qualitatively classified by a capillary specialist as indicative of 'clear microangiopathy' (CM), i.e. a scleroderma pattern, and 11 as 'not clear microangiopathy' (NCM), i.e. a 'normal' pattern. Pre-processing was performed, and fractal dimension (FD) and Kolmogorov complexity (KC) were calculated following image binarisation. FD and KC were compared between groups, and a k-means cluster analysis (n  =  2) on all images was performed, without prior knowledge of the group assigned to them (i.e. CM or NCM), using FD and KC as inputs. CM images had significantly reduced FD and KC compared to NCM images, and the cluster analysis displayed promising results that the quantitative classification of images into CM and NCM groups is possible using the mathematical measures of FD and KC. The analysis techniques used show promise for quantitative microvascular investigation in patients with systemic sclerosis.

Early Developmental and Evolutionary Origins of Gene Body DNA Methylation Patterns in Mammalian Placentas.

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Diane I Schroeder

2015-08-01

Full Text Available Over the last 20-80 million years the mammalian placenta has taken on a variety of morphologies through both divergent and convergent evolution. Recently we have shown that the human placenta genome has a unique epigenetic pattern of large partially methylated domains (PMDs and highly methylated domains (HMDs with gene body DNA methylation positively correlating with level of gene expression. In order to determine the evolutionary conservation of DNA methylation patterns and transcriptional regulatory programs in the placenta, we performed a genome-wide methylome (MethylC-seq analysis of human, rhesus macaque, squirrel monkey, mouse, dog, horse, and cow placentas as well as opossum extraembryonic membrane. We found that, similar to human placenta, mammalian placentas and opossum extraembryonic membrane have globally lower levels of methylation compared to somatic tissues. Higher relative gene body methylation was the conserved feature across all mammalian placentas, despite differences in PMD/HMDs and absolute methylation levels. Specifically, higher methylation over the bodies of genes involved in mitosis, vesicle-mediated transport, protein phosphorylation, and chromatin modification was observed compared with the rest of the genome. As in human placenta, higher methylation is associated with higher gene expression and is predictive of genic location across species. Analysis of DNA methylation in oocytes and preimplantation embryos shows a conserved pattern of gene body methylation similar to the placenta. Intriguingly, mouse and cow oocytes and mouse early embryos have PMD/HMDs but their placentas do not, suggesting that PMD/HMDs are a feature of early preimplantation methylation patterns that become lost during placental development in some species and following implantation of the embryo.

Pattern Matching Framework to Estimate the Urgency of Off-Normal Situations in NPPs

Energy Technology Data Exchange (ETDEWEB)

Shin, Jin Soo; Park, Sang Jun; Heo, Gyun Young [Kyung Hee University, Yongin (Korea, Republic of); Park, Jin Kyun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Hyo Jin; Park, Soon Yeol [Korea Hydro and Nuclear Power, Yeonggwang (Korea, Republic of)

2010-10-15

According to power plant operators, it was said that they could quite well recognize off-normal situations from an incipient stage and also anticipate the possibility of upcoming trips in case of skilled operators, even though it is difficult to clarify the cause of the off-normal situation. From the interview, we could assure the feasibility of two assumptions for the diagnosis of off-normal conditions: One is that we can predict whether an accidental shutdown happens or not if we observe the early stage when an off-normal starts to grow. The other is the observation at the early stage can provide the remaining time to a trip as well as the cause of such an off-normal situation. For this purpose, the development of on-line monitoring systems using various data processing techniques in nuclear power plants (NPPs) has been the subject of increasing attention and becomes important contributor to improve performance and economics. Many of studies have suggested the diagnostic methodologies. One of representative methods was to use the distance discrimination as a similarity measure, for example, such as the Euclidean distance. A variety of artificial intelligence techniques such as a neural network have been developed as well. In addition, some of these methodologies were to reduce the data dimensions for more effectively work. While sharing the same motivation with the previous achievements, this study proposed non-parametric pattern matching techniques to reduce the uncertainty in pursuance of selection of models and modeling processes. This could be characterized by the following two aspects: First, for overcoming considering only a few typical scenarios in the most of the studies, this study is getting the entire sets of off-normal situations which are anticipated in NPPs, which are created by a full-scope simulator. Second, many of the existing researches adopted the process of forming a diagnosis model which is so-called a training technique or a parametric

Pattern Matching Framework to Estimate the Urgency of Off-Normal Situations in NPPs

International Nuclear Information System (INIS)

Shin, Jin Soo; Park, Sang Jun; Heo, Gyun Young; Park, Jin Kyun; Kim, Hyo Jin; Park, Soon Yeol

2010-01-01

According to power plant operators, it was said that they could quite well recognize off-normal situations from an incipient stage and also anticipate the possibility of upcoming trips in case of skilled operators, even though it is difficult to clarify the cause of the off-normal situation. From the interview, we could assure the feasibility of two assumptions for the diagnosis of off-normal conditions: One is that we can predict whether an accidental shutdown happens or not if we observe the early stage when an off-normal starts to grow. The other is the observation at the early stage can provide the remaining time to a trip as well as the cause of such an off-normal situation. For this purpose, the development of on-line monitoring systems using various data processing techniques in nuclear power plants (NPPs) has been the subject of increasing attention and becomes important contributor to improve performance and economics. Many of studies have suggested the diagnostic methodologies. One of representative methods was to use the distance discrimination as a similarity measure, for example, such as the Euclidean distance. A variety of artificial intelligence techniques such as a neural network have been developed as well. In addition, some of these methodologies were to reduce the data dimensions for more effectively work. While sharing the same motivation with the previous achievements, this study proposed non-parametric pattern matching techniques to reduce the uncertainty in pursuance of selection of models and modeling processes. This could be characterized by the following two aspects: First, for overcoming considering only a few typical scenarios in the most of the studies, this study is getting the entire sets of off-normal situations which are anticipated in NPPs, which are created by a full-scope simulator. Second, many of the existing researches adopted the process of forming a diagnosis model which is so-called a training technique or a parametric

Evolutionary Pattern of N-Glycosylation Sequon Numbers  in Eukaryotic ABC Protein Superfamilies

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R. Shyama Prasad Rao

2010-02-01

Full Text Available Many proteins contain a large number of NXS/T sequences (where X is any amino acid except proline which are the potential sites of asparagine (N linked glycosylation. However, the patterns of occurrence of these N-glycosylation sequons in related proteins or groups of proteins and their underlying causes have largely been unexplored. We computed the actual and probabilistic occurrence of NXS/T sequons in ABC protein superfamilies from eight diverse eukaryotic organisms. The ABC proteins contained significantly higher NXS/T sequon numbers compared to respective genome-wide average, but the sequon density was significantly lower owing to the increase in protein size and decrease in sequon specific amino acids. However, mammalian ABC proteins have significantly higher sequon density, and both serine and threonine containing sequons (NXS and NXT have been positively selected—against the recent findings of only threonine specific Darwinian selection of sequons in proteins. The occurrence of sequons was positively correlated with the frequency of sequon specific amino acids and negatively correlated with proline and the NPS/T sequences. Further, the NPS/T sequences were significantly higher than expected in plant ABC proteins which have the lowest number of NXS/T sequons. Accord- ingly, compared to overall proteins, N-glycosylation sequons in ABC protein superfamilies have a distinct pattern of occurrence, and the results are discussed in an evolutionary perspective.

Esophageal Clearance Patterns in Normal Older Adults as Documented with Videofluoroscopic Esophagram

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Janice Jou

2009-01-01

Full Text Available Normal esophageal bolus transport in asymptomatic healthy older adults has not been well defined, potentially leading to ambiguity in differentiating esophageal swallowing patterns of dysphagic and healthy individuals. This pilot study of 24 young (45–64 years and old (65+years men and women was designed to assess radiographic esophageal bolus movement patterns in healthy adults using videofluoroscopic recording. Healthy, asymptomatic adults underwent videofluoroscopic esophagram to evaluate for the presence of ineffective esophageal clearance, namely, intraesophageal stasis and intraesophageal reflux. Intraesophageal stasis and intraesophageal reflux were visualized radiographically in these normal subjects. Intraesophageal stasis occurred significantly more frequently with semisolid (96% compared with liquid (16% barium, suggesting that a variety of barium consistencies, as opposed to only the traditional fluids, would better define the spectrum of esophageal transport. Intraesophageal reflux was observed more frequently in older males than in their younger counterparts. The rates of intraesophageal stasis and intraesophageal reflux were potentially high given that successive bolus presentations were spaced 10 seconds apart. These findings suggest a need for a more comprehensive definition regarding the range of normal esophageal bolus transport to (a prevent misdiagnosis of dysphagia and (b to enhance generalization to functional eating, which involves solid foods in addition to liquids.

Sex Differences in Social Behavior: Are the Social Role and Evolutionary Explanations Compatible?

Science.gov (United States)

Archer, John

1996-01-01

Examines competing claims of two explanations of sex differences in social behavior, social role theory, and evolutionary psychology. Findings associated with social role theory are weighed against evolutionary explanations. It is suggested that evolutionary theory better accounts for the overall pattern of sex differences and for their origins.…

18F-FDG PET-CT pattern in idiopathic normal pressure hydrocephalus

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Ryan A. Townley

Full Text Available Background: Idiopathic normal pressure hydrocephalus (iNPH is an important and treatable cause of neurologic impairment. Diagnosis is complicated due to symptoms overlapping with other age related disorders. The pathophysiology underlying iNPH is not well understood. We explored FDG-PET abnormalities in iNPH patients in order to determine if FDG-PET may serve as a biomarker to differentiate iNPH from common neurodegenerative disorders. Methods: We retrospectively compared 18F-FDG PET-CT imaging patterns from seven iNPH patients (mean age 74 ± 6 years to age and sex matched controls, as well as patients diagnosed with clinical Alzheimer's disease dementia (AD, Dementia with Lewy Bodies (DLB and Parkinson's Disease Dementia (PDD, and behavioral variant frontotemporal dementia (bvFTD. Partial volume corrected and uncorrected images were reviewed separately. Results: Patients with iNPH, when compared to controls, AD, DLB/PDD, and bvFTD, had significant regional hypometabolism in the dorsal striatum, involving the caudate and putamen bilaterally. These results remained highly significant after partial volume correction. Conclusions: In this study, we report a FDG-PET pattern of hypometabolism in iNPH involving the caudate and putamen with preserved cortical metabolism. This pattern may differentiate iNPH from degenerative diseases and has the potential to serve as a biomarker for iNPH in future studies. These findings also further our understanding of the pathophysiology underlying the iNPH clinical presentation. Keywords: FDG-PET, Normal pressure hydrocephalus, Hypometabolism, Caudate, Biomarker

A Cancer-Indicative microRNA Pattern in Normal Prostate Tissue

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Thorsten Schlomm

2013-03-01

Full Text Available We analyzed the levels of selected micro-RNAs in normal prostate tissue to assess their potential to indicate tumor foci elsewhere in the prostate. Histologically normal prostate tissue samples from 31 prostate cancer patients and two cancer negative control groups with either unsuspicious or elevated prostate specific antigen (PSA levels (14 and 17 individuals, respectively were analyzed. Based on the expression analysis of 157 microRNAs in a pool of prostate tissue samples and information from data bases/literature, we selected eight microRNAs for quantification by real-time polymerase chain reactions (RT-PCRs. Selected miRNAs were analyzed in histologically tumor-free biopsy samples from patients and healthy controls. We identified seven microRNAs (miR-124a, miR-146a & b, miR-185, miR-16 and let-7a & b, which displayed significant differential expression in normal prostate tissue from men with prostate cancer compared to both cancer negative control groups. Four microRNAs (miR-185, miR-16 and let-7a and let-7b remained to significantly discriminate normal tissues from prostate cancer patients from those of the cancer negative control group with elevated PSA levels. The transcript levels of these microRNAs were highly indicative for the presence of cancer in the prostates, independently of the PSA level. Our results suggest a microRNA-pattern in histologically normal prostate tissue, indicating prostate cancer elsewhere in the organ.

Normal patterns of 18F-FDG appendiceal uptake in children

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Reavey, Hamilton E. [Emory University, Department of Radiology and Imaging Sciences, Division of Nuclear Medicine Molecular Imaging, Atlanta, GA (United States); Alazraki, Adina L.; Simoneaux, Stephen F. [Emory University, Department of Radiology and Imaging Sciences, Division of Pediatric Imaging, Children' s Healthcare of Atlanta at Egleston, Atlanta, GA (United States)

2014-04-15

Prior to interpreting PET/CT, it is crucial to understand the normal biodistribution of fluorodeoxyglucose (FDG). It is also important to realize that the normal biodistribution can vary between adults and children. Although many studies have defined normal patterns of pediatric FDG uptake in structures like the thymus, brown fat and bone marrow, patterns of normal pediatric bowel activity, specifically uptake within the appendix, have not been well described. Active lymphoid tissue has increased FDG uptake when compared with inactive tissue. Since children have more active lymphoid tissue than adults, and because the appendix contains aggregated lymphoid tissue, we postulated that appendiceal uptake may be increased in pediatric patients. To define the normal level of appendiceal FDG activity in children by evaluating a series of consecutive FDG PET/CT scans performed for other indications. After obtaining IRB approval, we retrospectively reviewed 128 consecutive whole-body pediatric FDG PET/CT examinations obtained for a variety of clinical indications. CT scans on which the appendix could not be visualized were excluded from analysis. CT scans on which the appendix could be visualized were evaluated for underlying appendiceal pathology. Studies with appendiceal or periappendiceal pathology by CT criteria were excluded. A region of interest (ROI) was placed over a portion of each appendix and appendiceal maximum standardized uptake value (SUVmax) was calculated. If an adjacent loop of bowel activity interfered with accurate measurements of the appendix SUVmax, the scan was excluded from the analysis. A chart review was performed on patients with elevated appendiceal SUVmax values to ensure that the patients did not have clinical symptomatology suggestive of acute appendicitis. When the appendix or a portion of the appendix could be visualized and accurately measured, the SUVmax was determined. SUVmax of the appendix was compared to the SUVmax of normal liver and

Phylogeny and evolutionary patterns in the Dwarf crayfish subfamily (Decapoda: Cambarellinae.

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Carlos Pedraza-Lara

Full Text Available The Dwarf crayfish or Cambarellinae, is a morphologically singular subfamily of decapod crustaceans that contains only one genus, Cambarellus. Its intriguing distribution, along the river basins of the Gulf Coast of United States (Gulf Group and into Central México (Mexican Group, has until now lacked of satisfactory explanation. This study provides a comprehensive sampling of most of the extant species of Cambarellus and sheds light on its evolutionary history, systematics and biogeography. We tested the impact of Gulf Group versus Mexican Group geography on rates of cladogenesis using a maximum likelihood framework, testing different models of birth/extinction of lineages. We propose a comprehensive phylogenetic hypothesis for the subfamily based on mitochondrial and nuclear loci (3,833 bp using Bayesian and Maximum Likelihood methods. The phylogenetic structure found two phylogenetic groups associated to the two main geographic components (Gulf Group and Mexican Group and is partially consistent with the historical structure of river basins. The previous hypothesis, which divided the genus into three subgenera based on genitalia morphology was only partially supported (P = 0.047, resulting in a paraphyletic subgenus Pandicambarus. We found at least two cases in which phylogenetic structure failed to recover monophyly of recognized species while detecting several cases of cryptic diversity, corresponding to lineages not assigned to any described species. Cladogenetic patterns in the entire subfamily are better explained by an allopatric model of speciation. Diversification analyses showed similar cladogenesis patterns between both groups and did not significantly differ from the constant rate models. While cladogenesis in the Gulf Group is coincident in time with changes in the sea levels, in the Mexican Group, cladogenesis is congruent with the formation of the Trans-Mexican Volcanic Belt. Our results show how similar allopatric

Illumination normalization based on simplified local binary patterns for a face verification system

NARCIS (Netherlands)

Tao, Q.; Veldhuis, Raymond N.J.

2007-01-01

Illumination normalization is a very important step in face recognition. In this paper we propose a simple implementation of Local Binary Patterns, which effectively reduces the variability caused by illumination changes. In combination with a likelihood ratio classifier, this illumination

Evolutionary speed limited by water in arid Australia.

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Goldie, Xavier; Gillman, Len; Crisp, Mike; Wright, Shane

2010-09-07

The covariation of biodiversity with climate is a fundamental pattern in nature. However, despite the ubiquity of this relationship, a consensus on the ultimate cause remains elusive. The evolutionary speed hypothesis posits direct mechanistic links between ambient temperature, the tempo of micro-evolution and, ultimately, species richness. Previous research has demonstrated faster rates of molecular evolution in warmer climates for a broad range of poikilothermic and homeothermic organisms, in both terrestrial and aquatic environments. In terrestrial systems, species richness increases with both temperature and water availability and the interaction of those terms: productivity. However, the influence of water availability as an independent variable on micro-evolutionary processes has not been examined previously. Here, using methodology that limits the potentially confounding role of cladogenetic and demographic processes, we report, to our knowledge, the first evidence that woody plants living in the arid Australian Outback are evolving more slowly than related species growing at similar latitudes in moist habitats on the mesic continental margins. These results support a modified evolutionary speed explanation for the relationship between the water-energy balance and plant diversity patterns.

Evolutionary Aesthetics and Print Advertising

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Kamil Luczaj

2015-06-01

Full Text Available The article analyzes the extent to which predictions based on the theory of evolutionary aesthetics are utilized by the advertising industry. The purpose of a comprehensive content analysis of print advertising is to determine whether the items indicated by evolutionists such as animals, flowers, certain types of landscapes, beautiful humans, and some colors are part of real advertising strategies. This article has shown that many evolutionary hypotheses (although not all of them are supported by empirical data. Along with these hypotheses, some inferences from Bourdieu’s cultural capital theory were tested. It turned out that advertising uses both biological schemata and cultural patterns to make an image more likable.

Evolutionary cell biology: two origins, one objective.

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Lynch, Michael; Field, Mark C; Goodson, Holly V; Malik, Harmit S; Pereira-Leal, José B; Roos, David S; Turkewitz, Aaron P; Sazer, Shelley

2014-12-02

All aspects of biological diversification ultimately trace to evolutionary modifications at the cellular level. This central role of cells frames the basic questions as to how cells work and how cells come to be the way they are. Although these two lines of inquiry lie respectively within the traditional provenance of cell biology and evolutionary biology, a comprehensive synthesis of evolutionary and cell-biological thinking is lacking. We define evolutionary cell biology as the fusion of these two eponymous fields with the theoretical and quantitative branches of biochemistry, biophysics, and population genetics. The key goals are to develop a mechanistic understanding of general evolutionary processes, while specifically infusing cell biology with an evolutionary perspective. The full development of this interdisciplinary field has the potential to solve numerous problems in diverse areas of biology, including the degree to which selection, effectively neutral processes, historical contingencies, and/or constraints at the chemical and biophysical levels dictate patterns of variation for intracellular features. These problems can now be examined at both the within- and among-species levels, with single-cell methodologies even allowing quantification of variation within genotypes. Some results from this emerging field have already had a substantial impact on cell biology, and future findings will significantly influence applications in agriculture, medicine, environmental science, and synthetic biology.

Evolutionary Models for Simple Biosystems

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Bagnoli, Franco

The concept of evolutionary development of structures constituted a real revolution in biology: it was possible to understand how the very complex structures of life can arise in an out-of-equilibrium system. The investigation of such systems has shown that indeed, systems under a flux of energy or matter can self-organize into complex patterns, think for instance to Rayleigh-Bernard convection, Liesegang rings, patterns formed by granular systems under shear. Following this line, one could characterize life as a state of matter, characterized by the slow, continuous process that we call evolution. In this paper we try to identify the organizational level of life, that spans several orders of magnitude from the elementary constituents to whole ecosystems. Although similar structures can be found in other contexts like ideas (memes) in neural systems and self-replicating elements (computer viruses, worms, etc.) in computer systems, we shall concentrate on biological evolutionary structure, and try to put into evidence the role and the emergence of network structure in such systems.

Evolutionary convergence and biologically embodied cognition

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Keijzer, Franciscus

2017-01-01

The study of evolutionary patterns of cognitive convergence would be greatly helped by a clear demarcation of cognition. Cognition is often used as an equivalent of mind, making it difficult to pin down empirically or to apply it confidently beyond the human condition. Recent developments in

Physical activity patterns and estimated daily energy expenditures in normal and overweight tunisian schoolchildren.

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Zarrouk, Fayçal; Bouhlel, Ezdine; Feki, Youssef; Amri, Mohamed; Shephard, Roy J

2009-01-01

Our aim was to test the normality of physical activity patterns and energy expenditures in normal weight and overweight primary school students. Heart rate estimates of total daily energy expenditure (TEE), active energy expenditure (AEE), and activity patterns were made over 3 consecutive school days in healthy middle-class Tunisian children (46 boys, 44 girls, median age (25(th)-75(th)) percentile, 9.2 (8.8-9.9) years. Our cross-section included 52 students with a normal body mass index (BMI) and 38 who exceeded age-specific BMI limits. TEE, AEE and overall physical activity level (PAL) were not different between overweight children and those with a normal BMI [median values (25(th)-75(th)) 9.20 (8.20-9.84) vs. 8.88 (7.42-9.76) MJ/d; 3.56 (2.59-4.22) vs. 3.85 (2.77-4.78) MJ/d and 1.74 (1.54-2.04) vs. 1.89 (1.66-2.15) respectively]. Physical activity intensities (PAI) were expressed as percentages of the individual's heart rate reserve (%HRR). The median PAI for the entire day (PAI24) and for the waking part of day (PAIw) were lower in overweight than in normal weight individuals [16.3 (14.2-18.9) vs. 20.6 (17.9-22.3) %HRR, p spend more time in moderate activity and less time in sedentary pursuits than overweight children.

Control-group feature normalization for multivariate pattern analysis of structural MRI data using the support vector machine.

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Linn, Kristin A; Gaonkar, Bilwaj; Satterthwaite, Theodore D; Doshi, Jimit; Davatzikos, Christos; Shinohara, Russell T

2016-05-15

Normalization of feature vector values is a common practice in machine learning. Generally, each feature value is standardized to the unit hypercube or by normalizing to zero mean and unit variance. Classification decisions based on support vector machines (SVMs) or by other methods are sensitive to the specific normalization used on the features. In the context of multivariate pattern analysis using neuroimaging data, standardization effectively up- and down-weights features based on their individual variability. Since the standard approach uses the entire data set to guide the normalization, it utilizes the total variability of these features. This total variation is inevitably dependent on the amount of marginal separation between groups. Thus, such a normalization may attenuate the separability of the data in high dimensional space. In this work we propose an alternate approach that uses an estimate of the control-group standard deviation to normalize features before training. We study our proposed approach in the context of group classification using structural MRI data. We show that control-based normalization leads to better reproducibility of estimated multivariate disease patterns and improves the classifier performance in many cases. Copyright © 2016 Elsevier Inc. All rights reserved.

Evolutionary genomics and HIV restriction factors.

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Pyndiah, Nitisha; Telenti, Amalio; Rausell, Antonio

2015-03-01

To provide updated insights into innate antiviral immunity and highlight prototypical evolutionary features of well characterized HIV restriction factors. Recently, a new HIV restriction factor, Myxovirus resistance 2, has been discovered and the region/residue responsible for its activity identified using an evolutionary approach. Furthermore, IFI16, an innate immunity protein known to sense several viruses, has been shown to contribute to the defense to HIV-1 by causing cell death upon sensing HIV-1 DNA. Restriction factors against HIV show characteristic signatures of positive selection. Different patterns of accelerated sequence evolution can distinguish antiviral strategies--offense or defence--as well as the level of specificity of the antiviral properties. Sequence analysis of primate orthologs of restriction factors serves to localize functional domains and sites responsible for antiviral action. We use recent discoveries to illustrate how evolutionary genomic analyses help identify new antiviral genes and their mechanisms of action.

Normal and abnormal electrical activation of the heart. Imaging patterns obtained by phase analysis of equilibrium cardiac studies

International Nuclear Information System (INIS)

Pavel, D.; Byrom, E.; Swiryn, S.; Meyer-Pavel, C.; Rosen, K.

1981-01-01

By using a temporal Fourier analysis of gated equilibrium cardiac studies, phase images were obtained. These functional images were analysed qualitatively and quantitatively to determine if specific patterns can be found for normal versus abnormal electrical activation of the heart. The study included eight subjects with normal cardiac function and 24 patients with abnormal electrical activation: eight with left bundle branch block (LBBB), two with right bundle branch block (RBBB), six with Wolff-Parkinson-White syndrome (WPW), one with junctional rhythm, one with spontaneous sustained ventricular tachycardia (VT) (all with normal wall motion), two with chronic transvenous pacemakers, and four with induced sustained VT (all with regional wall motion abnormalities). The results show that the two ventricals have the same mean phase (within +-9 0 ) in normals, but significantly different mean phases in all patients with bundle branch blocks. Of the six WPW patients, three had a distinctive abnormal pattern. The patient with junctional rhythm, those with transvenous pacemakers, and those with VT all had abnormal patterns on the phase image. The phase image is capable of showing differences between patients with electrical activation and a variety of electrical abnormalities. Within the latter category distinct patterns can be associated with each type of abnormality. (author)

Homing pattern of indium-111 T-lymphocytes in normal and tumor bearing rats

International Nuclear Information System (INIS)

Kasi, L.P.; Glenn, H.J.; Mehta, K.; Teckemeyer, I.C.; Wong, W.; Haynie, T.P.

1985-01-01

T-lymphocytes play an important role in tumor immunology and possess cytotoxic capabilities. Purified T-lymphocytes were obtained by incubating mononuclear cells separated from peripheral blood of Fisher 344 rats in a nylon wool column at 37 0 C. The non-adherent T-lymphocytes which were eluted from the column had > 95% viability. About 1 x 10/sup 7/ purified T-lymphocytes were labeled with 30 μCi In-111 oxine (Labeling yield: 75 +-5%, viability >95%). The function of the labeled cells as estimated by their graft versus host reaction ability remained unaltered. To evaluate the distribution pattern, 1 x 10/sup 6/ In-111 T-lymphocytes (per 100g wt) were injected via tail vein in normal and in transplanted (right flank) solid hepatoma bearing Fisher 344 rats, and the percent uptake of activity of the total injected dose per organ and per gm tissue was estimated at 2, 24 and 48 hours post injection. In normal rats maximum uptakes were in the liver (24%-33%) with increasing uptakes in the spleen (6.8%-11%) and minimum uptakes in the kidneys, lungs, muscles, and blood from 2 to 48 hours after injection. The uptake pattern in tumor bearing rats were significantly different during the same time period: lower in the liver (17%-19%) and a decrease in the spleen (9%-0.4%). All other tissues displayed similar uptake patterns as in normal animals. Maximum tumor:muscle ratio (18.4) was found at 48 hours post injection. Further studies are indicated for the possible use of In-111 T-lymphocytes in T-lymphocyte disorders, inflammations, and as an additional tool in the diagnosis of tumors

Patterns of evolutionary conservation of essential genes correlate with their compensability.

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Tobias Bergmiller

2012-06-01

Full Text Available Essential genes code for fundamental cellular functions required for the viability of an organism. For this reason, essential genes are often highly conserved across organisms. However, this is not always the case: orthologues of genes that are essential in one organism are sometimes not essential in other organisms or are absent from their genomes. This suggests that, in the course of evolution, essential genes can be rendered nonessential. How can a gene become non-essential? Here we used genetic manipulation to deplete the products of 26 different essential genes in Escherichia coli. This depletion results in a lethal phenotype, which could often be rescued by the overexpression of a non-homologous, non-essential gene, most likely through replacement of the essential function. We also show that, in a smaller number of cases, the essential genes can be fully deleted from the genome, suggesting that complete functional replacement is possible. Finally, we show that essential genes whose function can be replaced in the laboratory are more likely to be non-essential or not present in other taxa. These results are consistent with the notion that patterns of evolutionary conservation of essential genes are influenced by their compensability-that is, by how easily they can be functionally replaced, for example through increased expression of other genes.

Multiscale structure in eco-evolutionary dynamics

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Stacey, Blake C.

In a complex system, the individual components are neither so tightly coupled or correlated that they can all be treated as a single unit, nor so uncorrelated that they can be approximated as independent entities. Instead, patterns of interdependency lead to structure at multiple scales of organization. Evolution excels at producing such complex structures. In turn, the existence of these complex interrelationships within a biological system affects the evolutionary dynamics of that system. I present a mathematical formalism for multiscale structure, grounded in information theory, which makes these intuitions quantitative, and I show how dynamics defined in terms of population genetics or evolutionary game theory can lead to multiscale organization. For complex systems, "more is different," and I address this from several perspectives. Spatial host--consumer models demonstrate the importance of the structures which can arise due to dynamical pattern formation. Evolutionary game theory reveals the novel effects which can result from multiplayer games, nonlinear payoffs and ecological stochasticity. Replicator dynamics in an environment with mesoscale structure relates to generalized conditionalization rules in probability theory. The idea of natural selection "acting at multiple levels" has been mathematized in a variety of ways, not all of which are equivalent. We will face down the confusion, using the experience developed over the course of this thesis to clarify the situation.

Comparative study between Steiner's cephalometric-radiographic patterns and the ones of Brazilian's, white teenagers, who present normal occlusion

International Nuclear Information System (INIS)

Domingues, A.P. de.

1986-01-01

The purpose of this study was to study comparatively the cephalometric-radiographic patterns of Steiner's analysis and the ones of Brazilians, white teenagers, who present normal occlusions. The sample was composed of fifty seven teleradiographies on lateral pattern from Brazilian teenagers. Those teenagers are white and their parents are Brazilian, descended from Mediterraneans. Also the examined teenagers had not undergone previous orthodontic treatment and as it was said above, present normal occlusion. (author) [pt

Evolutionary perspectives on ageing.

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Reichard, Martin

2017-10-01

From an evolutionary perspective, ageing is a decrease in fitness with chronological age - expressed by an increase in mortality risk and/or decline in reproductive success and mediated by deterioration of functional performance. While this makes ageing intuitively paradoxical - detrimental to individual fitness - evolutionary theory offers answers as to why ageing has evolved. In this review, I first briefly examine the classic evolutionary theories of ageing and their empirical tests, and highlight recent findings that have advanced our understanding of the evolution of ageing (condition-dependent survival, positive pleiotropy). I then provide an overview of recent theoretical extensions and modifications that accommodate those new discoveries. I discuss the role of indeterminate (asymptotic) growth for lifetime increases in fecundity and ageing trajectories. I outline alternative views that challenge a universal existence of senescence - namely the lack of a germ-soma distinction and the ability of tissue replacement and retrogression to younger developmental stages in modular organisms. I argue that rejuvenation at the organismal level is plausible, but includes a return to a simple developmental stage. This may exempt a particular genotype from somatic defects but, correspondingly, removes any information acquired during development. A resolution of the question of whether a rejuvenated individual is the same entity is central to the recognition of whether current evolutionary theories of ageing, with their extensions and modifications, can explain the patterns of ageing across the Tree of Life. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Novel Pattern of Yolk Processing in Developing Snake Eggs (Colubridae: Lampropeltini) and its Functional and Evolutionary Implications.

Science.gov (United States)

Powers, Kathryn G; Blackburn, Daniel G

2017-07-01

Early amniotic vertebrates evolved large-yolked eggs that permitted production of well-developed, terrestrial hatchlings. This reproductive pattern required new mechanisms for cellularizing the yolk and mobilizing it for embryonic use. In birds, cells that line the yolk sac cavity phagocytose and digest the yolk material, a pattern that is commonly assumed to be universal among oviparous amniotes. However, recent evidence challenges the assumption that all squamate reptiles conform to the avian developmental pattern. In this paper, scanning electron microscopy and histology were used to study mechanisms of yolk processing in two colubrid snakes, the kingsnake Lampropeltis getula and the milksnake L. triangulum. Endodermal cells from the yolk sac splanchnopleure proliferate massively as they invade the yolk sac cavity, forming elaborate chains of interlinked cells. These cells grow in size as they phagocytose yolk material. Subsequently, vitelline capillaries invade the masses of yolk-laden cells and become coated with the endodermal cells, forming an elaborate meshwork of cell-coated strands. The close association of cells, yolk, and blood vessels allows yolk material to be cellularized, digested, and transported for embryonic use. The overall pattern is like that of the corn snake Pantherophis guttatus, but contrasts markedly with that of birds. Given recent evidence that this developmental pattern may also occur in certain lizards, we postulate that it is ancestral for squamates. Studies of lizards, crocodilians, and turtles are needed to clarify the evolutionary history of this pattern and its implications for the evolution of the amniotic (terrestrial) vertebrate egg. © 2017 Wiley Periodicals, Inc.

Evolutionary signals of symbiotic persistence in the legume-rhizobia mutualism.

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Werner, Gijsbert D A; Cornwell, William K; Cornelissen, Johannes H C; Kiers, E Toby

2015-08-18

Understanding the origins and evolutionary trajectories of symbiotic partnerships remains a major challenge. Why are some symbioses lost over evolutionary time whereas others become crucial for survival? Here, we use a quantitative trait reconstruction method to characterize different evolutionary stages in the ancient symbiosis between legumes (Fabaceae) and nitrogen-fixing bacteria, asking how labile is symbiosis across different host clades. We find that more than half of the 1,195 extant nodulating legumes analyzed have a high likelihood (>95%) of being in a state of high symbiotic persistence, meaning that they show a continued capacity to form the symbiosis over evolutionary time, even though the partnership has remained facultative and is not obligate. To explore patterns associated with the likelihood of loss and retention of the N2-fixing symbiosis, we tested for correlations between symbiotic persistence and legume distribution, climate, soil and trait data. We found a strong latitudinal effect and demonstrated that low mean annual temperatures are associated with high symbiotic persistence in legumes. Although no significant correlations between soil variables and symbiotic persistence were found, nitrogen and phosphorus leaf contents were positively correlated with legumes in a state of high symbiotic persistence. This pattern suggests that highly demanding nutrient lifestyles are associated with more stable partnerships, potentially because they "lock" the hosts into symbiotic dependency. Quantitative reconstruction methods are emerging as a powerful comparative tool to study broad patterns of symbiont loss and retention across diverse partnerships.

Evolutionary signals of symbiotic persistence in the legume–rhizobia mutualism

Science.gov (United States)

Werner, Gijsbert D. A.; Cornwell, William K.; Cornelissen, Johannes H. C.; Kiers, E. Toby

2015-01-01

Understanding the origins and evolutionary trajectories of symbiotic partnerships remains a major challenge. Why are some symbioses lost over evolutionary time whereas others become crucial for survival? Here, we use a quantitative trait reconstruction method to characterize different evolutionary stages in the ancient symbiosis between legumes (Fabaceae) and nitrogen-fixing bacteria, asking how labile is symbiosis across different host clades. We find that more than half of the 1,195 extant nodulating legumes analyzed have a high likelihood (>95%) of being in a state of high symbiotic persistence, meaning that they show a continued capacity to form the symbiosis over evolutionary time, even though the partnership has remained facultative and is not obligate. To explore patterns associated with the likelihood of loss and retention of the N2-fixing symbiosis, we tested for correlations between symbiotic persistence and legume distribution, climate, soil and trait data. We found a strong latitudinal effect and demonstrated that low mean annual temperatures are associated with high symbiotic persistence in legumes. Although no significant correlations between soil variables and symbiotic persistence were found, nitrogen and phosphorus leaf contents were positively correlated with legumes in a state of high symbiotic persistence. This pattern suggests that highly demanding nutrient lifestyles are associated with more stable partnerships, potentially because they “lock” the hosts into symbiotic dependency. Quantitative reconstruction methods are emerging as a powerful comparative tool to study broad patterns of symbiont loss and retention across diverse partnerships. PMID:26041807

Contrasting patterns of evolutionary constraint and novelty revealed by comparative sperm proteomic analysis in Lepidoptera.

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Whittington, Emma; Forsythe, Desiree; Borziak, Kirill; Karr, Timothy L; Walters, James R; Dorus, Steve

2017-12-02

Rapid evolution is a hallmark of reproductive genetic systems and arises through the combined processes of sequence divergence, gene gain and loss, and changes in gene and protein expression. While studies aiming to disentangle the molecular ramifications of these processes are progressing, we still know little about the genetic basis of evolutionary transitions in reproductive systems. Here we conduct the first comparative analysis of sperm proteomes in Lepidoptera, a group that exhibits dichotomous spermatogenesis, in which males produce a functional fertilization-competent sperm (eupyrene) and an incompetent sperm morph lacking nuclear DNA (apyrene). Through the integrated application of evolutionary proteomics and genomics, we characterize the genomic patterns potentially associated with the origination and evolution of this unique spermatogenic process and assess the importance of genetic novelty in Lepidopteran sperm biology. Comparison of the newly characterized Monarch butterfly (Danaus plexippus) sperm proteome to those of the Carolina sphinx moth (Manduca sexta) and the fruit fly (Drosophila melanogaster) demonstrated conservation at the level of protein abundance and post-translational modification within Lepidoptera. In contrast, comparative genomic analyses across insects reveals significant divergence at two levels that differentiate the genetic architecture of sperm in Lepidoptera from other insects. First, a significant reduction in orthology among Monarch sperm genes relative to the remainder of the genome in non-Lepidopteran insect species was observed. Second, a substantial number of sperm proteins were found to be specific to Lepidoptera, in that they lack detectable homology to the genomes of more distantly related insects. Lastly, the functional importance of Lepidoptera specific sperm proteins is broadly supported by their increased abundance relative to proteins conserved across insects. Our results identify a burst of genetic novelty

Normalized burn ratios link fire severity with patterns of avian occurrence

Science.gov (United States)

Rose, Eli T.; Simons, Theodore R.; Klein, Rob; McKerrow, Alexa

2016-01-01

ContextRemotely sensed differenced normalized burn ratios (DNBR) provide an index of fire severity across the footprint of a fire. We asked whether this index was useful for explaining patterns of bird occurrence within fire adapted xeric pine-oak forests of the southern Appalachian Mountains.ObjectivesWe evaluated the use of DNBR indices for linking ecosystem process with patterns of bird occurrence. We compared field-based and remotely sensed fire severity indices and used each to develop occupancy models for six bird species to identify patterns of bird occurrence following fire.MethodsWe identified and sampled 228 points within fires that recently burned within Great Smoky Mountains National Park. We performed avian point counts and field-assessed fire severity at each bird census point. We also used Landsat™ imagery acquired before and after each fire to quantify fire severity using DNBR. We used non-parametric methods to quantify agreement between fire severity indices, and evaluated single season occupancy models incorporating fire severity summarized at different spatial scales.ResultsAgreement between field-derived and remotely sensed measures of fire severity was influenced by vegetation type. Although occurrence models using field-derived indices of fire severity outperformed those using DNBR, summarizing DNBR at multiple spatial scales provided additional insights into patterns of occurrence associated with different sized patches of high severity fire.ConclusionsDNBR is useful for linking the effects of fire severity to patterns of bird occurrence, and informing how high severity fire shapes patterns of bird species occurrence on the landscape.

Evolutionary analyses of non-genealogical bonds produced by introgressive descent.

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Bapteste, Eric; Lopez, Philippe; Bouchard, Frédéric; Baquero, Fernando; McInerney, James O; Burian, Richard M

2012-11-06

All evolutionary biologists are familiar with evolutionary units that evolve by vertical descent in a tree-like fashion in single lineages. However, many other kinds of processes contribute to evolutionary diversity. In vertical descent, the genetic material of a particular evolutionary unit is propagated by replication inside its own lineage. In what we call introgressive descent, the genetic material of a particular evolutionary unit propagates into different host structures and is replicated within these host structures. Thus, introgressive descent generates a variety of evolutionary units and leaves recognizable patterns in resemblance networks. We characterize six kinds of evolutionary units, of which five involve mosaic lineages generated by introgressive descent. To facilitate detection of these units in resemblance networks, we introduce terminology based on two notions, P3s (subgraphs of three nodes: A, B, and C) and mosaic P3s, and suggest an apparatus for systematic detection of introgressive descent. Mosaic P3s correspond to a distinct type of evolutionary bond that is orthogonal to the bonds of kinship and genealogy usually examined by evolutionary biologists. We argue that recognition of these evolutionary bonds stimulates radical rethinking of key questions in evolutionary biology (e.g., the relations among evolutionary players in very early phases of evolutionary history, the origin and emergence of novelties, and the production of new lineages). This line of research will expand the study of biological complexity beyond the usual genealogical bonds, revealing additional sources of biodiversity. It provides an important step to a more realistic pluralist treatment of evolutionary complexity.

Human genomic disease variants: a neutral evolutionary explanation.

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Dudley, Joel T; Kim, Yuseob; Liu, Li; Markov, Glenn J; Gerold, Kristyn; Chen, Rong; Butte, Atul J; Kumar, Sudhir

2012-08-01

Many perspectives on the role of evolution in human health include nonempirical assumptions concerning the adaptive evolutionary origins of human diseases. Evolutionary analyses of the increasing wealth of clinical and population genomic data have begun to challenge these presumptions. In order to systematically evaluate such claims, the time has come to build a common framework for an empirical and intellectual unification of evolution and modern medicine. We review the emerging evidence and provide a supporting conceptual framework that establishes the classical neutral theory of molecular evolution (NTME) as the basis for evaluating disease- associated genomic variations in health and medicine. For over a decade, the NTME has already explained the origins and distribution of variants implicated in diseases and has illuminated the power of evolutionary thinking in genomic medicine. We suggest that a majority of disease variants in modern populations will have neutral evolutionary origins (previously neutral), with a relatively smaller fraction exhibiting adaptive evolutionary origins (previously adaptive). This pattern is expected to hold true for common as well as rare disease variants. Ultimately, a neutral evolutionary perspective will provide medicine with an informative and actionable framework that enables objective clinical assessment beyond convenient tendencies to invoke past adaptive events in human history as a root cause of human disease.

An Evolutionary Psychology Approach to Consumer Choice

Directory of Open Access Journals (Sweden)

ZURINA BT MOHAIDIN

2013-07-01

Full Text Available Human behaviour can be explained not only through experience and environments but also by incorporating evolutionary explanation. Consumer behaviour could not be understood accurately without infusing Darwinian evolutionary theory which has contributed in the knowledge of human nature. Evolutionary psychology revolves around the human’s evolved mental and the impact on human’s traits and behaviour where the influence of the environment to our genes would determine our individual behaviour and traits, resulting in variation among us. Foraging which is a part of behavioural ecology involves many sequences or repetitions of animals’ activities and decision making which is useful to relate these patterns of activities to the decisions made in human consumption. The aim of this research is to investigate the similarities of human consumption and ecological behaviour by employing interpretative and comparative approach. It is hoped that by applying the evolutionary theory in explaining consumer choice, this study is able to contribute to the development of behavioural ecology in human consumption. The analysis of the data is done aggregately for 200 consumers and individually for 20 consumers, who have purchased four product categories over a year. This study concludes that the theories of evolutionary psychology can fit to the consumers’ buying behaviour implicating its usefulness in explaining the consumers’ choice.

Phylogenetic Pattern, Evolutionary Processes and Species Delimitation in the Genus Echinococcus.

Science.gov (United States)

Lymbery, A J

2017-01-01

An accurate and stable alpha taxonomy requires a clear conception of what constitutes a species and agreed criteria for delimiting different species. An evolutionary or general lineage concept defines a species as a single lineage of organisms with a common evolutionary trajectory, distinguishable from other such lineages. Delimiting evolutionary species is a two-step process. In the first step, phylogenetic reconstruction identifies putative species as groups of organisms that are monophyletic (share a common ancestor) and exclusive (more closely related to each other than to organisms outside the group). The second step is to assess whether members of the group possess genetic exchangeability (where cohesion is maintained by gene flow among populations) or ecological exchangeability (where cohesion is maintained because populations occupy the same ecological niche). Recent taxonomic reviews have recognized nine species within the genus Echinococcus. Phylogenetic reconstructions of the relationships between these putative species using mtDNA and nuclear gene sequences show that for the most part these nine species are monophyletic, although there are important incongruences that need to be resolved. Applying the criteria of genetic and ecological exchangeability suggests that seven of the currently recognized species represent evolutionarily distinct lineages. The species status of Echinococcus canadensis and Echinococcus ortleppi could not be confirmed. Coalescent-based analyses represent a promising approach to species delimitation in these closely related taxa. It seems likely, from a comparison of sister species groups, that speciation in the genus has been driven by geographic isolation, but biogeographic scenarios are largely speculative and require further testing. Copyright © 2017 Elsevier Ltd. All rights reserved.

Do arms races punctuate evolutionary stasis? Unified insights from phylogeny, phylogeography and microevolutionary processes.

Science.gov (United States)

Toju, Hirokazu; Sota, Teiji

2009-09-01

One of the major controversies in evolutionary biology concerns the processes underlying macroevolutionary patterns in which prolonged stasis is disrupted by rapid, short-term evolution that leads species to new adaptive zones. Recent advances in the understanding of contemporary evolution have suggested that such rapid evolution can occur in the wild as a result of environmental changes. Here, we examined a novel hypothesis that evolutionary stasis is punctuated by co-evolutionary arms races, which continuously alter adaptive peaks and landscapes. Based on the phylogeny of long-mouthed weevils in the genus Curculio, likelihood ratio tests showed that the macroevolutionary pattern of the weevils coincides with the punctuational evolution model. A coalescent analysis of a species, Curculio camelliae, the mouthpart of which has diverged considerably among populations because of an arms race with its host plant, further suggested that major evolutionary shifts had occurred within 7000 generations. Through a microevolutionary analysis of the species, we also found that natural selection acting through co-evolutionary interactions is potentially strong enough to drive rapid evolutionary shifts between adaptive zones. Overall, we posit that co-evolution is an important factor driving the history of organismal evolution.

Geography and major host evolutionary transitions shape the resource use of plant parasites.

Science.gov (United States)

Calatayud, Joaquín; Hórreo, José Luis; Madrigal-González, Jaime; Migeon, Alain; Rodríguez, Miguel Á; Magalhães, Sara; Hortal, Joaquín

2016-08-30

The evolution of resource use in herbivores has been conceptualized as an analog of the theory of island biogeography, assuming that plant species are islands separated by phylogenetic distances. Despite its usefulness, this analogy has paradoxically led to neglecting real biogeographical processes in the study of macroevolutionary patterns of herbivore-plant interactions. Here we show that host use is mostly determined by the geographical cooccurrence of hosts and parasites in spider mites (Tetranychidae), a globally distributed group of plant parasites. Strikingly, geography accounts for most of the phylogenetic signal in host use by these parasites. Beyond geography, only evolutionary transitions among major plant lineages (i.e., gymnosperms, commelinids, and eudicots) shape resource use patterns in these herbivores. Still, even these barriers have been repeatedly overcome in evolutionary time, resulting in phylogenetically diverse parasite communities feeding on similar hosts. Therefore, our results imply that patterns of apparent evolutionary conservatism may largely be a byproduct of the geographic cooccurrence of hosts and parasites.

Threat-detection in child development: an evolutionary perspective.

Science.gov (United States)

Boyer, Pascal; Bergstrom, Brian

2011-03-01

Evidence for developmental aspects of fear-targets and anxiety suggests a complex but stable pattern whereby specific kinds of fears emerge at different periods of development. This developmental schedule seems appropriate to dangers encountered repeatedly during human evolution. Also consistent with evolutionary perspective, the threat-detection systems are domain-specific, comprising different kinds of cues to do with predation, intraspecific violence, contamination-contagion and status loss. Proper evolutionary models may also be relevant to outstanding issues in the domain, notably the connections between typical development and pathology. Copyright © 2010 Elsevier Ltd. All rights reserved.

Deterministic Evolutionary Trajectories Influence Primary Tumor Growth: TRACERx Renal

DEFF Research Database (Denmark)

Turajlic, Samra; Xu, Hang; Litchfield, Kevin

2018-01-01

The evolutionary features of clear-cell renal cell carcinoma (ccRCC) have not been systematically studied to date. We analyzed 1,206 primary tumor regions from 101 patients recruited into the multi-center prospective study, TRACERx Renal. We observe up to 30 driver events per tumor and show...... that subclonal diversification is associated with known prognostic parameters. By resolving the patterns of driver event ordering, co-occurrence, and mutual exclusivity at clone level, we show the deterministic nature of clonal evolution. ccRCC can be grouped into seven evolutionary subtypes, ranging from tumors...... outcome. Our insights reconcile the variable clinical behavior of ccRCC and suggest evolutionary potential as a biomarker for both intervention and surveillance....

Evolutionary patterns and processes in the radiation of phyllostomid bats

Directory of Open Access Journals (Sweden)

Monteiro Leandro R

2011-05-01

Full Text Available Abstract Background The phyllostomid bats present the most extensive ecological and phenotypic radiation known among mammal families. This group is an important model system for studies of cranial ecomorphology and functional optimisation because of the constraints imposed by the requirements of flight. A number of studies supporting phyllostomid adaptation have focused on qualitative descriptions or correlating functional variables and diet, but explicit tests of possible evolutionary mechanisms and scenarios for phenotypic diversification have not been performed. We used a combination of morphometric and comparative methods to test hypotheses regarding the evolutionary processes behind the diversification of phenotype (mandible shape and size and diet during the phyllostomid radiation. Results The different phyllostomid lineages radiate in mandible shape space, with each feeding specialisation evolving towards different axes. Size and shape evolve quite independently, as the main directions of shape variation are associated with mandible elongation (nectarivores or the relative size of tooth rows and mandibular processes (sanguivores and frugivores, which are not associated with size changes in the mandible. The early period of phyllostomid diversification is marked by a burst of shape, size, and diet disparity (before 20 Mya, larger than expected by neutral evolution models, settling later to a period of relative phenotypic and ecological stasis. The best fitting evolutionary model for both mandible shape and size divergence was an Ornstein-Uhlenbeck process with five adaptive peaks (insectivory, carnivory, sanguivory, nectarivory and frugivory. Conclusions The radiation of phyllostomid bats presented adaptive and non-adaptive components nested together through the time frame of the family's evolution. The first 10 My of the radiation were marked by strong phenotypic and ecological divergence among ancestors of modern lineages, whereas the

Evolutionary patterns and processes in the radiation of phyllostomid bats

Science.gov (United States)

2011-01-01

Background The phyllostomid bats present the most extensive ecological and phenotypic radiation known among mammal families. This group is an important model system for studies of cranial ecomorphology and functional optimisation because of the constraints imposed by the requirements of flight. A number of studies supporting phyllostomid adaptation have focused on qualitative descriptions or correlating functional variables and diet, but explicit tests of possible evolutionary mechanisms and scenarios for phenotypic diversification have not been performed. We used a combination of morphometric and comparative methods to test hypotheses regarding the evolutionary processes behind the diversification of phenotype (mandible shape and size) and diet during the phyllostomid radiation. Results The different phyllostomid lineages radiate in mandible shape space, with each feeding specialisation evolving towards different axes. Size and shape evolve quite independently, as the main directions of shape variation are associated with mandible elongation (nectarivores) or the relative size of tooth rows and mandibular processes (sanguivores and frugivores), which are not associated with size changes in the mandible. The early period of phyllostomid diversification is marked by a burst of shape, size, and diet disparity (before 20 Mya), larger than expected by neutral evolution models, settling later to a period of relative phenotypic and ecological stasis. The best fitting evolutionary model for both mandible shape and size divergence was an Ornstein-Uhlenbeck process with five adaptive peaks (insectivory, carnivory, sanguivory, nectarivory and frugivory). Conclusions The radiation of phyllostomid bats presented adaptive and non-adaptive components nested together through the time frame of the family's evolution. The first 10 My of the radiation were marked by strong phenotypic and ecological divergence among ancestors of modern lineages, whereas the remaining 20 My were

Pattern of somatostatin receptors expression in normal and bladder cancer tissue samples.

Science.gov (United States)

Karavitakis, Markos; Msaouel, Pavlos; Michalopoulos, Vassilis; Koutsilieris, Michael

2014-06-01

Known risks factors for bladder cancer progression and recurrence are limited regarding their prognostic ability. Therefore identification of molecular determinants of disease progression could provide with more specific prognostic information and could be translated into new approaches for biomarker development. In the present study we evaluated, the expression patterns of somatostatin receptors 1-5 (SSTRs) in normal and tumor bladder tissues. The expression of SSTR1-5 was characterized in 45 normal and bladder cancer tissue samples using reverse transcriptase-polymerase chain reaction (RT-PCR). SSTR1 was expressed in 24 samples, SSTR2 in 15, SSTR3 in 23, SSTR4 in 16 and SSTR5 in all but one sample. Bladder cancer tissue samples expressed lower levels of SSTR3. Co-expression of SSTRs was associated with superficial disease. Our results demonstrate, for the first time, that there is expression of SSTR in normal and bladder cancer urothelium. Further studies are required to evaluate the prognostic and therapeutic significance of these findings. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Evolutionary aspects of life forms in angiosperm families

NARCIS (Netherlands)

Kremer, P; van Andel, J

1995-01-01

The distribution patterns of life forms among extant families, subclasses and classes are described with the aim of detecting evolutionary trends. The explosive diversification of angiosperms constrains the possibilities for detecting such trends. Moreover, the extant groups of seed plants are only

Testing evolutionary hypotheses for phenotypic divergence using landscape genetics.

Science.gov (United States)

Funk, W Chris; Murphy, Melanie A

2010-02-01

Understanding the evolutionary causes of phenotypic variation among populations has long been a central theme in evolutionary biology. Several factors can influence phenotypic divergence, including geographic isolation, genetic drift, divergent natural or sexual selection, and phenotypic plasticity. But the relative importance of these factors in generating phenotypic divergence in nature is still a tantalizing and unresolved problem in evolutionary biology. The origin and maintenance of phenotypic divergence is also at the root of many ongoing debates in evolutionary biology, such as the extent to which gene flow constrains adaptive divergence (Garant et al. 2007) and the relative importance of genetic drift, natural selection, and sexual selection in initiating reproductive isolation and speciation (Coyne & Orr 2004). In this issue, Wang & Summers (2010) test the causes of one of the most fantastic examples of phenotypic divergence in nature: colour pattern divergence among populations of the strawberry poison frog (Dendrobates pumilio) in Panama and Costa Rica (Fig. 1). This study provides a beautiful example of the use of the emerging field of landscape genetics to differentiate among hypotheses for phenotypic divergence. Using landscape genetic analyses, Wang & Summers were able to reject the hypotheses that colour pattern divergence is due to isolation-by-distance (IBD) or landscape resistance. Instead, the hypothesis left standing is that colour divergence is due to divergent selection, in turn driving reproductive isolation among populations with different colour morphs. More generally, this study provides a wonderful example of how the emerging field of landscape genetics, which has primarily been applied to questions in conservation and ecology, now plays an essential role in evolutionary research.

Testing the cranial evolutionary allometric 'rule' in Galliformes.

Science.gov (United States)

Linde-Medina, M

2016-09-01

Recent comparative studies have indicated the existence of a common cranial evolutionary allometric (CREA) pattern in mammals and birds, in which smaller species have relatively smaller faces and bigger braincases than larger species. In these studies, cranial allometry was tested using a multivariate regression between shape (described using landmarks coordinates) and size (i.e. centroid size), after accounting for phylogenetic relatedness. Alternatively, cranial allometry can be determined by comparing the sizes of two anatomical parts using a bivariate regression analysis. In this analysis, a slope higher or lower than one indicates the existence of positive or negative allometry, respectively. Thus, in those species that support the CREA 'rule', positive allometry is expected for the association between face size and braincase size, which would indicate that larger species have disproportionally larger faces. In this study, I applied these two approaches to explore cranial allometry in 83 Galliformes (Aves, Galloanserae), ranging in mean body weight from 30 g to 2.5 kg. The multivariate regression between shape and centroid size revealed the existence of a significant allometric pattern resembling CREA, whereas the second analysis revealed a negative allometry for beak size and braincase size (i.e. contrary to the CREA 'rule', larger galliform species have disproportionally shorter beaks than smaller galliform species). This study suggests that the presence of CREA may be overestimated when using cranium size as the standard measurement. © 2016 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2016 European Society For Evolutionary Biology.

Motion Normalized Proportional Control for Improved Pattern Recognition-Based Myoelectric Control.

Science.gov (United States)

Scheme, Erik; Lock, Blair; Hargrove, Levi; Hill, Wendy; Kuruganti, Usha; Englehart, Kevin

2014-01-01

This paper describes two novel proportional control algorithms for use with pattern recognition-based myoelectric control. The systems were designed to provide automatic configuration of motion-specific gains and to normalize the control space to the user's usable dynamic range. Class-specific normalization parameters were calculated using data collected during classifier training and require no additional user action or configuration. The new control schemes were compared to the standard method of deriving proportional control using a one degree of freedom Fitts' law test for each of the wrist flexion/extension, wrist pronation/supination and hand close/open degrees of freedom. Performance was evaluated using the Fitts' law throughput value as well as more descriptive metrics including path efficiency, overshoot, stopping distance and completion rate. The proposed normalization methods significantly outperformed the incumbent method in every performance category for able bodied subjects (p < 0.001) and nearly every category for amputee subjects. Furthermore, one proposed method significantly outperformed both other methods in throughput (p < 0.0001), yielding 21% and 40% improvement over the incumbent method for amputee and able bodied subjects, respectively. The proposed control schemes represent a computationally simple method of fundamentally improving myoelectric control users' ability to elicit robust, and controlled, proportional velocity commands.

Normal human gait patterns in Peruvian individuals: an exploratory assessment using VICON motion capture system

Science.gov (United States)

Dongo, R.; Moscoso, M.; Callupe, R.; Pajaya, J.; Elías, D.

2017-11-01

Gait analysis is of clinical relevance for clinicians. However, normal gait patterns used in foreign literature could be different from local individuals. The aim of this study was to determine the normal gait patterns and parameters of Peruvian individuals in order to have a local referent for clinical assessments and making diagnosis and treatment Peruvian people with lower motor neuron injuries. A descriptive study with 34 subjects was conducted to assess their gait cycle. VICON® cameras were used to capture body movements. For the analyses, we calculated spatiotemporal gait parameters and average angles of displacement of the hip, knee, and ankle joints with their respective 95% confidence intervals. The results showed gait speed was 0.58m/s, cadence was 102.1steps/min, and the angular displacement of the hip, knee and ankle joints were all lower than those described in the literature. In the graphs, gait cycles were close to those reported in previous studies, but the parameters of speed, cadence and angles of displacements are lower than the ones shown in the literature. These results could be used as a better reference pattern in the clinical setting.

Evolutionary dynamics under interactive diversity

Science.gov (United States)

Su, Qi; Li, Aming; Wang, Long

2017-10-01

As evidenced by many cases in human societies, individuals often make different behavior decisions in different interactions, and adaptively adjust their behavior in changeable interactive scenarios. However, up to now, how such diverse interactive behavior affects cooperation dynamics has still remained unknown. Here we develop a general framework of interactive diversity, which models individuals’ separated behavior against distinct opponents and their adaptive adjustment in response to opponents’ strategies, to explore the evolution of cooperation. We find that interactive diversity enables individuals to reciprocate every single opponent, and thus sustains large-scale reciprocal interactions. Our work witnesses an impressive boost of cooperation for a notably extensive range of parameters and for all pairwise games. These results are robust against well-mixed and various networked populations, and against degree-normalized and cumulative payoff patterns. From the perspective of network dynamics, distinguished from individuals competing for nodes in most previous work, in this paper, the system evolves in the form of behavior disseminating along edges. We propose a theoretical method based on evolution of edges, which predicts well both the frequency of cooperation and the compact cooperation clusters. Our thorough investigation clarifies the positive role of interactive diversity in resolving social dilemmas and highlights the significance of understanding evolutionary dynamics from the viewpoint of edge dynamics.

Bannatyne-Recategorized WISC-R Patterns of Mentally Retarded, Learning Disabled, Normal, and Intellectually Superior Children: A Meta-Analysis.

Science.gov (United States)

Mueller, Horst H.; And Others

1983-01-01

Metaanalytical procedures examined the Wechsler Intelligence Scale-Revised subtest performance patterns of 36 samples of below average, normal average, learning disabled average, and above average IQ children from research. Relative patterning of WISC-R subtests as reflected in children's Bannatyne-recategorized performance profiles appeared to be…

The four cornerstones of Evolutionary Toxicology.

Science.gov (United States)

Bickham, John W

2011-05-01

Evolutionary Toxicology is the study of the effects of chemical pollutants on the genetics of natural populations. Research in Evolutionary Toxicology uses experimental designs familiar to the ecotoxicologist with matched reference and contaminated sites and the selection of sentinel species. It uses the methods of molecular genetics and population genetics, and is based on the theories and concepts of evolutionary biology and conservation genetics. Although it is a relatively young field, interest is rapidly growing among ecotoxicologists and more and more field studies and even controlled laboratory experiments are appearing in the literature. A number of population genetic impacts have been observed in organisms exposed to pollutants which I refer to here as the four cornerstones of Evolutionary Toxicology. These include (1) genome-wide changes in genetic diversity, (2) changes in allelic or genotypic frequencies caused by contaminant-induced selection acting at survivorship loci, (3) changes in dispersal patterns or gene flow which alter the genetic relationships among populations, and (4) changes in allelic or genotypic frequencies caused by increased mutation rates. It is concluded that population genetic impacts of pollution exposure are emergent effects that are not necessarily predictable from the mode of toxicity of the pollutant. Thus, to attribute an effect to a particular contaminant requires a careful experimental design which includes selection of appropriate reference sites, detailed chemistry analyses of environmental samples and tissues, and the use of appropriate biomarkers to establish exposure and effect. This paper describes the field of Evolutionary Toxicology and discusses relevant field studies and their findings. © Springer Science+Business Media, LLC 2011

Evolutionary modelling of transitions to sustainable development

International Nuclear Information System (INIS)

Safarzynska, K.

2010-01-01

This thesis has examined how evolutionary economics can contribute to modelling the micromechanisms that underlie transitions towards sustainable development. In general, transitions are fundamental or structural system changes. They involve, or even require, escaping lock-in of dominant, environmentally unsustainable technologies, introducing major technical or social innovations, and changing prevailing social practices and structures. Due to the complexity of socioeconomic interactions, it is not always possible to identify, and thus target with appropriate policy instruments, causes of specific unsustainable patterns of behaviour. Formal modelling exercises can help improve our understanding of the interaction of various transition mechanisms which are otherwise difficult to grasp intuitively. They allow exploring effects of policy interventions in complex systems. However, existing models of transitions focus on social phenomena and seldom address economic problems. As opposed, mainstream (neoclassical) economic models of technological change do not account for social interactions, and changing heterogeneity of users and their perspectives - even though all of these can influence the direction of innovations and patterns of socio-technological development. Evolutionary economics offers an approach that goes beyond neoclassical economics - in the sense of employing more realistic assumptions regarding the behaviour and heterogeneity of consumers, firms and investors. It can complement current transition models by providing them with a better understanding of associated economic dynamics. In this thesis, formal models were proposed to illustrate the usefulness of a range of evolutionary-economic techniques for modelling transitions. Modelling exercises aimed to explain the core properties of socio-economic systems, such as lock-in, path-dependence, coevolution, group selection and recombinant innovation. The studies collected in this dissertation illustrate that

Single-unit pattern generators for quadruped locomotion

DEFF Research Database (Denmark)

Morse, Gregory; Risi, Sebastian; Snyder, Charles R

2013-01-01

Legged robots can potentially venture beyond the limits of wheeled vehicles. While creating controllers for such robots by hand is possible, evolutionary algorithms are an alternative that can reduce the burden of hand-crafting robotic controllers. Although major evolutionary approaches to legged...... on a new type of neuron called a single-unit pattern generator (SUPG). The SUPG, which is indirectly encoded by a compositional pattern producing network (CPPN) evolved by HyperNEAT, produces a flexible temporal activation pattern that can be reset and repeated at any time through an explicit trigger input...

Evolutionary history of the somatostatin and somatostatin receptors

Indian Academy of Sciences (India)

Somatostatin and its receptors have a critical role in mammalian growth through their control pattern of secretion of growth hormone, but the evolutionary history of somatostatin and somatostatin receptors are ill defined. We used comparative whole genome analysis of Danio rerio, Carassius auratus, Xenopus tropicalis, ...

Evolutionary Nephrology.

Science.gov (United States)

Chevalier, Robert L

2017-05-01

Progressive kidney disease follows nephron loss, hyperfiltration, and incomplete repair, a process described as "maladaptive." In the past 20 years, a new discipline has emerged that expands research horizons: evolutionary medicine. In contrast to physiologic (homeostatic) adaptation, evolutionary adaptation is the result of reproductive success that reflects natural selection. Evolutionary explanations for physiologically maladaptive responses can emerge from mismatch of the phenotype with environment or evolutionary tradeoffs. Evolutionary adaptation to a terrestrial environment resulted in a vulnerable energy-consuming renal tubule and a hypoxic, hyperosmolar microenvironment. Natural selection favors successful energy investment strategy: energy is allocated to maintenance of nephron integrity through reproductive years, but this declines with increasing senescence after ~40 years of age. Risk factors for chronic kidney disease include restricted fetal growth or preterm birth (life history tradeoff resulting in fewer nephrons), evolutionary selection for APOL1 mutations (that provide resistance to trypanosome infection, a tradeoff), and modern life experience (Western diet mismatch leading to diabetes and hypertension). Current advances in genomics, epigenetics, and developmental biology have revealed proximate causes of kidney disease, but attempts to slow kidney disease remain elusive. Evolutionary medicine provides a complementary approach by addressing ultimate causes of kidney disease. Marked variation in nephron number at birth, nephron heterogeneity, and changing susceptibility to kidney injury throughout life history are the result of evolutionary processes. Combined application of molecular genetics, evolutionary developmental biology (evo-devo), developmental programming and life history theory may yield new strategies for prevention and treatment of chronic kidney disease.

Evolutionary Nephrology

Directory of Open Access Journals (Sweden)

Robert L. Chevalier

2017-05-01

Full Text Available Progressive kidney disease follows nephron loss, hyperfiltration, and incomplete repair, a process described as “maladaptive.” In the past 20 years, a new discipline has emerged that expands research horizons: evolutionary medicine. In contrast to physiologic (homeostatic adaptation, evolutionary adaptation is the result of reproductive success that reflects natural selection. Evolutionary explanations for physiologically maladaptive responses can emerge from mismatch of the phenotype with environment or from evolutionary tradeoffs. Evolutionary adaptation to a terrestrial environment resulted in a vulnerable energy-consuming renal tubule and a hypoxic, hyperosmolar microenvironment. Natural selection favors successful energy investment strategy: energy is allocated to maintenance of nephron integrity through reproductive years, but this declines with increasing senescence after ∼40 years of age. Risk factors for chronic kidney disease include restricted fetal growth or preterm birth (life history tradeoff resulting in fewer nephrons, evolutionary selection for APOL1 mutations (which provide resistance to trypanosome infection, a tradeoff, and modern life experience (Western diet mismatch leading to diabetes and hypertension. Current advances in genomics, epigenetics, and developmental biology have revealed proximate causes of kidney disease, but attempts to slow kidney disease remain elusive. Evolutionary medicine provides a complementary approach by addressing ultimate causes of kidney disease. Marked variation in nephron number at birth, nephron heterogeneity, and changing susceptibility to kidney injury throughout the life history are the result of evolutionary processes. Combined application of molecular genetics, evolutionary developmental biology (evo-devo, developmental programming, and life history theory may yield new strategies for prevention and treatment of chronic kidney disease.

Three dimensional analysis of histone methylation patterns in normal and tumor cell nuclei

Directory of Open Access Journals (Sweden)

M Cremer

2009-06-01

Full Text Available Histone modifications represent an important epigenetic mechanism for the organization of higher order chromatin structure and gene regulation. Methylation of position-specific lysine residues in the histone H3 and H4 amino termini has been linked with the formation of constitutive and facultative heterochromatin as well as with specifically repressed single gene loci. Using an antibody, directed against dimethylated lysine 9 of histone H3 and several other lysine methylation sites, we visualized the nuclear distribution pattern of chromatin flagged by these methylated lysines in 3D preserved nuclei of normal and malignant cell types. Optical confocal serial sections were used for a quantitative evaluation. We demonstrate distinct differences of these histone methylation patterns among nuclei of different cell types after exit of the cell cycle. Changes in the pattern formation were also observed during the cell cycle. Our data suggest an important role of methylated histones in the reestablishment of higher order chromatin arrangements during telophase/early G1. Cell type specific histone methylation patterns are possibly causally involved in the formation of cell type specific heterochromatin compartments, composed of (pericentromeric regions and chromosomal subregions from neighboring chromosome territories, which contain silent genes.

Evolutionary patterns in the dentition of duplicidentata (mammalia) and a novel trend in the molarization of premolars.

Science.gov (United States)

Kraatz, Brian P; Meng, Jin; Weksler, Marcelo; Li, Chuankui

2010-09-20

The cusp homology of Lagomorpha has long been problematic largely because their teeth are highly derived relative to their more typically tribosphenic ancestors. Within this context, the lagomorph central cusp has been particularly difficult to homologize with other tribosphenic cusps; authors have previously considered it the paracone, protocone, metacone, amphicone, or an entirely new cusp. Here we present newly described fossil duplicidentates (Lagomorpha and Mimotonidae) in the context of a well-constrained phylogeny to establish a nomenclatural system for cusps based on the tribosphenic pattern. We show that the central cusp of lagomorphs is homologous with the metaconule of other mammals. We also show that the buccal acquisition of a second cusp on the premolars (molarization) within duplicidentates is atypical with respect to other mammalian lineages; within the earliest lagomorphs, a second buccal cusp is added mesially to an isolated buccal cusp. The distal shift of the 'ancestral' paracone within early duplicidentates amounts to the changing of a paracone into a metacone in these lineages. For this reason, we support a strictly topological approach to cusp names, and suggest a discontinuity in nomenclature to capture the complexity of the interplay between evolutionary history and the developmental process that have produced cusp patterns in duplicidentates.

Evolutionary patterns in the dentition of duplicidentata (mammalia and a novel trend in the molarization of premolars.

Directory of Open Access Journals (Sweden)

Brian P Kraatz

Full Text Available BACKGROUND: The cusp homology of Lagomorpha has long been problematic largely because their teeth are highly derived relative to their more typically tribosphenic ancestors. Within this context, the lagomorph central cusp has been particularly difficult to homologize with other tribosphenic cusps; authors have previously considered it the paracone, protocone, metacone, amphicone, or an entirely new cusp. METHODOLOGY/PRINCIPAL FINDINGS: Here we present newly described fossil duplicidentates (Lagomorpha and Mimotonidae in the context of a well-constrained phylogeny to establish a nomenclatural system for cusps based on the tribosphenic pattern. We show that the central cusp of lagomorphs is homologous with the metaconule of other mammals. We also show that the buccal acquisition of a second cusp on the premolars (molarization within duplicidentates is atypical with respect to other mammalian lineages; within the earliest lagomorphs, a second buccal cusp is added mesially to an isolated buccal cusp. CONCLUSIONS/SIGNIFICANCE: The distal shift of the 'ancestral' paracone within early duplicidentates amounts to the changing of a paracone into a metacone in these lineages. For this reason, we support a strictly topological approach to cusp names, and suggest a discontinuity in nomenclature to capture the complexity of the interplay between evolutionary history and the developmental process that have produced cusp patterns in duplicidentates.

Formation of patterned arrays of Au nanoparticles on SiC surface by template confined dewetting of normal and oblique deposited nanoscale films

Energy Technology Data Exchange (ETDEWEB)

Ruffino, F., E-mail: francesco.ruffino@ct.infn.it; Grimaldi, M.G.

2013-06-01

We report on the formation of patterned arrays of Au nanoparticles (NPs) on 6H SiC surface. To this end, we exploit the thermal-induced dewetting properties of a template confined deposited nanoscale Au film. In this approach, the Au surface pattern order, on the SiC substrate, is established by a template confined deposition using a micrometric template. Then, a dewetting process of the patterned Au film is induced by thermal processes. We compare the results, about the patterns formation, obtained for normal and oblique deposited Au films. We show that the normal and oblique depositions, through the same template, originate different patterns of the Au film. As a consequence of these different starting patterns, after the thermal processes, different patterns for the arrays of NPs originating from the dewetting mechanisms are obtained. For each fixed deposition angle α, the pattern evolution is analyzed, by scanning electron microscopy, as a function of the annealing time at 1173 K (900 °C). From these analyses, quantitative evaluations on the NPs size evolution are drawn. - Highlights: • Micrometric template-confined nanoscale gold films are deposited on silicon carbide. • The dewetting process of template-confined gold films on silicon carbide is studied. • Comparison of dewetting process of normal and oblique deposited gold films is drawn. • Patterned arrays of gold nanoparticles on silicon carbide surface are produced.

Formation of patterned arrays of Au nanoparticles on SiC surface by template confined dewetting of normal and oblique deposited nanoscale films

International Nuclear Information System (INIS)

Ruffino, F.; Grimaldi, M.G.

2013-01-01

We report on the formation of patterned arrays of Au nanoparticles (NPs) on 6H SiC surface. To this end, we exploit the thermal-induced dewetting properties of a template confined deposited nanoscale Au film. In this approach, the Au surface pattern order, on the SiC substrate, is established by a template confined deposition using a micrometric template. Then, a dewetting process of the patterned Au film is induced by thermal processes. We compare the results, about the patterns formation, obtained for normal and oblique deposited Au films. We show that the normal and oblique depositions, through the same template, originate different patterns of the Au film. As a consequence of these different starting patterns, after the thermal processes, different patterns for the arrays of NPs originating from the dewetting mechanisms are obtained. For each fixed deposition angle α, the pattern evolution is analyzed, by scanning electron microscopy, as a function of the annealing time at 1173 K (900 °C). From these analyses, quantitative evaluations on the NPs size evolution are drawn. - Highlights: • Micrometric template-confined nanoscale gold films are deposited on silicon carbide. • The dewetting process of template-confined gold films on silicon carbide is studied. • Comparison of dewetting process of normal and oblique deposited gold films is drawn. • Patterned arrays of gold nanoparticles on silicon carbide surface are produced

The pachytene checkpoint and its relationship to evolutionary patterns of polyploidization and hybrid sterility.

Science.gov (United States)

Li, X C; Barringer, B C; Barbash, D A

2009-01-01

Sterility is a commonly observed phenotype in interspecific hybrids. Sterility may result from chromosomal or genic incompatibilities, and much progress has been made toward understanding the genetic basis of hybrid sterility in various taxa. The underlying mechanisms causing hybrid sterility, however, are less well known. The pachytene checkpoint is a meiotic surveillance system that many organisms use to detect aberrant meiotic products, in order to prevent the production of defective gametes. We suggest that activation of the pachytene checkpoint may be an important mechanism contributing to two types of hybrid sterility. First, the pachytene checkpoint may form the mechanistic basis of some gene-based hybrid sterility phenotypes. Second, the pachytene checkpoint may be an important mechanism that mediates chromosomal-based hybrid sterility phenotypes involving gametes with non-haploid (either non-reduced or aneuploid) chromosome sets. Studies in several species suggest that the strength of the pachytene checkpoint is sexually dimorphic, observations that warrant future investigation into whether such variation may contribute to differences in patterns of sterility between male and female interspecific hybrids. In addition, plants seem to lack the pachytene checkpoint, which correlates with increased production of unreduced gametes and a higher incidence of polyploid species in plants versus animals. Although the pachytene checkpoint occurs in many animals and in fungi, at least some of the genes that execute the pachytene checkpoint are different among organisms. This finding suggests that the penetrance of the pachytene checkpoint, and even its presence or absence can evolve rapidly. The surprising degree of evolutionary flexibility in this meiotic surveillance system may contribute to the observed variation in patterns of hybrid sterility and in rates of polyploidization.

Relationship between eye dominance and pattern electroretinograms in normal human subjects.

Science.gov (United States)

Kamis, Umit; Gunduz, Kemal; Okudan, Nilsel; Gokbel, Hakki; Bodur, Sait; Tan, Uner

2005-02-01

The authors conducted a study in 100 non-smoker healthy normal human subjects to find a relationship between eye dominance and macular function as tested by using transient stimulus and electroretinography. Eye preference procedure was carried out using two reference points and pattern electroretinograms (PERGs) were recorded using black and white checks, each check subtending 23'. Trace averager was retriggered every 300 milliseconds (ms) with data collection time of 150 ms. The difference in PERG P50 amplitudes between right and left eyes was analyzed using Student's t test. There was no significant difference in PERG P50 amplitudes between the right and left eye dominant subjects as well as no significant differences between the right and left eyes in right eye dominants and left eye dominants, but in the left-eye dominant group the left eye PERG P50 amplitudes were significantly higher in females than males. Although pattern-reversal visual evoked potentials of healthy subjects provide electrophysiological evidence of lateralization in the nervous system, sensory eye dominance seems to have no correlation with macular function.

Cultural evolutionary theory: How culture evolves and why it matters.

Science.gov (United States)

Creanza, Nicole; Kolodny, Oren; Feldman, Marcus W

2017-07-24

Human cultural traits-behaviors, ideas, and technologies that can be learned from other individuals-can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics because cultural evolution has many parallels with, as well as clear differences from, genetic evolution. Furthermore, cultural and genetic evolution can interact with one another and influence both transmission and selection. This interaction requires theoretical treatments of gene-culture coevolution and dual inheritance, in addition to purely cultural evolution. In addition, cultural evolutionary theory is a natural component of studies in demography, human ecology, and many other disciplines. Here, we review the core concepts in cultural evolutionary theory as they pertain to the extension of biology through culture, focusing on cultural evolutionary applications in population genetics, ecology, and demography. For each of these disciplines, we review the theoretical literature and highlight relevant empirical studies. We also discuss the societal implications of the study of cultural evolution and of the interactions of humans with one another and with their environment.

Recovery after mass extinction: evolutionary assembly in large-scale biosphere dynamics.

Science.gov (United States)

Solé, Ricard V; Montoya, José M; Erwin, Douglas H

2002-01-01

Biotic recoveries following mass extinctions are characterized by a process in which whole ecologies are reconstructed from low-diversity systems, often characterized by opportunistic groups. The recovery process provides an unexpected window to ecosystem dynamics. In many aspects, recovery is very similar to ecological succession, but important differences are also apparently linked to the innovative patterns of niche construction observed in the fossil record. In this paper, we analyse the similarities and differences between ecological succession and evolutionary recovery to provide a preliminary ecological theory of recoveries. A simple evolutionary model with three trophic levels is presented, and its properties (closely resembling those observed in the fossil record) are compared with characteristic patterns of ecological response to disturbances in continuous models of three-level ecosystems. PMID:12079530

18F-FDG PET-CT pattern in idiopathic normal pressure hydrocephalus.

Science.gov (United States)

Townley, Ryan A; Botha, Hugo; Graff-Radford, Jonathan; Boeve, Bradley F; Petersen, Ronald C; Senjem, Matthew L; Knopman, David S; Lowe, Val; Jack, Clifford R; Jones, David T

2018-01-01

Idiopathic normal pressure hydrocephalus (iNPH) is an important and treatable cause of neurologic impairment. Diagnosis is complicated due to symptoms overlapping with other age related disorders. The pathophysiology underlying iNPH is not well understood. We explored FDG-PET abnormalities in iNPH patients in order to determine if FDG-PET may serve as a biomarker to differentiate iNPH from common neurodegenerative disorders. We retrospectively compared 18 F-FDG PET-CT imaging patterns from seven iNPH patients (mean age 74 ± 6 years) to age and sex matched controls, as well as patients diagnosed with clinical Alzheimer's disease dementia (AD), Dementia with Lewy Bodies (DLB) and Parkinson's Disease Dementia (PDD), and behavioral variant frontotemporal dementia (bvFTD). Partial volume corrected and uncorrected images were reviewed separately. Patients with iNPH, when compared to controls, AD, DLB/PDD, and bvFTD, had significant regional hypometabolism in the dorsal striatum, involving the caudate and putamen bilaterally. These results remained highly significant after partial volume correction. In this study, we report a FDG-PET pattern of hypometabolism in iNPH involving the caudate and putamen with preserved cortical metabolism. This pattern may differentiate iNPH from degenerative diseases and has the potential to serve as a biomarker for iNPH in future studies. These findings also further our understanding of the pathophysiology underlying the iNPH clinical presentation.

Evolutionary molecular medicine.

Science.gov (United States)

Nesse, Randolph M; Ganten, Detlev; Gregory, T Ryan; Omenn, Gilbert S

2012-05-01

Evolution has long provided a foundation for population genetics, but some major advances in evolutionary biology from the twentieth century that provide foundations for evolutionary medicine are only now being applied in molecular medicine. They include the need for both proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, competition between alleles, co-evolution, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are transforming evolutionary biology in ways that create even more opportunities for progress at its interfaces with genetics, medicine, and public health. This article reviews 15 evolutionary principles and their applications in molecular medicine in hopes that readers will use them and related principles to speed the development of evolutionary molecular medicine.

Diabetes and Obesity—An Evolutionary Perspective

Directory of Open Access Journals (Sweden)

Sylvia Kirchengast

2017-01-01

Full Text Available Obesity and type II diabetes belong to the most serious public health challenges of the 21st century. Initially both diseases were typical of affluent societies. Currently both conditions however are increasingly found in low and middle income countries. In future obesity and diabetes are expected to reach epidemic proportions and affect developing countries to a greater extent than developed ones. A globalization of obesity and diabetes is observable. Recently prevalence rates increased, especially in Asia, the Near and Middle East, the Western Pacific region and even in Sub-Saharan Africa. Evolutionary Anthropology tries to understand the evolutionary mechanisms promoting rising obesity and diabetes type II rates. Homo sapiens evolved in an environment quite different from our recent one. Profound changes in physical activity patterns and nutritional habits during the last 10,000 years and increasingly during the last 200 years increased the risk of obesity and diabetes type II. Consequently our recent environment is called “obesogenic”. This mismatch has been recently observable among societies experiencing rapid cultural changes characterized by Westernization and modernization. This review focuses on obesity and type II diabetes from the viewpoint of evolutionary anthropology.

Spatial evolutionary epidemiology of spreading epidemics.

Science.gov (United States)

Lion, S; Gandon, S

2016-10-26

Most spatial models of host-parasite interactions either neglect the possibility of pathogen evolution or consider that this process is slow enough for epidemiological dynamics to reach an equilibrium on a fast timescale. Here, we propose a novel approach to jointly model the epidemiological and evolutionary dynamics of spatially structured host and pathogen populations. Starting from a multi-strain epidemiological model, we use a combination of spatial moment equations and quantitative genetics to analyse the dynamics of mean transmission and virulence in the population. A key insight of our approach is that, even in the absence of long-term evolutionary consequences, spatial structure can affect the short-term evolution of pathogens because of the build-up of spatial differentiation in mean virulence. We show that spatial differentiation is driven by a balance between epidemiological and genetic effects, and this quantity is related to the effect of kin competition discussed in previous studies of parasite evolution in spatially structured host populations. Our analysis can be used to understand and predict the transient evolutionary dynamics of pathogens and the emergence of spatial patterns of phenotypic variation. © 2016 The Author(s).

Normalized GNSS Interference Pattern Technique for Altimetry

Directory of Open Access Journals (Sweden)

Miguel Angel Ribot

2014-06-01

Full Text Available It is well known that reflected signals from Global Navigation Satellite Systems (GNSS can be used for altimetry applications, such as monitoring of water levels and determining snow height. Due to the interference of these reflected signals and the motion of satellites in space, the signal-to-noise ratio (SNR measured at the receiver slowly oscillates. The oscillation rate is proportional to the change in the propagation path difference between the direct and reflected signals, which depends on the satellite elevation angle. Assuming a known receiver position, it is possible to compute the distance between the antenna and the surface of reflection from the measured oscillation rate. This technique is usually known as the interference pattern technique (IPT. In this paper, we propose to normalize the measurements in order to derive an alternative model of the SNR variations. From this model, we define a maximum likelihood estimate of the antenna height that reduces the estimation time to a fraction of one period of the SNR variation. We also derive the Cramér–Rao lower bound for the IPT and use it to assess the sensitivity of different parameters to the estimation of the antenna height. Finally, we propose an experimental framework, and we use it to assess our approach with real GPS L1 C/A signals.

Patterns and Processes of Vertebrate Evolution

Science.gov (United States)

Carroll, Robert Lynn

1997-04-01

This new text provides an integrated view of the forces that influence the patterns and rates of vertebrate evolution from the level of living populations and species to those that resulted in the origin of the major vertebrate groups. The evolutionary roles of behavior, development, continental drift, and mass extinctions are compared with the importance of variation and natural selection that were emphasized by Darwin. It is extensively illustrated, showing major transitions between fish and amphibians, dinosaurs and birds, and land mammals to whales. No book since Simpson's Major Features of Evolution has attempted such a broad study of the patterns and forces of evolutionary change. Undergraduate students taking a general or advanced course on evolution, and graduate students and professionals in evolutionary biology and paleontology will find the book of great interest.

On the evolution of misunderstandings about evolutionary psychology.

Science.gov (United States)

Young, J; Persell, R

2000-04-01

Some of the controversy surrounding evolutionary explanations of human behavior may be due to cognitive information-processing patterns that are themselves the result of evolutionary processes. Two such patterns are (1) the tendency to oversimplify information so as to reduce demand on cognitive resources and (2) our strong desire to generate predictability and stability from perceptions of the external world. For example, research on social stereotyping has found that people tend to focus automatically on simplified social-categorical information, to use such information when deciding how to behave, and to rely on such information even in the face of contradictory evidence. Similarly, an undying debate over nature vs. nurture is shaped by various data-reduction strategies that frequently oversimplify, and thus distort, the intent of the supporting arguments. This debate is also often marked by an assumption that either the nature or the nurture domain may be justifiably excluded at an explanatory level because one domain appears to operate in a sufficiently stable and predictable way for a particular argument. As a result, critiques in-veighed against evolutionary explanations of behavior often incorporate simplified--and erroneous--assumptions about either the mechanics of how evolution operates or the inevitable implications of evolution for understanding human behavior. The influences of these tendencies are applied to a discussion of the heritability of behavioral characteristics. It is suggested that the common view that Mendelian genetics can explain the heritability of complex behaviors, with a one-gene-one-trait process, is misguided. Complex behaviors are undoubtedly a product of a more complex interaction between genes and environment, ensuring that both nature and nurture must be accommodated in a yet-to-be-developed post-Mendelian model of genetic influence. As a result, current public perceptions of evolutionary explanations of behavior are

How cultural evolutionary theory can inform social psychology and vice versa.

Science.gov (United States)

Mesoudi, Alex

2009-10-01

Cultural evolutionary theory is an interdisciplinary field in which human culture is viewed as a Darwinian process of variation, competition, and inheritance, and the tools, methods, and theories developed by evolutionary biologists to study genetic evolution are adapted to study cultural change. It is argued here that an integration of the theories and findings of mainstream social psychology and of cultural evolutionary theory can be mutually beneficial. Social psychology provides cultural evolution with a set of empirically verified microevolutionary cultural processes, such as conformity, model-based biases, and content biases, that are responsible for specific patterns of cultural change. Cultural evolutionary theory provides social psychology with ultimate explanations for, and an understanding of the population-level consequences of, many social psychological phenomena, such as social learning, conformity, social comparison, and intergroup processes, as well as linking social psychology with other social science disciplines such as cultural anthropology, archaeology, and sociology.

Cyclooxygenase-2 expression in the normal human eye and its expression pattern in selected eye tumours

DEFF Research Database (Denmark)

Wang, Jinmei; Wu, Yazhen; Heegaard, Steffen

2011-01-01

Purpose: Cyclooxygenase-2 (COX-2) is an enzyme involved in neoplastic processes. The purpose of the present study is to investigate COX-2 expression in the normal human eye and the expression pattern in selected eye tumours involving COX-2 expressing cells. Methods: Immunohistochemical staining...... using antibodies against COX-2 was performed on paraffin sections of normal human eyes and selected eye tumours arising from cells expressing COX-2. Results: Cyclooxygenase-2 expression was found in various structures of the normal eye. Abundant expression was seen in the cornea, iris, ciliary body...... and retina. The COX-2 expression was less in tumours deriving from the ciliary epithelium and also in retinoblastoma. Conclusion: Cyclooxygenase-2 is constitutively expressed in normal human eyes. The expression of COX-2 is much lower in selected eye tumours involving COX-2 expressing cells....

Optimizing a reconfigurable material via evolutionary computation

Science.gov (United States)

Wilken, Sam; Miskin, Marc Z.; Jaeger, Heinrich M.

2015-08-01

Rapid prototyping by combining evolutionary computation with simulations is becoming a powerful tool for solving complex design problems in materials science. This method of optimization operates in a virtual design space that simulates potential material behaviors and after completion needs to be validated by experiment. However, in principle an evolutionary optimizer can also operate on an actual physical structure or laboratory experiment directly, provided the relevant material parameters can be accessed by the optimizer and information about the material's performance can be updated by direct measurements. Here we provide a proof of concept of such direct, physical optimization by showing how a reconfigurable, highly nonlinear material can be tuned to respond to impact. We report on an entirely computer controlled laboratory experiment in which a 6 ×6 grid of electromagnets creates a magnetic field pattern that tunes the local rigidity of a concentrated suspension of ferrofluid and iron filings. A genetic algorithm is implemented and tasked to find field patterns that minimize the force transmitted through the suspension. Searching within a space of roughly 1010 possible configurations, after testing only 1500 independent trials the algorithm identifies an optimized configuration of layered rigid and compliant regions.

Evolutionary origin of the Asteraceae capitulum: Insights from Calyceraceae.

Science.gov (United States)

Pozner, Raúl; Zanotti, Christian; Johnson, Leigh A

2012-01-01

Phylogenies based on molecular data are revealing that generalizations about complex morphological structures often obscure variation and developmental patterns important for understanding the evolution of forms, as is the case for inflorescence morphology within the well-supported MGCA clade (Menyanthaceae + Goodeniaceae + Calyceraceae + Asteraceae). While the basal families share a basic thyrsic/thyrsoid structure of their inflorescences, Asteraceae possesses a capitulum that is widely interpreted as a racemose, condensed inflorescence. Elucidating the poorly known inflorescence structure of Calyceraceae, sister to Asteraceae, should help clarify how the Asteraceae capitulum evolved from thyrsic/thyrsoid inflorescences. The early development and structure of the inflorescence of eight species (five genera) of Calyceraceae were studied by SEM, and patterns of evolutionary change were interpreted via phylogenetic character mapping. The basic inflorescence structure of Calyceraceae is a cephalioid (a very condensed botryoid/thyrsoid). Optimization of inflorescence characters on a DNA sequence-derived tree suggests that the Asteraceae capitulum derives from a simple cephalioid through two morphological changes: loss of the terminal flower and suppression of the cymose branching pattern in the peripheral branches. Widely understood as a condensed raceme, the Asteraceae capitulum is the evolutionary result of a very reduced, condensed thyrsoid. Starting from that point, evolution worked separately only on the racemose developmental control/pattern within Asteraceae and mainly on the cymose developmental control/pattern within Calyceraceae, producing head-like inflorescences in both groups but with very different diversification potential. We also discuss possible remnants of the ancestral cephalioid structure in some Asteraceae.

Evolutionary trade-offs in plants mediate the strength of trophic cascades.

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Mooney, Kailen A; Halitschke, Rayko; Kessler, Andre; Agrawal, Anurag A

2010-03-26

Predators determine herbivore and plant biomass via so-called trophic cascades, and the strength of such effects is influenced by ecosystem productivity. To determine whether evolutionary trade-offs among plant traits influence patterns of trophic control, we manipulated predators and soil fertility and measured impacts of a major herbivore (the aphid Aphis nerii) on 16 milkweed species (Asclepias spp.) in a phylogenetic field experiment. Herbivore density was determined by variation in predation and trade-offs between herbivore resistance and plant growth strategy. Neither herbivore density nor predator effects on herbivores predicted the cascading effects of predators on plant biomass. Instead, cascade strength was strongly and positively associated with milkweed response to soil fertility. Accordingly, contemporary patterns of trophic control are driven by evolutionary convergent trade-offs faced by plants.

Introduced species as evolutionary traps

Science.gov (United States)

Schlaepfer, Martin A.; Sherman, P.W.; Blossey, B.; Runge, M.C.

2005-01-01

Invasive species can alter environments in such a way that normal behavioural decision-making rules of native species are no longer adaptive. The evolutionary trap concept provides a useful framework for predicting and managing the impact of harmful invasive species. We discuss how native species can respond to changes in their selective regime via evolution or learning. We also propose novel management strategies to promote the long-term co-existence of native and introduced species in cases where the eradication of the latter is either economically or biologically unrealistic.

Normal Patterns of Deja Experience in a Healthy, Blind Male: Challenging Optical Pathway Delay Theory

Science.gov (United States)

O'Connor, Akira R.; Moulin, Christopher J. A.

2006-01-01

We report the case of a 25-year-old healthy, blind male, MT, who experiences normal patterns of deja vu. The optical pathway delay theory of deja vu formation assumes that neuronal input from the optical pathways is necessary for the formation of the experience. Surprisingly, although the sensation of deja vu is known to be experienced by blind…

Ecological and evolutionary patterns of freshwater maturation in Pacific and Atlantic salmonines

Science.gov (United States)

Sloat, Matthew R.; Fraser, Dylan J.; Dunham, Jason B.; Falke, Jeffery A.; Jordan, Chris E.; McMillan, John R.; Ohms, Haley A.

2014-01-01

Reproductive tactics and migratory strategies in Pacific and Atlantic salmonines are inextricably linked through the effects of migration (or lack thereof) on age and size at maturity. In this review, we focus on the ecological and evolutionary patterns of freshwater maturation in salmonines, a key process resulting in the diversification of their life histories. We demonstrate that the energetics of maturation and reproduction provides a unifying theme for understanding both the proximate and ultimate causes of variation in reproductive schedules among species, populations, and the sexes. We use probabilistic maturation reaction norms to illustrate how variation in individual condition, in terms of body size, growth rate, and lipid storage, influences the timing of maturation. This useful framework integrates both genetic and environmental contributions to conditional strategies for maturation and, in doing so, demonstrates how flexible life histories can be both heritable and subject to strong environmental influences. We review evidence that the propensity for freshwater maturation in partially anadromous species is predictable across environmental gradients at geographic and local spatial scales. We note that growth is commonly associated with the propensity for freshwater maturation, but that life-history responses to changes in growth caused by temperature may be strikingly different than changes caused by differences in food availability. We conclude by exploring how contemporary management actions can constrain or promote the diversity of maturation phenotypes in Pacific and Atlantic salmonines and caution against underestimating the role of freshwater maturing forms in maintaining the resiliency of these iconic species.

Micro-evolutionary divergence patterns of mandible shapes in wild house mouse (Mus musculus populations

Directory of Open Access Journals (Sweden)

Tautz Diethard

2011-10-01

Full Text Available Abstract Background Insights into the micro-evolutionary patterns of morphological traits require an assessment of the natural variation of the trait within and between populations and closely related species. The mouse mandible is a particularly suitable morphological trait for such an analysis, since it has long been used as a model to study the quantitative genetics of shape. In addition, many distinct populations, sub-species and closely related species are known for the house mouse. However, morphological comparisons among wild caught animals require an assessment in how far environmental and technical factors could interfere with the shape change measurements. Results Using geometric morphometrics, we have surveyed mandible shapes in 15 natural populations of the genus Mus, with a focus on the subspecies Mus musculus domesticus. In parallel we have carefully assessed possibly confounding technical and biological factors. We find that there are distinct differences on average between populations, subspecies and species, but these differences are smaller than differences between individuals within populations. Populations from summer-dry regions, although more ancestral, are less distinct from each other than are populations from the more recently colonized northern areas. Populations with especially distinct shapes occur in an area of sympatry of M. m. domesticus and M. spretus and on recently colonized sub-antarctic islands. We have also studied a number of inbred strains to assess in how far their mandible shapes resemble those from the wild. We find that they fall indeed into the shape space of natural variation between individuals in populations. Conclusions Although mandible shapes in natural populations can be influenced by environmental variables, these influences are insufficient to explain the average extent of shape differences between populations, such that evolutionary processes must be invoked to explain this level of diversity

Toward a general evolutionary theory of oncogenesis.

Science.gov (United States)

Ewald, Paul W; Swain Ewald, Holly A

2013-01-01

We propose an evolutionary framework, the barrier theory of cancer, which is based on the distinction between barriers to oncogenesis and restraints. Barriers are defined as mechanisms that prevent oncogenesis. Restraints, which are more numerous, inhibit but do not prevent oncogenesis. Processes that compromise barriers are essential causes of cancer; those that interfere with restraints are exacerbating causes. The barrier theory is built upon the three evolutionary processes involved in oncogenesis: natural selection acting on multicellular organisms to mold barriers and restraints, natural selection acting on infectious organisms to abrogate these protective mechanisms, and oncogenic selection which is responsible for the evolution of normal cells into cancerous cells. The barrier theory is presented as a first step toward the development of a general evolutionary theory of cancer. Its attributes and implications for intervention are compared with those of other major conceptual frameworks for understanding cancer: the clonal diversification model, the stem cell theory and the hallmarks of cancer. The barrier theory emphasizes the practical value of distinguishing between essential and exacerbating causes. It also stresses the importance of determining the scope of infectious causation of cancer, because individual pathogens can be responsible for multiple essential causes in infected cells.

Pointing and the Evolution of Language: An Applied Evolutionary Epistemological Approach

Directory of Open Access Journals (Sweden)

Nathalie Gontier

2013-07-01

Full Text Available Numerous evolutionary linguists have indicated that human pointing behaviour might be associated with the evolution of language. At an ontogenetic level, and in normal individuals, pointing develops spontaneously and the onset of human pointing precedes as well as facilitates phases in speech and language development. Phylogenetically, pointing behaviour might have preceded and facilitated the evolutionary origin of both gestural and vocal language. Contrary to wild non-human primates, captive and human-reared nonhuman primates also demonstrate pointing behaviour. In this article, we analyse the debates on pointing and its role it might have played in language evolution from a meta-level. From within an Applied Evolutionary Epistemological approach, we examine how exactly we can determine whether pointing has been a unit, a level or a mechanism in language evolution.

Evolutionary thinking

Science.gov (United States)

Hunt, Tam

2014-01-01

Evolution as an idea has a lengthy history, even though the idea of evolution is generally associated with Darwin today. Rebecca Stott provides an engaging and thoughtful overview of this history of evolutionary thinking in her 2013 book, Darwin's Ghosts: The Secret History of Evolution. Since Darwin, the debate over evolution—both how it takes place and, in a long war of words with religiously-oriented thinkers, whether it takes place—has been sustained and heated. A growing share of this debate is now devoted to examining how evolutionary thinking affects areas outside of biology. How do our lives change when we recognize that all is in flux? What can we learn about life more generally if we study change instead of stasis? Carter Phipps’ book, Evolutionaries: Unlocking the Spiritual and Cultural Potential of Science's Greatest Idea, delves deep into this relatively new development. Phipps generally takes as a given the validity of the Modern Synthesis of evolutionary biology. His story takes us into, as the subtitle suggests, the spiritual and cultural implications of evolutionary thinking. Can religion and evolution be reconciled? Can evolutionary thinking lead to a new type of spirituality? Is our culture already being changed in ways that we don't realize by evolutionary thinking? These are all important questions and Phipps book is a great introduction to this discussion. Phipps is an author, journalist, and contributor to the emerging “integral” or “evolutionary” cultural movement that combines the insights of Integral Philosophy, evolutionary science, developmental psychology, and the social sciences. He has served as the Executive Editor of EnlightenNext magazine (no longer published) and more recently is the co-founder of the Institute for Cultural Evolution, a public policy think tank addressing the cultural roots of America's political challenges. What follows is an email interview with Phipps. PMID:26478766

Compassion: An Evolutionary Analysis and Empirical Review

OpenAIRE

Goetz, Jennifer L.; Keltner, Dacher; Simon-Thomas, Emiliana

2010-01-01

What is compassion? And how did it evolve? In this review, we integrate three evolutionary arguments that converge on the hypothesis that compassion evolved as a distinct affective experience whose primary function is to facilitate cooperation and protection of the weak and those who suffer. Our empirical review reveals compassion to have distinct appraisal processes attuned to undeserved suffering, distinct signaling behavior related to caregiving patterns of touch, posture, and vocalization...

Evolutionary Stable Strategy

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 21; Issue 9. Evolutionary Stable Strategy: Application of Nash Equilibrium in Biology. General Article Volume 21 Issue 9 September 2016 pp 803- ... Keywords. Evolutionary game theory, evolutionary stable state, conflict, cooperation, biological games.

Towards an Explanation of Overeating Patterns Among Normal Weight College Women: Development and Validation of a Structural Equation Model

OpenAIRE

Russ, Christine Runyan II

1998-01-01

Although research describing relationships between psychosocial factors and various eating patterns is growing, a model which explains the mechanisms through which these factors may operate is lacking. A model to explain overeating patterns among normal weight college females was developed and tested. The model contained the following variables: global adjustment, eating and weight cognitions, emotional eating, and self-efficacy. Three hundred ninety-o...

Ecological and evolutionary drivers of the elevational gradient of diversity.

Science.gov (United States)

Laiolo, Paola; Pato, Joaquina; Obeso, José Ramón

2018-05-02

Ecological, evolutionary, spatial and neutral theories make distinct predictions and provide distinct explanations for the mechanisms that control the relationship between diversity and the environment. Here, we test predictions of the elevational diversity gradient focusing on Iberian bumblebees, grasshoppers and birds. Processes mediated by local abundance and regional diversity concur in explaining local diversity patterns along elevation. Effects expressed through variation in abundance were similar among taxa and point to the overriding role of a physical factor, temperature. This determines how energy is distributed among individuals and ultimately how the resulting pattern of abundance affects species incidence. Effects expressed through variation in regional species pools depended instead on taxon-specific evolutionary history, and lead to diverging responses under similar environmental pressures. Local filters and regional variation also explain functional diversity gradients, in line with results from species richness that indicate an (local) ecological and (regional) historical unfolding of diversity-elevation relationships. © 2018 John Wiley & Sons Ltd/CNRS.

Expression-robust 3D face recognition via weighted sparse representation of multi-scale and multi-component local normal patterns

KAUST Repository

Li, Huibin

2014-06-01

In the theory of differential geometry, surface normal, as a first order surface differential quantity, determines the orientation of a surface at each point and contains informative local surface shape information. To fully exploit this kind of information for 3D face recognition (FR), this paper proposes a novel highly discriminative facial shape descriptor, namely multi-scale and multi-component local normal patterns (MSMC-LNP). Given a normalized facial range image, three components of normal vectors are first estimated, leading to three normal component images. Then, each normal component image is encoded locally to local normal patterns (LNP) on different scales. To utilize spatial information of facial shape, each normal component image is divided into several patches, and their LNP histograms are computed and concatenated according to the facial configuration. Finally, each original facial surface is represented by a set of LNP histograms including both global and local cues. Moreover, to make the proposed solution robust to the variations of facial expressions, we propose to learn the weight of each local patch on a given encoding scale and normal component image. Based on the learned weights and the weighted LNP histograms, we formulate a weighted sparse representation-based classifier (W-SRC). In contrast to the overwhelming majority of 3D FR approaches which were only benchmarked on the FRGC v2.0 database, we carried out extensive experiments on the FRGC v2.0, Bosphorus, BU-3DFE and 3D-TEC databases, thus including 3D face data captured in different scenarios through various sensors and depicting in particular different challenges with respect to facial expressions. The experimental results show that the proposed approach consistently achieves competitive rank-one recognition rates on these databases despite their heterogeneous nature, and thereby demonstrates its effectiveness and its generalizability. © 2014 Elsevier B.V.

An Evolutionary Approach to the Climate Change Negotiation Game

Energy Technology Data Exchange (ETDEWEB)

Courtois, P. [CIRED and University of Paris, Paris (France); Pereau, J.C. [OEP, University of Marne-la-Vallee, Marne-la-Vallee (France); Tazdait, T. [CIRED and OEP, University of Marne-la-Vallee, Marne-la-Vallee (France)

2001-10-01

We describe in this paper an evolutionary game theoretic model aiming at representing the climate change negotiation. The model is used to examine the outcome of climate change negotiations in a framework which seeks to closely represent negotiation patterns. Evolutionary setting allows us to consider a decision making structure characterised by agents with bounded knowledge practising mimics and learning from past events and strategies. We show on that framework that a third significant alternative to the binary coordination-defection strategies needs to be considered: a unilateral commitment as precautionary strategy. As a means to widen cooperation, we examine the influence of linking environmental and trade policies via the implementation of a trade penalty on non cooperative behaviours.

An Evolutionary Approach to the Climate Change Negotiation Game

International Nuclear Information System (INIS)

Courtois, P.; Pereau, J.C.; Tazdait, T.

2001-10-01

We describe in this paper an evolutionary game theoretic model aiming at representing the climate change negotiation. The model is used to examine the outcome of climate change negotiations in a framework which seeks to closely represent negotiation patterns. Evolutionary setting allows us to consider a decision making structure characterised by agents with bounded knowledge practising mimics and learning from past events and strategies. We show on that framework that a third significant alternative to the binary coordination-defection strategies needs to be considered: a unilateral commitment as precautionary strategy. As a means to widen cooperation, we examine the influence of linking environmental and trade policies via the implementation of a trade penalty on non cooperative behaviours

Mathematics and evolutionary biology make bioinformatics education comprehensible

Science.gov (United States)

Weisstein, Anton E.

2013-01-01

The patterns of variation within a molecular sequence data set result from the interplay between population genetic, molecular evolutionary and macroevolutionary processes—the standard purview of evolutionary biologists. Elucidating these patterns, particularly for large data sets, requires an understanding of the structure, assumptions and limitations of the algorithms used by bioinformatics software—the domain of mathematicians and computer scientists. As a result, bioinformatics often suffers a ‘two-culture’ problem because of the lack of broad overlapping expertise between these two groups. Collaboration among specialists in different fields has greatly mitigated this problem among active bioinformaticians. However, science education researchers report that much of bioinformatics education does little to bridge the cultural divide, the curriculum too focused on solving narrow problems (e.g. interpreting pre-built phylogenetic trees) rather than on exploring broader ones (e.g. exploring alternative phylogenetic strategies for different kinds of data sets). Herein, we present an introduction to the mathematics of tree enumeration, tree construction, split decomposition and sequence alignment. We also introduce off-line downloadable software tools developed by the BioQUEST Curriculum Consortium to help students learn how to interpret and critically evaluate the results of standard bioinformatics analyses. PMID:23821621

Mathematics and evolutionary biology make bioinformatics education comprehensible.

Science.gov (United States)

Jungck, John R; Weisstein, Anton E

2013-09-01

The patterns of variation within a molecular sequence data set result from the interplay between population genetic, molecular evolutionary and macroevolutionary processes-the standard purview of evolutionary biologists. Elucidating these patterns, particularly for large data sets, requires an understanding of the structure, assumptions and limitations of the algorithms used by bioinformatics software-the domain of mathematicians and computer scientists. As a result, bioinformatics often suffers a 'two-culture' problem because of the lack of broad overlapping expertise between these two groups. Collaboration among specialists in different fields has greatly mitigated this problem among active bioinformaticians. However, science education researchers report that much of bioinformatics education does little to bridge the cultural divide, the curriculum too focused on solving narrow problems (e.g. interpreting pre-built phylogenetic trees) rather than on exploring broader ones (e.g. exploring alternative phylogenetic strategies for different kinds of data sets). Herein, we present an introduction to the mathematics of tree enumeration, tree construction, split decomposition and sequence alignment. We also introduce off-line downloadable software tools developed by the BioQUEST Curriculum Consortium to help students learn how to interpret and critically evaluate the results of standard bioinformatics analyses.

Padrão citológico de punção aspirativa do tecido tireoidiano morfologicamente normal Cytologic pattern for fine-needle aspiration among morphologically normal thyroids

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Daysi Maria de Alcântara Jones

2006-02-01

Full Text Available Nódulos tireoidianos pequenos com diagnóstico citológico de padrão folicular causam muita inquietação porque, se por um lado podem representar uma lesão que exige muito rigor no acompanhamento, por outro poderão representar material aspirado do tecido tireoidiano normal. OBJETIVO: Verificar o padrão citológico do tecido tireoidiano normal obtido através de punções aspirativa e não-aspirativa em cadáveres. MÉTODOS: Estudo observacional em que se procedeu a dissecção anatômica da tireóide normal e se efetuou a citoaspiração da glândula, em 38 casos. Dois patologistas cegos para a metodologia do estudo, sem conhecer a correspondência entre citologia e histologia, analisaram os esfregaços e os cortes histológicos. RESULTADOS: As tireóides normais forneceram diagnóstico citológico de bócio adenomatoso em 70,4% das vezes para um observador e 92,6% para o outro. Houve uma concordância regular entre os observadores, com kappa de 0,51 (p Small thyroid nodules, which are diagnosed as follicular pattern for fine-needle aspiration, are a cause of great worry. They may present a lesion requiring rigorous follow up, or on other hand, there is a risk that some normal thyroid tissue is removed during the procedure. OBJECTIVE: To verify the cytology of a normal thyroid tissue, for aspiration and non-aspiration puncture, in autopsy material. METHODS: Observational study involving the anatomical dissection and cytoaspiration of normal thyroid glands in 38 cadavers. Two blind pathologists, unaware of the cytology and histology, analyzed the smears and the histological cuts. RESULTS: One of pathologists identified a diagnostic cytology of adenomatous goiter in 70.4% of the 38 normal glands found, while the other observed it in 92.4%. There was regular agreement between them, with Kappa of 0.51 (p < 0.0001. Contrary to what was expected, follicular patterns were not found among the cytological samples. RESULTS: The cytological aspect of

EvoluCode: Evolutionary Barcodes as a Unifying Framework for Multilevel Evolutionary Data.

Science.gov (United States)

Linard, Benjamin; Nguyen, Ngoc Hoan; Prosdocimi, Francisco; Poch, Olivier; Thompson, Julie D

2012-01-01

Evolutionary systems biology aims to uncover the general trends and principles governing the evolution of biological networks. An essential part of this process is the reconstruction and analysis of the evolutionary histories of these complex, dynamic networks. Unfortunately, the methodologies for representing and exploiting such complex evolutionary histories in large scale studies are currently limited. Here, we propose a new formalism, called EvoluCode (Evolutionary barCode), which allows the integration of different evolutionary parameters (eg, sequence conservation, orthology, synteny …) in a unifying format and facilitates the multilevel analysis and visualization of complex evolutionary histories at the genome scale. The advantages of the approach are demonstrated by constructing barcodes representing the evolution of the complete human proteome. Two large-scale studies are then described: (i) the mapping and visualization of the barcodes on the human chromosomes and (ii) automatic clustering of the barcodes to highlight protein subsets sharing similar evolutionary histories and their functional analysis. The methodologies developed here open the way to the efficient application of other data mining and knowledge extraction techniques in evolutionary systems biology studies. A database containing all EvoluCode data is available at: http://lbgi.igbmc.fr/barcodes.

Evolutionary change - patterns and processes

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Francisco M. Salzano

2005-12-01

Full Text Available The present review considered: (a the factors that conditioned the early transition from non-life to life; (b genome structure and complexity in prokaryotes, eukaryotes, and organelles; (c comparative human chromosome genomics; and (d the Brazilian contribution to some of these studies. Understanding the dialectical conflict between freedom and organization is fundamental to give meaning to the patterns and processes of organic evolution.A presente revisão considerou: (a os fatores que condicionaram a transição inicial entre não-vida e vida; (b a estrutura e complexidade genômica em procariotos, eucariotos e organelas; (c a genômica comparada dos cromossomos humanos; (d a contribuição brasileira a alguns desses estudos. A compreensão do conflito dialético entre liberdade e organização é fundamental para dar significado aos padrões e processos da evolução orgânica.

Exploring social influence on evolutionary prisoner’s dilemma games in networks

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Zong, Hengshan; Jia, Guozhu; Cheng, Yang

2015-11-01

Though numerous studies demonstrate the importance of social influence in deciding individual decision-making process in networks, little has been done to explore its impact on players’ behavioral patterns in evolutionary prisoner’s dilemma games (PDGs). This study investigates how social influenced strategy updating rules may affect the final equilibrium of game dynamics. The results show that weak social influence usually inhibits cooperation, while strong social influence has a mediating effect. The impacts of network structure and the existence of rebels in social influence scenarios are also tested. The paper provides a comprehensive interpretation on social influence effects on evolutionary PDGs in networks.

Evolutionary plant physiology: Charles Darwin's forgotten synthesis

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Kutschera, Ulrich; Niklas, Karl J.

2009-11-01

Charles Darwin dedicated more than 20 years of his life to a variety of investigations on higher plants (angiosperms). It has been implicitly assumed that these studies in the fields of descriptive botany and experimental plant physiology were carried out to corroborate his principle of descent with modification. However, Darwin’s son Francis, who was a professional plant biologist, pointed out that the interests of his father were both of a physiological and an evolutionary nature. In this article, we describe Darwin’s work on the physiology of higher plants from a modern perspective, with reference to the following topics: circumnutations, tropisms and the endogenous oscillator model; the evolutionary patterns of auxin action; the root-brain hypothesis; phloem structure and photosynthesis research; endosymbioses and growth-promoting bacteria; photomorphogenesis and phenotypic plasticity; basal metabolic rate, the Pfeffer-Kleiber relationship and metabolic optimality theory with respect to adaptive evolution; and developmental constraints versus functional equivalence in relationship to directional natural selection. Based on a review of these various fields of inquiry, we deduce the existence of a Darwinian (evolutionary) approach to plant physiology and define this emerging scientific discipline as the experimental study and theoretical analysis of the functions of green, sessile organisms from a phylogenetic perspective.

Evolutionary plant physiology: Charles Darwin's forgotten synthesis.

Science.gov (United States)

Kutschera, Ulrich; Niklas, Karl J

2009-11-01

Charles Darwin dedicated more than 20 years of his life to a variety of investigations on higher plants (angiosperms). It has been implicitly assumed that these studies in the fields of descriptive botany and experimental plant physiology were carried out to corroborate his principle of descent with modification. However, Darwin's son Francis, who was a professional plant biologist, pointed out that the interests of his father were both of a physiological and an evolutionary nature. In this article, we describe Darwin's work on the physiology of higher plants from a modern perspective, with reference to the following topics: circumnutations, tropisms and the endogenous oscillator model; the evolutionary patterns of auxin action; the root-brain hypothesis; phloem structure and photosynthesis research; endosymbioses and growth-promoting bacteria; photomorphogenesis and phenotypic plasticity; basal metabolic rate, the Pfeffer-Kleiber relationship and metabolic optimality theory with respect to adaptive evolution; and developmental constraints versus functional equivalence in relationship to directional natural selection. Based on a review of these various fields of inquiry, we deduce the existence of a Darwinian (evolutionary) approach to plant physiology and define this emerging scientific discipline as the experimental study and theoretical analysis of the functions of green, sessile organisms from a phylogenetic perspective.

Evolutionary games on multilayer networks: a colloquium

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Wang, Zhen; Wang, Lin; Szolnoki, Attila; Perc, Matjaž

2015-05-01

Networks form the backbone of many complex systems, ranging from the Internet to human societies. Accordingly, not only is the range of our interactions limited and thus best described and modeled by networks, it is also a fact that the networks that are an integral part of such models are often interdependent or even interconnected. Networks of networks or multilayer networks are therefore a more apt description of social systems. This colloquium is devoted to evolutionary games on multilayer networks, and in particular to the evolution of cooperation as one of the main pillars of modern human societies. We first give an overview of the most significant conceptual differences between single-layer and multilayer networks, and we provide basic definitions and a classification of the most commonly used terms. Subsequently, we review fascinating and counterintuitive evolutionary outcomes that emerge due to different types of interdependencies between otherwise independent populations. The focus is on coupling through the utilities of players, through the flow of information, as well as through the popularity of different strategies on different network layers. The colloquium highlights the importance of pattern formation and collective behavior for the promotion of cooperation under adverse conditions, as well as the synergies between network science and evolutionary game theory.

Evolutionary responses of native plant species to invasive plants: a review.

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Oduor, Ayub M O

2013-12-01

Strong competition from invasive plant species often leads to declines in abundances and may, in certain cases, cause localized extinctions of native plant species. Nevertheless, studies have shown that certain populations of native plant species can co-exist with invasive plant species,suggesting the possibility of adaptive evolutionary responses of those populations to the invasive plants. Empirical inference of evolutionary responses of the native plant species to invasive plants has involved experiments comparing two conspecific groups of native plants for differences in expression of growth/reproductive traits: populations that have experienced competition from the invasive plant species (i.e. experienced natives) versus populations with no known history of interactions with the invasive plant species (i.e. naıve natives). Here, I employ a meta-analysis to obtain a general pattern of inferred evolutionary responses of native plant species from 53 such studies. In general, the experienced natives had significantly higher growth/reproductive performances than naıve natives, when grown with or without competition from invasive plants.While the current results indicate that certain populations of native plant species could potentially adapt evolutionarily to invasive plant species, the ecological and evolutionary mechanisms that probably underlie such evolutionary responses remain unexplored and should be the focus of future studies.

Clonality and evolutionary history of rhabdomyosarcoma.

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Li Chen

2015-03-01

Full Text Available To infer the subclonality of rhabdomyosarcoma (RMS and predict the temporal order of genetic events for the tumorigenic process, and to identify novel drivers, we applied a systematic method that takes into account germline and somatic alterations in 44 tumor-normal RMS pairs using deep whole-genome sequencing. Intriguingly, we find that loss of heterozygosity of 11p15.5 and mutations in RAS pathway genes occur early in the evolutionary history of the PAX-fusion-negative-RMS (PFN-RMS subtype. We discover several early mutations in non-RAS mutated samples and predict them to be drivers in PFN-RMS including recurrent mutation of PKN1. In contrast, we find that PAX-fusion-positive (PFP subtype tumors have undergone whole-genome duplication in the late stage of cancer evolutionary history and have acquired fewer mutations and subclones than PFN-RMS. Moreover we predict that the PAX3-FOXO1 fusion event occurs earlier than the whole genome duplication. Our findings provide information critical to the understanding of tumorigenesis of RMS.

Analyses of Evolutionary Characteristics of the Hemagglutinin-Esterase Gene of Influenza C Virus during a Period of 68 Years Reveals Evolutionary Patterns Different from Influenza A and B Viruses

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Yuki Furuse

2016-11-01

Full Text Available Infections with the influenza C virus causing respiratory symptoms are common, particularly among children. Since isolation and detection of the virus are rarely performed, compared with influenza A and B viruses, the small number of available sequences of the virus makes it difficult to analyze its evolutionary dynamics. Recently, we reported the full genome sequence of 102 strains of the virus. Here, we exploited the data to elucidate the evolutionary characteristics and phylodynamics of the virus compared with influenza A and B viruses. Along with our data, we obtained public sequence data of the hemagglutinin-esterase gene of the virus; the dataset consists of 218 unique sequences of the virus collected from 14 countries between 1947 and 2014. Informatics analyses revealed that (1 multiple lineages have been circulating globally; (2 there have been weak and infrequent selective bottlenecks; (3 the evolutionary rate is low because of weak positive selection and a low capability to induce mutations; and (4 there is no significant positive selection although a few mutations affecting its antigenicity have been induced. The unique evolutionary dynamics of the influenza C virus must be shaped by multiple factors, including virological, immunological, and epidemiological characteristics.

Molecular signatures in childhood acute leukemia and their correlations to expression patterns in normal hematopoietic subpopulations.

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Andersson, Anna; Olofsson, Tor; Lindgren, David; Nilsson, Björn; Ritz, Cecilia; Edén, Patrik; Lassen, Carin; Råde, Johan; Fontes, Magnus; Mörse, Helena; Heldrup, Jesper; Behrendtz, Mikael; Mitelman, Felix; Höglund, Mattias; Johansson, Bertil; Fioretos, Thoas

2005-12-27

Global expression profiles of a consecutive series of 121 childhood acute leukemias (87 B lineage acute lymphoblastic leukemias, 11 T cell acute lymphoblastic leukemias, and 23 acute myeloid leukemias), six normal bone marrows, and 10 normal hematopoietic subpopulations of different lineages and maturations were ascertained by using 27K cDNA microarrays. Unsupervised analyses revealed segregation according to lineages and primary genetic changes, i.e., TCF3(E2A)/PBX1, IGH@/MYC, ETV6(TEL)/RUNX1(AML1), 11q23/MLL, and hyperdiploidy (>50 chromosomes). Supervised discriminatory analyses were used to identify differentially expressed genes correlating with lineage and primary genetic change. The gene-expression profiles of normal hematopoietic cells were also studied. By using principal component analyses (PCA), a differentiation axis was exposed, reflecting lineages and maturation stages of normal hematopoietic cells. By applying the three principal components obtained from PCA of the normal cells on the leukemic samples, similarities between malignant and normal cell lineages and maturations were investigated. Apart from showing that leukemias segregate according to lineage and genetic subtype, we provide an extensive study of the genes correlating with primary genetic changes. We also investigated the expression pattern of these genes in normal hematopoietic cells of different lineages and maturations, identifying genes preferentially expressed by the leukemic cells, suggesting an ectopic activation of a large number of genes, likely to reflect regulatory networks of pathogenetic importance that also may provide attractive targets for future directed therapies.

Polymorphic Evolutionary Games.

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Fishman, Michael A

2016-06-07

In this paper, I present an analytical framework for polymorphic evolutionary games suitable for explicitly modeling evolutionary processes in diploid populations with sexual reproduction. The principal aspect of the proposed approach is adding diploid genetics cum sexual recombination to a traditional evolutionary game, and switching from phenotypes to haplotypes as the new game׳s pure strategies. Here, the relevant pure strategy׳s payoffs derived by summing the payoffs of all the phenotypes capable of producing gametes containing that particular haplotype weighted by the pertinent probabilities. The resulting game is structurally identical to the familiar Evolutionary Games with non-linear pure strategy payoffs (Hofbauer and Sigmund, 1998. Cambridge University Press), and can be analyzed in terms of an established analytical framework for such games. And these results can be translated into the terms of genotypic, and whence, phenotypic evolutionary stability pertinent to the original game. Copyright © 2016 Elsevier Ltd. All rights reserved.

THE THEORY OF THE FIRM AND THE EVOLUTIONARY GAMES

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Sirghi Nicoleta

2013-07-01

Full Text Available The neoclassical theory of the firm deals with the pattern of perfect competition, within which the perfect information available to economic agents provides instant allocation of production factors and access to economic goods. The Austrian School (C. Menger, L. von Mises, Hayek, etc. supported the idea of minimal state intervention on the markets, bringing important conceptual developments on the theory of the firm. Hirschleifer (1982 put forward the model of social and institutional functioning, arguing that the game theory is able to predict the outcome of the collective behavior and the human characteristics necessary for building the respective institutions.The evolutionary theory provides the firm and the entrepreneur the recognition of the functions of innovation, of generating and exploiting information and of organizing and coordinating production. The evolutionary perspective of the firm assumes the existence of a body of knowledge that is acquired through and builds up the organizational memory, subsequently found in routines, all choices being made based on these routines (Nelson and Winter, 2002. The evolution of the firm is considered to be similar to natural selection, but unlike the classic market selection, the evolutionists suggest the existence of a plurality of selection media. The present research is structured as follows: a brief introduction into the theories of the firm, the second part of the paper analyzes the theories of the firm from an institutional, neo-institutional and evolutionary perspective. In the third part of the paper the evolutionary games are described and analyzed from the evolutionary perspective of the firm. The last part of the paper represents a study of the “hawk-dove” game dynamic replicator. The final conclusions of the paper show that the evolutionary theory brings valuable contributions to the foundation of explanations regarding economic phenomena, indicating new directions for advanced

Remembering the evolutionary Freud.

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Young, Allan

2006-03-01

Throughout his career as a writer, Sigmund Freud maintained an interest in the evolutionary origins of the human mind and its neurotic and psychotic disorders. In common with many writers then and now, he believed that the evolutionary past is conserved in the mind and the brain. Today the "evolutionary Freud" is nearly forgotten. Even among Freudians, he is regarded to be a red herring, relevant only to the extent that he diverts attention from the enduring achievements of the authentic Freud. There are three ways to explain these attitudes. First, the evolutionary Freud's key work is the "Overview of the Transference Neurosis" (1915). But it was published at an inopportune moment, forty years after the author's death, during the so-called "Freud wars." Second, Freud eventually lost interest in the "Overview" and the prospect of a comprehensive evolutionary theory of psychopathology. The publication of The Ego and the Id (1923), introducing Freud's structural theory of the psyche, marked the point of no return. Finally, Freud's evolutionary theory is simply not credible. It is based on just-so stories and a thoroughly discredited evolutionary mechanism, Lamarckian use-inheritance. Explanations one and two are probably correct but also uninteresting. Explanation number three assumes that there is a fundamental difference between Freud's evolutionary narratives (not credible) and the evolutionary accounts of psychopathology that currently circulate in psychiatry and mainstream journals (credible). The assumption is mistaken but worth investigating.

Understanding the mind from an evolutionary perspective: an overview of evolutionary psychology.

Science.gov (United States)

Shackelford, Todd K; Liddle, James R

2014-05-01

The theory of evolution by natural selection provides the only scientific explanation for the existence of complex adaptations. The design features of the brain, like any organ, are the result of selection pressures operating over deep time. Evolutionary psychology posits that the human brain comprises a multitude of evolved psychological mechanisms, adaptations to specific and recurrent problems of survival and reproduction faced over human evolutionary history. Although some mistakenly view evolutionary psychology as promoting genetic determinism, evolutionary psychologists appreciate and emphasize the interactions between genes and environments. This approach to psychology has led to a richer understanding of a variety of psychological phenomena, and has provided a powerful foundation for generating novel hypotheses. Critics argue that evolutionary psychologists resort to storytelling, but as with any branch of science, empirical testing is a vital component of the field, with hypotheses standing or falling with the weight of the evidence. Evolutionary psychology is uniquely suited to provide a unifying theoretical framework for the disparate subdisciplines of psychology. An evolutionary perspective has provided insights into several subdisciplines of psychology, while simultaneously demonstrating the arbitrary nature of dividing psychological science into such subdisciplines. Evolutionary psychologists have amassed a substantial empirical and theoretical literature, but as a relatively new approach to psychology, many questions remain, with several promising directions for future research. For further resources related to this article, please visit the WIREs website. The authors have declared no conflicts of interest for this article. © 2014 John Wiley & Sons, Ltd.

Application of network methods for understanding evolutionary dynamics in discrete habitats.

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Greenbaum, Gili; Fefferman, Nina H

2017-06-01

In populations occupying discrete habitat patches, gene flow between habitat patches may form an intricate population structure. In such structures, the evolutionary dynamics resulting from interaction of gene-flow patterns with other evolutionary forces may be exceedingly complex. Several models describing gene flow between discrete habitat patches have been presented in the population-genetics literature; however, these models have usually addressed relatively simple settings of habitable patches and have stopped short of providing general methodologies for addressing nontrivial gene-flow patterns. In the last decades, network theory - a branch of discrete mathematics concerned with complex interactions between discrete elements - has been applied to address several problems in population genetics by modelling gene flow between habitat patches using networks. Here, we present the idea and concepts of modelling complex gene flows in discrete habitats using networks. Our goal is to raise awareness to existing network theory applications in molecular ecology studies, as well as to outline the current and potential contribution of network methods to the understanding of evolutionary dynamics in discrete habitats. We review the main branches of network theory that have been, or that we believe potentially could be, applied to population genetics and molecular ecology research. We address applications to theoretical modelling and to empirical population-genetic studies, and we highlight future directions for extending the integration of network science with molecular ecology. © 2017 John Wiley & Sons Ltd.

Looking at the origin of phenotypic variation from pattern formation ...

Indian Academy of Sciences (India)

Prakash

evolutionary considerations, a large number of researchers, ... This article critically reviews some widespread views about the overall functioning of development. ... Thus, a great deal about the evolution and functioning of ... variants and thus take patterns of phenotypic variation as ..... Evolutionary thinking to the rescue.

DrawCompileEvolve: Sparking interactive evolutionary art with human creations

DEFF Research Database (Denmark)

Zhang, Jinhong; Taarnby, Rasmus; Liapis, Antonios

2015-01-01

This paper presents DrawCompileEvolve, a web-based drawing tool which allows users to draw simple primitive shapes, group them together or define patterns in their groupings (e.g. symmetry, repetition). The user’s vector drawing is then compiled into an indirectly encoded genetic representation......, which can be evolved interactively, allowing the user to change the image’s colors, patterns and ultimately transform it. The human artist has direct control while drawing the initial seed of an evolutionary run and indirect control while interactively evolving it, thus making DrawCompileEvolve a mixed...

Nerve ultrasound normal values - Readjustment of the ultrasound pattern sum score UPSS.

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Grimm, Alexander; Axer, Hubertus; Heiling, Bianka; Winter, Natalie

2018-07-01

Reference values are crucial for nerve ultrasound. Here, we reevaluated normal nerve and fascicle cross-sectional area (CSA) values in humans and compared them to published values. Based on these data, ultrasound pattern sum score (UPSS) boundary values were revisited and readjusted. Ultrasound of different peripheral nerves was performed in 100 healthy subjects at anatomically defined landmarks. Correlations with age, gender, height and weight were calculated. Overall, correspondence to other published reference values was high. Gender-dependency was found for the proximal median nerve. Dependency from height occurred in the tibial nerve (TN). Weight-dependency was not found. However, the most obvious differences were found in the TN between men >60 years and women values were defined using the mean plus the twofold standard deviation for all subjects and nerve segments except for the TN, in which different cut-offs were proposed for elder men. Accordingly, the cut-offs for the UPSS were re-adjusted, none of the individuals revealed more than 2 points at maximum. The influence of distinct epidemiological factors on nerve size is most prominent in the TN, for which thus several normal values are useful. Adjusted reference values improve the accuracy of the UPSS. Copyright © 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

[Evolutionary medicine].

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Wjst, M

2013-12-01

Evolutionary medicine allows new insights into long standing medical problems. Are we "really stoneagers on the fast lane"? This insight might have enormous consequences and will allow new answers that could never been provided by traditional anthropology. Only now this is made possible using data from molecular medicine and systems biology. Thereby evolutionary medicine takes a leap from a merely theoretical discipline to practical fields - reproductive, nutritional and preventive medicine, as well as microbiology, immunology and psychiatry. Evolutionary medicine is not another "just so story" but a serious candidate for the medical curriculum providing a universal understanding of health and disease based on our biological origin. © Georg Thieme Verlag KG Stuttgart · New York.

Core principles of evolutionary medicine

Science.gov (United States)

Grunspan, Daniel Z; Nesse, Randolph M; Barnes, M Elizabeth; Brownell, Sara E

2018-01-01

Abstract Background and objectives Evolutionary medicine is a rapidly growing field that uses the principles of evolutionary biology to better understand, prevent and treat disease, and that uses studies of disease to advance basic knowledge in evolutionary biology. Over-arching principles of evolutionary medicine have been described in publications, but our study is the first to systematically elicit core principles from a diverse panel of experts in evolutionary medicine. These principles should be useful to advance recent recommendations made by The Association of American Medical Colleges and the Howard Hughes Medical Institute to make evolutionary thinking a core competency for pre-medical education. Methodology The Delphi method was used to elicit and validate a list of core principles for evolutionary medicine. The study included four surveys administered in sequence to 56 expert panelists. The initial open-ended survey created a list of possible core principles; the three subsequent surveys winnowed the list and assessed the accuracy and importance of each principle. Results Fourteen core principles elicited at least 80% of the panelists to agree or strongly agree that they were important core principles for evolutionary medicine. These principles over-lapped with concepts discussed in other articles discussing key concepts in evolutionary medicine. Conclusions and implications This set of core principles will be helpful for researchers and instructors in evolutionary medicine. We recommend that evolutionary medicine instructors use the list of core principles to construct learning goals. Evolutionary medicine is a young field, so this list of core principles will likely change as the field develops further. PMID:29493660

Applying evolutionary anthropology.

Science.gov (United States)

Gibson, Mhairi A; Lawson, David W

2015-01-01

Evolutionary anthropology provides a powerful theoretical framework for understanding how both current environments and legacies of past selection shape human behavioral diversity. This integrative and pluralistic field, combining ethnographic, demographic, and sociological methods, has provided new insights into the ultimate forces and proximate pathways that guide human adaptation and variation. Here, we present the argument that evolutionary anthropological studies of human behavior also hold great, largely untapped, potential to guide the design, implementation, and evaluation of social and public health policy. Focusing on the key anthropological themes of reproduction, production, and distribution we highlight classic and recent research demonstrating the value of an evolutionary perspective to improving human well-being. The challenge now comes in transforming relevance into action and, for that, evolutionary behavioral anthropologists will need to forge deeper connections with other applied social scientists and policy-makers. We are hopeful that these developments are underway and that, with the current tide of enthusiasm for evidence-based approaches to policy, evolutionary anthropology is well positioned to make a strong contribution. © 2015 Wiley Periodicals, Inc.

Applying Evolutionary Anthropology

Science.gov (United States)

Gibson, Mhairi A; Lawson, David W

2015-01-01

Evolutionary anthropology provides a powerful theoretical framework for understanding how both current environments and legacies of past selection shape human behavioral diversity. This integrative and pluralistic field, combining ethnographic, demographic, and sociological methods, has provided new insights into the ultimate forces and proximate pathways that guide human adaptation and variation. Here, we present the argument that evolutionary anthropological studies of human behavior also hold great, largely untapped, potential to guide the design, implementation, and evaluation of social and public health policy. Focusing on the key anthropological themes of reproduction, production, and distribution we highlight classic and recent research demonstrating the value of an evolutionary perspective to improving human well-being. The challenge now comes in transforming relevance into action and, for that, evolutionary behavioral anthropologists will need to forge deeper connections with other applied social scientists and policy-makers. We are hopeful that these developments are underway and that, with the current tide of enthusiasm for evidence-based approaches to policy, evolutionary anthropology is well positioned to make a strong contribution. PMID:25684561

Religion and psychosis: a common evolutionary trajectory?

Science.gov (United States)

Dein, Simon; Littlewood, Roland

2011-07-01

In this article we propose that schizophrenia and religious cognition engage cognate mental modules in the over-attribution of agency and the overextension of theory of mind. We argue similarities and differences between assumptions of ultrahuman agents with omniscient minds and certain ''pathological'' forms of thinking in schizophrenia: thought insertion, withdrawal and broadcasting, and delusions of reference. In everyday religious cognition agency detection and theory of mind modules function ''normally,'' whereas in schizophrenia both modules are impaired. It is suggested that religion and schizophrenia have perhaps had a related evolutionary trajectory.

Dietary patterns of obese and normal-weight women of reproductive age in urban slum areas in Central Jakarta.

Science.gov (United States)

Yulia; Khusun, Helda; Fahmida, Umi

2016-07-01

Developing countries including Indonesia imperatively require an understanding of factors leading to the emerging problem of obesity, especially within low socio-economic groups, whose dietary pattern may contribute to obesity. In this cross-sectional study, we compared the dietary patterns and food consumption of 103 obese and 104 normal-weight women of reproductive age (19-49 years) in urban slum areas in Central Jakarta. A single 24-h food recall was used to assess energy and macronutrient intakes (carbohydrate, protein and fat) and calculate energy density. A principal component analysis was used to define the dietary patterns from the FFQ. Obese women had significantly higher intakes of energy (8436·6 (sd 2358·1) v. 7504·4 (sd 1887·8) kJ (2016·4 (sd 563·6) v. 1793·6 (sd 451·2) kcal)), carbohydrate (263·9 (sd 77·0) v. 237·6 (sd 63·0) g) and fat (83·11 (sd 31·3) v. 70·2 (sd 26·1) g) compared with normal-weight women; however, their protein intake (59·4 (sd 19·1) v. 55·9 (sd 18·5) g) and energy density (8·911 (sd 2·30) v. 8·58 (sd 1·88) kJ/g (2·13 (sd 0·55) v. 2·05 (sd 0·45) kcal/g)) did not differ significantly. Two dietary patterns were revealed and subjectively named 'more healthy' and 'less healthy'. The 'less healthy' pattern was characterised by the consumption of fried foods (snacks, soyabean and roots and tubers) and meat and poultry products, whereas the more healthy pattern was characterised by the consumption of seafood, vegetables, eggs, milk and milk products and non-fried snacks. Subjects with a high score for the more healthy pattern had a lower obesity risk compared with those with a low score. Thus, obesity is associated with high energy intake and unhealthy dietary patterns characterised by consumption of oils and fats through fried foods and snacks.

Evolutionary patterns of Escherichia coli small RNAs and their regulatory interactions.

Science.gov (United States)

Peer, Asaf; Margalit, Hanah

2014-07-01

Most bacterial small RNAs (sRNAs) are post-transcriptional regulators of gene expression, exerting their regulatory function by base-pairing with their target mRNAs. While it has become evident that sRNAs play central regulatory roles in the cell, little is known about their evolution and the evolution of their regulatory interactions. Here we used the prokaryotic phylogenetic tree to reconstruct the evolutionary history of Escherichia coli sRNAs and their binding sites on target mRNAs. We discovered that sRNAs currently present in E. coli mainly accumulated inside the Enterobacteriales order, succeeding the appearance of other types of noncoding RNAs and concurrently with the evolution of a variant of the Hfq protein exhibiting a longer C-terminal region. Our analysis of the evolutionary ages of sRNA-mRNA interactions revealed that while all sRNAs were evolutionarily older than most of their known binding sites on mRNA targets, for quite a few sRNAs there was at least one binding site that coappeared with or preceded them. It is conceivable that the establishment of these first interactions forced selective pressure on the sRNAs, after which additional targets were acquired by fitting a binding site to the active region of the sRNA. This conjecture is supported by the appearance of many binding sites on target mRNAs only after the sRNA gain, despite the prior presence of the target gene in ancestral genomes. Our results suggest a selective mechanism that maintained the sRNAs across the phylogenetic tree, and shed light on the evolution of E. coli post-transcriptional regulatory network. © 2014 Peer and Margalit; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

Evolutionary Expectations

DEFF Research Database (Denmark)

Nash, Ulrik William

2014-01-01

, they are correlated among people who share environments because these individuals satisfice within their cognitive bounds by using cues in order of validity, as opposed to using cues arbitrarily. Any difference in expectations thereby arise from differences in cognitive ability, because two individuals with identical...... cognitive bounds will perceive business opportunities identically. In addition, because cues provide information about latent causal structures of the environment, changes in causality must be accompanied by changes in cognitive representations if adaptation is to be maintained. The concept of evolutionary......The concept of evolutionary expectations descends from cue learning psychology, synthesizing ideas on rational expectations with ideas on bounded rationality, to provide support for these ideas simultaneously. Evolutionary expectations are rational, but within cognitive bounds. Moreover...

Evolutionary Awareness

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Gregory Gorelik

2014-10-01

Full Text Available In this article, we advance the concept of “evolutionary awareness,” a metacognitive framework that examines human thought and emotion from a naturalistic, evolutionary perspective. We begin by discussing the evolution and current functioning of the moral foundations on which our framework rests. Next, we discuss the possible applications of such an evolutionarily-informed ethical framework to several domains of human behavior, namely: sexual maturation, mate attraction, intrasexual competition, culture, and the separation between various academic disciplines. Finally, we discuss ways in which an evolutionary awareness can inform our cross-generational activities—which we refer to as “intergenerational extended phenotypes”—by helping us to construct a better future for ourselves, for other sentient beings, and for our environment.

Evolutionary Developmental Robotics: Improving Morphology and Control of Physical Robots.

Science.gov (United States)

Vujovic, Vuk; Rosendo, Andre; Brodbeck, Luzius; Iida, Fumiya

2017-01-01

Evolutionary algorithms have previously been applied to the design of morphology and control of robots. The design space for such tasks can be very complex, which can prevent evolution from efficiently discovering fit solutions. In this article we introduce an evolutionary-developmental (evo-devo) experiment with real-world robots. It allows robots to grow their leg size to simulate ontogenetic morphological changes, and this is the first time that such an experiment has been performed in the physical world. To test diverse robot morphologies, robot legs of variable shapes were generated during the evolutionary process and autonomously built using additive fabrication. We present two cases with evo-devo experiments and one with evolution, and we hypothesize that the addition of a developmental stage can be used within robotics to improve performance. Moreover, our results show that a nonlinear system-environment interaction exists, which explains the nontrivial locomotion patterns observed. In the future, robots will be present in our daily lives, and this work introduces for the first time physical robots that evolve and grow while interacting with the environment.

EVOLUTIONARY FOUNDATIONS FOR MOLECULAR MEDICINE

Science.gov (United States)

Nesse, Randolph M.; Ganten, Detlev; Gregory, T. Ryan; Omenn, Gilbert S.

2015-01-01

Evolution has long provided a foundation for population genetics, but many major advances in evolutionary biology from the 20th century are only now being applied in molecular medicine. They include the distinction between proximate and evolutionary explanations, kin selection, evolutionary models for cooperation, and new strategies for tracing phylogenies and identifying signals of selection. Recent advances in genomics are further transforming evolutionary biology and creating yet more opportunities for progress at the interface of evolution with genetics, medicine, and public health. This article reviews 15 evolutionary principles and their applications in molecular medicine in hopes that readers will use them and others to speed the development of evolutionary molecular medicine. PMID:22544168

Normalization of Complete Genome Characteristics: Application to Evolution from Primitive Organisms to Homo sapiens.

Science.gov (United States)

Sorimachi, Kenji; Okayasu, Teiji; Ohhira, Shuji

2015-04-01

Normalized nucleotide and amino acid contents of complete genome sequences can be visualized as radar charts. The shapes of these charts depict the characteristics of an organism's genome. The normalized values calculated from the genome sequence theoretically exclude experimental errors. Further, because normalization is independent of both target size and kind, this procedure is applicable not only to single genes but also to whole genomes, which consist of a huge number of different genes. In this review, we discuss the applications of the normalization of the nucleotide and predicted amino acid contents of complete genomes to the investigation of genome structure and to evolutionary research from primitive organisms to Homo sapiens. Some of the results could never have been obtained from the analysis of individual nucleotide or amino acid sequences but were revealed only after the normalization of nucleotide and amino acid contents was applied to genome research. The discovery that genome structure was homogeneous was obtained only after normalization methods were applied to the nucleotide or predicted amino acid contents of genome sequences. Normalization procedures are also applicable to evolutionary research. Thus, normalization of the contents of whole genomes is a useful procedure that can help to characterize organisms.

Attractive evolutionary equilibria

NARCIS (Netherlands)

Joosten, Reinoud A.M.G.; Roorda, Berend

2011-01-01

We present attractiveness, a refinement criterion for evolutionary equilibria. Equilibria surviving this criterion are robust to small perturbations of the underlying payoff system or the dynamics at hand. Furthermore, certain attractive equilibria are equivalent to others for certain evolutionary

IDEA: Interactive Display for Evolutionary Analyses.

Science.gov (United States)

Egan, Amy; Mahurkar, Anup; Crabtree, Jonathan; Badger, Jonathan H; Carlton, Jane M; Silva, Joana C

2008-12-08

The availability of complete genomic sequences for hundreds of organisms promises to make obtaining genome-wide estimates of substitution rates, selective constraints and other molecular evolution variables of interest an increasingly important approach to addressing broad evolutionary questions. Two of the programs most widely used for this purpose are codeml and baseml, parts of the PAML (Phylogenetic Analysis by Maximum Likelihood) suite. A significant drawback of these programs is their lack of a graphical user interface, which can limit their user base and considerably reduce their efficiency. We have developed IDEA (Interactive Display for Evolutionary Analyses), an intuitive graphical input and output interface which interacts with PHYLIP for phylogeny reconstruction and with codeml and baseml for molecular evolution analyses. IDEA's graphical input and visualization interfaces eliminate the need to edit and parse text input and output files, reducing the likelihood of errors and improving processing time. Further, its interactive output display gives the user immediate access to results. Finally, IDEA can process data in parallel on a local machine or computing grid, allowing genome-wide analyses to be completed quickly. IDEA provides a graphical user interface that allows the user to follow a codeml or baseml analysis from parameter input through to the exploration of results. Novel options streamline the analysis process, and post-analysis visualization of phylogenies, evolutionary rates and selective constraint along protein sequences simplifies the interpretation of results. The integration of these functions into a single tool eliminates the need for lengthy data handling and parsing, significantly expediting access to global patterns in the data.

Normal parenchymal enhancement patterns in women undergoing MR screening of the breast

International Nuclear Information System (INIS)

Jansen, Sanaz A.; Lin, Vicky C.; Giger, Maryellen L.; Li, Hui; Karczmar, Gregory S.; Newstead, Gillian M.

2011-01-01

To characterize the kinetic and morphological presentation of normal breast tissue on DCE-MRI in a large cohort of asymptomatic women, and to relate these characteristics to breast tissue density. 335 consecutive breast MR examinations in 229 asymptomatic women undergoing high-risk screening evaluations based on recommendations from the American Cancer Society including strong family history and genetic predisposition were selected for IRB-approved review (average age 49.2 ± 10.5 years). Breast tissue density was assessed on precontrast T 2 -weighted images. Parenchymal enhancement pattern (PEP) was qualitatively classified as minimal, homogeneous, heterogeneous or nodular. Quantitative analysis of parenchymal enhancement kinetics (PEK) was performed, including calculation of initial and peak enhancement percentages (E 1 , E peak ), the time to peak enhancement (T peak ) and the signal enhancement ratio (SER). 41.8% of examinations were classified as minimal, 13.7% homogeneous, 23.9% heterogeneous and 21.2% nodular PEP. Women with heterogeneously or extremely dense breasts exhibited a higher proportion of nodular PEP (44.2% (27/61)) and significantly higher E 1 , and E peak (p < 0.003) compared with those with less dense breasts. Qualitative and quantitative parenchymal enhancement characteristics vary by breast tissue density. In future work, the association between image-derived MR features of the normal breast and breast cancer risk should be explored. (orig.)

Generative models versus underlying symmetries to explain biological pattern.

Science.gov (United States)

Frank, S A

2014-06-01

Mathematical models play an increasingly important role in the interpretation of biological experiments. Studies often present a model that generates the observations, connecting hypothesized process to an observed pattern. Such generative models confirm the plausibility of an explanation and make testable hypotheses for further experiments. However, studies rarely consider the broad family of alternative models that match the same observed pattern. The symmetries that define the broad class of matching models are in fact the only aspects of information truly revealed by observed pattern. Commonly observed patterns derive from simple underlying symmetries. This article illustrates the problem by showing the symmetry associated with the observed rate of increase in fitness in a constant environment. That underlying symmetry reveals how each particular generative model defines a single example within the broad class of matching models. Further progress on the relation between pattern and process requires deeper consideration of the underlying symmetries. © 2014 The Author. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Differences in aortic vortex flow pattern between normal and patients with stroke: qualitative and quantitative assessment using transesophageal contrast echocardiography.

Science.gov (United States)

Son, Jang-Won; Hong, Geu-Ru; Hong, Woosol; Kim, Minji; Houle, Helene; Vannan, Mani A; Pedrizzetti, Gianni; Chung, Namsik

2016-06-01

The flow in the aorta forms a vortex, which is a critical determinant of the flow dynamics in the aorta. Arteriosclerosis can alter the blood flow pattern of the aorta and cause characteristic alterations of the vortex. However, this change in aortic vortex has not yet been studied. This study aimed to characterize aortic vortex flow pattern using transesophageal contrast echocardiography in normal and stroke patients. A total of 85 patients who diagnosed with ischemic stroke and 16 normal controls were recruited for this study. The 16 normal control subjects were designated as the control group, and the 85 ischemic stroke patients were designated as the stroke group. All subjects underwent contrast transesophageal echocardiography (TEE), and particle image velocimetry was used to assess aortic vortex flow. Qualitative and quantitative analyses of vortex flow morphology, location, phasic variation, and pulsatility were undertaken and compared between the groups. In the control group, multiple irregularly-shaped vortices were observed in a peripheral location in the descending thoracic aorta. In contrast, the stroke group had a single, round, merged, and more centrally located aortic vortex flow. In the quantitative analysis of vortex, vortex depth, which represents the location of the major vortex in the aorta, was significantly higher in the control group than in the stroke group (0.599 ± 0.159 vs. 0.522 ± 0.101, respectively, P = 0.013). Vortex relative strength, which is the pulsatility parameter of the vortex itself, was significantly higher in the stroke group than in the control group (0.367 ± 0.148 vs. 0.304 ± 0.087, respectively, P = 0.025). It was feasible to visualize and quantify the characteristic morphology and pulsatility of the aortic vortex flow using contrast TEE, and aortic vortex pattern significantly differed between normal and stroke patients.

Open Issues in Evolutionary Robotics.

Science.gov (United States)

Silva, Fernando; Duarte, Miguel; Correia, Luís; Oliveira, Sancho Moura; Christensen, Anders Lyhne

2016-01-01

One of the long-term goals in evolutionary robotics is to be able to automatically synthesize controllers for real autonomous robots based only on a task specification. While a number of studies have shown the applicability of evolutionary robotics techniques for the synthesis of behavioral control, researchers have consistently been faced with a number of issues preventing the widespread adoption of evolutionary robotics for engineering purposes. In this article, we review and discuss the open issues in evolutionary robotics. First, we analyze the benefits and challenges of simulation-based evolution and subsequent deployment of controllers versus evolution on real robotic hardware. Second, we discuss specific evolutionary computation issues that have plagued evolutionary robotics: (1) the bootstrap problem, (2) deception, and (3) the role of genomic encoding and genotype-phenotype mapping in the evolution of controllers for complex tasks. Finally, we address the absence of standard research practices in the field. We also discuss promising avenues of research. Our underlying motivation is the reduction of the current gap between evolutionary robotics and mainstream robotics, and the establishment of evolutionary robotics as a canonical approach for the engineering of autonomous robots.

Patterns in Orthoptera biodiversity. I. Adaptations in ecological and evolutionary contexts

Directory of Open Access Journals (Sweden)

Claudio J. Bidau

2014-10-01

Full Text Available The Orthoptera have inhabited the Earth for ca 300 million years and today include about 25,000 described species. Although orthopterans are mainly known to the general public by their most conspicuous species such as rangeland grasshoppers, locusts, katydids and crickets, they include an amazing diversity of forms and life-styles. In this review, I bring together a series of facts about orthopteran biology that demonstrate their enormous biodiversity, concentrating on ecological and evolutionary characteristics such as habitat variation, modes of feeding, defense mechanisms and phase transformation. In a second part of this review I will consider subjects of more direct human interest as their use as food, their importance in folk medicine and their role as entertainment.

Gene Coexpression and Evolutionary Conservation Analysis of the Human Preimplantation Embryos

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Tiancheng Liu

2015-01-01

Full Text Available Evolutionary developmental biology (EVO-DEVO tries to decode evolutionary constraints on the stages of embryonic development. Two models—the “funnel-like” model and the “hourglass” model—have been proposed by investigators to illustrate the fluctuation of selective pressure on these stages. However, selective indices of stages corresponding to mammalian preimplantation embryonic development (PED were undetected in previous studies. Based on single cell RNA sequencing of stages during human PED, we used coexpression method to identify gene modules activated in each of these stages. Through measuring the evolutionary indices of gene modules belonging to each stage, we observed change pattern of selective constraints on PED for the first time. The selective pressure decreases from the zygote stage to the 4-cell stage and increases at the 8-cell stage and then decreases again from 8-cell stage to the late blastocyst stages. Previous EVO-DEVO studies concerning the whole embryo development neglected the fluctuation of selective pressure in these earlier stages, and the fluctuation was potentially correlated with events of earlier stages, such as zygote genome activation (ZGA. Such oscillation in an earlier stage would further affect models of the evolutionary constraints on whole embryo development. Therefore, these earlier stages should be measured intensively in future EVO-DEVO studies.

Shelves around the Iberian Peninsula (II): Evolutionary sedimentary patterns; Las plataformas continentales de la Peninsula Iberica (II): Patrones sedimentarios evolutivos

Energy Technology Data Exchange (ETDEWEB)

Lobo, F. J.; Duran, R.; Roque, C.; Ribo, M.; Carrera, G.; Mendes, I.; Ferrin, A.; Fernandez-Salas, L. M.; Garcia-Gil, S.; Galpalsoro, I.; Rosa, F.; Barcenas, P.

2015-07-01

We present a synthetic view of continental-shelf evolutionary patterns around the Iberian Peninsula, focusing on proposed sequence stratigraphy interpretations and attempting a comparison between Atlantic- and Mediterranean-type shelf-margin constructions. Most of the studied shelves show a dominance of regressive to low stand deposition through successive pro gradations, particularly evident in the Pliocene-Quaternary, documenting the influence of glacio-eustasy. Transgressive to high stand development predating the Last Glacial Maximum seems to be favoured off major rivers, but the highest variability is seen during post glacial evolution. Transgressive deposits tend to show a higher spatial variability, ranging from pro graded para sequences to extensive sand sheets. Holocene high- stand deposits usually show a more homogeneous character, with development of proximal wedge-shaped deposits and a distal sheet-like deposition. Atlantic continental shelves off Iberia display three different types of shelf growth: depositional shelves, shelves with restricted pro gradation and erosional shelves. They result from the interplay between depositional and hydrodynamic regimes, with the occurrence of a latitudinal gradation from erosional shelves in the Cantabrian continental shelf to depositional shelves in the northern Gulf of Cadiz shelf. Some shelf sectors do not correspond to this general pattern, as shelf sedimentation is mainly controlled by morpho-structural features (e.g., ria environments and shelves crossed by major tectonic accidents). The Mediterranean continental shelves of Iberia show two basic types, high- versus low-supply shelves, and their growth patterns are mainly a response to the amount of fluvial supply. The low-supply style is clearly the most frequent type, and it may show further complexity according to the occurrence of submarine canyons and/or morpho-structural control. (Author)

Evolutionary Pattern of Improved 1-Mile Running Performance

NARCIS (Netherlands)

Foster, C.S.; de Koning, J.J.; Thiel, C.

2014-01-01

The official world records (WR) for the 1-mile run for men (3: 43.13) and for women (4: 12.58) have improved 12.2% and 32.3%, respectively, since the first WR recognized by the International Association of Athletics Federations. Previous observations have suggested that the pacing pattern for

Synergistic Coherence of Bifurcation Evolutionary Processes of Mergers and Acquisitions of Enterprises

Directory of Open Access Journals (Sweden)

Ivanchenko Hennadii F.

2016-08-01

Full Text Available The aim of the article is developing information tools for the economic and mathematical modeling of the dynamics of evolutionary processes concerning trophic relationships of populations of enterprises, which allowed to conduct the phase and bifurcation analysis of possible dynamic regimes of the populations’ evolution, determine the mechanisms of influence of the external environment and the internal structure of the system, identify patterns and limits of stability of M&A processes. In the work the main provisions of the evolutionary concept concerning development of the population of enterprises as an economic system are analyzed, the provisions of the evolutionary concept of population systems’ development are considered, the basis of evolutionary modeling methods allowing to analyze the functioning of populations of enterprises in terms of individual strategies of each enterprise’s behavior is studied. The basic principles of synergy of the life cycle evolution for populations of enterprises are determined. An evolutionary approach to the evaluation of a synergistic effect of M & A is proposed. The evolutionary modeling of the scenario for self-organization of populations of dairy industry enterprises through a combination of statistical and expert data is applied. There also created a model of the population of firms reflecting behavioral and resource and technological characteristics of the studied in the work real population of industrial enterprises, which form the input flows of matter, energy and information to the dairy industry, which allows to combine the reflection of main possible options in terms of the external conditions of the population functioning and its internal structure.

A new molecular logic for BMP-mediated dorsoventral patterning in the leech Helobdella.

Science.gov (United States)

Kuo, Dian-Han; Weisblat, David A

2011-08-09

Bone morphogenetic protein (BMP) signaling is broadly implicated in dorsoventral (DV) patterning of bilaterally symmetric animals [1-3], and its role in axial patterning apparently predates the birth of Bilateria [4-7]. In fly and vertebrate embryos, BMPs and their antagonists (primarily Sog/chordin) diffuse and interact to generate signaling gradients that pattern fields of cells [8-10]. Work in other species reveals diversity in essential facets of this ancient patterning process, however. Here, we report that BMP signaling patterns the DV axis of segmental ectoderm in the leech Helobdella, a clitellate annelid (superphylum Lophotrochozoa) featuring stereotyped developmental cell lineages, but the detailed mechanisms of DV patterning in Helobdella differ markedly from fly and vertebrates. In Helobdella, BMP2/4s are expressed broadly, rather than in dorsal territory, whereas a dorsally expressed BMP5-8 specifies dorsal fate by short-range signaling. A BMP antagonist, gremlin, is upregulated by BMP5-8 in dorsolateral, rather than ventral territory, and yet the BMP-antagonizing activity of gremlin is required for normal ventral cell fates. Gremlin promotes ventral fates without disrupting dorsal fates by selectively inhibiting BMP2/4s, not BMP5-8. Thus, DV patterning in the development of the leech revealed unexpected evolutionary plasticity of the conserved BMP patterning system, presumably reflecting its adaptation to different modes of embryogenesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

Oxidation-specific epitopes are danger-associated molecular patterns recognized by pattern recognition receptors of innate immunity

DEFF Research Database (Denmark)

Miller, Yury I; Choi, Soo-Ho; Wiesner, Philipp

2011-01-01

are a major target of innate immunity, recognized by a variety of "pattern recognition receptors" (PRRs). By analogy with microbial "pathogen-associated molecular patterns" (PAMPs), we postulate that host-derived, oxidation-specific epitopes can be considered to represent "danger (or damage......)-associated molecular patterns" (DAMPs). We also argue that oxidation-specific epitopes present on apoptotic cells and their cellular debris provided the primary evolutionary pressure for the selection of such PRRs. Furthermore, because many PAMPs on microbes share molecular identity and/or mimicry with oxidation...

Growing into obesity: patterns of height growth in those who become normal weight, overweight, or obese as young adults.

Science.gov (United States)

Stovitz, Steven D; Demerath, Ellen W; Hannan, Peter J; Lytle, Leslie A; Himes, John H

2011-01-01

To study whether patterns of height growth differ by adult obesity status, and determine the contribution of subcutaneous fatness as an explanatory variable for any differences. A multicenter, prospective longitudinal cohort assessed in 3rd grade (8.8 years), 5th grade (11.1 years), 8th grade (14.1 years), and 12th grade (18.3 years). Exposures were young adult obesity status classified by CDC adult BMI categories at 12th grade. Skinfolds were measured in third, fifth, and eighth grades. Outcome was mean height (cm) at the four measurements using repeated-measures ANCOVA for young adult obesity status, and height increments between grades by adult obesity status in sequential models including initial height and, secondarily, initial skinfolds. Adjusted for age, and race/ethnicity, young adult obesity status explained a small, but statistically significant amount of height growth among both females and males within each of the three intervals. Compared with normal weight young adults, overweight or obese young adults stood taller in childhood, but had relatively less growth in height throughout the teenage years. There was no association between adult height and weight status. Skinfolds explained only a small amount of the height patterns in the three weight groups. Childhood and adolescent height growth patterns differ between those who become young adults who are normal weight and those who become overweight or obese. Since differences in fatness explain only a small amount of these height growth patterns, research is needed to identify other determinants. Copyright © 2011 Wiley-Liss, Inc.

Animal egg as evolutionary innovation: a solution to the "embryonic hourglass" puzzle.

Science.gov (United States)

Newman, Stuart A

2011-11-15

The evolutionary origin of the egg stage of animal development presents several difficulties for conventional developmental and evolutionary narratives. If the egg's internal organization represents a template for key features of the developed organism, why can taxa within a given phylum exhibit very different egg types, pass through a common intermediate morphology (the so-called "phylotypic stage"), only to diverge again, thus exemplifying the embryonic "hourglass"? Moreover, if different egg types typically represent adaptations to different environmental conditions, why do birds and mammals, for example, have such vastly different eggs with respect to size, shape, and postfertilization dynamics, whereas all these features are more similar for ascidians and mammals? Here, I consider the possibility that different body plans had their origin in self-organizing physical processes in ancient clusters of cells, and suggest that eggs represented a set of independent evolutionary innovations subsequently inserted into the developmental trajectories of such aggregates. I first describe how "dynamical patterning modules" (DPMs) associations between components of the metazoan developmental-genetic toolkit and certain physical processes and effects may have organized primitive animal body plans independently of an egg stage. Next, I describe how adaptive specialization of cells released from such aggregates could have become "proto-eggs," which regenerated the parental cell clusters by cleavage, conserving the characteristic DPMs available to a lineage. Then, I show how known processes of cytoplasmic reorganization following fertilization are often based on spontaneous, self-organizing physical effects ("egg-patterning processes": EPPs). I suggest that rather than acting as developmental blueprints or prepatterns, the EPPs refine the phylotypic body plans determined by the DPMs by setting the boundary and initial conditions under which these multicellular patterning

Deciphering the evolutionary history of open and closed mitosis.

Science.gov (United States)

Sazer, Shelley; Lynch, Michael; Needleman, Daniel

2014-11-17

The origin of the nucleus at the prokaryote-to-eukaryote transition represents one of the most important events in the evolution of cellular organization. The nuclear envelope encircles the chromosomes in interphase and is a selectively permeable barrier between the nucleoplasm and cytoplasm and an organizational scaffold for the nucleus. It remains intact in the 'closed' mitosis of some yeasts, but loses its integrity in the 'open' mitosis of mammals. Instances of both types of mitosis within two evolutionary clades indicate multiple evolutionary transitions between open and closed mitosis, although the underlying genetic changes that influenced these transitions remain unknown. A survey of the diversity of mitotic nuclei that fall between these extremes is the starting point from which to determine the physiologically relevant characteristics distinguishing open from closed mitosis and to understand how they evolved and why they are retained in present-day organisms. The field is now poised to begin addressing these issues by defining and documenting patterns of mitotic nuclear variation within and among species and mapping them onto a phylogenic tree. Deciphering the evolutionary history of open and closed mitosis will complement cell biological and genetic approaches aimed at deciphering the fundamental organizational principles of the nucleus. Copyright © 2014 Elsevier Ltd. All rights reserved.

IDEA: Interactive Display for Evolutionary Analyses

Directory of Open Access Journals (Sweden)

Carlton Jane M

2008-12-01

Full Text Available Abstract Background The availability of complete genomic sequences for hundreds of organisms promises to make obtaining genome-wide estimates of substitution rates, selective constraints and other molecular evolution variables of interest an increasingly important approach to addressing broad evolutionary questions. Two of the programs most widely used for this purpose are codeml and baseml, parts of the PAML (Phylogenetic Analysis by Maximum Likelihood suite. A significant drawback of these programs is their lack of a graphical user interface, which can limit their user base and considerably reduce their efficiency. Results We have developed IDEA (Interactive Display for Evolutionary Analyses, an intuitive graphical input and output interface which interacts with PHYLIP for phylogeny reconstruction and with codeml and baseml for molecular evolution analyses. IDEA's graphical input and visualization interfaces eliminate the need to edit and parse text input and output files, reducing the likelihood of errors and improving processing time. Further, its interactive output display gives the user immediate access to results. Finally, IDEA can process data in parallel on a local machine or computing grid, allowing genome-wide analyses to be completed quickly. Conclusion IDEA provides a graphical user interface that allows the user to follow a codeml or baseml analysis from parameter input through to the exploration of results. Novel options streamline the analysis process, and post-analysis visualization of phylogenies, evolutionary rates and selective constraint along protein sequences simplifies the interpretation of results. The integration of these functions into a single tool eliminates the need for lengthy data handling and parsing, significantly expediting access to global patterns in the data.

Evolutionary Demography

DEFF Research Database (Denmark)

Levitis, Daniel

2015-01-01

of biological and cultural evolution. Demographic variation within and among human populations is influenced by our biology, and therefore by natural selection and our evolutionary background. Demographic methods are necessary for studying populations of other species, and for quantifying evolutionary fitness......Demography is the quantitative study of population processes, while evolution is a population process that influences all aspects of biological organisms, including their demography. Demographic traits common to all human populations are the products of biological evolution or the interaction...

Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects

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Ahmadreza Keihani

2018-05-01

Full Text Available Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects.Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25 and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35 were chosen. A hardware setup with low THD rate (<0.1% was designed to present these patterns on LED. Twenty two normal subjects (aged 23–30 (25 ± 2.1 yrs were enrolled. Visual analog scale (VAS was used for subjective fatigue evaluation after presentation of each stimulus pattern. PSD, CCA, and LASSO methods were employed to analyze SSVEP responses. The data including SSVEP features and fatigue rate for different visual stimuli patterns were statistically evaluated.Results: All 9 visual stimuli patterns elicited SSVEP responses. Overall, obtained accuracy rates were 88.35% for PSD and > 90% for CCA and LASSO (for TWs > 1 s. High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24% than simple patterns group (98.48%. Repeated measure ANOVA showed significant difference between rhythmic pattern features (P < 0.0005. Overall, there was no significant difference between the VAS of rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], (P = 0.63. Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65] as well as least individual pattern VAS (P25

Proteomics in evolutionary ecology.

Science.gov (United States)

Baer, B; Millar, A H

2016-03-01

Evolutionary ecologists are traditionally gene-focused, as genes propagate phenotypic traits across generations and mutations and recombination in the DNA generate genetic diversity required for evolutionary processes. As a consequence, the inheritance of changed DNA provides a molecular explanation for the functional changes associated with natural selection. A direct focus on proteins on the other hand, the actual molecular agents responsible for the expression of a phenotypic trait, receives far less interest from ecologists and evolutionary biologists. This is partially due to the central dogma of molecular biology that appears to define proteins as the 'dead-end of molecular information flow' as well as technical limitations in identifying and studying proteins and their diversity in the field and in many of the more exotic genera often favored in ecological studies. Here we provide an overview of a newly forming field of research that we refer to as 'Evolutionary Proteomics'. We point out that the origins of cellular function are related to the properties of polypeptide and RNA and their interactions with the environment, rather than DNA descent, and that the critical role of horizontal gene transfer in evolution is more about coopting new proteins to impact cellular processes than it is about modifying gene function. Furthermore, post-transcriptional and post-translational processes generate a remarkable diversity of mature proteins from a single gene, and the properties of these mature proteins can also influence inheritance through genetic and perhaps epigenetic mechanisms. The influence of post-transcriptional diversification on evolutionary processes could provide a novel mechanistic underpinning for elements of rapid, directed evolutionary changes and adaptations as observed for a variety of evolutionary processes. Modern state-of the art technologies based on mass spectrometry are now available to identify and quantify peptides, proteins, protein

EvolQG - An R package for evolutionary quantitative genetics [version 2; referees: 1 approved, 2 approved with reservations

Directory of Open Access Journals (Sweden)

Diogo Melo

2016-06-01

Full Text Available We present an open source package for performing evolutionary quantitative genetics analyses in the R environment for statistical computing. Evolutionary theory shows that evolution depends critically on the available variation in a given population. When dealing with many quantitative traits this variation is expressed in the form of a covariance matrix, particularly the additive genetic covariance matrix or sometimes the phenotypic matrix, when the genetic matrix is unavailable and there is evidence the phenotypic matrix is sufficiently similar to the genetic matrix. Given this mathematical representation of available variation, the EvolQG package provides functions for calculation of relevant evolutionary statistics; estimation of sampling error; corrections for this error; matrix comparison via correlations, distances and matrix decomposition; analysis of modularity patterns; and functions for testing evolutionary hypotheses on taxa diversification.

Evolutionary analysis of groundwater flow: Application of multivariate statistical analysis to hydrochemical data in the Densu Basin, Ghana

Science.gov (United States)

Yidana, Sandow Mark; Bawoyobie, Patrick; Sakyi, Patrick; Fynn, Obed Fiifi

2018-02-01

An evolutionary trend has been postulated through the analysis of hydrochemical data of a crystalline rock aquifer system in the Densu Basin, Southern Ghana. Hydrochemcial data from 63 groundwater samples, taken from two main groundwater outlets (Boreholes and hand dug wells) were used to postulate an evolutionary theory for the basin. Sequential factor and hierarchical cluster analysis were used to disintegrate the data into three factors and five clusters (spatial associations). These were used to characterize the controls on groundwater hydrochemistry and its evolution in the terrain. The dissolution of soluble salts and cation exchange processes are the dominant processes controlling groundwater hydrochemistry in the terrain. The trend of evolution of this set of processes follows the pattern of groundwater flow predicted by a calibrated transient groundwater model in the area. The data suggest that anthropogenic activities represent the second most important process in the hydrochemistry. Silicate mineral weathering is the third most important set of processes. Groundwater associations resulting from Q-mode hierarchical cluster analysis indicate an evolutionary pattern consistent with the general groundwater flow pattern in the basin. These key findings are at variance with results of previous investigations and indicate that when carefully done, groundwater hydrochemical data can be very useful for conceptualizing groundwater flow in basins.

Assessing fluctuating evolutionary pressure in yeast and mammal evolutionary rate covariation using bioinformatics of meiotic protein genetic sequences

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Dehipawala, Sunil; Nguyen, A.; Tremberger, G.; Cheung, E.; Holden, T.; Lieberman, D.; Cheung, T.

2013-09-01

The evolutionary rate co-variation in meiotic proteins has been reported for yeast and mammal using phylogenic branch lengths which assess retention, duplication and mutation. The bioinformatics of the corresponding DNA sequences could be classified as a diagram of fractal dimension and Shannon entropy. Results from biomedical gene research provide examples on the diagram methodology. The identification of adaptive selection using entropy marker and functional-structural diversity using fractal dimension would support a regression analysis where the coefficient of determination would serve as evolutionary pathway marker for DNA sequences and be an important component in the astrobiology community. Comparisons between biomedical genes such as EEF2 (elongation factor 2 human, mouse, etc), WDR85 in epigenetics, HAR1 in human specificity, clinical trial targeted cancer gene CD47, SIRT6 in spermatogenesis, and HLA-C in mosquito bite immunology demonstrate the diagram classification methodology. Comparisons to the SEPT4-XIAP pair in stem cell apoptosis, testesexpressed taste genes TAS1R3-GNAT3 pair, and amyloid beta APLP1-APLP2 pair with the yeast-mammal DNA sequences for meiotic proteins RAD50-MRE11 pair and NCAPD2-ICK pair have accounted for the observed fluctuating evolutionary pressure systematically. Regression with high R-sq values or a triangular-like cluster pattern for concordant pairs in co-variation among the studied species could serve as evidences for the possible location of common ancestors in the entropy-fractal dimension diagram, consistent with an example of the human-chimp common ancestor study using the FOXP2 regulated genes reported in human fetal brain study. The Deinococcus radiodurans R1 Rad-A could be viewed as an outlier in the RAD50 diagram and also in the free energy versus fractal dimension regression Cook's distance, consistent with a non-Earth source for this radiation resistant bacterium. Convergent and divergent fluctuating evolutionary

Labor Patterns in Women Attempting Vaginal Birth After Cesarean With Normal Neonatal Outcomes

Science.gov (United States)

GRANTZ, Katherine L.; GONZALEZ-QUINTERO, Victor; TROENDLE, James; REDDY, Uma M.; HINKLE, Stefanie N.; KOMINIAREK, Michelle A.; LU, Zhaohui; ZHANG, Jun

2015-01-01

Objective To describe labor patterns in women with a trial of labor after cesarean (TOLAC) with normal neonatal outcomes. Study Design In a retrospective observational study at 12 U.S. centers (2002–2008), we examined time interval for each centimeter of cervical dilation and compared labor progression stratified by spontaneous or induced labor in 2,892 multiparous women with TOLAC (second delivery) and 56,301 nulliparous women at 37 0/7 to 41 6/7 weeks of gestation. Analyses were performed including women with intrapartum cesarean delivery, and then repeated limiting only to women who delivered vaginally. Results Labor was induced in 23.4% of TOLAC and 44.1% of nulliparous women (Plabor (Plabor (P=.099); however, TOLAC had lower maximum doses of oxytocin compared to nulliparous women: median (90th percentile): 6 (18) mU/min versus 12 (28) mU/min, respectively (Plabor duration for TOLAC versus nulliparous women with spontaneous labor from 4–10cm was 0.9 (2.2) hours longer (P=.007). For women who entered labor spontaneously and achieved vaginal delivery, labor patterns for TOLAC were similar to nulliparous women. For induced labor, labor duration for TOLAC versus nulliparous women from 4–10cm was 1.5 (4.6) hours longer (Plabor patterns were slower for induced TOLAC compared to nulliparous women. Conclusions Labor duration for TOLAC was slower compared to nulliparous labor, particularly for induced labor. By improved understanding of the rates of progress at different points in labor, this new information on labor curves in women undergoing TOLAC, particularly for induction, should help physicians when managing labor. PMID:25935774

Ecstasy and new patterns of drug use: a normal population study.

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Pedersen, W; Skrondal, A

1999-11-01

(i) To describe illegal drug use patterns in an adolescent normal population sample with special emphasis on MDMA, ecstasy; (ii) to investigate where ecstasy is introduced in a hypothesized drug use sequence, and (iii) to contrast the predictors of ecstasy use with those of other illegal substances. Special attention was given to the relationship to subcultural music preferences and house-party-going. A school-based survey of the total cohort of adolescents enrolled in the school system in a city. 10,812 adolescents, age 14-17 years, response rate 94.3%. Oslo, the capital and only metropolitan town in Norway. Social class was measured by the occupation standard ISCO 88, questions were posed as regards frequency of alcohol use and alcohol intoxication, cigarette smoking and use of cannabis, amphetamines, ecstasy and heroin. Alcohol problems were measured by a shortened version of Rutgers Alcohol Problem Index (RAPI), conduct problems were measured according to the four categories of acts forming the basis of the diagnosis conduct disorder in DSM-IV, internalizing mental health problems were measured using items from Hopkins Symptoms Checklist (HCL). A number of questions were asked as regards subcultural music preferences and house-party-going. STATISTICAL MODELS: A hypothesized cumulative sequence in drug use was investigated by means of latent class analysis, and the predictors of the various patterns of drug use were estimated and compared by means of multinominal logistic regression analysis. The use of ecstasy was often intermingled with the use of cannabis, amphetamines and heroin, in a pattern of polydrug use. The latent class analysis revealed the following drug use sequence: (1) alcohol, (2) cigarettes, (3) cannabis, (4) amphetamines, (5) ecstasy and (6) heroin. There was no significant association between ecstasy use and parental social class or residential area of the town. All patterns of illegal drug use were highly associated with cigarette smoking

PREDICTION OF BLOOD PATTERN IN S-SHAPED MODEL OF ARTERY UNDER NORMAL BLOOD PRESSURE

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Mohd Azrul Hisham Mohd Adib

2013-06-01

Full Text Available Athletes are susceptible to a wide variety of traumatic and non-traumatic vascular injuries to the lower limb. This paper aims to predict the three-dimensional flow pattern of blood through an S-shaped geometrical artery model. This model has created by using Fluid Structure Interaction (FSI software. The modeling of the geometrical S-shaped artery is suitable for understanding the pattern of blood flow under constant normal blood pressure. In this study, a numerical method is used that works on the assumption that the blood is incompressible and Newtonian; thus, a laminar type of flow can be considered. The authors have compared the results with a previous study with FSI validation simulation. The validation and verification of the simulation studies is performed by comparing the maximum velocity at t = 0.4 s, because at this time, the blood accelerates rapidly. In addition, the resulting blood flow at various times, under the same boundary conditions in the S-shaped geometrical artery model, is presented. The graph shows that velocity increases linearly with time. Thus, it can be concluded that the flow of blood increases with respect to the pressure inside the body.

Distribution pattern of urine albumin creatinine ratio and the prevalence of high-normal levels in untreated asymptomatic non-diabetic hypertensive patients.

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Ohmaru, Natsuki; Nakatsu, Takaaki; Izumi, Reishi; Mashima, Keiichi; Toki, Misako; Kobayashi, Asako; Ogawa, Hiroko; Hirohata, Satoshi; Ikeda, Satoru; Kusachi, Shozo

2011-01-01

Even high-normal albuminuria is reportedly associated with cardiovascular events. We determined the urine albumin creatinine ratio (UACR) in spot urine samples and analyzed the UACR distribution and the prevalence of high-normal levels. The UACR was determined using immunoturbidimetry in 332 untreated asymptomatic non-diabetic Japanese patients with hypertension and in 69 control subjects. The microalbuminuria and macroalbuminuria levels were defined as a UCAR ≥30 and creatinine and a UCAR ≥300 µg/mg·creatinine, respectively. The distribution patterns showed a highly skewed distribution for the lower levels, and a common logarithmic transformation produced a close fit to a Gaussian distribution with median, 25th and 75th percentile values of 22.6, 13.5 and 48.2 µg/mg·creatinine, respectively. When a high-normal UACR was set at >20 to creatinine, 19.9% (66/332) of the hypertensive patients exhibited a high-normal UACR. Microalbuminuria and macroalbuminuria were observed in 36.1% (120/336) and 2.1% (7/332) of the patients, respectively. UACR was significantly correlated with the systolic and diastolic blood pressures and the pulse pressure. A stepwise multivariate analysis revealed that these pressures as well as age were independent factors that increased UACR. The UACR distribution exhibited a highly skewed pattern, with approximately 60% of untreated, non-diabetic hypertensive patients exhibiting a high-normal or larger UACR. Both hypertension and age are independent risk factors that increase the UACR. The present study indicated that a considerable percentage of patients require anti-hypertensive drugs with antiproteinuric effects at the start of treatment.

Masturbation, sexuality, and adaptation: normalization in adolescence.

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Shapiro, Theodore

2008-03-01

During adolescence the central masturbation fantasy that is formulated during childhood takes its final form and paradoxically must now be directed outward for appropriate object finding and pair matching in the service of procreative aims. This is a step in adaptation that requires a further developmental landmark that I have called normalization. The path toward airing these private fantasies is facilitated by chumship relationships as a step toward further exposure to the social surround. Hartmann's structuring application of adaptation within psychoanalysis is used as a framework for understanding the process that simultaneously serves intrapsychic and social demands and permits goals that follow evolutionary principles. Variations in the normalization process from masturbatory isolation to a variety of forms of sexual socialization are examined in sociological data concerning current adolescent sexual behavior and in case examples that indicate some routes to normalized experience and practice.

Attractive evolutionary equilibria

OpenAIRE

Roorda, Berend; Joosten, Reinoud

2011-01-01

We present attractiveness, a refinement criterion for evolutionary equilibria. Equilibria surviving this criterion are robust to small perturbations of the underlying payoff system or the dynamics at hand. Furthermore, certain attractive equilibria are equivalent to others for certain evolutionary dynamics. For instance, each attractive evolutionarily stable strategy is an attractive evolutionarily stable equilibrium for certain barycentric ray-projection dynamics, and vice versa.

Unique features of Myf-5 in turtles: nucleotide deletion, alternative splicing, and unusual expression pattern.

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Ohya, Yoshie Kawashima; Usuda, Ryo; Kuraku, Shigehiro; Nagashima, Hiroshi; Kuratani, Shigeru

2006-01-01

Turtles characteristically possess a bony shell and show an extensive reduction of the trunk muscles. To gain insight into the evolution of this animal group, we focused on the underlying mechanism of the turtle-specific developmental pattern associated with the somitic mesoderm, which differentiates into both skeleton and muscle. We isolated Myf-5, a member of the myogenic-transcription-factor-encoding gene family expressed in the myotome, from the Chinese soft-shelled turtle Pelodiscus sinensis. We detected a deletion of 12 sequential nucleotides in P. sinensis Myf-5 (PsMyf-5), which appears to be shared by the turtle group. The expression pattern of PsMyf-5 in P. sinensis embryos differed from those of its orthologs in other amniotes, especially in the hypaxial region of the flank. We also identified two isoforms of the PsMyf-5 protein, a normal form similar to those of other vertebrates, and a short form produced by a translational frameshift. The short PsMyf-5 showed weaker myogenic activity in cultured cells than that of the normal protein, although the tissue distribution of the two isoforms overlapped perfectly. We propose that the unusual features of PsMyf-5 may be related to the unique developmental patterns of this animal group, and constitute one of the molecular bases for their evolutionary origin.

A multilevel evolutionary framework for sustainability analysis

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Timothy M. Waring

2015-06-01

Full Text Available Sustainability theory can help achieve desirable social-ecological states by generalizing lessons across contexts and improving the design of sustainability interventions. To accomplish these goals, we argue that theory in sustainability science must (1 explain the emergence and persistence of social-ecological states, (2 account for endogenous cultural change, (3 incorporate cooperation dynamics, and (4 address the complexities of multilevel social-ecological interactions. We suggest that cultural evolutionary theory broadly, and cultural multilevel selection in particular, can improve on these fronts. We outline a multilevel evolutionary framework for describing social-ecological change and detail how multilevel cooperative dynamics can determine outcomes in environmental dilemmas. We show how this framework complements existing sustainability frameworks with a description of the emergence and persistence of sustainable institutions and behavior, a means to generalize causal patterns across social-ecological contexts, and a heuristic for designing and evaluating effective sustainability interventions. We support these assertions with case examples from developed and developing countries in which we track cooperative change at multiple levels of social organization as they impact social-ecological outcomes. Finally, we make suggestions for further theoretical development, empirical testing, and application.

Cyclic dominance in evolutionary games: a review

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Szolnoki, Attila; Mobilia, Mauro; Jiang, Luo-Luo; Szczesny, Bartosz; Rucklidge, Alastair M.; Perc, Matjaž

2014-01-01

Rock is wrapped by paper, paper is cut by scissors and scissors are crushed by rock. This simple game is popular among children and adults to decide on trivial disputes that have no obvious winner, but cyclic dominance is also at the heart of predator–prey interactions, the mating strategy of side-blotched lizards, the overgrowth of marine sessile organisms and competition in microbial populations. Cyclical interactions also emerge spontaneously in evolutionary games entailing volunteering, reward, punishment, and in fact are common when the competing strategies are three or more, regardless of the particularities of the game. Here, we review recent advances on the rock–paper–scissors (RPS) and related evolutionary games, focusing, in particular, on pattern formation, the impact of mobility and the spontaneous emergence of cyclic dominance. We also review mean-field and zero-dimensional RPS models and the application of the complex Ginzburg–Landau equation, and we highlight the importance and usefulness of statistical physics for the successful study of large-scale ecological systems. Directions for future research, related, for example, to dynamical effects of coevolutionary rules and invasion reversals owing to multi-point interactions, are also outlined. PMID:25232048

Phylogenetic niche conservatism and the evolutionary basis of ecological speciation.

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Pyron, R Alexander; Costa, Gabriel C; Patten, Michael A; Burbrink, Frank T

2015-11-01

Phylogenetic niche conservatism (PNC) typically refers to the tendency of closely related species to be more similar to each other in terms of niche than they are to more distant relatives. This has been implicated as a potential driving force in speciation and other species-richness patterns, such as latitudinal gradients. However, PNC has not been very well defined in most previous studies. Is it a pattern or a process? What are the underlying endogenous (e.g. genetic) and exogenous (e.g. ecological) factors that cause niches to be conserved? What degree of similarity is necessary to qualify as PNC? Is it possible for the evolutionary processes causing niches to be conserved to also result in niche divergence in different habitats? Here, we revisit these questions, codifying a theoretical and operational definition of PNC as a mechanistic evolutionary process resulting from several factors. We frame this both from a macroevolutionary and population-genetic perspective. We discuss how different axes of physical (e.g. geographic) and environmental (e.g. climatic) heterogeneity interact with the fundamental process of PNC to produce different outcomes of ecological speciation. We also review tests for PNC, and suggest ways that these could be improved or better utilized in future studies. Ultimately, PNC as a process has a well-defined mechanistic basis in organisms, and future studies investigating ecological speciation would be well served to consider this, and frame hypothesis testing in terms of the processes and expected patterns described herein. The process of PNC may lead to patterns where niches are conserved (more similar than expected), constrained (divergent within a limited subset of available niches), or divergent (less similar than expected), based on degree of phylogenetic relatedness between species. © 2014 Cambridge Philosophical Society.

Evolutionary principles and their practical application.

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Hendry, Andrew P; Kinnison, Michael T; Heino, Mikko; Day, Troy; Smith, Thomas B; Fitt, Gary; Bergstrom, Carl T; Oakeshott, John; Jørgensen, Peter S; Zalucki, Myron P; Gilchrist, George; Southerton, Simon; Sih, Andrew; Strauss, Sharon; Denison, Robert F; Carroll, Scott P

2011-03-01

Evolutionary principles are now routinely incorporated into medicine and agriculture. Examples include the design of treatments that slow the evolution of resistance by weeds, pests, and pathogens, and the design of breeding programs that maximize crop yield or quality. Evolutionary principles are also increasingly incorporated into conservation biology, natural resource management, and environmental science. Examples include the protection of small and isolated populations from inbreeding depression, the identification of key traits involved in adaptation to climate change, the design of harvesting regimes that minimize unwanted life-history evolution, and the setting of conservation priorities based on populations, species, or communities that harbor the greatest evolutionary diversity and potential. The adoption of evolutionary principles has proceeded somewhat independently in these different fields, even though the underlying fundamental concepts are the same. We explore these fundamental concepts under four main themes: variation, selection, connectivity, and eco-evolutionary dynamics. Within each theme, we present several key evolutionary principles and illustrate their use in addressing applied problems. We hope that the resulting primer of evolutionary concepts and their practical utility helps to advance a unified multidisciplinary field of applied evolutionary biology.

Evolutionary relationships between miRNA genes and their activity.

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Zhu, Yan; Skogerbø, Geir; Ning, Qianqian; Wang, Zhen; Li, Biqing; Yang, Shuang; Sun, Hong; Li, Yixue

2012-12-22

The emergence of vertebrates is characterized by a strong increase in miRNA families. MicroRNAs interact broadly with many transcripts, and the evolution of such a system is intriguing. However, evolutionary questions concerning the origin of miRNA genes and their subsequent evolution remain unexplained. In order to systematically understand the evolutionary relationship between miRNAs gene and their function, we classified human known miRNAs into eight groups based on their evolutionary ages estimated by maximum parsimony method. New miRNA genes with new functional sequences accumulated more dynamically in vertebrates than that observed in Drosophila. Different levels of evolutionary selection were observed over miRNA gene sequences with different time of origin. Most genic miRNAs differ from their host genes in time of origin, there is no particular relationship between the age of a miRNA and the age of its host genes, genic miRNAs are mostly younger than the corresponding host genes. MicroRNAs originated over different time-scales are often predicted/verified to target the same or overlapping sets of genes, opening the possibility of substantial functional redundancy among miRNAs of different ages. Higher degree of tissue specificity and lower expression level was found in young miRNAs. Our data showed that compared with protein coding genes, miRNA genes are more dynamic in terms of emergence and decay. Evolution patterns are quite different between miRNAs of different ages. MicroRNAs activity is under tight control with well-regulated expression increased and targeting decreased over time. Our work calls attention to the study of miRNA activity with a consideration of their origin time.

Evolutionary Inference across Eukaryotes Identifies Specific Pressures Favoring Mitochondrial Gene Retention.

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Johnston, Iain G; Williams, Ben P

2016-02-24

Since their endosymbiotic origin, mitochondria have lost most of their genes. Although many selective mechanisms underlying the evolution of mitochondrial genomes have been proposed, a data-driven exploration of these hypotheses is lacking, and a quantitatively supported consensus remains absent. We developed HyperTraPS, a methodology coupling stochastic modeling with Bayesian inference, to identify the ordering of evolutionary events and suggest their causes. Using 2015 complete mitochondrial genomes, we inferred evolutionary trajectories of mtDNA gene loss across the eukaryotic tree of life. We find that proteins comprising the structural cores of the electron transport chain are preferentially encoded within mitochondrial genomes across eukaryotes. A combination of high GC content and high protein hydrophobicity is required to explain patterns of mtDNA gene retention; a model that accounts for these selective pressures can also predict the success of artificial gene transfer experiments in vivo. This work provides a general method for data-driven inference of the ordering of evolutionary and progressive events, here identifying the distinct features shaping mitochondrial genomes of present-day species. Copyright © 2016 Elsevier Inc. All rights reserved.

Local phylogenetic divergence and global evolutionary convergence of skull function in reef fishes of the family Labridae.

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Westneat, Mark W; Alfaro, Michael E; Wainwright, Peter C; Bellwood, David R; Grubich, Justin R; Fessler, Jennifer L; Clements, Kendall D; Smith, Lydia L

2005-05-22

The Labridae is one of the most structurally and functionally diversified fish families on coral and rocky reefs around the world, providing a compelling system for examination of evolutionary patterns of functional change. Labrid fishes have evolved a diverse array of skull forms for feeding on prey ranging from molluscs, crustaceans, plankton, detritus, algae, coral and other fishes. The species richness and diversity of feeding ecology in the Labridae make this group a marine analogue to the cichlid fishes. Despite the importance of labrids to coastal reef ecology, we lack evolutionary analysis of feeding biomechanics among labrids. Here, we combine a molecular phylogeny of the Labridae with the biomechanics of skull function to reveal a broad pattern of repeated convergence in labrid feeding systems. Mechanically fast jaw systems have evolved independently at least 14 times from ancestors with forceful jaws. A repeated phylogenetic pattern of functional divergence in local regions of the labrid tree produces an emergent family-wide pattern of global convergence in jaw function. Divergence of close relatives, convergence among higher clades and several unusual 'breakthroughs' in skull function characterize the evolution of functional complexity in one of the most diverse groups of reef fishes.

Dynamic lymph flow scintigraphy in lymphoedema: Description of a new procedure and normal and abnormal patterns

International Nuclear Information System (INIS)

Nawaz, K.; Hamad, M.M.; Sadek, S.; Awdeh, M.; Eklof, B.; Abdel-Dayem, H.M.

1986-01-01

A dynamic study of lymphatic flow was performed in 23 patients complaining of lymphoedema of the lower limbs. All were injected intradermally with 1 mCi (37 MBq) of 99 Tcsup(m)-labelled human serum albumin (HSA) in the medial web on the dorsum of each foot. Image acquisition for the lower pelvis and both thighs was started within 5 min. A GE 500A gamma camera with an extra-large field of view and a low energy, all purpose collimator interfaced with a GE Star computer was used. Images were acquired in the dynamic mode with a 128x128 matrix every minute up to 40 min. Delayed images for the same region and for both legs were taken at 90 min. Time-activity curves for equal regions of interest over the inguinal regions on both sides were generated. Three patterns were recognized. (1) Normal flow (12 patients) with symmetrical or slightly increased or decreased flow on one side compared with the other, characterized by early appearance of medial bands and inguinal and pelvic lymph nodes in the early and delayed images. (2) An obstructed pattern (5 patients) characterized by subcutaneous pooling, absent medial bands in the dynamic part of the study, a flat curve on the affected side representing background activity, and absent inguinal and pelvic nodes in the delayed images. Occasionally the obstruction was incomplete and there was a delayed appearance of the nodes, which were less in number and smaller in size than on the normal side. (3) An enhanced pattern (6 patients) characterized by fast flow of lymph through the dilated lymphatics, occasionally subcutaneous pooling and an increase in the number and size of inguinal and pelvic lymph nodes on the affected side. The authors conclude that intradermal injection of 99 Tcsup(m)-HSA can be used to study the pathophysiology of lymphatic flow in the most difficult group of patients suffering from chronic lymphoedema of the lower limbs

Algorithmic Mechanism Design of Evolutionary Computation.

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Pei, Yan

2015-01-01

We consider algorithmic design, enhancement, and improvement of evolutionary computation as a mechanism design problem. All individuals or several groups of individuals can be considered as self-interested agents. The individuals in evolutionary computation can manipulate parameter settings and operations by satisfying their own preferences, which are defined by an evolutionary computation algorithm designer, rather than by following a fixed algorithm rule. Evolutionary computation algorithm designers or self-adaptive methods should construct proper rules and mechanisms for all agents (individuals) to conduct their evolution behaviour correctly in order to definitely achieve the desired and preset objective(s). As a case study, we propose a formal framework on parameter setting, strategy selection, and algorithmic design of evolutionary computation by considering the Nash strategy equilibrium of a mechanism design in the search process. The evaluation results present the efficiency of the framework. This primary principle can be implemented in any evolutionary computation algorithm that needs to consider strategy selection issues in its optimization process. The final objective of our work is to solve evolutionary computation design as an algorithmic mechanism design problem and establish its fundamental aspect by taking this perspective. This paper is the first step towards achieving this objective by implementing a strategy equilibrium solution (such as Nash equilibrium) in evolutionary computation algorithm.

Gene genealogies indicates abundant gene conversions and independent evolutionary histories of the mating-type chromosomes in the evolutionary history of Neurospora tetrasperma

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Whittle Carrie A

2010-07-01

Full Text Available Abstract Background The self-fertile filamentous ascomycete Neurospora tetrasperma contains a large (~7 Mbp and young (mat chromosomes. The objective of the present study is to reveal the evolutionary history, including key genomic events, associated with the various regions of the mat chromosomes among ten strains representing all the nine known species (lineages contained within the N. tetrasperma species complex. Results Comparative analysis of sequence divergence among alleles of 24 mat-linked genes (mat A and mat a indicates that a large region of suppressed recombination exists within the mat chromosome for each of nine lineages of N. tetrasperma sensu latu. The recombinationally suppressed region varies in size and gene composition among lineages, and is flanked on both ends by normally recombining regions. Genealogical analyses among lineages reveals that eight gene conversion events have occurred between homologous mat A and mat a-linked alleles of genes located within the region of restricted recombination during the evolutionary history of N. tetrasperma. Conclusions We conclude that the region of suppressed recombination in the mat chromosomes has likely been subjected to independent contraction and/or expansion during the evolutionary history of the N. tetrasperma species complex. Furthermore, we infer that gene conversion events are likely a common phenomenon within this recombinationally suppressed genomic region. We argue that gene conversions might provide an efficient mechanism of adaptive editing of functional genes, including the removal of deleterious mutations, within the young recombinationally suppressed region of the mat chromosomes.

Magnetic resonance imaging of the spinal marrow: Basic understanding of the normal marrow pattern and its variant

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Nouh, Mohamed Ragab; Eid, Ahmed Fathi

2015-01-01

For now, magnetic resonance (MR) is the best noninvasive imaging modality to evaluate vertebral bone marrow thanks to its inherent soft-tissue contrast and non-ionizing nature. A daily challenging scenario for every radiologist interpreting MR of the vertebral column is discerning the diseased from normal marrow. This requires the radiologist to be acquainted with the used MR techniques to judge the spinal marrow as well as its normal MR variants. Conventional sequences used basically to image marrow include T1W, fat-suppressed T2W and short tau inversion recovery (STIR) imaging provides gross morphological data. Interestingly, using non-routine MR sequences; such as opposed phase, diffusion weighted, MR spectroscopy and contrasted-enhanced imaging; may elucidate the nature of bone marrow heterogeneities; by inferring cellular and chemical composition; and adding new functional prospects. Recalling the normal composition of bone marrow elements and the physiologic processes of spinal marrow conversion and reconversion eases basic understanding of spinal marrow imaging. Additionally, orientation with some common variants seen during spinal marrow MR imaging as hemangiomas and bone islands is a must. Moreover, awareness of the age-associated bone marrow changes as well as changes accompanying different variations of the subject’s health state is essential for radiologists to avoid overrating normal MR marrow patterns as pathologic states and metigate unnecessary further work-up. PMID:26753060

Mandibulary dental arch form differences between level four polynomial method and pentamorphic pattern for normal occlusion sample

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Y. Yuliana

2011-07-01

Full Text Available The aim of an orthodontic treatment is to achieve aesthetic, dental health and the surrounding tissues, occlusal functional relationship, and stability. The success of an orthodontic treatment is influenced by many factors, such as diagnosis and treatment plan. In order to do a diagnosis and a treatment plan, medical record, clinical examination, radiographic examination, extra oral and intra oral photos, as well as study model analysis are needed. The purpose of this study was to evaluate the differences in dental arch form between level four polynomial and pentamorphic arch form and to determine which one is best suitable for normal occlusion sample. This analytic comparative study was conducted at Faculty of Dentistry Universitas Padjadjaran on 13 models by comparing the dental arch form using the level four polynomial method based on mathematical calculations, the pattern of the pentamorphic arch and mandibular normal occlusion as a control. The results obtained were tested using statistical analysis T student test. The results indicate a significant difference both in the form of level four polynomial method and pentamorphic arch form when compared with mandibular normal occlusion dental arch form. Level four polynomial fits better, compare to pentamorphic arch form.

Evolutionary Explanations of Eating Disorders

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Igor Kardum

2008-12-01

Full Text Available This article reviews several most important evolutionary mechanisms that underlie eating disorders. The first part clarifies evolutionary foundations of mental disorders and various mechanisms leading to their development. In the second part selective pressures and evolved adaptations causing contemporary epidemic of obesity as well as differences in dietary regimes and life-style between modern humans and their ancestors are described. Concerning eating disorders, a number of current evolutionary explanations of anorexia nervosa are presented together with their main weaknesses. Evolutionary explanations of eating disorders based on the reproductive suppression hypothesis and its variants derived from kin selection theory and the model of parental manipulation were elaborated. The sexual competition hypothesis of eating disorder, adapted to flee famine hypothesis as well as explanation based on the concept of social attention holding power and the need to belonging were also explained. The importance of evolutionary theory in modern conceptualization and research of eating disorders is emphasized.

A Comprehensive Curation Shows the Dynamic Evolutionary Patterns of Prokaryotic CRISPRs

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Guoqin Mai

2016-01-01

Full Text Available Motivation. Clustered regularly interspaced short palindromic repeat (CRISPR is a genetic element with active regulation roles for foreign invasive genes in the prokaryotic genomes and has been engineered to work with the CRISPR-associated sequence (Cas gene Cas9 as one of the modern genome editing technologies. Due to inconsistent definitions, the existing CRISPR detection programs seem to have missed some weak CRISPR signals. Results. This study manually curates all the currently annotated CRISPR elements in the prokaryotic genomes and proposes 95 updates to the annotations. A new definition is proposed to cover all the CRISPRs. The comprehensive comparison of CRISPR numbers on the taxonomic levels of both domains and genus shows high variations for closely related species even in the same genus. The detailed investigation of how CRISPRs are evolutionarily manipulated in the 8 completely sequenced species in the genus Thermoanaerobacter demonstrates that transposons act as a frequent tool for splitting long CRISPRs into shorter ones along a long evolutionary history.

The citation field of evolutionary economics

NARCIS (Netherlands)

Dolfsma, Wilfred; Leydesdorff, Loet

2010-01-01

Evolutionary economics has developed into an academic field of its own, institutionalized around, amongst others, the Journal of Evolutionary Economics (JEE). This paper analyzes the way and extent to which evolutionary economics has become an interdisciplinary journal, as its aim was: a journal

Towards a mechanistic foundation of evolutionary theory.

Science.gov (United States)

Doebeli, Michael; Ispolatov, Yaroslav; Simon, Burt

2017-02-15

Most evolutionary thinking is based on the notion of fitness and related ideas such as fitness landscapes and evolutionary optima. Nevertheless, it is often unclear what fitness actually is, and its meaning often depends on the context. Here we argue that fitness should not be a basal ingredient in verbal or mathematical descriptions of evolution. Instead, we propose that evolutionary birth-death processes, in which individuals give birth and die at ever-changing rates, should be the basis of evolutionary theory, because such processes capture the fundamental events that generate evolutionary dynamics. In evolutionary birth-death processes, fitness is at best a derived quantity, and owing to the potential complexity of such processes, there is no guarantee that there is a simple scalar, such as fitness, that would describe long-term evolutionary outcomes. We discuss how evolutionary birth-death processes can provide useful perspectives on a number of central issues in evolution.

Plug pattern optimization for gamma knife radiosurgery treatment planning

International Nuclear Information System (INIS)

Zhang Pengpeng; Wu, Jackie; Dean, David; Xing Lei; Xue Jinyue; Maciunas, Robert; Sibata, Claudio

2003-01-01

Purpose: To develop a novel dose optimization algorithm for improving the sparing of critical structures during gamma knife radiosurgery by shaping the plug pattern of each individual shot. Method and Materials: We first use a geometric information (medial axis) aided guided evolutionary simulated annealing (GESA) optimization algorithm to determine the number of shots and isocenter location, size, and weight of each shot. Then we create a plug quality score system that checks the dose contribution to the volume of interest by each plug in the treatment plan. A positive score implies that the corresponding source could be open to improve tumor coverage, whereas a negative score means the source could be blocked for the purpose of sparing normal and critical structures. The plug pattern is then optimized via the GESA algorithm that is integrated with this score system. Weight and position of each shot are also tuned in this procedure. Results: An acoustic tumor case is used to evaluate our algorithm. Compared to the treatment plan generated without plug patterns, adding an optimized plug pattern into the treatment planning process boosts tumor coverage index from 95.1% to 97.2%, reduces RTOG conformity index from 1.279 to 1.167, lowers Paddick's index from 1.34 to 1.20, and trims the critical structure receiving more than 30% maximum dose from 16 mm 3 to 6 mm 3 . Conclusions: Automated GESA-based plug pattern optimization of gamma knife radiosurgery frees the treatment planning team from the manual forward planning procedure and provides an optimal treatment plan

NERBio: using selected word conjunctions, term normalization, and global patterns to improve biomedical named entity recognition.

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Tsai, Richard Tzong-Han; Sung, Cheng-Lung; Dai, Hong-Jie; Hung, Hsieh-Chuan; Sung, Ting-Yi; Hsu, Wen-Lian

2006-12-18

Biomedical named entity recognition (Bio-NER) is a challenging problem because, in general, biomedical named entities of the same category (e.g., proteins and genes) do not follow one standard nomenclature. They have many irregularities and sometimes appear in ambiguous contexts. In recent years, machine-learning (ML) approaches have become increasingly common and now represent the cutting edge of Bio-NER technology. This paper addresses three problems faced by ML-based Bio-NER systems. First, most ML approaches usually employ singleton features that comprise one linguistic property (e.g., the current word is capitalized) and at least one class tag (e.g., B-protein, the beginning of a protein name). However, such features may be insufficient in cases where multiple properties must be considered. Adding conjunction features that contain multiple properties can be beneficial, but it would be infeasible to include all conjunction features in an NER model since memory resources are limited and some features are ineffective. To resolve the problem, we use a sequential forward search algorithm to select an effective set of features. Second, variations in the numerical parts of biomedical terms (e.g., "2" in the biomedical term IL2) cause data sparseness and generate many redundant features. In this case, we apply numerical normalization, which solves the problem by replacing all numerals in a term with one representative numeral to help classify named entities. Third, the assignment of NE tags does not depend solely on the target word's closest neighbors, but may depend on words outside the context window (e.g., a context window of five consists of the current word plus two preceding and two subsequent words). We use global patterns generated by the Smith-Waterman local alignment algorithm to identify such structures and modify the results of our ML-based tagger. This is called pattern-based post-processing. To develop our ML-based Bio-NER system, we employ conditional

Strain Map of the Tongue in Normal and ALS Speech Patterns from Tagged and Diffusion MRI.

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Xing, Fangxu; Prince, Jerry L; Stone, Maureen; Reese, Timothy G; Atassi, Nazem; Wedeen, Van J; El Fakhri, Georges; Woo, Jonghye

2018-02-01

Amyotrophic Lateral Sclerosis (ALS) is a neurological disease that causes death of neurons controlling muscle movements. Loss of speech and swallowing functions is a major impact due to degeneration of the tongue muscles. In speech studies using magnetic resonance (MR) techniques, diffusion tensor imaging (DTI) is used to capture internal tongue muscle fiber structures in three-dimensions (3D) in a non-invasive manner. Tagged magnetic resonance images (tMRI) are used to record tongue motion during speech. In this work, we aim to combine information obtained with both MR imaging techniques to compare the functionality characteristics of the tongue between normal and ALS subjects. We first extracted 3D motion of the tongue using tMRI from fourteen normal subjects in speech. The estimated motion sequences were then warped using diffeomorphic registration into the b0 spaces of the DTI data of two normal subjects and an ALS patient. We then constructed motion atlases by averaging all warped motion fields in each b0 space, and computed strain in the line of action along the muscle fiber directions provided by tractography. Strain in line with the fiber directions provides a quantitative map of the potential active region of the tongue during speech. Comparison between normal and ALS subjects explores the changing volume of compressing tongue tissues in speech facing the situation of muscle degradation. The proposed framework provides for the first time a dynamic map of contracting fibers in ALS speech patterns, and has the potential to provide more insight into the detrimental effects of ALS on speech.

Obese motorcycle riders have a different injury pattern and longer hospital length of stay than the normal-weight patients.

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Liu, Hang-Tsung; Rau, Cheng-Shyuan; Wu, Shao-Chun; Chen, Yi-Chun; Hsu, Shiun-Yuan; Hsieh, Hsiao-Yun; Hsieh, Ching-Hua

2016-04-14

The adverse effects of obesity on the physical health have been extensively studied in the general population, but not in motorcycle riders (includes both drivers and pillions). The aim of this study was to compare injury patterns, injury severities, mortality rates, and in-hospital or intensive care unit (ICU) length of stay (LOS) between obese and normal-weight patients who were hospitalized for the treatment of trauma following motorcycle accidents in a level I trauma center. Detailed data of 466 obese adult patients with a body mass index (BMI) ≥30 kg/m(2) and 2701 normal-weight patients (25 > BMI ≥18.5 kg/m(2)) who had sustained motorcycle accident-related injuries were retrieved from the Trauma Registry System between January 1, 2009 and December 31, 2013. We used the Pearson's chi-squared test, Fisher's exact test, and independent Student's t-test to analyze differences between the two groups. Compared to normal-weight motorcycle riders, more obese riders were men and drivers as opposed to pillions. In addition, fewer obese motorcycle riders showed alcohol intoxication. Analyses of the patients' Abbreviated Injury Scale (AIS) scores revealed that obese motorcycle riders presented with a higher rate of injury to the thorax, but a lower rate of injury to the face than normal-weight patients. In addition, obese motorcycle riders had a 2.7-fold greater incidence of humeral, 1.9-fold greater incidence of pelvic, and 1.5-fold greater incidence of rib fractures. In contrast, normal-weight motorcycle riders sustained a significantly higher rate of maxillary and clavicle fractures. Obese motorcycle riders had a significant longer in-hospital LOS than normal-weight motorcycle riders did (10.6 days vs. 9.5 days, respectively; p = 0.044), with an increase in in-hospital LOS of 0.82 days associated with every 10-unit increase in BMI. No statistically significant differences in Injury Severity Score (ISS), New Injury Severity Score (NISS), Trauma

Tables and intercomparisons of evolutionary sequences of models for massive stars

International Nuclear Information System (INIS)

Chin, Chaowen; Stothers, R.B.

1990-01-01

Tables of evolutionary sequences of models for massive stars have been prepared for a variety of physical input parameters that are normally treated as free. These parameters include the interior convective mixing scheme, the mixing length in the outer convective envelope, the rate of stellar-wind mass loss, the initial stellar mass, and the initial chemical composition. Ranges of specified initial mass and initial chemical composition are M = 10-120 solar masses, Xe = 0.602-0.739, and Ze = 0.021-0.044. The tables cover evolution of the star from the ZAMS to either the end of core H burning or the end of core He burning. Differences among the evolutionary tracks are illustrated primarily in terms of the interior mixing scheme, since the amount and timing of stellar wind mass loss are still very uncertain for initial masses above about 30 solar masses. 52 refs

Evolutionary thinking: "A conversation with Carter Phipps about the role of evolutionary thinking in modern culture".

Science.gov (United States)

Hunt, Tam

2014-12-01

Evolution as an idea has a lengthy history, even though the idea of evolution is generally associated with Darwin today. Rebecca Stott provides an engaging and thoughtful overview of this history of evolutionary thinking in her 2013 book, Darwin's Ghosts: The Secret History of Evolution. Since Darwin, the debate over evolution-both how it takes place and, in a long war of words with religiously-oriented thinkers, whether it takes place-has been sustained and heated. A growing share of this debate is now devoted to examining how evolutionary thinking affects areas outside of biology. How do our lives change when we recognize that all is in flux? What can we learn about life more generally if we study change instead of stasis? Carter Phipps' book, Evolutionaries: Unlocking the Spiritual and Cultural Potential of Science's Greatest Idea, delves deep into this relatively new development. Phipps generally takes as a given the validity of the Modern Synthesis of evolutionary biology. His story takes us into, as the subtitle suggests, the spiritual and cultural implications of evolutionary thinking. Can religion and evolution be reconciled? Can evolutionary thinking lead to a new type of spirituality? Is our culture already being changed in ways that we don't realize by evolutionary thinking? These are all important questions and Phipps book is a great introduction to this discussion. Phipps is an author, journalist, and contributor to the emerging "integral" or "evolutionary" cultural movement that combines the insights of Integral Philosophy, evolutionary science, developmental psychology, and the social sciences. He has served as the Executive Editor of EnlightenNext magazine (no longer published) and more recently is the co-founder of the Institute for Cultural Evolution, a public policy think tank addressing the cultural roots of America's political challenges. What follows is an email interview with Phipps.

Where Evolutionary Psychology Meets Cognitive Neuroscience: A Précis to Evolutionary Cognitive Neuroscience1

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Austen L. Krill

2007-01-01

Full Text Available Cognitive neuroscience, the study of brain-behavior relationships, has long attempted to map the brain. The discipline is flourishing, with an increasing number of functional neuroimaging studies appearing in the scientific literature daily. Unlike biology and even psychology, the cognitive neurosciences have only recently begun to apply evolutionary meta-theory and methodological guidance. Approaching cognitive neuroscience from an evolutionary perspective allows scientists to apply biologically based theoretical guidance to their investigations and can be conducted in both humans and nonhuman animals. In fact, several investigations of this sort are underway in laboratories around the world. This paper and two new volumes (Platek, Keenan, and Shackelford [Eds.], 2007; Platek and Shackelford [Eds.], under contract represent the first formal attempts to document the burgeoning field of evolutionary cognitive neuroscience. Here, we briefly review the current state of the science of evolutionary cognitive neuroscience, the methods available to the evolutionary cognitive neuroscientist, and what we foresee as the future directions of the discipline.

Essays on nonlinear evolutionary game dynamics

NARCIS (Netherlands)

Ochea, M.I.

2010-01-01

Evolutionary game theory has been viewed as an evolutionary repair of rational actor game theory in the hope that a population of boundedly rational players may attain convergence to classic rational solutions, such as the Nash Equilibrium, via some learning or evolutionary process. In this thesis

Approaches to understanding the impact of life-history features on plant-pathogen co-evolutionary dynamics

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Jeremy J. Burdon; Peter H. Thrall; Adnane Nemri

2012-01-01

Natural plant-pathogen associations are complex interactions in which the interplay of environment, host, and pathogen factors results in spatially heterogeneous ecological and epidemiological dynamics. The evolutionary patterns that result from the interaction of these factors are still relatively poorly understood. Recently, integration of the appropriate spatial and...

Comparative study cephalometric-radiographic of the cephalo-facio-dental patterns in patients who presented normal occlusion and class II, division 1 malocclusions, considering variations of the FMA angle

International Nuclear Information System (INIS)

David, S.M.N.

1986-01-01

The proposal of this job was to study cephalo-facio-dental patterns comparatively in patients who presented normal occlusion and Class II, division 1 malocclusions, considering variations of the FMA angle. The sample was composed of seventy-five telerradiographies on lateral pattern, obtained from Brazilian teenagers students of the ABC area (Santo Andre, Sao Bernardo do Campo and Sao Caetano do Sul), 'whites', who presented normal occlusion and Class II, division 1 malocclusions, without previous orthodontic treatment: their parents were Brazilian. (author) [pt

A group of facial normal descriptors for recognizing 3D identical twins

KAUST Repository

Li, Huibin

2012-09-01

In this paper, to characterize and distinguish identical twins, three popular texture descriptors: i.e. local binary patterns (LBPs), gabor filters (GFs) and local gabor binary patterns (LGBPs) are employed to encode the normal components (x, y and z) of the 3D facial surfaces of identical twins respectively. A group of facial normal descriptors are thus achieved, including Normal Local Binary Patterns descriptor (N-LBPs), Normal Gabor Filters descriptor (N-GFs) and Normal Local Gabor Binary Patterns descriptor (N-LGBPs). All these normal encoding based descriptors are further fed into sparse representation classifier (SRC) for identification. Experimental results on the 3D TEC database demonstrate that these proposed normal encoding based descriptors are very discriminative and efficient, achieving comparable performance to the best of state-of-the-art algorithms. © 2012 IEEE.

Systemic sclerosis with normal or nonspecific nailfold capillaroscopy.

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Fichel, Fanny; Baudot, Nathalie; Gaitz, Jean-Pierre; Trad, Salim; Barbe, Coralie; Francès, Camille; Senet, Patricia

2014-01-01

In systemic sclerosis (SSc), a specific nailfold videocapillaroscopy (NVC) pattern is observed in 90% of cases and seems to be associated with severity and progression of the disease. To describe the characteristics of SSc patients with normal or nonspecific (normal/nonspecific) NVC. In a retrospective cohort study, clinical features and visceral involvements of 25 SSc cases with normal/nonspecific NVC were compared to 63 SSc controls with the SSc-specific NVC pattern. Normal/nonspecific NVC versus SSc-specific NVC pattern was significantly associated with absence of skin sclerosis (32 vs. 6.3%, p = 0.004), absence of telangiectasia (47.8 vs. 17.3%, p = 0.006) and absence of sclerodactyly (60 vs. 25.4%, p = 0.002), and less frequent severe pulmonary involvement (26.3 vs. 58.2%, p = 0.017). Normal/nonspecific NVC in SSc patients appears to be associated with less severe skin involvement and less frequent severe pulmonary involvement. © 2014 S. Karger AG, Basel.

Species packing in eco-evolutionary models of seasonally fluctuating environments.

Science.gov (United States)

Kremer, Colin T; Klausmeier, Christopher A

2017-09-01

As ecology and evolution become ever more entwined, many areas of ecological theory are being re-examined. Eco-evolutionary analyses of classic coexistence mechanisms are yielding new insights into the structure and stability of communities. We examine fluctuation-dependent coexistence models, identifying communities that are both ecologically and evolutionarily stable. Members of these communities possess distinct environmental preferences, revealing widespread patterns of limiting similarity. This regularity leads to consistent changes in the structure of communities across fluctuation regimes. However, at high amplitudes, subtle differences in the form of fluctuations dramatically affect the collapse of communities. We also show that identical fluctuations can support multiple evolutionarily stable communities - a novel example of alternative stable states within eco-evolutionary systems. Consequently, the configuration of communities will depend on historical contingencies, including details of the adaptive process. Integrating evolution into the study of coexistence offers new insights, while enriching our understanding of ecology. © 2017 John Wiley & Sons Ltd/CNRS.

Evolutionary and developmental modules.

Science.gov (United States)

Lacquaniti, Francesco; Ivanenko, Yuri P; d'Avella, Andrea; Zelik, Karl E; Zago, Myrka

2013-01-01

The identification of biological modules at the systems level often follows top-down decomposition of a task goal, or bottom-up decomposition of multidimensional data arrays into basic elements or patterns representing shared features. These approaches traditionally have been applied to mature, fully developed systems. Here we review some results from two other perspectives on modularity, namely the developmental and evolutionary perspective. There is growing evidence that modular units of development were highly preserved and recombined during evolution. We first consider a few examples of modules well identifiable from morphology. Next we consider the more difficult issue of identifying functional developmental modules. We dwell especially on modular control of locomotion to argue that the building blocks used to construct different locomotor behaviors are similar across several animal species, presumably related to ancestral neural networks of command. A recurrent theme from comparative studies is that the developmental addition of new premotor modules underlies the postnatal acquisition and refinement of several different motor behaviors in vertebrates.

Integrating genomics into evolutionary medicine.

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Rodríguez, Juan Antonio; Marigorta, Urko M; Navarro, Arcadi

2014-12-01

The application of the principles of evolutionary biology into medicine was suggested long ago and is already providing insight into the ultimate causes of disease. However, a full systematic integration of medical genomics and evolutionary medicine is still missing. Here, we briefly review some cases where the combination of the two fields has proven profitable and highlight two of the main issues hindering the development of evolutionary genomic medicine as a mature field, namely the dissociation between fitness and health and the still considerable difficulties in predicting phenotypes from genotypes. We use publicly available data to illustrate both problems and conclude that new approaches are needed for evolutionary genomic medicine to overcome these obstacles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Form of an evolutionary tradeoff affects eco-evolutionary dynamics in a predator-prey system.

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Kasada, Minoru; Yamamichi, Masato; Yoshida, Takehito

2014-11-11

Evolution on a time scale similar to ecological dynamics has been increasingly recognized for the last three decades. Selection mediated by ecological interactions can change heritable phenotypic variation (i.e., evolution), and evolution of traits, in turn, can affect ecological interactions. Hence, ecological and evolutionary dynamics can be tightly linked and important to predict future dynamics, but our understanding of eco-evolutionary dynamics is still in its infancy and there is a significant gap between theoretical predictions and empirical tests. Empirical studies have demonstrated that the presence of genetic variation can dramatically change ecological dynamics, whereas theoretical studies predict that eco-evolutionary dynamics depend on the details of the genetic variation, such as the form of a tradeoff among genotypes, which can be more important than the presence or absence of the genetic variation. Using a predator-prey (rotifer-algal) experimental system in laboratory microcosms, we studied how different forms of a tradeoff between prey defense and growth affect eco-evolutionary dynamics. Our experimental results show for the first time to our knowledge that different forms of the tradeoff produce remarkably divergent eco-evolutionary dynamics, including near fixation, near extinction, and coexistence of algal genotypes, with quantitatively different population dynamics. A mathematical model, parameterized from completely independent experiments, explains the observed dynamics. The results suggest that knowing the details of heritable trait variation and covariation within a population is essential for understanding how evolution and ecology will interact and what form of eco-evolutionary dynamics will result.

Practical advantages of evolutionary computation

Science.gov (United States)

Fogel, David B.

1997-10-01

Evolutionary computation is becoming a common technique for solving difficult, real-world problems in industry, medicine, and defense. This paper reviews some of the practical advantages to using evolutionary algorithms as compared with classic methods of optimization or artificial intelligence. Specific advantages include the flexibility of the procedures, as well as their ability to self-adapt the search for optimum solutions on the fly. As desktop computers increase in speed, the application of evolutionary algorithms will become routine.

New insights into the phylogenetic relationships, character evolution, and phytogeographic patterns of Calceolaria (Calceolariaceae).

Science.gov (United States)

Cosacov, Andrea; Sérsic, Alicia N; Sosa, Victoria; De-Nova, J Arturo; Nylinder, Stephan; Cocucci, Andrea A

2009-12-01

Biogeographical patterns and diversification processes in Andean and Patagonian flora are not yet well understood. Calceolaria is a highly diversified genus of these areas, representing one of the most specialized plant-pollinator systems because flowers produce nonvolatile oils, a very unusual floral reward. Phylogenetic analyses with molecular (ITS and matK) and morphological characters from 103 Calceolaria species were conducted to examine relationships, to understand biogeographic patterns, and to detect evolutionary patterns of floral and ecological characters. Total evidence analysis retrieved three major clades, which strongly correspond to the three previously recognized subgenera, although only subgenus Rosula was retrieved as a monophyletic group. A single historical event explains the expansion from the southern to central Andes, while different parallel evolutionary lines show a northward expansion from the central to northern Andes across the Huancabamba Deflection, an important geographical barrier in northern Peru. Polyploidy, acquisition of elaiophores, and a nototribic pollination mechanism are key aspects of the evolutionary history of Calceolaria. Pollination interactions were more frequently established with Centris than with Chalepogenus oil-collecting bee species. The repeated loss of the oil gland and shifts to pollen as the only reward suggest an evolutionary tendency from highly to moderately specialized pollination systems.

Different evolutionary pathways underlie the morphology of wrist bones in hominoids.

Science.gov (United States)

Kivell, Tracy L; Barros, Anna P; Smaers, Jeroen B

2013-10-23

The hominoid wrist has been a focus of numerous morphological analyses that aim to better understand long-standing questions about the evolution of human and hominoid hand use. However, these same analyses also suggest various scenarios of complex and mosaic patterns of morphological evolution within the wrist and potentially multiple instances of homoplasy that would benefit from require formal analysis within a phylogenetic context.We identify morphological features that principally characterize primate - and, in particular, hominoid (apes, including humans) - wrist evolution and reveal the rate, process and evolutionary timing of patterns of morphological change on individual branches of the primate tree of life. Linear morphological variables of five wrist bones - the scaphoid, lunate, triquetrum, capitate and hamate - are analyzed in a diverse sample of extant hominoids (12 species, 332 specimens), Old World (8 species, 43 specimens) and New World (4 species, 26 specimens) monkeys, fossil Miocene apes (8 species, 20 specimens) and Plio-Pleistocene hominins (8 species, 18 specimens). Results reveal a combination of parallel and synapomorphic morphology within haplorrhines, and especially within hominoids, across individual wrist bones. Similar morphology of some wrist bones reflects locomotor behaviour shared between clades (scaphoid, triquetrum and capitate) while others (lunate and hamate) indicate clade-specific synapomorphic morphology. Overall, hominoids show increased variation in wrist bone morphology compared with other primate clades, supporting previous analyses, and demonstrate several occurrences of parallel evolution, particularly between orangutans and hylobatids, and among hominines (extant African apes, humans and fossil hominins). Our analyses indicate that different evolutionary processes can underlie the evolution of a single anatomical unit (the wrist) to produce diversity in functional and morphological adaptations across individual wrist

Evolutionary dynamics of cooperation in neutral populations

Science.gov (United States)

Szolnoki, Attila; Perc, Matjaž

2018-01-01

Cooperation is a difficult proposition in the face of Darwinian selection. Those that defect have an evolutionary advantage over cooperators who should therefore die out. However, spatial structure enables cooperators to survive through the formation of homogeneous clusters, which is the hallmark of network reciprocity. Here we go beyond this traditional setup and study the spatiotemporal dynamics of cooperation in a population of populations. We use the prisoner's dilemma game as the mathematical model and show that considering several populations simultaneously gives rise to fascinating spatiotemporal dynamics and pattern formation. Even the simplest assumption that strategies between different populations are payoff-neutral with one another results in the spontaneous emergence of cyclic dominance, where defectors of one population become prey of cooperators in the other population, and vice versa. Moreover, if social interactions within different populations are characterized by significantly different temptations to defect, we observe that defectors in the population with the largest temptation counterintuitively vanish the fastest, while cooperators that hang on eventually take over the whole available space. Our results reveal that considering the simultaneous presence of different populations significantly expands the complexity of evolutionary dynamics in structured populations, and it allows us to understand the stability of cooperation under adverse conditions that could never be bridged by network reciprocity alone.

4D flow MRI assessment of right atrial flow patterns in the normal heart - influence of caval vein arrangement and implications for the patent foramen ovale.

Directory of Open Access Journals (Sweden)

Jehill D Parikh

Full Text Available To investigate atrial flow patterns in the normal adult heart, to explore whether caval vein arrangement and patency of the foramen ovale (PFO may be associated with flow pattern.Time-resolved, three-dimensional velocity encoded magnetic resonance imaging (4D flow was employed to assess atrial flow patterns in thirteen healthy subjects (6 male, 40 years, range 25-50 and thirteen subjects (6 male, 40 years, range 21-50 with cryptogenic stroke and patent foramen ovale (CS-PFO. Right atrial flow was defined as vortical, helico-vortical, helical and multiple vortices. Time-averaged and peak systolic and diastolic flows in the caval and pulmonary veins and their anatomical arrangement were compared.A spectrum of right atrial flow was observed across the four defined categories. The right atrial flow patterns were strongly associated with the relative position of the caval veins. Right atrial flow patterns other than vortical were more common (p = 0.015 and the separation between the superior and inferior vena cava greater (10±5mm versus 3±3mm, p = 0.002 in the CS-PFO group. In the left atrium all subjects except one had counter-clockwise vortical flow. Vortex size varied and was associated with left lower pulmonary vein flow (systolic r = 0.61, p = 0.001, diastolic r = 0.63 p = 0.002. A diastolic vortex was less common and time-averaged left atrial velocity was greater in the CS-PFO group (17±2cm/sec versus 15±1, p = 0.048. One CS-PFO subject demonstrated vortical retrograde flow in the descending aortic arch; all other subjects had laminar descending aortic flow.Right atrial flow patterns in the normal heart are heterogeneous and are associated with the relative position of the caval veins. Patterns, other than 'typical' vortical flow, are more prevalent in the right atrium of those with cryptogenic stroke in the context of PFO. Left atrial flow patterns are more homogenous in normal hearts and show a relationship with flow arising from the left

Climate variability slows evolutionary responses of Colias butterflies to recent climate change.

Science.gov (United States)

Kingsolver, Joel G; Buckley, Lauren B

2015-03-07

How does recent climate warming and climate variability alter fitness, phenotypic selection and evolution in natural populations? We combine biophysical, demographic and evolutionary models with recent climate data to address this question for the subalpine and alpine butterfly, Colias meadii, in the southern Rocky Mountains. We focus on predicting patterns of selection and evolution for a key thermoregulatory trait, melanin (solar absorptivity) on the posterior ventral hindwings, which affects patterns of body temperature, flight activity, adult and egg survival, and reproductive success in Colias. Both mean annual summer temperatures and thermal variability within summers have increased during the past 60 years at subalpine and alpine sites. At the subalpine site, predicted directional selection on wing absorptivity has shifted from generally positive (favouring increased wing melanin) to generally negative during the past 60 years, but there is substantial variation among years in the predicted magnitude and direction of selection and the optimal absorptivity. The predicted magnitude of directional selection at the alpine site declined during the past 60 years and varies substantially among years, but selection has generally been positive at this site. Predicted evolutionary responses to mean climate warming at the subalpine site since 1980 is small, because of the variability in selection and asymmetry of the fitness function. At both sites, the predicted effects of adaptive evolution on mean population fitness are much smaller than the fluctuations in mean fitness due to climate variability among years. Our analyses suggest that variation in climate within and among years may strongly limit evolutionary responses of ectotherms to mean climate warming in these habitats. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Calculating evolutionary dynamics in structured populations.

Directory of Open Access Journals (Sweden)

Charles G Nathanson

2009-12-01

Full Text Available Evolution is shaping the world around us. At the core of every evolutionary process is a population of reproducing individuals. The outcome of an evolutionary process depends on population structure. Here we provide a general formula for calculating evolutionary dynamics in a wide class of structured populations. This class includes the recently introduced "games in phenotype space" and "evolutionary set theory." There can be local interactions for determining the relative fitness of individuals, but we require global updating, which means all individuals compete uniformly for reproduction. We study the competition of two strategies in the context of an evolutionary game and determine which strategy is favored in the limit of weak selection. We derive an intuitive formula for the structure coefficient, sigma, and provide a method for efficient numerical calculation.

Evolutionary Multiplayer Games

OpenAIRE

Gokhale, Chaitanya S.; Traulsen, Arne

2014-01-01

Evolutionary game theory has become one of the most diverse and far reaching theories in biology. Applications of this theory range from cell dynamics to social evolution. However, many applications make it clear that inherent non-linearities of natural systems need to be taken into account. One way of introducing such non-linearities into evolutionary games is by the inclusion of multiple players. An example is of social dilemmas, where group benefits could e.g.\\ increase less than linear wi...

The evolutionary history of colour polymorphism in Ischnura damselflies.

Science.gov (United States)

Sánchez-Guillén, Rosa A; Cordero-Rivera, Adolfo; Rivas-Torres, Anais; Wellenreuther, Maren; Bybee, Seth; Hansson, Bengt; Velasquez-Vélez, María I; Realpe, Emilio; Chávez-Ríos, Jesús R; Villalobos, Fabricio; Dumont, Henri

2018-05-10

A major challenge in evolutionary biology consists of understanding how genetic and phenotypic variation is created and maintained. In the present study, we investigated the origin(s) and evolutionary patterns of the female-limited colour polymorphism in ischnuran damselflies. These consist of the presence of one to three colour morphs: one androchrome morph with a colouration that is similar to the male, and two gynochrome morphs (infuscans and aurantiaca) with female-specific colouration. We (i) documented the colour and mating system of 44 of the 75 taxa within the genus Ischnura, (ii) reconstructed the evolutionary history of colour and mating system to identify the ancestral state, (iii) evaluated the stability of the colour morph status over time, and (iv) tested for a correlation between colour and mating system. We found that the ances tral female colour of Ischnura was monomorphic and aurantiaca and that colour morph status changed over time; characterised by many gains and losses across the species tree. Our results further showed that colour polymorphism is significantly more frequent among polyandric species, whereas monandric species tend to be monomorphic. Research on some Ischnura species has shown that colour morphs have evolved to reduce male mating harassment, and our finding that the same phenotypic morphs have evolved multiple times (convergent evolution) suggests that several species in this genus might be experiencing similar selective pressures. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Chromosome-wide mapping of DNA methylation patterns in normal and malignant prostate cells reveals pervasive methylation of gene-associated and conserved intergenic sequences

Directory of Open Access Journals (Sweden)

De Marzo Angelo M

2011-06-01

Full Text Available Abstract Background DNA methylation has been linked to genome regulation and dysregulation in health and disease respectively, and methods for characterizing genomic DNA methylation patterns are rapidly emerging. We have developed/refined methods for enrichment of methylated genomic fragments using the methyl-binding domain of the human MBD2 protein (MBD2-MBD followed by analysis with high-density tiling microarrays. This MBD-chip approach was used to characterize DNA methylation patterns across all non-repetitive sequences of human chromosomes 21 and 22 at high-resolution in normal and malignant prostate cells. Results Examining this data using computational methods that were designed specifically for DNA methylation tiling array data revealed widespread methylation of both gene promoter and non-promoter regions in cancer and normal cells. In addition to identifying several novel cancer hypermethylated 5' gene upstream regions that mediated epigenetic gene silencing, we also found several hypermethylated 3' gene downstream, intragenic and intergenic regions. The hypermethylated intragenic regions were highly enriched for overlap with intron-exon boundaries, suggesting a possible role in regulation of alternative transcriptional start sites, exon usage and/or splicing. The hypermethylated intergenic regions showed significant enrichment for conservation across vertebrate species. A sampling of these newly identified promoter (ADAMTS1 and SCARF2 genes and non-promoter (downstream or within DSCR9, C21orf57 and HLCS genes hypermethylated regions were effective in distinguishing malignant from normal prostate tissues and/or cell lines. Conclusions Comparison of chromosome-wide DNA methylation patterns in normal and malignant prostate cells revealed significant methylation of gene-proximal and conserved intergenic sequences. Such analyses can be easily extended for genome-wide methylation analysis in health and disease.

Asymmetric Evolutionary Games

Science.gov (United States)

McAvoy, Alex; Hauert, Christoph

2015-01-01

Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner’s Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games. PMID:26308326

Phylogeography in Nassarius mud snails: Complex patterns in congeneric species.

Directory of Open Access Journals (Sweden)

Chuanliang Pu

Full Text Available One major goal for phylogeographical studies is to elucidate respective roles of multiple evolutionary and ecological forces that shape the current distribution patterns. In marine and coastal ecosystems, it has been generated a common realization that species with enormous population size and pelagic larval stages can disperse across broad geographical scales, leading to weak or even no phylogeographical structure across large geographical scales. However, the violation of such realization has been frequently reported, and it remains largely unexplored on mechanisms responsible for various phylogeographical patterns observed in different species at varied geographical scales. Here, we used a species-rich genus Nassarius to assess and compare phylogeographical patterns in congeneric species, and discuss causes and consequences underlying varied phylogeographical patterns. Interestingly, we observed complex phylogeographical patterns both within single species and across multiple species, and multiple analyses showed varied levels of genetic heterogeneity among sites within and across species. Available evidence suggests that related species with similar biological characteristics may not be necessary to result in consistent phylogeographical patterns. Multiple factors, including larval ecology, interactions between dispersal and natural selection, and human activity-mediated dispersal, can partially explain the complex patterns observed in this study. Deep investigations should be performed on these factors, particularly their respective roles in determining evolutionary/ecological processes to form phylogeographical patterns in species with high dispersal capacities in marine and coastal ecosystems.

Industrial Applications of Evolutionary Algorithms

CERN Document Server

Sanchez, Ernesto; Tonda, Alberto

2012-01-01

This book is intended as a reference both for experienced users of evolutionary algorithms and for researchers that are beginning to approach these fascinating optimization techniques. Experienced users will find interesting details of real-world problems, and advice on solving issues related to fitness computation, modeling and setting appropriate parameters to reach optimal solutions. Beginners will find a thorough introduction to evolutionary computation, and a complete presentation of all evolutionary algorithms exploited to solve different problems. The book could fill the gap between the

Chaos emerging in soil failure patterns observed during tillage: Normalized deterministic nonlinear prediction (NDNP) and its application.

Science.gov (United States)

Sakai, Kenshi; Upadhyaya, Shrinivasa K; Andrade-Sanchez, Pedro; Sviridova, Nina V

2017-03-01

Real-world processes are often combinations of deterministic and stochastic processes. Soil failure observed during farm tillage is one example of this phenomenon. In this paper, we investigated the nonlinear features of soil failure patterns in a farm tillage process. We demonstrate emerging determinism in soil failure patterns from stochastic processes under specific soil conditions. We normalized the deterministic nonlinear prediction considering autocorrelation and propose it as a robust way of extracting a nonlinear dynamical system from noise contaminated motion. Soil is a typical granular material. The results obtained here are expected to be applicable to granular materials in general. From a global scale to nano scale, the granular material is featured in seismology, geotechnology, soil mechanics, and particle technology. The results and discussions presented here are applicable in these wide research areas. The proposed method and our findings are useful with respect to the application of nonlinear dynamics to investigate complex motions generated from granular materials.

Evolutionary transitions between beneficial and phytopathogenic Rhodococcus challenge disease management.

Science.gov (United States)

Savory, Elizabeth A; Fuller, Skylar L; Weisberg, Alexandra J; Thomas, William J; Gordon, Michael I; Stevens, Danielle M; Creason, Allison L; Belcher, Michael S; Serdani, Maryna; Wiseman, Michele S; Grünwald, Niklaus J; Putnam, Melodie L; Chang, Jeff H

2017-12-12

Understanding how bacteria affect plant health is crucial for developing sustainable crop production systems. We coupled ecological sampling and genome sequencing to characterize the population genetic history of Rhodococcus and the distribution patterns of virulence plasmids in isolates from nurseries. Analysis of chromosome sequences shows that plants host multiple lineages of Rhodococcus , and suggested that these bacteria are transmitted due to independent introductions, reservoir populations, and point source outbreaks. We demonstrate that isolates lacking virulence genes promote beneficial plant growth, and that the acquisition of a virulence plasmid is sufficient to transition beneficial symbionts to phytopathogens. This evolutionary transition, along with the distribution patterns of plasmids, reveals the impact of horizontal gene transfer in rapidly generating new pathogenic lineages and provides an alternative explanation for pathogen transmission patterns. Results also uncovered a misdiagnosed epidemic that implicated beneficial Rhodococcus bacteria as pathogens of pistachio. The misdiagnosis perpetuated the unnecessary removal of trees and exacerbated economic losses.

Core principles of evolutionary medicine: A Delphi study.

Science.gov (United States)

Grunspan, Daniel Z; Nesse, Randolph M; Barnes, M Elizabeth; Brownell, Sara E

2018-01-01

Evolutionary medicine is a rapidly growing field that uses the principles of evolutionary biology to better understand, prevent and treat disease, and that uses studies of disease to advance basic knowledge in evolutionary biology. Over-arching principles of evolutionary medicine have been described in publications, but our study is the first to systematically elicit core principles from a diverse panel of experts in evolutionary medicine. These principles should be useful to advance recent recommendations made by The Association of American Medical Colleges and the Howard Hughes Medical Institute to make evolutionary thinking a core competency for pre-medical education. The Delphi method was used to elicit and validate a list of core principles for evolutionary medicine. The study included four surveys administered in sequence to 56 expert panelists. The initial open-ended survey created a list of possible core principles; the three subsequent surveys winnowed the list and assessed the accuracy and importance of each principle. Fourteen core principles elicited at least 80% of the panelists to agree or strongly agree that they were important core principles for evolutionary medicine. These principles over-lapped with concepts discussed in other articles discussing key concepts in evolutionary medicine. This set of core principles will be helpful for researchers and instructors in evolutionary medicine. We recommend that evolutionary medicine instructors use the list of core principles to construct learning goals. Evolutionary medicine is a young field, so this list of core principles will likely change as the field develops further.

Conceptual Barriers to Progress Within Evolutionary Biology.

Science.gov (United States)

Laland, Kevin N; Odling-Smee, John; Feldman, Marcus W; Kendal, Jeremy

2009-08-01

In spite of its success, Neo-Darwinism is faced with major conceptual barriers to further progress, deriving directly from its metaphysical foundations. Most importantly, neo-Darwinism fails to recognize a fundamental cause of evolutionary change, "niche construction". This failure restricts the generality of evolutionary theory, and introduces inaccuracies. It also hinders the integration of evolutionary biology with neighbouring disciplines, including ecosystem ecology, developmental biology, and the human sciences. Ecology is forced to become a divided discipline, developmental biology is stubbornly difficult to reconcile with evolutionary theory, and the majority of biologists and social scientists are still unhappy with evolutionary accounts of human behaviour. The incorporation of niche construction as both a cause and a product of evolution removes these disciplinary boundaries while greatly generalizing the explanatory power of evolutionary theory.

Evolutionary Statistical Procedures

CERN Document Server

Baragona, Roberto; Poli, Irene

2011-01-01

This proposed text appears to be a good introduction to evolutionary computation for use in applied statistics research. The authors draw from a vast base of knowledge about the current literature in both the design of evolutionary algorithms and statistical techniques. Modern statistical research is on the threshold of solving increasingly complex problems in high dimensions, and the generalization of its methodology to parameters whose estimators do not follow mathematically simple distributions is underway. Many of these challenges involve optimizing functions for which analytic solutions a

How can we estimate natural selection on endocrine traits? Lessons from evolutionary biology.

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Bonier, Frances; Martin, Paul R

2016-11-30

An evolutionary perspective can enrich almost any endeavour in biology, providing a deeper understanding of the variation we see in nature. To this end, evolutionary endocrinologists seek to describe the fitness consequences of variation in endocrine traits. Much of the recent work in our field, however, follows a flawed approach to the study of how selection shapes endocrine traits. Briefly, this approach relies on among-individual correlations between endocrine phenotypes (often circulating hormone levels) and fitness metrics to estimate selection on those endocrine traits. Adaptive plasticity in both endocrine and fitness-related traits can drive these correlations, generating patterns that do not accurately reflect natural selection. We illustrate why this approach to studying selection on endocrine traits is problematic, referring to work from evolutionary biologists who, decades ago, described this problem as it relates to a variety of other plastic traits. We extend these arguments to evolutionary endocrinology, where the likelihood that this flaw generates bias in estimates of selection is unusually high due to the exceptional responsiveness of hormones to environmental conditions, and their function to induce adaptive life-history responses to environmental variation. We end with a review of productive approaches for investigating the fitness consequences of variation in endocrine traits that we expect will generate exciting advances in our understanding of endocrine system evolution. © 2016 The Author(s).

Brain perfusion SPECT in the mouse: normal pattern according to gender and age.

Science.gov (United States)

Apostolova, Ivayla; Wunder, Andreas; Dirnagl, Ulrich; Michel, Roger; Stemmer, Nina; Lukas, Mathias; Derlin, Thorsten; Gregor-Mamoudou, Betina; Goldschmidt, Jürgen; Brenner, Winfried; Buchert, Ralph

2012-12-01

Regional cerebral blood flow (rCBF) is a useful surrogate marker of neuronal activity and a parameter of primary interest in the diagnosis of many diseases. The increasing use of mouse models spawns the demand for in vivo measurement of rCBF in the mouse. Small animal SPECT provides excellent spatial resolution at adequate sensitivity and is therefore a promising tool for imaging the mouse brain. This study evaluates the feasibility of mouse brain perfusion SPECT and assesses the regional pattern of normal Tc-99m-HMPAO uptake and the impact of age and gender. Whole-brain kinetics was compared between Tc-99m-HMPAO and Tc-99m-ECD using rapid dynamic planar scans in 10 mice. Assessment of the regional uptake pattern was restricted to the more suitable tracer, HMPAO. Two HMPAO SPECTs were performed in 18 juvenile mice aged 7.5 ± 1.5weeks, and in the same animals at young adulthood, 19.1 ± 4.0 weeks (nanoSPECT/CTplus, general purpose mouse apertures: 1.2kcps/MBq, 0.7mm FWHM). The 3-D MRI Digital Atlas Database of an adult C57BL/6J mouse brain was used for region-of-interest (ROI) analysis. SPECT images were stereotactically normalized using SPM8 and a custom made, left-right symmetric HMPAO template in atlas space. For testing lateral asymmetry, each SPECT was left-right flipped prior to stereotactical normalization. Flipped and unflipped SPECTs were compared by paired testing. Peak brain uptake was similar for ECD and HMPAO: 1.8 ± 0.2 and 2.1 ± 0.6 %ID (p=0.357). Washout after the peak was much faster for ECD than for HMPAO: 24 ± 7min vs. 4.6 ± 1.7h (p=0.001). The general linear model for repeated measures with gender as an intersubject factor revealed an increase in relative HMPAO uptake with age in the neocortex (p=0.018) and the hippocampus (p=0.012). A decrease was detected in the midbrain (p=0.025). Lateral asymmetry, with HMPAO uptake larger in the left hemisphere, was detected primarily in the neocortex, both at juvenile age (asymmetry index AI=2.7 ± 1

DNA Methylation and Somatic Mutations Converge on the Cell Cycle and Define Similar Evolutionary Histories in Brain Tumors

NARCIS (Netherlands)

T. Mazor (Tali); A. Pankov (Aleksandr); B.E. Johnson (Brett E.); C. Hong (Chibo); E.G. Hamilton (Emily G.); R.J.A. Bell (Robert J.A.); I.V. Smirnov (Ivan V.); G.F. Reis (Gerald F.); J.J. Phillips (Joanna J.); M.J. Barnes (Michael); A. Idbaih (Ahmed); A. Alentorn (Agusti); J.J. Kloezeman (Jenneke); M.L.M. Lamfers (Martine); A.W. Bollen (Andrew W.); B.S. Taylor (Barry S.); A.M. Molinaro (Annette M.); A. Olshen (Adam); S.M. Chang (Susan); J.S. Song (Jun S.); J.F. Costello (Joseph F.)

2015-01-01

textabstractThe evolutionary history of tumor cell populations can be reconstructed from patterns of genetic alterations. In contrast to stable genetic events, epigenetic states are reversible and sensitive to the microenvironment, prompting the question whether epigenetic information can similarly

Axial flow velocity patterns in a normal human pulmonary artery model: pulsatile in vitro studies.

Science.gov (United States)

Sung, H W; Yoganathan, A P

1990-01-01

It has been clinically observed that the flow velocity patterns in the pulmonary artery are directly modified by disease. The present study addresses the hypothesis that altered velocity patterns relate to the severity of various diseases in the pulmonary artery. This paper lays a foundation for that analysis by providing a detailed description of flow velocity patterns in the normal pulmonary artery, using flow visualization and laser Doppler anemometry techniques. The studies were conducted in an in vitro rigid model in a right heart pulse duplicator system. In the main pulmonary artery, a broad central flow field was observed throughout systole. The maximum axial velocity (150 cm s-1) was measured at peak systole. In the left pulmonary artery, the axial velocities were approximately evenly distributed in the perpendicular plane. However, in the bifurcation plane, they were slightly skewed toward the inner wall at peak systole and during the deceleration phase. In the right pulmonary artery, the axial velocity in the perpendicular plane had a very marked M-shaped profile at peak systole and during the deceleration phase, due to a pair of strong secondary flows. In the bifurcation plane, higher axial velocities were observed along the inner wall, while lower axial velocities were observed along the outer wall and in the center. Overall, relatively low levels of turbulence were observed in all the branches during systole. The maximum turbulence intensity measured was at the boundary of the broad central flow field in the main pulmonary artery at peak systole.

Part E: Evolutionary Computation

DEFF Research Database (Denmark)

2015-01-01

of Computational Intelligence. First, comprehensive surveys of genetic algorithms, genetic programming, evolution strategies, parallel evolutionary algorithms are presented, which are readable and constructive so that a large audience might find them useful and – to some extent – ready to use. Some more general...... kinds of evolutionary algorithms, have been prudently analyzed. This analysis was followed by a thorough analysis of various issues involved in stochastic local search algorithms. An interesting survey of various technological and industrial applications in mechanical engineering and design has been...... topics like the estimation of distribution algorithms, indicator-based selection, etc., are also discussed. An important problem, from a theoretical and practical point of view, of learning classifier systems is presented in depth. Multiobjective evolutionary algorithms, which constitute one of the most...

Behavioural, ecological, and evolutionary aspects of diversity in frog colour patterns

OpenAIRE

Rojas Zuluaga, Bibiana

2017-01-01

The role of colours and colour patterns in behavioural ecology has been extensively studied in a variety of contexts and taxa, while almost overlooked in many others. For decades anurans have been the focus of research on acoustic signalling due to the prominence of vocalisations in their communication. Much less attention has been paid to the enormous diversity of colours, colour patterns, and other types of putative visual signals exhibited by frogs. With the exception of some anecdotal obs...

NERBio: using selected word conjunctions, term normalization, and global patterns to improve biomedical named entity recognition

Directory of Open Access Journals (Sweden)

Hung Hsieh-Chuan

2006-12-01

Full Text Available Abstract Background Biomedical named entity recognition (Bio-NER is a challenging problem because, in general, biomedical named entities of the same category (e.g., proteins and genes do not follow one standard nomenclature. They have many irregularities and sometimes appear in ambiguous contexts. In recent years, machine-learning (ML approaches have become increasingly common and now represent the cutting edge of Bio-NER technology. This paper addresses three problems faced by ML-based Bio-NER systems. First, most ML approaches usually employ singleton features that comprise one linguistic property (e.g., the current word is capitalized and at least one class tag (e.g., B-protein, the beginning of a protein name. However, such features may be insufficient in cases where multiple properties must be considered. Adding conjunction features that contain multiple properties can be beneficial, but it would be infeasible to include all conjunction features in an NER model since memory resources are limited and some features are ineffective. To resolve the problem, we use a sequential forward search algorithm to select an effective set of features. Second, variations in the numerical parts of biomedical terms (e.g., "2" in the biomedical term IL2 cause data sparseness and generate many redundant features. In this case, we apply numerical normalization, which solves the problem by replacing all numerals in a term with one representative numeral to help classify named entities. Third, the assignment of NE tags does not depend solely on the target word's closest neighbors, but may depend on words outside the context window (e.g., a context window of five consists of the current word plus two preceding and two subsequent words. We use global patterns generated by the Smith-Waterman local alignment algorithm to identify such structures and modify the results of our ML-based tagger. This is called pattern-based post-processing. Results To develop our ML

Contemporary issues in evolutionary biology

Indian Academy of Sciences (India)

These discussions included, among others, the possible consequences of nonDNA-based inheritance—epigenetics and cultural evolution, niche construction, and developmental mechanisms on our understanding of the evolutionary process, speciation, complexity in biology, and constructing a formal evolutionary theory.

Evolutionary Co-Option of Floral Meristem Identity Genes for Patterning of the Flower-Like Asteraceae Inflorescence.

Science.gov (United States)

Zhao, Yafei; Zhang, Teng; Broholm, Suvi K; Tähtiharju, Sari; Mouhu, Katriina; Albert, Victor A; Teeri, Teemu H; Elomaa, Paula

2016-09-01

The evolutionary success of Asteraceae, the largest family of flowering plants, has been attributed to the unique inflorescence architecture of the family, which superficially resembles an individual flower. Here, we show that Asteraceae inflorescences (flower heads, or capitula) resemble solitary flowers not only morphologically but also at the molecular level. By conducting functional analyses for orthologs of the flower meristem identity genes LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) in Gerbera hybrida, we show that GhUFO is the master regulator of flower meristem identity, while GhLFY has evolved a novel, homeotic function during the evolution of head-like inflorescences. Resembling LFY expression in a single flower meristem, uniform expression of GhLFY in the inflorescence meristem defines the capitulum as a determinate structure that can assume floral fate upon ectopic GhUFO expression. We also show that GhLFY uniquely regulates the ontogeny of outer, expanded ray flowers but not inner, compact disc flowers, indicating that the distinction of different flower types in Asteraceae is connected with their independent evolutionary origins from separate branching systems. © 2016 American Society of Plant Biologists. All rights reserved.

An Evolutionary Algorithm to Mine High-Utility Itemsets

Directory of Open Access Journals (Sweden)

Jerry Chun-Wei Lin

2015-01-01

Full Text Available High-utility itemset mining (HUIM is a critical issue in recent years since it can be used to reveal the profitable products by considering both the quantity and profit factors instead of frequent itemset mining (FIM of association rules (ARs. In this paper, an evolutionary algorithm is presented to efficiently mine high-utility itemsets (HUIs based on the binary particle swarm optimization. A maximal pattern (MP-tree strcutrue is further designed to solve the combinational problem in the evolution process. Substantial experiments on real-life datasets show that the proposed binary PSO-based algorithm has better results compared to the state-of-the-art GA-based algorithm.

Research traditions and evolutionary explanations in medicine.

Science.gov (United States)

Méthot, Pierre-Olivier

2011-02-01

In this article, I argue that distinguishing 'evolutionary' from 'Darwinian' medicine will help us assess the variety of roles that evolutionary explanations can play in a number of medical contexts. Because the boundaries of evolutionary and Darwinian medicine overlap to some extent, however, they are best described as distinct 'research traditions' rather than as competing paradigms. But while evolutionary medicine does not stand out as a new scientific field of its own, Darwinian medicine is united by a number of distinctive theoretical and methodological claims. For example, evolutionary medicine and Darwinian medicine can be distinguished with respect to the styles of evolutionary explanations they employ. While the former primarily involves 'forward looking' explanations, the latter depends mostly on 'backward looking' explanations. A forward looking explanation tries to predict the effects of ongoing evolutionary processes on human health and disease in contemporary environments (e.g., hospitals). In contrast, a backward looking explanation typically applies evolutionary principles from the vantage point of humans' distant biological past in order to assess present states of health and disease. Both approaches, however, are concerned with the prevention and control of human diseases. In conclusion, I raise some concerns about the claim that 'nothing in medicine makes sense except in the light of evolution'.

Applications of evolutionary economic geography

NARCIS (Netherlands)

Boschma, R.A.; Frenken, K.; Puranam, Krishna Kishore; Ravi Kumar Jain B., xx

2008-01-01

This paper is written as the first chapter of an edited volume on evolutionary economics and economic geography (Frenken, K., editor, Applied Evolutionary Economics and Economic Geography, Cheltenham: Edward Elgar, expected publication date February 2007). The paper reviews empirical applications of

Diversity and evolutionary patterns of immune genes in free-ranging Namibian leopards (Panthera pardus pardus).

Science.gov (United States)

Castro-Prieto, Aines; Wachter, Bettina; Melzheimer, Joerg; Thalwitzer, Susanne; Sommer, Simone

2011-01-01

The genes of the major histocompatibility complex (MHC) are a key component of the mammalian immune system and have become important molecular markers for fitness-related genetic variation in wildlife populations. Currently, no information about the MHC sequence variation and constitution in African leopards exists. In this study, we isolated and characterized genetic variation at the adaptively most important region of MHC class I and MHC class II-DRB genes in 25 free-ranging African leopards from Namibia and investigated the mechanisms that generate and maintain MHC polymorphism in the species. Using single-stranded conformation polymorphism analysis and direct sequencing, we detected 6 MHC class I and 6 MHC class II-DRB sequences, which likely correspond to at least 3 MHC class I and 3 MHC class II-DRB loci. Amino acid sequence variation in both MHC classes was higher or similar in comparison to other reported felids. We found signatures of positive selection shaping the diversity of MHC class I and MHC class II-DRB loci during the evolutionary history of the species. A comparison of MHC class I and MHC class II-DRB sequences of the leopard to those of other felids revealed a trans-species mode of evolution. In addition, the evolutionary relationships of MHC class II-DRB sequences between African and Asian leopard subspecies are discussed.

Mitochondria and the evolutionary roots of cancer

International Nuclear Information System (INIS)

Davila, Alfonso F; Zamorano, Pedro

2013-01-01

Cancer disease is inherent to, and widespread among, metazoans. Yet, some of the hallmarks of cancer such as uncontrolled cell proliferation, lack of apoptosis, hypoxia, fermentative metabolism and free cell motility (metastasis) are akin to a prokaryotic lifestyle, suggesting a link between cancer disease and evolution. In this hypothesis paper, we propose that cancer cells represent a phenotypic reversion to the earliest stage of eukaryotic evolution. This reversion is triggered by the dysregulation of the mitochondria due to cumulative oxidative damage to mitochondrial and nuclear DNA. As a result, the phenotype of normal, differentiated cells gradually reverts to the phenotype of a facultative anaerobic, heterotrophic cell optimized for survival and proliferation in hypoxic environments. This phenotype matches the phenotype of the last eukaryotic common ancestor (LECA) that resulted from the endosymbiosis between an α-proteobacteria (which later became the mitochondria) and an archaebacteria. As such, the evolution of cancer within one individual can be viewed as a recapitulation of the evolution of the eukaryotic cell from fully differentiated cells to LECA. This evolutionary model of cancer is compatible with the current understanding of the disease, and explains the evolutionary basis for most of the hallmarks of cancer, as well as the link between the disease and aging. It could also open new avenues for treatment directed at reestablishing the synergy between the mitochondria and the cancerous cell. (paper)

Evolutionary dynamics of incubation periods.

Science.gov (United States)

Ottino-Loffler, Bertrand; Scott, Jacob G; Strogatz, Steven H

2017-12-21

The incubation period for typhoid, polio, measles, leukemia and many other diseases follows a right-skewed, approximately lognormal distribution. Although this pattern was discovered more than sixty years ago, it remains an open question to explain its ubiquity. Here, we propose an explanation based on evolutionary dynamics on graphs. For simple models of a mutant or pathogen invading a network-structured population of healthy cells, we show that skewed distributions of incubation periods emerge for a wide range of assumptions about invader fitness, competition dynamics, and network structure. The skewness stems from stochastic mechanisms associated with two classic problems in probability theory: the coupon collector and the random walk. Unlike previous explanations that rely crucially on heterogeneity, our results hold even for homogeneous populations. Thus, we predict that two equally healthy individuals subjected to equal doses of equally pathogenic agents may, by chance alone, show remarkably different time courses of disease.

Evolutionary adaptations to dietary changes.

Science.gov (United States)

Luca, F; Perry, G H; Di Rienzo, A

2010-08-21

Through cultural innovation and changes in habitat and ecology, there have been a number of major dietary shifts in human evolution, including meat eating, cooking, and those associated with plant and animal domestication. The identification of signatures of adaptations to such dietary changes in the genome of extant primates (including humans) may shed light not only on the evolutionary history of our species, but also on the mechanisms that underlie common metabolic diseases in modern human populations. In this review, we provide a brief overview of the major dietary shifts that occurred during hominin evolution, and we discuss the methods and approaches used to identify signals of natural selection in patterns of sequence variation. We then review the results of studies aimed at detecting the genetic loci that played a major role in dietary adaptations and conclude by outlining the potential of future studies in this area.

Reconstructing the Evolutionary History of Paralogous APETALA1/FRUITFULL-Like Genes in Grasses (Poaceae)

Science.gov (United States)

Preston, Jill C.; Kellogg, Elizabeth A.

2006-01-01

Gene duplication is an important mechanism for the generation of evolutionary novelty. Paralogous genes that are not silenced may evolve new functions (neofunctionalization) that will alter the developmental outcome of preexisting genetic pathways, partition ancestral functions (subfunctionalization) into divergent developmental modules, or function redundantly. Functional divergence can occur by changes in the spatio-temporal patterns of gene expression and/or by changes in the activities of their protein products. We reconstructed the evolutionary history of two paralogous monocot MADS-box transcription factors, FUL1 and FUL2, and determined the evolution of sequence and gene expression in grass AP1/FUL-like genes. Monocot AP1/FUL-like genes duplicated at the base of Poaceae and codon substitutions occurred under relaxed selection mostly along the branch leading to FUL2. Following the duplication, FUL1 was apparently lost from early diverging taxa, a pattern consistent with major changes in grass floral morphology. Overlapping gene expression patterns in leaves and spikelets indicate that FUL1 and FUL2 probably share some redundant functions, but that FUL2 may have become temporally restricted under partial subfunctionalization to particular stages of floret development. These data have allowed us to reconstruct the history of AP1/FUL-like genes in Poaceae and to hypothesize a role for this gene duplication in the evolution of the grass spikelet. PMID:16816429

Urban Evolutionary Ecology and the Potential Benefits of Implementing Genomics.

Science.gov (United States)

Schell, Christopher J

2018-02-14

Urban habitats are quickly becoming exceptional models to address adaptation under rapid environmental change, given the expansive temporal and spatial scales with which anthropogenic landscape conversion occurs. Urban ecologists in the last 10-15 years have done an extraordinary job of highlighting phenotypic patterns that correspond with urban living, as well as delineating urban population structure using traditional genetic markers. The underpinning genetic mechanisms that govern those phenotypic patterns, however, are less well established. Moreover, the power of traditional molecular studies is constrained by the number of markers being evaluated, which limits the potential to assess fine-scale population structure potentially common in urban areas. With the recent proliferation of low-cost, high-throughput sequencing methods, we can begin to address an emerging question in urban ecology: are species adapted to local optima within cities or are they expressing latent phenotypic plasticity? Here, I provide a comprehensive review of previous urban ecological studies, with special focus on the molecular ecology and phenotypic adjustments documented in urban terrestrial and amphibious fauna. I subsequently pinpoint areas in the literature that could benefit from a genomic investigation and briefly discuss the suitability of specific techniques in addressing eco-evolutionary questions within urban ecology. Though many challenges exist with implementing genomics into urban ecology, such studies provide an exceptional opportunity to advance our understanding of eco-evolutionary processes in metropolitan areas. © The American Genetic Association 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Revising the recent evolutionary history of equids using ancient DNA.

Science.gov (United States)

Orlando, Ludovic; Metcalf, Jessica L; Alberdi, Maria T; Telles-Antunes, Miguel; Bonjean, Dominique; Otte, Marcel; Martin, Fabiana; Eisenmann, Véra; Mashkour, Marjan; Morello, Flavia; Prado, Jose L; Salas-Gismondi, Rodolfo; Shockey, Bruce J; Wrinn, Patrick J; Vasil'ev, Sergei K; Ovodov, Nikolai D; Cherry, Michael I; Hopwood, Blair; Male, Dean; Austin, Jeremy J; Hänni, Catherine; Cooper, Alan

2009-12-22

The rich fossil record of the family Equidae (Mammalia: Perissodactyla) over the past 55 MY has made it an icon for the patterns and processes of macroevolution. Despite this, many aspects of equid phylogenetic relationships and taxonomy remain unresolved. Recent genetic analyses of extinct equids have revealed unexpected evolutionary patterns and a need for major revisions at the generic, subgeneric, and species levels. To investigate this issue we examine 35 ancient equid specimens from four geographic regions (South America, Europe, Southwest Asia, and South Africa), of which 22 delivered 87-688 bp of reproducible aDNA mitochondrial sequence. Phylogenetic analyses support a major revision of the recent evolutionary history of equids and reveal two new species, a South American hippidion and a descendant of a basal lineage potentially related to Middle Pleistocene equids. Sequences from specimens assigned to the giant extinct Cape zebra, Equus capensis, formed a separate clade within the modern plain zebra species, a phenotypicically plastic group that also included the extinct quagga. In addition, we revise the currently recognized extinction times for two hemione-related equid groups. However, it is apparent that the current dataset cannot solve all of the taxonomic and phylogenetic questions relevant to the evolution of Equus. In light of these findings, we propose a rapid DNA barcoding approach to evaluate the taxonomic status of the many Late Pleistocene fossil Equidae species that have been described from purely morphological analyses.

Evolutionary dynamics of human autoimmune disease genes and malfunctioned immunological genes

Directory of Open Access Journals (Sweden)

Podder Soumita

2012-01-01

Full Text Available Abstract Background One of the main issues of molecular evolution is to divulge the principles in dictating the evolutionary rate differences among various gene classes. Immunological genes have received considerable attention in evolutionary biology as candidates for local adaptation and for studying functionally important polymorphisms. The normal structure and function of immunological genes will be distorted when they experience mutations leading to immunological dysfunctions. Results Here, we examined the fundamental differences between the genes which on mutation give rise to autoimmune or other immune system related diseases and the immunological genes that do not cause any disease phenotypes. Although the disease genes examined are analogous to non-disease genes in product, expression, function, and pathway affiliation, a statistically significant decrease in evolutionary rate has been found in autoimmune disease genes relative to all other immune related diseases and non-disease genes. Possible ways of accumulation of mutation in the three steps of the central dogma (DNA-mRNA-Protein have been studied to trace the mutational effects predisposed to disease consequence and acquiring higher selection pressure. Principal Component Analysis and Multivariate Regression Analysis have established the predominant role of single nucleotide polymorphisms in guiding the evolutionary rate of immunological disease and non-disease genes followed by m-RNA abundance, paralogs number, fraction of phosphorylation residue, alternatively spliced exon, protein residue burial and protein disorder. Conclusions Our study provides an empirical insight into the etiology of autoimmune disease genes and other immunological diseases. The immediate utility of our study is to help in disease gene identification and may also help in medicinal improvement of immune related disease.

Evolutionary disarmament in interspecific competition.

Science.gov (United States)

Kisdi, E; Geritz, S A

2001-12-22

Competitive asymmetry, which is the advantage of having a larger body or stronger weaponry than a contestant, drives spectacular evolutionary arms races in intraspecific competition. Similar asymmetries are well documented in interspecific competition, yet they seldom lead to exaggerated traits. Here we demonstrate that two species with substantially different size may undergo parallel coevolution towards a smaller size under the same ecological conditions where a single species would exhibit an evolutionary arms race. We show that disarmament occurs for a wide range of parameters in an ecologically explicit model of competition for a single shared resource; disarmament also occurs in a simple Lotka-Volterra competition model. A key property of both models is the interplay between evolutionary dynamics and population density. The mechanism does not rely on very specific features of the model. Thus, evolutionary disarmament may be widespread and may help to explain the lack of interspecific arms races.

Incorporating evolutionary principles into environmental management and policy

DEFF Research Database (Denmark)

Lankau, Richard; Jørgensen, Peter Søgaard; Harris, David J.

2011-01-01

As policymakers and managers work to mitigate the effects of rapid anthropogenic environmental changes, they need to consider organisms’ responses. In light of recent evidence that evolution can be quite rapid, this now includes evolutionary responses. Evolutionary principles have a long history...... in conservation biology, and the necessary next step for the field is to consider ways in which conservation policy makers and managers can proactively manipulate evolutionary processes to achieve their goals. In this review, we aim to illustrate the potential conservation benefits of an increased understanding...... of evolutionary history and prescriptive manipulation of three basic evolutionary factors: selection, variation, and gene flow. For each, we review and propose ways that policy makers and managers can use evolutionary thinking to preserve threatened species, combat pest species, or reduce undesirable evolutionary...

Evolutionary economics and industry location

NARCIS (Netherlands)

Boschma, R.A.; Frenken, K.

2003-01-01

This paper aims to provide the outlines of an evolutionary economic geography of industry location. We discuss two evolutionary explanations of industry location, that is, one that concentrates on spin-offs, and one that focuses attention on knowledge and agglomeration economies. We claim that both

Evolutionary institutionalism.

Science.gov (United States)

Fürstenberg, Dr Kai

Institutions are hard to define and hard to study. Long prominent in political science have been two theories: Rational Choice Institutionalism (RCI) and Historical Institutionalism (HI). Arising from the life sciences is now a third: Evolutionary Institutionalism (EI). Comparative strengths and weaknesses of these three theories warrant review, and the value-to-be-added by expanding the third beyond Darwinian evolutionary theory deserves consideration. Should evolutionary institutionalism expand to accommodate new understanding in ecology, such as might apply to the emergence of stability, and in genetics, such as might apply to political behavior? Core arguments are reviewed for each theory with more detailed exposition of the third, EI. Particular attention is paid to EI's gene-institution analogy; to variation, selection, and retention of institutional traits; to endogeneity and exogeneity; to agency and structure; and to ecosystem effects, institutional stability, and empirical limitations in behavioral genetics. RCI, HI, and EI are distinct but complementary. Institutional change, while amenable to rational-choice analysis and, retrospectively, to criticaljuncture and path-dependency analysis, is also, and importantly, ecological. Stability, like change, is an emergent property of institutions, which tend to stabilize after change in a manner analogous to allopatric speciation. EI is more than metaphorically biological in that institutional behaviors are driven by human behaviors whose evolution long preceded the appearance of institutions themselves.

Evolutionary foundations for cancer biology.

Science.gov (United States)

Aktipis, C Athena; Nesse, Randolph M

2013-01-01

New applications of evolutionary biology are transforming our understanding of cancer. The articles in this special issue provide many specific examples, such as microorganisms inducing cancers, the significance of within-tumor heterogeneity, and the possibility that lower dose chemotherapy may sometimes promote longer survival. Underlying these specific advances is a large-scale transformation, as cancer research incorporates evolutionary methods into its toolkit, and asks new evolutionary questions about why we are vulnerable to cancer. Evolution explains why cancer exists at all, how neoplasms grow, why cancer is remarkably rare, and why it occurs despite powerful cancer suppression mechanisms. Cancer exists because of somatic selection; mutations in somatic cells result in some dividing faster than others, in some cases generating neoplasms. Neoplasms grow, or do not, in complex cellular ecosystems. Cancer is relatively rare because of natural selection; our genomes were derived disproportionally from individuals with effective mechanisms for suppressing cancer. Cancer occurs nonetheless for the same six evolutionary reasons that explain why we remain vulnerable to other diseases. These four principles-cancers evolve by somatic selection, neoplasms grow in complex ecosystems, natural selection has shaped powerful cancer defenses, and the limitations of those defenses have evolutionary explanations-provide a foundation for understanding, preventing, and treating cancer.

Protein 3D structure computed from evolutionary sequence variation.

Directory of Open Access Journals (Sweden)

Debora S Marks

Full Text Available The evolutionary trajectory of a protein through sequence space is constrained by its function. Collections of sequence homologs record the outcomes of millions of evolutionary experiments in which the protein evolves according to these constraints. Deciphering the evolutionary record held in these sequences and exploiting it for predictive and engineering purposes presents a formidable challenge. The potential benefit of solving this challenge is amplified by the advent of inexpensive high-throughput genomic sequencing.In this paper we ask whether we can infer evolutionary constraints from a set of sequence homologs of a protein. The challenge is to distinguish true co-evolution couplings from the noisy set of observed correlations. We address this challenge using a maximum entropy model of the protein sequence, constrained by the statistics of the multiple sequence alignment, to infer residue pair couplings. Surprisingly, we find that the strength of these inferred couplings is an excellent predictor of residue-residue proximity in folded structures. Indeed, the top-scoring residue couplings are sufficiently accurate and well-distributed to define the 3D protein fold with remarkable accuracy.We quantify this observation by computing, from sequence alone, all-atom 3D structures of fifteen test proteins from different fold classes, ranging in size from 50 to 260 residues, including a G-protein coupled receptor. These blinded inferences are de novo, i.e., they do not use homology modeling or sequence-similar fragments from known structures. The co-evolution signals provide sufficient information to determine accurate 3D protein structure to 2.7-4.8 Å C(α-RMSD error relative to the observed structure, over at least two-thirds of the protein (method called EVfold, details at http://EVfold.org. This discovery provides insight into essential interactions constraining protein evolution and will facilitate a comprehensive survey of the universe of

Evolutionary principles and their practical application

DEFF Research Database (Denmark)

Hendry, A. P.; Kinnison, M. T.; Heino, M.

2011-01-01

Evolutionary principles are now routinely incorporated into medicine and agriculture. Examples include the design of treatments that slow the evolution of resistance by weeds, pests, and pathogens, and the design of breeding programs that maximize crop yield or quality. Evolutionary principles...... are also increasingly incorporated into conservation biology, natural resource management, and environmental science. Examples include the protection of small and isolated populations from inbreeding depression, the identification of key traits involved in adaptation to climate change, the design...... of harvesting regimes that minimize unwanted life-history evolution, and the setting of conservation priorities based on populations, species, or communities that harbor the greatest evolutionary diversity and potential. The adoption of evolutionary principles has proceeded somewhat independently...

Epigenetic Tracking, a Method to Generate Arbitrary Shapes By Using Evolutionary-Developmental Techniques

OpenAIRE

Fontana, Alessandro

2008-01-01

This paper describes an Artificial Embryology method (called ``Epigenetic Tracking'') to generate predefined arbitrarily shaped 2-dimensional arrays of cells by means of evolutionary techniques. It is based on a model of development, whose key features are: i) the distinction bewteen ``normal'' and ``driver'' cells, being the latter able to receive guidance from the genome, ii) the implementation of the proliferation/apoptosis events in such a way that many cells are created/deleted at once, ...

Evolutionary Co-Option of Floral Meristem Identity Genes for Patterning of the Flower-Like Asteraceae Inflorescence1

Science.gov (United States)

Broholm, Suvi K.; Tähtiharju, Sari

2016-01-01

The evolutionary success of Asteraceae, the largest family of flowering plants, has been attributed to the unique inflorescence architecture of the family, which superficially resembles an individual flower. Here, we show that Asteraceae inflorescences (flower heads, or capitula) resemble solitary flowers not only morphologically but also at the molecular level. By conducting functional analyses for orthologs of the flower meristem identity genes LEAFY (LFY) and UNUSUAL FLORAL ORGANS (UFO) in Gerbera hybrida, we show that GhUFO is the master regulator of flower meristem identity, while GhLFY has evolved a novel, homeotic function during the evolution of head-like inflorescences. Resembling LFY expression in a single flower meristem, uniform expression of GhLFY in the inflorescence meristem defines the capitulum as a determinate structure that can assume floral fate upon ectopic GhUFO expression. We also show that GhLFY uniquely regulates the ontogeny of outer, expanded ray flowers but not inner, compact disc flowers, indicating that the distinction of different flower types in Asteraceae is connected with their independent evolutionary origins from separate branching systems. PMID:27382139

Evolutionary and developmental implications of asymmetric brain folding in a large primate pedigree

OpenAIRE

Atkinson, Elizabeth G.; Rogers, Jeffrey; Cheverud, James M.

2016-01-01

Bilateral symmetry is a fundamental property of the vertebrate central nervous system. Local deviations from symmetry provide various types of information about the development, evolution and function of elements within the CNS, especially the cerebral hemispheres. Here, we quantify the pattern and extent of asymmetry in cortical folding within the cerebrum of Papio baboons and assess the evolutionary and developmental implications of the findings. Analyses of directional asymmetry show a pop...

Gender Inequality in Interaction--An Evolutionary Account

Science.gov (United States)

Hopcroft, Rosemary L.

2009-01-01

In this article I argue that evolutionary theorizing can help sociologists and feminists better understand gender inequality. Evolutionary theory explains why control of the sexuality of young women is a priority across most human societies both past and present. Evolutionary psychology has extended our understanding of male violence against…

The eco-evolutionary impacts of domestication and agricultural practices on wild species.

Science.gov (United States)

Turcotte, Martin M; Araki, Hitoshi; Karp, Daniel S; Poveda, Katja; Whitehead, Susan R

2017-01-19

Agriculture is a dominant evolutionary force that drives the evolution of both domesticated and wild species. However, the various mechanisms of agriculture-induced evolution and their socio-ecological consequences are not often synthetically discussed. Here, we explore how agricultural practices and evolutionary changes in domesticated species cause evolution in wild species. We do so by examining three processes by which agriculture drives evolution. First, differences in the traits of domesticated species, compared with their wild ancestors, alter the selective environment and create opportunities for wild species to specialize. Second, selection caused by agricultural practices, including both those meant to maximize productivity and those meant to control pest species, can lead to pest adaptation. Third, agriculture can cause non-selective changes in patterns of gene flow in wild species. We review evidence for these processes and then discuss their ecological and sociological impacts. We finish by identifying important knowledge gaps and future directions related to the eco-evolutionary impacts of agriculture including their extent, how to prevent the detrimental evolution of wild species, and finally, how to use evolution to minimize the ecological impacts of agriculture.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'. © 2016 The Author(s).

Evolutionary and genetic analysis of the VP2 gene of canine parvovirus.

Science.gov (United States)

Li, Gairu; Ji, Senlin; Zhai, Xiaofeng; Zhang, Yuxiang; Liu, Jie; Zhu, Mengyan; Zhou, Jiyong; Su, Shuo

2017-07-17

Canine parvovirus (CPV) type 2 emerged in 1978 in the USA and quickly spread among dog populations all over the world with high morbidity. Although CPV is a DNA virus, its genomic substitution rate is similar to some RNA viruses. Therefore, it is important to trace the evolution of CPV to monitor the appearance of mutations that might affect vaccine effectiveness. Our analysis shows that the VP2 genes of CPV isolated from 1979 to 2016 are divided into six groups: GI, GII, GIII, GIV, GV, and GVI. Amino acid mutation analysis revealed several undiscovered important mutation sites: F267Y, Y324I, and T440A. Of note, the evolutionary rate of the CPV VP2 gene from Asia and Europe decreased. Codon usage analysis showed that the VP2 gene of CPV exhibits high bias with an ENC ranging from 34.93 to 36.7. Furthermore, we demonstrate that natural selection plays a major role compared to mutation pressure driving CPV evolution. There are few studies on the codon usage of CPV. Here, we comprehensively studied the genetic evolution, codon usage pattern, and evolutionary characterization of the VP2 gene of CPV. The novel findings revealing the evolutionary process of CPV will greatly serve future CPV research.

The origins and evolutionary history of human non-coding RNA regulatory networks.

Science.gov (United States)

Sherafatian, Masih; Mowla, Seyed Javad

2017-04-01

The evolutionary history and origin of the regulatory function of animal non-coding RNAs are not well understood. Lack of conservation of long non-coding RNAs and small sizes of microRNAs has been major obstacles in their phylogenetic analysis. In this study, we tried to shed more light on the evolution of ncRNA regulatory networks by changing our phylogenetic strategy to focus on the evolutionary pattern of their protein coding targets. We used available target databases of miRNAs and lncRNAs to find their protein coding targets in human. We were able to recognize evolutionary hallmarks of ncRNA targets by phylostratigraphic analysis. We found the conventional 3'-UTR and lesser known 5'-UTR targets of miRNAs to be enriched at three consecutive phylostrata. Firstly, in eukaryata phylostratum corresponding to the emergence of miRNAs, our study revealed that miRNA targets function primarily in cell cycle processes. Moreover, the same overrepresentation of the targets observed in the next two consecutive phylostrata, opisthokonta and eumetazoa, corresponded to the expansion periods of miRNAs in animals evolution. Coding sequence targets of miRNAs showed a delayed rise at opisthokonta phylostratum, compared to the 3' and 5' UTR targets of miRNAs. LncRNA regulatory network was the latest to evolve at eumetazoa.

Evolutionary dynamics of protein domain architecture in plants

Directory of Open Access Journals (Sweden)

Zhang Xue-Cheng

2012-01-01

Full Text Available Abstract Background Protein domains are the structural, functional and evolutionary units of the protein. Protein domain architectures are the linear arrangements of domain(s in individual proteins. Although the evolutionary history of protein domain architecture has been extensively studied in microorganisms, the evolutionary dynamics of domain architecture in the plant kingdom remains largely undefined. To address this question, we analyzed the lineage-based protein domain architecture content in 14 completed green plant genomes. Results Our analyses show that all 14 plant genomes maintain similar distributions of species-specific, single-domain, and multi-domain architectures. Approximately 65% of plant domain architectures are universally present in all plant lineages, while the remaining architectures are lineage-specific. Clear examples are seen of both the loss and gain of specific protein architectures in higher plants. There has been a dynamic, lineage-wise expansion of domain architectures during plant evolution. The data suggest that this expansion can be largely explained by changes in nuclear ploidy resulting from rounds of whole genome duplications. Indeed, there has been a decrease in the number of unique domain architectures when the genomes were normalized into a presumed ancestral genome that has not undergone whole genome duplications. Conclusions Our data show the conservation of universal domain architectures in all available plant genomes, indicating the presence of an evolutionarily conserved, core set of protein components. However, the occurrence of lineage-specific domain architectures indicates that domain architecture diversity has been maintained beyond these core components in plant genomes. Although several features of genome-wide domain architecture content are conserved in plants, the data clearly demonstrate lineage-wise, progressive changes and expansions of individual protein domain architectures, reinforcing

A dynamic parking charge optimal control model under perspective of commuters' evolutionary game behavior

Science.gov (United States)

Lin, XuXun; Yuan, PengCheng

2018-01-01

In this research we consider commuters' dynamic learning effect by modeling the trip mode choice behavior from a new perspective of dynamic evolutionary game theory. We explore the behavior pattern of different types of commuters and study the evolution path and equilibrium properties under different traffic conditions. We further establish a dynamic parking charge optimal control (referred to as DPCOC) model to alter commuters' trip mode choice while minimizing the total social cost. Numerical tests show. (1) Under fixed parking fee policy, the evolutionary results are completely decided by the travel time and the only method for public transit induction is to increase the parking charge price. (2) Compared with fixed parking fee policy, DPCOC policy proposed in this research has several advantages. Firstly, it can effectively turn the evolutionary path and evolutionary stable strategy to a better situation while minimizing the total social cost. Secondly, it can reduce the sensitivity of trip mode choice behavior to traffic congestion and improve the ability to resist interferences and emergencies. Thirdly, it is able to control the private car proportion to a stable state and make the trip behavior more predictable for the transportation management department. The research results can provide theoretical basis and decision-making references for commuters' mode choice prediction, dynamic setting of urban parking charge prices and public transit induction.

Muscle protein analysis. II. Two-dimensional electrophoresis of normal and diseased human skeletal muscle

Energy Technology Data Exchange (ETDEWEB)

Giometti, C.S. (Argonne National Lab., IL); Barany, M.; Danon, M.J.; Anderson, N.G.

1980-07-01

High-resolution two-dimensional electrophoresis was used to analyze the major proteins of normal and pathological human-muscle samples. The normal human-muscle pattern contains four myosin light chains: three that co-migrate with the myosin light chains from rabbit fast muscle (extensor digitorum longus), and one that co-migrates with the light chain 2 from rabbit slow muscle (soleus). Of seven Duchenne muscular dystrophy samples, four yielded patterns with decreased amounts of actin and myosin relative to normal muscle, while three samples gave patterns comparable to that for normal muscle. Six samples from patients with myotonic dystrophy also gave normal patterns. In nemaline rod myopathy, in contrast, the pattern was deficient in two of the fast-type myosin light chains.

Making evolutionary biology a basic science for medicine

Science.gov (United States)

Nesse, Randolph M.; Bergstrom, Carl T.; Ellison, Peter T.; Flier, Jeffrey S.; Gluckman, Peter; Govindaraju, Diddahally R.; Niethammer, Dietrich; Omenn, Gilbert S.; Perlman, Robert L.; Schwartz, Mark D.; Thomas, Mark G.; Stearns, Stephen C.; Valle, David

2010-01-01

New applications of evolutionary biology in medicine are being discovered at an accelerating rate, but few physicians have sufficient educational background to use them fully. This article summarizes suggestions from several groups that have considered how evolutionary biology can be useful in medicine, what physicians should learn about it, and when and how they should learn it. Our general conclusion is that evolutionary biology is a crucial basic science for medicine. In addition to looking at established evolutionary methods and topics, such as population genetics and pathogen evolution, we highlight questions about why natural selection leaves bodies vulnerable to disease. Knowledge about evolution provides physicians with an integrative framework that links otherwise disparate bits of knowledge. It replaces the prevalent view of bodies as machines with a biological view of bodies shaped by evolutionary processes. Like other basic sciences, evolutionary biology needs to be taught both before and during medical school. Most introductory biology courses are insufficient to establish competency in evolutionary biology. Premedical students need evolution courses, possibly ones that emphasize medically relevant aspects. In medical school, evolutionary biology should be taught as one of the basic medical sciences. This will require a course that reviews basic principles and specific medical applications, followed by an integrated presentation of evolutionary aspects that apply to each disease and organ system. Evolutionary biology is not just another topic vying for inclusion in the curriculum; it is an essential foundation for a biological understanding of health and disease. PMID:19918069

Evolutionary constraints shape caste-specific gene expression across 15 ant species.

Science.gov (United States)

Morandin, Claire; Mikheyev, Alexander S; Pedersen, Jes Søe; Helanterä, Heikki

2017-05-01

Development of polymorphic phenotypes from similar genomes requires gene expression differences. However, little is known about how morph-specific gene expression patterns vary on a broad phylogenetic scale. We hypothesize that evolution of morph-specific gene expression, and consequently morph-specific phenotypic evolution, may be constrained by gene essentiality and the amount of pleiotropic constraints. Here, we use comparative transcriptomics of queen and worker morphs, that is, castes, from 15 ant species to understand the constraints of morph-biased gene expression. In particular, we investigate how measures of evolutionary constraints at the sequence level (expression level, connectivity, and number of gene ontology [GO] terms) correlate with morph-biased expression. Our results show that genes indeed vary in their potential to become morph-biased. The existence of genes that are constrained in becoming caste-biased potentially limits the evolutionary decoupling of the caste phenotypes, that is, it might result in "caste load" occasioning from antagonistic fitness variation, similarly to sexually antagonistic fitness variation between males and females. On the other hand, we suggest that genes under low constraints are released from antagonistic variation and thus more likely to be co-opted for morph specific use. Overall, our results suggest that the factors that affect sequence evolutionary rates and evolution of plastic expression may largely overlap. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Contemporary issues in evolutionary biology

Indian Academy of Sciences (India)

We are delighted to bring to the readers, a set of peer-reviewed papers on evolutionary biology, published as a special issue of the Journal of Genetics. These papers emanated from ruminations upon and discussions at the Foundations of. Evolutionary Theory: the Ongoing Synthesis meeting at Coorg, India, in February ...

Enhancer of the rudimentary gene homologue (ERH expression pattern in sporadic human breast cancer and normal breast tissue

Directory of Open Access Journals (Sweden)

Knüchel Ruth

2008-05-01

Full Text Available Abstract Background The human gene ERH (Enhancer of the Rudimentary gene Homologue has previously been identified by in silico analysis of four million ESTs as a gene differentially expressed in breast cancer. The biological function of ERH protein has not been fully elucidated, however functions in cell cycle progression, pyrimidine metabolism a possible interaction with p21(Cip1/Waf1 via the Ciz1 zinc finger protein have been suggested. The aim of the present study was a systematic characterization of ERH expression in human breast cancer in order to evaluate possible clinical applications of this molecule. Methods The expression pattern of ERH was analyzed using multiple tissue northern blots (MTN on a panel of 16 normal human tissues and two sets of malignant/normal breast and ovarian tissue samples. ERH expression was further analyzed in breast cancer and normal breast tissues and in tumorigenic as well as non-tumorigenic breast cancer cell lines, using quantitative RT-PCR and non-radioisotopic in situ hybridization (ISH. Results Among normal human tissues, ERH expression was most abundant in testis, heart, ovary, prostate, and liver. In the two MTN sets of malignant/normal breast and ovarian tissue,ERH was clearly more abundantly expressed in all tumours than in normal tissue samples. Quantitative RT-PCR analyses showed that ERH expression was significantly more abundant in tumorigenic than in non-tumorigenic breast cancer cell lines (4.5-fold; p = 0.05, two-tailed Mann-Whitney U-test; the same trend was noted in a set of 25 primary invasive breast cancers and 16 normal breast tissue samples (2.5-fold; p = 0.1. These findings were further confirmed by non-radioisotopic ISH in human breast cancer and normal breast tissue. Conclusion ERH expression is clearly up-regulated in malignant as compared with benign breast cells both in primary human breast cancer and in cell models of breast cancer. Since similar results were obtained for ovarian

Molecular evolutionary rates are not correlated with temperature and latitude in Squamata: an exception to the metabolic theory of ecology?

Science.gov (United States)

Rolland, Jonathan; Loiseau, Oriane; Romiguier, Jonathan; Salamin, Nicolas

2016-05-20

The metabolic theory of ecology stipulates that molecular evolutionary rates should correlate with temperature and latitude in ectothermic organisms. Previous studies have shown that most groups of vertebrates, such as amphibians, turtles and even endothermic mammals, have higher molecular evolutionary rates in regions where temperature is high. However, the association between molecular evolutionary rates and temperature or latitude has never been tested in Squamata. We used a large dataset including the spatial distributions and environmental variables for 1,651 species of Squamata and compared the contrast of the rates of molecular evolution with the contrast of temperature and latitude between sister species. Using major axis regressions and a new algorithm to choose independent sister species pairs, we found that temperature and absolute latitude were not associated with molecular evolutionary rates. This absence of association in such a diverse ectothermic group questions the mechanisms explaining current pattern of species diversity in Squamata and challenges the presupposed universality of the metabolic theory of ecology.

Neurocranium versus Face: A Morphometric Approach with Classical Anthropometric Variables for Characterizing Patterns of Cranial Integration in Extant Hominoids and Extinct Hominins.

Directory of Open Access Journals (Sweden)

Juan Antonio Pérez-Claros

Full Text Available The relative importance of the two main cranial complexes, the neurocranium and the splanchnocranium, has been examined in the five species of extant hominoids and in a huge sample of extinct hominins using six standard craniometric variables that measure the length, width and height of each cranial module. Factor analysis and two-block partial least squares were used for establishing the major patterns of developmental and evolutionary integration between both cranial modules. The results obtained show that all extant hominoids (including the anatomically modern humans share a conserved pattern of developmental integration, a result that agrees with previous studies. The pattern of evolutionary integration between both cranial modules in australopiths runs in parallel to developmental integration. In contrast, the pattern of evolutionary and developmental integration of the species of the genus Homo is the opposite, which is probably the consequence of distinctive selective regimes for both hominin groups.

Neurocranium versus Face: A Morphometric Approach with Classical Anthropometric Variables for Characterizing Patterns of Cranial Integration in Extant Hominoids and Extinct Hominins.

Science.gov (United States)

Pérez-Claros, Juan Antonio; Jiménez-Arenas, Juan Manuel; Palmqvist, Paul

2015-01-01

The relative importance of the two main cranial complexes, the neurocranium and the splanchnocranium, has been examined in the five species of extant hominoids and in a huge sample of extinct hominins using six standard craniometric variables that measure the length, width and height of each cranial module. Factor analysis and two-block partial least squares were used for establishing the major patterns of developmental and evolutionary integration between both cranial modules. The results obtained show that all extant hominoids (including the anatomically modern humans) share a conserved pattern of developmental integration, a result that agrees with previous studies. The pattern of evolutionary integration between both cranial modules in australopiths runs in parallel to developmental integration. In contrast, the pattern of evolutionary and developmental integration of the species of the genus Homo is the opposite, which is probably the consequence of distinctive selective regimes for both hominin groups.

General Methods for Evolutionary Quantitative Genetic Inference from Generalized Mixed Models.

Science.gov (United States)

de Villemereuil, Pierre; Schielzeth, Holger; Nakagawa, Shinichi; Morrissey, Michael

2016-11-01

Methods for inference and interpretation of evolutionary quantitative genetic parameters, and for prediction of the response to selection, are best developed for traits with normal distributions. Many traits of evolutionary interest, including many life history and behavioral traits, have inherently nonnormal distributions. The generalized linear mixed model (GLMM) framework has become a widely used tool for estimating quantitative genetic parameters for nonnormal traits. However, whereas GLMMs provide inference on a statistically convenient latent scale, it is often desirable to express quantitative genetic parameters on the scale upon which traits are measured. The parameters of fitted GLMMs, despite being on a latent scale, fully determine all quantities of potential interest on the scale on which traits are expressed. We provide expressions for deriving each of such quantities, including population means, phenotypic (co)variances, variance components including additive genetic (co)variances, and parameters such as heritability. We demonstrate that fixed effects have a strong impact on those parameters and show how to deal with this by averaging or integrating over fixed effects. The expressions require integration of quantities determined by the link function, over distributions of latent values. In general cases, the required integrals must be solved numerically, but efficient methods are available and we provide an implementation in an R package, QGglmm. We show that known formulas for quantities such as heritability of traits with binomial and Poisson distributions are special cases of our expressions. Additionally, we show how fitted GLMM can be incorporated into existing methods for predicting evolutionary trajectories. We demonstrate the accuracy of the resulting method for evolutionary prediction by simulation and apply our approach to data from a wild pedigreed vertebrate population. Copyright © 2016 de Villemereuil et al.

Pattern visual evoked potentials in dyslexic versus normal children

Directory of Open Access Journals (Sweden)

Javad Heravian

2015-01-01

Conclusion: The sensitivity of PVEP has high validity to detect visual deficits in children with dyslexic problem. However, no significant difference was found between dyslexia and normal children using high contrast stimuli.

MEGA5: Molecular Evolutionary Genetics Analysis Using Maximum Likelihood, Evolutionary Distance, and Maximum Parsimony Methods

Science.gov (United States)

Tamura, Koichiro; Peterson, Daniel; Peterson, Nicholas; Stecher, Glen; Nei, Masatoshi; Kumar, Sudhir

2011-01-01

Comparative analysis of molecular sequence data is essential for reconstructing the evolutionary histories of species and inferring the nature and extent of selective forces shaping the evolution of genes and species. Here, we announce the release of Molecular Evolutionary Genetics Analysis version 5 (MEGA5), which is a user-friendly software for mining online databases, building sequence alignments and phylogenetic trees, and using methods of evolutionary bioinformatics in basic biology, biomedicine, and evolution. The newest addition in MEGA5 is a collection of maximum likelihood (ML) analyses for inferring evolutionary trees, selecting best-fit substitution models (nucleotide or amino acid), inferring ancestral states and sequences (along with probabilities), and estimating evolutionary rates site-by-site. In computer simulation analyses, ML tree inference algorithms in MEGA5 compared favorably with other software packages in terms of computational efficiency and the accuracy of the estimates of phylogenetic trees, substitution parameters, and rate variation among sites. The MEGA user interface has now been enhanced to be activity driven to make it easier for the use of both beginners and experienced scientists. This version of MEGA is intended for the Windows platform, and it has been configured for effective use on Mac OS X and Linux desktops. It is available free of charge from http://www.megasoftware.net. PMID:21546353

Evolutionary relevance facilitates visual information processing.

Science.gov (United States)

Jackson, Russell E; Calvillo, Dusti P

2013-11-03

Visual search of the environment is a fundamental human behavior that perceptual load affects powerfully. Previously investigated means for overcoming the inhibitions of high perceptual load, however, generalize poorly to real-world human behavior. We hypothesized that humans would process evolutionarily relevant stimuli more efficiently than evolutionarily novel stimuli, and evolutionary relevance would mitigate the repercussions of high perceptual load during visual search. Animacy is a significant component to evolutionary relevance of visual stimuli because perceiving animate entities is time-sensitive in ways that pose significant evolutionary consequences. Participants completing a visual search task located evolutionarily relevant and animate objects fastest and with the least impact of high perceptual load. Evolutionarily novel and inanimate objects were located slowest and with the highest impact of perceptual load. Evolutionary relevance may importantly affect everyday visual information processing.

Mean-Potential Law in Evolutionary Games

Science.gov (United States)

Nałecz-Jawecki, Paweł; Miekisz, Jacek

2018-01-01

The Letter presents a novel way to connect random walks, stochastic differential equations, and evolutionary game theory. We introduce a new concept of a potential function for discrete-space stochastic systems. It is based on a correspondence between one-dimensional stochastic differential equations and random walks, which may be exact not only in the continuous limit but also in finite-state spaces. Our method is useful for computation of fixation probabilities in discrete stochastic dynamical systems with two absorbing states. We apply it to evolutionary games, formulating two simple and intuitive criteria for evolutionary stability of pure Nash equilibria in finite populations. In particular, we show that the 1 /3 law of evolutionary games, introduced by Nowak et al. [Nature, 2004], follows from a more general mean-potential law.

Is evolutionary psychology a metatheory for psychology? A discussion of four major issues in psychology from an evolutionary developmental perspective

NARCIS (Netherlands)

Ploeger, A.; van der Maas, H.L.J.; Raijmakers, M.E.J.

2008-01-01

Evolutionary psychology has been proposed as a metatheoretical framework for psychology. We argue that evolutionary psychology should be expanded if it is to offer new insights regarding the major issues in psychology. Evolutionary developmental biology can provide valuable new insights into issues

Comparison of evolutionary computation algorithms for solving bi ...

Indian Academy of Sciences (India)

failure probability. Multiobjective Evolutionary Computation algorithms (MOEAs) are well-suited for Multiobjective task scheduling on heterogeneous environment. The two Multi-Objective Evolutionary Algorithms such as Multiobjective Genetic. Algorithm (MOGA) and Multiobjective Evolutionary Programming (MOEP) with.

Species co-evolutionary algorithm: a novel evolutionary algorithm based on the ecology and environments for optimization

DEFF Research Database (Denmark)

Li, Wuzhao; Wang, Lei; Cai, Xingjuan

2015-01-01

and affect each other in many ways. The relationships include competition, predation, parasitism, mutualism and pythogenesis. In this paper, we consider the five relationships between solutions to propose a co-evolutionary algorithm termed species co-evolutionary algorithm (SCEA). In SCEA, five operators...

Use of Sine Shaped High-Frequency Rhythmic Visual Stimuli Patterns for SSVEP Response Analysis and Fatigue Rate Evaluation in Normal Subjects.

Science.gov (United States)

Keihani, Ahmadreza; Shirzhiyan, Zahra; Farahi, Morteza; Shamsi, Elham; Mahnam, Amin; Makkiabadi, Bahador; Haidari, Mohsen R; Jafari, Amir H

2018-01-01

Background: Recent EEG-SSVEP signal based BCI studies have used high frequency square pulse visual stimuli to reduce subjective fatigue. However, the effect of total harmonic distortion (THD) has not been considered. Compared to CRT and LCD monitors, LED screen displays high-frequency wave with better refresh rate. In this study, we present high frequency sine wave simple and rhythmic patterns with low THD rate by LED to analyze SSVEP responses and evaluate subjective fatigue in normal subjects. Materials and Methods: We used patterns of 3-sequence high-frequency sine waves (25, 30, and 35 Hz) to design our visual stimuli. Nine stimuli patterns, 3 simple (repetition of each of above 3 frequencies e.g., P25-25-25) and 6 rhythmic (all of the frequencies in 6 different sequences e.g., P25-30-35) were chosen. A hardware setup with low THD rate ( 90% for CCA and LASSO (for TWs > 1 s). High frequency rhythmic patterns group with low THD rate showed higher accuracy rate (99.24%) than simple patterns group (98.48%). Repeated measure ANOVA showed significant difference between rhythmic pattern features ( P rhythmic [3.85 ± 2.13] compared to the simple patterns group [3.96 ± 2.21], ( P = 0.63). Rhythmic group had lower within group VAS variation (min = P25-30-35 [2.90 ± 2.45], max = P35-25-30 [4.81 ± 2.65]) as well as least individual pattern VAS (P25-30-35). Discussion and Conclusion: Overall, rhythmic and simple pattern groups had higher and similar accuracy rates. Rhythmic stimuli patterns showed insignificantly lower fatigue rate than simple patterns. We conclude that both rhythmic and simple visual high frequency sine wave stimuli require further research for human subject SSVEP-BCI studies.

Postmenopausal Health and Disease from the Perspective of Evolutionary Medicine

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Andrew W. Froehle

2013-09-01

Full Text Available Menopause normally occurs between 45-55 years of age, marks the end of a woman’s reproductive lifespan, and is accompanied by a reduction in estrogen that has substantial physiological effects. The standard medical view is that these changes underlie high postmenopausal disease rates, defining menopause as an estrogen deficiency condition needing treatment. This view stems from the idea that extended postmenopausal longevity is a consequence of recent technological developments, such that women now outlive their evolutionarily-programmed physiological functional lifespan.Increasingly, however, researchers employing an evolutionary medicine framework have used data from comparative demography, comparative biology, and human behavioral ecology to challenge the mainstream medical view. Instead, these data suggest that a two-decade human postmenopausal lifespan is an evolved, species-typical trait that distinguishes humans from other primates, and has deep roots in our evolutionary past. This view rejects the inevitability of high rates of postmenopausal disease and the concept of menopause as pathology. Rather, high postmenopausal disease risk likely stems from specific lifestyle differences between industrialized societies and foraging societies of the type that dominated human evolutionary history. Women in industrialized societies tend to have higher estrogen levels during premenopausal life, and experience a greater reduction in estrogen across menopause than do women living in foraging societies, with potentially important physiological consequences. The anthropological approach to understanding postmenopausal disease risk reframes the postmenopausal lifespan as an integral period in the human life cycle, and offers alternative avenues for disease prevention by highlighting the importance of lifestyle effects on health.

Alternative Evolutionary Paths to Bacterial Antibiotic Resistance Cause Distinct Collateral Effects.

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Barbosa, Camilo; Trebosc, Vincent; Kemmer, Christian; Rosenstiel, Philip; Beardmore, Robert; Schulenburg, Hinrich; Jansen, Gunther

2017-09-01

When bacteria evolve resistance against a particular antibiotic, they may simultaneously gain increased sensitivity against a second one. Such collateral sensitivity may be exploited to develop novel, sustainable antibiotic treatment strategies aimed at containing the current, dramatic spread of drug resistance. To date, the presence and molecular basis of collateral sensitivity has only been studied in few bacterial species and is unknown for opportunistic human pathogens such as Pseudomonas aeruginosa. In the present study, we assessed patterns of collateral effects by experimentally evolving 160 independent populations of P. aeruginosa to high levels of resistance against eight commonly used antibiotics. The bacteria evolved resistance rapidly and expressed both collateral sensitivity and cross-resistance. The pattern of such collateral effects differed to those previously reported for other bacterial species, suggesting interspecific differences in the underlying evolutionary trade-offs. Intriguingly, we also identified contrasting patterns of collateral sensitivity and cross-resistance among the replicate populations adapted to the same drug. Whole-genome sequencing of 81 independently evolved populations revealed distinct evolutionary paths of resistance to the selective drug, which determined whether bacteria became cross-resistant or collaterally sensitive towards others. Based on genomic and functional genetic analysis, we demonstrate that collateral sensitivity can result from resistance mutations in regulatory genes such as nalC or mexZ, which mediate aminoglycoside sensitivity in β-lactam-adapted populations, or the two-component regulatory system gene pmrB, which enhances penicillin sensitivity in gentamicin-resistant populations. Our findings highlight substantial variation in the evolved collateral effects among replicates, which in turn determine their potential in antibiotic therapy. © The Author 2017. Published by Oxford University Press on

Adaptive developmental delay in Chagas disease vectors: an evolutionary ecology approach.

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Frédéric Menu

2010-05-01

Full Text Available The developmental time of vector insects is important in population dynamics, evolutionary biology, epidemiology and in their responses to global climatic change. In the triatomines (Triatominae, Reduviidae, vectors of Chagas disease, evolutionary ecology concepts, which may allow for a better understanding of their biology, have not been applied. Despite delay in the molting in some individuals observed in triatomines, no effort was made to explain this variability.We applied four methods: (1 an e-mail survey sent to 30 researchers with experience in triatomines, (2 a statistical description of the developmental time of eleven triatomine species, (3 a relationship between development time pattern and climatic inter-annual variability, (4 a mathematical optimization model of evolution of developmental delay (diapause.85.6% of responses informed on prolonged developmental times in 5(th instar nymphs, with 20 species identified with remarkable developmental delays. The developmental time analysis showed some degree of bi-modal pattern of the development time of the 5(th instars in nine out of eleven species but no trend between development time pattern and climatic inter-annual variability was observed. Our optimization model predicts that the developmental delays could be due to an adaptive risk-spreading diapause strategy, only if survival throughout the diapause period and the probability of random occurrence of "bad" environmental conditions are sufficiently high.Developmental delay may not be a simple non-adaptive phenotypic plasticity in development time, and could be a form of adaptive diapause associated to a physiological mechanism related to the postponement of the initiation of reproduction, as an adaptation to environmental stochasticity through a spreading of risk (bet-hedging strategy. We identify a series of parameters that can be measured in the field and laboratory to test this hypothesis. The importance of these findings is

Large-Scale Phylogenomic Analysis Reveals the Complex Evolutionary History of Rabies Virus in Multiple Carnivore Hosts.

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Cécile Troupin

2016-12-01

Full Text Available The natural evolution of rabies virus (RABV provides a potent example of multiple host shifts and an important opportunity to determine the mechanisms that underpin viral emergence. Using 321 genome sequences spanning an unprecedented diversity of RABV, we compared evolutionary rates and selection pressures in viruses sampled from multiple primary host shifts that occurred on various continents. Two major phylogenetic groups, bat-related RABV and dog-related RABV, experiencing markedly different evolutionary dynamics were identified. While no correlation between time and genetic divergence was found in bat-related RABV, the evolution of dog-related RABV followed a generally clock-like structure, although with a relatively low evolutionary rate. Subsequent molecular clock dating indicated that dog-related RABV likely underwent a rapid global spread following the intensification of intercontinental trade starting in the 15th century. Strikingly, although dog RABV has jumped to various wildlife species from the order Carnivora, we found no clear evidence that these host-jumping events involved adaptive evolution, with RABV instead characterized by strong purifying selection, suggesting that ecological processes also play an important role in shaping patterns of emergence. However, specific amino acid changes were associated with the parallel emergence of RABV in ferret-badgers in Asia, and some host shifts were associated with increases in evolutionary rate, particularly in the ferret-badger and mongoose, implying that changes in host species can have important impacts on evolutionary dynamics.

Fixation Time for Evolutionary Graphs

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Nie, Pu-Yan; Zhang, Pei-Ai

Evolutionary graph theory (EGT) is recently proposed by Lieberman et al. in 2005. EGT is successful for explaining biological evolution and some social phenomena. It is extremely important to consider the time of fixation for EGT in many practical problems, including evolutionary theory and the evolution of cooperation. This study characterizes the time to asymptotically reach fixation.

Evolutionary computation in zoology and ecology.

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Boone, Randall B

2017-12-01

Evolutionary computational methods have adopted attributes of natural selection and evolution to solve problems in computer science, engineering, and other fields. The method is growing in use in zoology and ecology. Evolutionary principles may be merged with an agent-based modeling perspective to have individual animals or other agents compete. Four main categories are discussed: genetic algorithms, evolutionary programming, genetic programming, and evolutionary strategies. In evolutionary computation, a population is represented in a way that allows for an objective function to be assessed that is relevant to the problem of interest. The poorest performing members are removed from the population, and remaining members reproduce and may be mutated. The fitness of the members is again assessed, and the cycle continues until a stopping condition is met. Case studies include optimizing: egg shape given different clutch sizes, mate selection, migration of wildebeest, birds, and elk, vulture foraging behavior, algal bloom prediction, and species richness given energy constraints. Other case studies simulate the evolution of species and a means to project shifts in species ranges in response to a changing climate that includes competition and phenotypic plasticity. This introduction concludes by citing other uses of evolutionary computation and a review of the flexibility of the methods. For example, representing species' niche spaces subject to selective pressure allows studies on cladistics, the taxon cycle, neutral versus niche paradigms, fundamental versus realized niches, community structure and order of colonization, invasiveness, and responses to a changing climate.

Evolutionary Naturalism and the Logical Structure of Valuation: The Other Side of Error Theory

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Richard A Richards

2006-01-01

Full Text Available On one standard philosophical position adopted by evolutionary naturalists, human ethical systems are nothing more than evolutionary adaptations that facilitate social behavior. Belief in an absolute moral foundation is therefore in error. But evolutionary naturalism, by its commitment to the basic valutional concept of fitness, reveals another, logical error: standard conceptions of value in terms of simple predication and properties are mistaken. Valuation has instead, a relational structure that makes reference to respects, subjects and environments. This relational nature is illustrated by the analogy commonly drawn between value and color. Color perception, as recognized by the ecological concept, is relational and dependent on subject and environment. In a similar way, value is relational and dependent on subject and environment. This makes value subjective, but also objective in that it is grounded on facts about mattering. At bottom, values are complex relational facts. The view presented here, unlike other prominent relational and naturalistic conceptions of value, recognizes the full range of valuation in nature. The advantages of this relational conception are first, that it gets valuation right; second, it provides a framework to better explain and understand valuation in all its varieties and patterns.

Evolutionary Naturalism and the Logical Structure of Valuation: The Other Side of Error Theory

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Richard A Richards

2005-01-01

Full Text Available On one standard philosophical position adopted by evolutionary naturalists, human ethical systems are nothing more than evolutionary adaptations that facilitate social behavior. Belief in an absolute moral foundation is therefore in error. But evolutionary naturalism, by its commitment to the basic valutional concept of fitness, reveals another, logical error: standard conceptions of value in terms of simple predication and properties are mistaken. Valuation has instead, a relational structure that makes reference to respects, subjects and environments. This relational nature is illustrated by the analogy commonly drawn between value and color. Color perception, as recognized by the ecological concept, is relational and dependent on subject and environment. In a similar way, value is relational and dependent on subject and environment. This makes value subjective, but also objective in that it is grounded on facts about mattering. At bottom, values are complex relational facts. The view presented here, unlike other prominent relational and naturalistic conceptions of value, recognizes the full range of valuation in nature. The advantages of this relational conception are first, that it gets valuation right; second, it provides a framework to better explain and understand valuation in all its varieties and patterns.

Evolutionary accounts of human behavioural diversity

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Brown, Gillian R.; Dickins, Thomas E.; Sear, Rebecca; Laland, Kevin N.

2011-01-01

Human beings persist in an extraordinary range of ecological settings, in the process exhibiting enormous behavioural diversity, both within and between populations. People vary in their social, mating and parental behaviour and have diverse and elaborate beliefs, traditions, norms and institutions. The aim of this theme issue is to ask whether, and how, evolutionary theory can help us to understand this diversity. In this introductory article, we provide a background to the debate surrounding how best to understand behavioural diversity using evolutionary models of human behaviour. In particular, we examine how diversity has been viewed by the main subdisciplines within the human evolutionary behavioural sciences, focusing in particular on the human behavioural ecology, evolutionary psychology and cultural evolution approaches. In addition to differences in focus and methodology, these subdisciplines have traditionally varied in the emphasis placed on human universals, ecological factors and socially learned behaviour, and on how they have addressed the issue of genetic variation. We reaffirm that evolutionary theory provides an essential framework for understanding behavioural diversity within and between human populations, but argue that greater integration between the subfields is critical to developing a satisfactory understanding of diversity. PMID:21199836

Evolutionary equations with applications in natural sciences

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Mokhtar-Kharroubi, Mustapha

2015-01-01

With the unifying theme of abstract evolutionary equations, both linear and nonlinear, in a complex environment, the book presents a multidisciplinary blend of topics, spanning the fields of theoretical and applied functional analysis, partial differential equations, probability theory and numerical analysis applied to various models coming from theoretical physics, biology, engineering and complexity theory. The unique features of the book are: the first simultaneous presentation of two complementary approaches to fragmentation and coagulation problems, by weak compactness methods and by using semigroup techniques, comprehensive exposition of probabilistic methods of analysis of long term dynamics of dynamical systems, semigroup analysis of biological problems and cutting edge pattern formation theory. The book will appeal to postgraduate students and researchers specializing in applications of mathematics to problems arising in natural sciences and engineering.

ChloroMitoCU: Codon patterns across organelle genomes for functional genomics and evolutionary applications.

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Sablok, Gaurav; Chen, Ting-Wen; Lee, Chi-Ching; Yang, Chi; Gan, Ruei-Chi; Wegrzyn, Jill L; Porta, Nicola L; Nayak, Kinshuk C; Huang, Po-Jung; Varotto, Claudio; Tang, Petrus

2017-06-01

Organelle genomes are widely thought to have arisen from reduction events involving cyanobacterial and archaeal genomes, in the case of chloroplasts, or α-proteobacterial genomes, in the case of mitochondria. Heterogeneity in base composition and codon preference has long been the subject of investigation of topics ranging from phylogenetic distortion to the design of overexpression cassettes for transgenic expression. From the overexpression point of view, it is critical to systematically analyze the codon usage patterns of the organelle genomes. In light of the importance of codon usage patterns in the development of hyper-expression organelle transgenics, we present ChloroMitoCU, the first-ever curated, web-based reference catalog of the codon usage patterns in organelle genomes. ChloroMitoCU contains the pre-compiled codon usage patterns of 328 chloroplast genomes (29,960 CDS) and 3,502 mitochondrial genomes (49,066 CDS), enabling genome-wide exploration and comparative analysis of codon usage patterns across species. ChloroMitoCU allows the phylogenetic comparison of codon usage patterns across organelle genomes, the prediction of codon usage patterns based on user-submitted transcripts or assembled organelle genes, and comparative analysis with the pre-compiled patterns across species of interest. ChloroMitoCU can increase our understanding of the biased patterns of codon usage in organelle genomes across multiple clades. ChloroMitoCU can be accessed at: http://chloromitocu.cgu.edu.tw/. © The Author 2017. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Evolutionary Relevance Facilitates Visual Information Processing

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Russell E. Jackson

2013-07-01

Full Text Available Visual search of the environment is a fundamental human behavior that perceptual load affects powerfully. Previously investigated means for overcoming the inhibitions of high perceptual load, however, generalize poorly to real-world human behavior. We hypothesized that humans would process evolutionarily relevant stimuli more efficiently than evolutionarily novel stimuli, and evolutionary relevance would mitigate the repercussions of high perceptual load during visual search. Animacy is a significant component to evolutionary relevance of visual stimuli because perceiving animate entities is time-sensitive in ways that pose significant evolutionary consequences. Participants completing a visual search task located evolutionarily relevant and animate objects fastest and with the least impact of high perceptual load. Evolutionarily novel and inanimate objects were located slowest and with the highest impact of perceptual load. Evolutionary relevance may importantly affect everyday visual information processing.

Creating ensembles of oblique decision trees with evolutionary algorithms and sampling

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Cantu-Paz, Erick [Oakland, CA; Kamath, Chandrika [Tracy, CA

2006-06-13

A decision tree system that is part of a parallel object-oriented pattern recognition system, which in turn is part of an object oriented data mining system. A decision tree process includes the step of reading the data. If necessary, the data is sorted. A potential split of the data is evaluated according to some criterion. An initial split of the data is determined. The final split of the data is determined using evolutionary algorithms and statistical sampling techniques. The data is split. Multiple decision trees are combined in ensembles.

Institutional Inertia and Institutional Change in an Expanding Normal-Form Game

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Torsten Heinrich

2013-08-01

Full Text Available We investigate aspects of institutional change in an evolutionary game-theoretic framework, in principle focusing on problems of coordination in groups when new solutions to a problem become available. In an evolutionary game with an underlying dilemma structure, we let a number of new strategies become gradually available to the agents. The dilemma structure of the situation is not changed by these. Older strategies offer a lesser payoff than newly available ones. The problem that agents have to solve for realizing improved results is, therefore, to coordinate on newly available strategies. Strategies are taken to represent institutions; the coordination on a new strategy by agents, hence, represents a change in the institutional framework of a group. The simulations we run show a stable pattern regarding such institutional changes. A number of institutions are found to coexist, with the specific number depending on the relation of payoffs achievable through the coordination of different strategies. Usually, the strategies leading to the highest possible payoff are not among these. This can be taken to reflect the heterogeneity of rules in larger groups, with different subgroups showing different behavior patterns.

A Note on Evolutionary Algorithms and Its Applications

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Bhargava, Shifali

2013-01-01

This paper introduces evolutionary algorithms with its applications in multi-objective optimization. Here elitist and non-elitist multiobjective evolutionary algorithms are discussed with their advantages and disadvantages. We also discuss constrained multiobjective evolutionary algorithms and their applications in various areas.

Exploring the miRNA regulatory network using evolutionary correlations.

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Benedikt Obermayer

2014-10-01

Full Text Available Post-transcriptional regulation by miRNAs is a widespread and highly conserved phenomenon in metazoans, with several hundreds to thousands of conserved binding sites for each miRNA, and up to two thirds of all genes under miRNA regulation. At the same time, the effect of miRNA regulation on mRNA and protein levels is usually quite modest and associated phenotypes are often weak or subtle. This has given rise to the notion that the highly interconnected miRNA regulatory network exerts its function less through any individual link and more via collective effects that lead to a functional interdependence of network links. We present a Bayesian framework to quantify conservation of miRNA target sites using vertebrate whole-genome alignments. The increased statistical power of our phylogenetic model allows detection of evolutionary correlation in the conservation patterns of site pairs. Such correlations could result from collective functions in the regulatory network. For instance, co-conservation of target site pairs supports a selective benefit of combinatorial regulation by multiple miRNAs. We find that some miRNA families are under pronounced co-targeting constraints, indicating a high connectivity in the regulatory network, while others appear to function in a more isolated way. By analyzing coordinated targeting of different curated gene sets, we observe distinct evolutionary signatures for protein complexes and signaling pathways that could reflect differences in control strategies. Our method is easily scalable to analyze upcoming larger data sets, and readily adaptable to detect high-level selective constraints between other genomic loci. We thus provide a proof-of-principle method to understand regulatory networks from an evolutionary perspective.

The clinical significance of normal mammograms and normal sonograms in patients with palpable abnormalities of the breast

International Nuclear Information System (INIS)

Lee, Jin Hwa; Yoon, Seong Kuk; Choi, Sun Seob; Nam, Kyung Jin; Cho, Se Heon; Kim, Dae Cheol; Kim, Jung Il; Kim, Eun Kyung

2006-01-01

We wanted to evaluate the clinical significance of normal mammograms and normal sonograms in patients with palpable abnormalities of the breast. From Apr 2003 to Feb 2005, 107 patients with 113 palpable abnormalities who had combined normal sonographic and normal mammographic findings were retrospectively studied. The evaluated parameters included age of the patients, the clinical referrals, the distribution of the locations of the palpable abnormalities, whether there was a past surgical history, the mammographic densities and the sonographic echo patterns (purely hyperechoic fibrous tissue, mixed fibroglandular breast tissue, predominantly isoechoic glandular tissue and isoechoic subcutaneous fat tissue) at the sites of clinical concern, whether there was a change in imaging and/or the physical examination results at follow-up, and whether there were biopsy results. This study period was chosen to allow a follow-up period of at least 12 months. The patients' ages ranged from 22 to 66 years (mean age: 48.8 years) and 62 (58%) of the 107 patients were between 41 and 50 years old (58%). The most common location of the palpable abnormalities was the upper outer portion of the breast (45%) and most of the mammographic densities were dense patterns (BI-RADS Type 3 or 4: 91%). Our cases showed similar distribution for all the types of sonographic echo patterns. 23 patients underwent biopsy; all the biopsy specimens were benign. For the 84 patients with 90 palpable abnormalities who were followed, there was no interval development of breast cancer in the areas of clinical concern. Our results suggest that we can follow up and prevent unnecessary biopsies in women with palpable abnormalities when both the mammography and ultrasonography show normal tissue, but this study was limited by its small sample size. Therefore, a larger study will be needed to better define the negative predictive value of combined normal sonographic and mammographic findings

Conflicting evolutionary patterns due to mitochondrial introgression and multilocus phylogeography of the Patagonian freshwater crab Aegla neuquensis.

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Brian R Barber

Full Text Available BACKGROUND: Multiple loci and population genetic methods were employed to study the phylogeographic history of the Patagonian freshwater crab Aegla neuquensis (Aeglidae: Decopoda. This taxon occurs in two large river systems in the Patagonian Steppe, from the foothills of the Andes Mountains east to the Atlantic Ocean. METHODOLOGY/PRINCIPAL FINDINGS: A nuclear phylogeny and multilocus nested clade phylogeographic analysis detected a fragmentation event between the Negro and Chico-Chubut river systems. This event occurred approximately 137 thousand years ago. An isolation-with-migration analysis and maximum-likelihood estimates of gene flow showed asymmetrical exchange of genetic material between these two river systems exclusively in their headwaters. We used information theory to determine the best-fit demographic history between these two river systems under an isolation-with-migration model. The best-fit model suggests that the Negro and the ancestral populations have the same effective population sizes; whereas the Chico-Chubut population is smaller and shows that gene flow from the Chico-Chubut into the Negro is four times higher than in the reverse direction. Much of the Chico-Chubut system appears to have only been recently colonized while the Negro populations appear to have been in place for most of the evolutionary history of this taxon. CONCLUSIONS/SIGNIFICANCE: Due to mitochondrial introgression, three nuclear loci provided different phylogeographic resolution than the three mitochondrial genes for an ancient fragmentation event observed in the nuclear phylogeny. However, the mitochondrial locus provided greater resolution on more recent evolutionary events. Our study, therefore, demonstrates the need to include both nuclear and mitochondrial loci for a more complete understanding of evolutionary histories and associated phylogeographic events. Our results suggest that gene flow between these systems, before and after fragmentation

Applied evolutionary economics and economic geography

NARCIS (Netherlands)

Frenken, K.

2007-01-01

Applied Evolutionary Economics and Economic Geography" aims to further advance empirical methodologies in evolutionary economics, with a special emphasis on geography and firm location. It does so by bringing together a select group of leading scholars including economists, geographers and

The spatial and temporal distributions of arthropods in forest canopies: uniting disparate patterns with hypotheses for specialisation.

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Wardhaugh, Carl W

2014-11-01

Arguably the majority of species on Earth utilise tropical rainforest canopies, and much progress has been made in describing arboreal assemblages, especially for arthropods. The most commonly described patterns for tropical rainforest insect communities are host specificity, spatial specialisation (predominantly vertical stratification), and temporal changes in abundance (seasonality and circadian rhythms). Here I review the recurrent results with respect to each of these patterns and discuss the evolutionary selective forces that have generated them in an attempt to unite these patterns in a holistic evolutionary framework. I propose that species can be quantified along a generalist-specialist scale not only with respect to host specificity, but also other spatial and temporal distribution patterns, where specialisation is a function of the extent of activity across space and time for particular species. When all of these distribution patterns are viewed through the paradigm of specialisation, hypotheses that have been proposed to explain the evolution of host specificity can also be applied to explain the generation and maintenance of other spatial and temporal distribution patterns. The main driver for most spatial and temporal distribution patterns is resource availability. Generally, the distribution of insects follows that of the resources they exploit, which are spatially stratified and vary temporally in availability. Physiological adaptations are primarily important for host specificity, where nutritional and chemical variation among host plants in particular, but also certain prey species and fungi, influence host range. Physiological tolerances of abiotic conditions are also important for explaining the spatial and temporal distributions of some insect species, especially in drier forest environments where desiccation is an ever-present threat. However, it is likely that for most species in moist tropical rainforests, abiotic conditions are valuable

Diversity-Guided Evolutionary Algorithms

DEFF Research Database (Denmark)

Ursem, Rasmus Kjær

2002-01-01

Population diversity is undoubtably a key issue in the performance of evolutionary algorithms. A common hypothesis is that high diversity is important to avoid premature convergence and to escape local optima. Various diversity measures have been used to analyze algorithms, but so far few...... algorithms have used a measure to guide the search. The diversity-guided evolutionary algorithm (DGEA) uses the wellknown distance-to-average-point measure to alternate between phases of exploration (mutation) and phases of exploitation (recombination and selection). The DGEA showed remarkable results...

Global patterns of amphibian phylogenetic diversity

DEFF Research Database (Denmark)

Fritz, Susanne; Rahbek, Carsten

2012-01-01

Aim  Phylogenetic diversity can provide insight into how evolutionary processes may have shaped contemporary patterns of species richness. Here, we aim to test for the influence of phylogenetic history on global patterns of amphibian species richness, and to identify areas where macroevolutionary...... processes such as diversification and dispersal have left strong signatures on contemporary species richness. Location  Global; equal-area grid cells of approximately 10,000 km2. Methods  We generated an amphibian global supertree (6111 species) and repeated analyses with the largest available molecular...... phylogeny (2792 species). We combined each tree with global species distributions to map four indices of phylogenetic diversity. To investigate congruence between global spatial patterns of amphibian species richness and phylogenetic diversity, we selected Faith’s phylogenetic diversity (PD) index...

Nuclear fuel management optimization using adaptive evolutionary algorithms with heuristics

International Nuclear Information System (INIS)

Axmann, J.K.; Van de Velde, A.

1996-01-01

Adaptive Evolutionary Algorithms in combination with expert knowledge encoded in heuristics have proved to be a robust and powerful optimization method for the design of optimized PWR fuel loading pattern. Simple parallel algorithmic structures coupled with a low amount of communications between computer processor units in use makes it possible for workstation clusters to be employed efficiently. The extension of classic evolution strategies not only by new and alternative methods but also by the inclusion of heuristics with effects on the exchange probabilities of the fuel assemblies at specific core positions leads to the RELOPAT optimization code of the Technical University of Braunschweig. In combination with the new, neutron-physical 3D nodal core simulator PRISM developed by SIEMENS the PRIMO loading pattern optimization system has been designed. Highly promising results in the recalculation of known reload plans for German PWR's new lead to a commercially usable program. (author)

Phylogenetic inference with weighted codon evolutionary distances.

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Criscuolo, Alexis; Michel, Christian J

2009-04-01

We develop a new approach to estimate a matrix of pairwise evolutionary distances from a codon-based alignment based on a codon evolutionary model. The method first computes a standard distance matrix for each of the three codon positions. Then these three distance matrices are weighted according to an estimate of the global evolutionary rate of each codon position and averaged into a unique distance matrix. Using a large set of both real and simulated codon-based alignments of nucleotide sequences, we show that this approach leads to distance matrices that have a significantly better treelikeness compared to those obtained by standard nucleotide evolutionary distances. We also propose an alternative weighting to eliminate the part of the noise often associated with some codon positions, particularly the third position, which is known to induce a fast evolutionary rate. Simulation results show that fast distance-based tree reconstruction algorithms on distance matrices based on this codon position weighting can lead to phylogenetic trees that are at least as accurate as, if not better, than those inferred by maximum likelihood. Finally, a well-known multigene dataset composed of eight yeast species and 106 codon-based alignments is reanalyzed and shows that our codon evolutionary distances allow building a phylogenetic tree which is similar to those obtained by non-distance-based methods (e.g., maximum parsimony and maximum likelihood) and also significantly improved compared to standard nucleotide evolutionary distance estimates.

Genes, communities & invasive species: understanding the ecological and evolutionary dynamics of host-pathogen interactions.

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Burdon, J J; Thrall, P H; Ericson, L

2013-08-01

Reciprocal interactions between hosts and pathogens drive ecological, epidemiological and co-evolutionary trajectories, resulting in complex patterns of diversity at population, species and community levels. Recent results confirm the importance of negative frequency-dependent rather than 'arms-race' processes in the evolution of individual host-pathogen associations. At the community level, complex relationships between species abundance and diversity dampen or alter pathogen impacts. Invasive pathogens challenge these controls reflecting the earliest stages of evolutionary associations (akin to arms-race) where disease effects may be so great that they overwhelm the host's and community's ability to respond. Viewing these different stabilization/destabilization phases as a continuum provides a valuable perspective to assessment of the role of genetics and ecology in the dynamics of both natural and invasive host-pathogen associations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sex differences in life history drive evolutionary transitions among maternal, paternal, and bi-parental care.

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Klug, Hope; Bonsall, Michael B; Alonzo, Suzanne H

2013-04-01

Evolutionary transitions among maternal, paternal, and bi-parental care have been common in many animal groups. We use a mathematical model to examine the effect of male and female life-history characteristics (stage-specific maturation and mortality) on evolutionary transitions among maternal, paternal, and bi-parental care. When males and females are relatively similar - that is, when females initially invest relatively little into eggs and both sexes have similar mortality and maturation - transitions among different patterns of care are unlikely to be strongly favored. As males and females become more different, transitions are more likely. If females initially invest heavily into eggs and this reduces their expected future reproductive success, transitions to increased maternal care (paternal → maternal, paternal → bi-parental, bi-parental → maternal) are favored. This effect of anisogamy (i.e., the fact that females initially invest more into each individual zygote than males) might help explain the predominance of maternal care in nature and differs from previous work that found no effect of anisogamy on the origin of different sex-specific patterns of care from an ancestral state of no care. When male mortality is high or male egg maturation rate is low, males have reduced future reproductive potential and transitions to increased paternal care (maternal → paternal, bi-parental → paternal, maternal → bi-parental) are favored. Offspring need (i.e., low offspring survival in the absence of care) also plays a role in transitions to paternal care. In general, basic life-history differences between the sexes can drive evolutionary transitions among different sex-specific patterns of care. The finding that simple life-history differences can alone lead to transitions among maternal and paternal care suggests that the effect of inter-sexual life-history differences should be considered as a baseline scenario when attempting to understand how other

Interpreting Evolutionary Diagrams: When Topology and Process Conflict

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Catley, Kefyn M.; Novick, Laura R.; Shade, Courtney K.

2010-01-01

The authors argue that some diagrams in biology textbooks and the popular press presented as depicting evolutionary relationships suggest an inappropriate (anagenic) conception of evolutionary history. The goal of this research was to provide baseline data that begin to document how college students conceptualize the evolutionary relationships…

Evolutionary engineering of industrial microorganisms-strategies and applications.

Science.gov (United States)

Zhu, Zhengming; Zhang, Juan; Ji, Xiaomei; Fang, Zhen; Wu, Zhimeng; Chen, Jian; Du, Guocheng

2018-06-01

Microbial cells have been widely used in the industry to obtain various biochemical products, and evolutionary engineering is a common method in biological research to improve their traits, such as high environmental tolerance and improvement of product yield. To obtain better integrate functions of microbial cells, evolutionary engineering combined with other biotechnologies have attracted more attention in recent years. Classical laboratory evolution has been proven effective to letting more beneficial mutations occur in different genes but also has some inherent limitations such as a long evolutionary period and uncontrolled mutation frequencies. However, recent studies showed that some new strategies may gradually overcome these limitations. In this review, we summarize the evolutionary strategies commonly used in industrial microorganisms and discuss the combination of evolutionary engineering with other biotechnologies such as systems biology and inverse metabolic engineering. Finally, we prospect the importance and application prospect of evolutionary engineering as a powerful tool especially in optimization of industrial microbial cell factories.

Democratizing evolutionary biology, lessons from insects

DEFF Research Database (Denmark)

Dunn, Robert Roberdeau; Beasley, DeAnna E.

2016-01-01

The engagement of the public in the scientific process is an old practice. Yet with recent advances in technology, the role of the citizen scientist in studying evolutionary processes has increased. Insects provide ideal models for understanding these evolutionary processes at large scales. This ...

Evolutionary theory and the naturalist fallacy

DEFF Research Database (Denmark)

Grodal, Torben Kragh

2008-01-01

that great work of art are also automatically fitness-enhancing in the present day environment, at that there are simple correllations between whether a work of art has a high aesthetic value and whether it is fitness-enhancing or not.  Keywords :  Evolutionary aesthetics, film theory, literary theory......The article is an invited response to a target article by Joseph Carroll entitled "An evolutionary paradigm for literary study". It argues that the target article  misuse the fact that works of art are based on adaptations that were fitness-enhancing in the era of evolutionary adaptations to claim...

Secular trends in new childhood epidemics: insights from evolutionary medicine.

Science.gov (United States)

Brüne, Martin; Hochberg, Ze'ev

2013-10-21

In the last few decades, pediatric medicine has observed a dramatic increase in the prevalence of hitherto rare illnesses, among which obesity, diabetes, allergies and other autoimmune diseases stand out. In addition, secular trends towards earlier onset of puberty and sexual activity contribute to the psychological problems of youth and adolescents. All this has occurred in spite of the improved health care provision for children, yet traditional concepts of medicine have failed to explain these new "epidemics". A recent conference and science school of the European Society of Paediatric Endocrinology (ESPE) in Acre, Israel, has taken up this challenge. Experts across disciplines including medicine, anthropology and developmental psychology discussed potential causes of childhood ill-health from an evolutionary point-of-view. Seen from an evolutionary vantage point, the "epidemics" of childhood obesity, diabetes and psychological dysfunction appear, in part, to be related to a mismatch between ancestral adaptations and novel environmental contingencies. These include changing exposures to pathogens, which impact on the function of the immune system, as well as changing patterns of parenting, which influence the timing of puberty and the risk for developing psychopathology.

Evolutionary public health: introducing the concept.

Science.gov (United States)

Wells, Jonathan C K; Nesse, Randolph M; Sear, Rebecca; Johnstone, Rufus A; Stearns, Stephen C

2017-07-29

The emerging discipline of evolutionary medicine is breaking new ground in understanding why people become ill. However, the value of evolutionary analyses of human physiology and behaviour is only beginning to be recognised in the field of public health. Core principles come from life history theory, which analyses the allocation of finite amounts of energy between four competing functions-maintenance, growth, reproduction, and defence. A central tenet of evolutionary theory is that organisms are selected to allocate energy and time to maximise reproductive success, rather than health or longevity. Ecological interactions that influence mortality risk, nutrient availability, and pathogen burden shape energy allocation strategies throughout the life course, thereby affecting diverse health outcomes. Public health interventions could improve their own effectiveness by incorporating an evolutionary perspective. In particular, evolutionary approaches offer new opportunities to address the complex challenges of global health, in which populations are differentially exposed to the metabolic consequences of poverty, high fertility, infectious diseases, and rapid changes in nutrition and lifestyle. The effect of specific interventions is predicted to depend on broader factors shaping life expectancy. Among the important tools in this approach are mathematical models, which can explore probable benefits and limitations of interventions in silico, before their implementation in human populations. Copyright © 2017 Elsevier Ltd. All rights reserved.

A teleofunctional account of evolutionary mismatch.

Science.gov (United States)

Cofnas, Nathan

When the environment in which an organism lives deviates in some essential way from that to which it is adapted, this is described as "evolutionary mismatch," or "evolutionary novelty." The notion of mismatch plays an important role, explicitly or implicitly, in evolution-informed cognitive psychology, clinical psychology, and medicine. The evolutionary novelty of our contemporary environment is thought to have significant implications for our health and well-being. However, scientists have generally been working without a clear definition of mismatch. This paper defines mismatch as deviations in the environment that render biological traits unable, or impaired in their ability, to produce their selected effects (i.e., to perform their proper functions in Neander's sense). The machinery developed by Millikan in connection with her account of proper function, and with her related teleosemantic account of representation, is used to identify four major types, and several subtypes, of evolutionary mismatch. While the taxonomy offered here does not in itself resolve any scientific debates, the hope is that it can be used to better formulate empirical hypotheses concerning the effects of mismatch. To illustrate, it is used to show that the controversial hypothesis that general intelligence evolved as an adaptation to handle evolutionary novelty can, contra some critics, be formulated in a conceptually coherent way.

The evolutionary ecology of molecular replicators.

Science.gov (United States)

Nee, Sean

2016-08-01

By reasonable criteria, life on the Earth consists mainly of molecular replicators. These include viruses, transposons, transpovirons, coviruses and many more, with continuous new discoveries like Sputnik Virophage. Their study is inherently multidisciplinary, spanning microbiology, genetics, immunology and evolutionary theory, and the current view is that taking a unified approach has great power and promise. We support this with a new, unified, model of their evolutionary ecology, using contemporary evolutionary theory coupling the Price equation with game theory, studying the consequences of the molecular replicators' promiscuous use of each others' gene products for their natural history and evolutionary ecology. Even at this simple expository level, we can make a firm prediction of a new class of replicators exploiting viruses such as lentiviruses like SIVs, a family which includes HIV: these have been explicitly stated in the primary literature to be non-existent. Closely connected to this departure is the view that multicellular organism immunology is more about the management of chronic infections rather than the elimination of acute ones and new understandings emerging are changing our view of the kind of theatre we ourselves provide for the evolutionary play of molecular replicators. This study adds molecular replicators to bacteria in the emerging field of sociomicrobiology.

Multiobjective Multifactorial Optimization in Evolutionary Multitasking.

Science.gov (United States)

Gupta, Abhishek; Ong, Yew-Soon; Feng, Liang; Tan, Kay Chen

2016-05-03

In recent decades, the field of multiobjective optimization has attracted considerable interest among evolutionary computation researchers. One of the main features that makes evolutionary methods particularly appealing for multiobjective problems is the implicit parallelism offered by a population, which enables simultaneous convergence toward the entire Pareto front. While a plethora of related algorithms have been proposed till date, a common attribute among them is that they focus on efficiently solving only a single optimization problem at a time. Despite the known power of implicit parallelism, seldom has an attempt been made to multitask, i.e., to solve multiple optimization problems simultaneously. It is contended that the notion of evolutionary multitasking leads to the possibility of automated transfer of information across different optimization exercises that may share underlying similarities, thereby facilitating improved convergence characteristics. In particular, the potential for automated transfer is deemed invaluable from the standpoint of engineering design exercises where manual knowledge adaptation and reuse are routine. Accordingly, in this paper, we present a realization of the evolutionary multitasking paradigm within the domain of multiobjective optimization. The efficacy of the associated evolutionary algorithm is demonstrated on some benchmark test functions as well as on a real-world manufacturing process design problem from the composites industry.

Evolutionary heritage influences Amazon tree ecology

Science.gov (United States)

Coelho de Souza, Fernanda; Dexter, Kyle G.; Phillips, Oliver L.; Brienen, Roel J. W.; Chave, Jerome; Galbraith, David R.; Lopez Gonzalez, Gabriela; Monteagudo Mendoza, Abel; Pennington, R. Toby; Poorter, Lourens; Alexiades, Miguel; Álvarez-Dávila, Esteban; Andrade, Ana; Aragão, Luis E. O. C.; Araujo-Murakami, Alejandro; Arets, Eric J. M. M.; Aymard C, Gerardo A.; Baraloto, Christopher; Barroso, Jorcely G.; Bonal, Damien; Boot, Rene G. A.; Camargo, José L. C.; Comiskey, James A.; Valverde, Fernando Cornejo; de Camargo, Plínio B.; Di Fiore, Anthony; Erwin, Terry L.; Feldpausch, Ted R.; Ferreira, Leandro; Fyllas, Nikolaos M.; Gloor, Emanuel; Herault, Bruno; Herrera, Rafael; Higuchi, Niro; Honorio Coronado, Eurídice N.; Killeen, Timothy J.; Laurance, William F.; Laurance, Susan; Lloyd, Jon; Lovejoy, Thomas E.; Malhi, Yadvinder; Maracahipes, Leandro; Marimon, Beatriz S.; Marimon-Junior, Ben H.; Mendoza, Casimiro; Morandi, Paulo; Neill, David A.; Vargas, Percy Núñez; Oliveira, Edmar A.; Lenza, Eddie; Palacios, Walter A.; Peñuela-Mora, Maria C.; Pipoly, John J.; Pitman, Nigel C. A.; Prieto, Adriana; Quesada, Carlos A.; Ramirez-Angulo, Hirma; Rudas, Agustin; Ruokolainen, Kalle; Salomão, Rafael P.; Silveira, Marcos; ter Steege, Hans; Thomas-Caesar, Raquel; van der Hout, Peter; van der Heijden, Geertje M. F.; van der Meer, Peter J.; Vasquez, Rodolfo V.; Vieira, Simone A.; Vilanova, Emilio; Vos, Vincent A.; Wang, Ophelia; Young, Kenneth R.; Zagt, Roderick J.; Baker, Timothy R.

2016-01-01

Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiosperm lineages and species with widely differing life-history characteristics, providing an excellent system to investigate the combined influences of evolutionary heritage and selection in determining trait variation. We used trait data related to the major axes of life-history variation among tropical trees (e.g. growth and mortality rates) from 577 inventory plots in closed-canopy forest, mapped onto a phylogenetic hypothesis spanning more than 300 genera including all major angiosperm clades to test for evolutionary constraints on traits. We found significant phylogenetic signal (PS) for all traits, consistent with evolutionarily related genera having more similar characteristics than expected by chance. Although there is also evidence for repeated evolution of pioneer and shade tolerant life-history strategies within independent lineages, the existence of significant PS allows clearer predictions of the links between evolutionary diversity, ecosystem function and the response of tropical forests to global change. PMID:27974517

Evolutionary heritage influences Amazon tree ecology.

Science.gov (United States)

Coelho de Souza, Fernanda; Dexter, Kyle G; Phillips, Oliver L; Brienen, Roel J W; Chave, Jerome; Galbraith, David R; Lopez Gonzalez, Gabriela; Monteagudo Mendoza, Abel; Pennington, R Toby; Poorter, Lourens; Alexiades, Miguel; Álvarez-Dávila, Esteban; Andrade, Ana; Aragão, Luis E O C; Araujo-Murakami, Alejandro; Arets, Eric J M M; Aymard C, Gerardo A; Baraloto, Christopher; Barroso, Jorcely G; Bonal, Damien; Boot, Rene G A; Camargo, José L C; Comiskey, James A; Valverde, Fernando Cornejo; de Camargo, Plínio B; Di Fiore, Anthony; Elias, Fernando; Erwin, Terry L; Feldpausch, Ted R; Ferreira, Leandro; Fyllas, Nikolaos M; Gloor, Emanuel; Herault, Bruno; Herrera, Rafael; Higuchi, Niro; Honorio Coronado, Eurídice N; Killeen, Timothy J; Laurance, William F; Laurance, Susan; Lloyd, Jon; Lovejoy, Thomas E; Malhi, Yadvinder; Maracahipes, Leandro; Marimon, Beatriz S; Marimon-Junior, Ben H; Mendoza, Casimiro; Morandi, Paulo; Neill, David A; Vargas, Percy Núñez; Oliveira, Edmar A; Lenza, Eddie; Palacios, Walter A; Peñuela-Mora, Maria C; Pipoly, John J; Pitman, Nigel C A; Prieto, Adriana; Quesada, Carlos A; Ramirez-Angulo, Hirma; Rudas, Agustin; Ruokolainen, Kalle; Salomão, Rafael P; Silveira, Marcos; Stropp, Juliana; Ter Steege, Hans; Thomas-Caesar, Raquel; van der Hout, Peter; van der Heijden, Geertje M F; van der Meer, Peter J; Vasquez, Rodolfo V; Vieira, Simone A; Vilanova, Emilio; Vos, Vincent A; Wang, Ophelia; Young, Kenneth R; Zagt, Roderick J; Baker, Timothy R

2016-12-14

Lineages tend to retain ecological characteristics of their ancestors through time. However, for some traits, selection during evolutionary history may have also played a role in determining trait values. To address the relative importance of these processes requires large-scale quantification of traits and evolutionary relationships among species. The Amazonian tree flora comprises a high diversity of angiosperm lineages and species with widely differing life-history characteristics, providing an excellent system to investigate the combined influences of evolutionary heritage and selection in determining trait variation. We used trait data related to the major axes of life-history variation among tropical trees (e.g. growth and mortality rates) from 577 inventory plots in closed-canopy forest, mapped onto a phylogenetic hypothesis spanning more than 300 genera including all major angiosperm clades to test for evolutionary constraints on traits. We found significant phylogenetic signal (PS) for all traits, consistent with evolutionarily related genera having more similar characteristics than expected by chance. Although there is also evidence for repeated evolution of pioneer and shade tolerant life-history strategies within independent lineages, the existence of significant PS allows clearer predictions of the links between evolutionary diversity, ecosystem function and the response of tropical forests to global change. © 2016 The Authors.

Evaluation of early systolic flow pattern in left ventricle by tagging cine MRI in normal volunteers

International Nuclear Information System (INIS)

Sakakura, Kazuyoshi; Anno, Naoko; Kondo, Takeshi

1992-01-01

The tagging method is a new technique, which permits to apply discretionary lines (tags) on MR images. To evaluate intra left ventricular (LV) flow pattern, we performed ECG-gated gradient field echo cine MRI using tagging method in five normal male volunteers, aged 22-42 years. The horizontal long axis view of LV was imaged by multiphasic field echo pulse sequence. The three parallel tags (basal, middle and apical portion) were established on the horizontal long axis view of LV just after the triggered QRS waves. And the initial two images (70 ms and 120 ms after the triggered QRS waves) were analyzed. On the two tags (middle and apical portion) of these three tags, we measured the distance of displacement of the tags on three points (the near site of IVS, middle portion and the near site of free wall) respectively. At 70 ms after the trigger point, the only tagged blood at the near site of free wall flowed toward the apex. At 120 ms after the trigger point, all the tagged blood flowed toward the outflow tract of LV. And the maximum blood flow velocity was observed at the near site of IVS on middle portion of LV (166.0 mm/s). These results coincided with earlier studies by Doppler echocardiography. But we could not observe intra LV blood flow patterns throughout one cardiac cycle in this pulse sequence, because the tags had flowed out from LV and had become unclear due to spin relaxation and mixing. We concluded that the tagging method was useful to evaluate intra left ventricular blood flow patterns in early systolic phase. (author)

How to Identify and Interpret Evolutionary Tree Diagrams

Science.gov (United States)

Kong, Yi; Anderson, Trevor; Pelaez, Nancy

2016-01-01

Evolutionary trees are key tools for modern biology and are commonly portrayed in textbooks to promote learning about biological evolution. However, many people have difficulty in understanding what evolutionary trees are meant to portray. In fact, some ideas that current professional biologists depict with evolutionary trees are neither clearly…

Transcriptome-wide patterns of divergence during allopatric evolution.

Science.gov (United States)

Pereira, Ricardo J; Barreto, Felipe S; Pierce, N Tessa; Carneiro, Miguel; Burton, Ronald S

2016-04-01

Recent studies have revealed repeated patterns of genomic divergence associated with species formation. Such patterns suggest that natural selection tends to target a set of available genes, but is also indicative that closely related taxa share evolutionary constraints that limit genetic variability. Studying patterns of genomic divergence among populations within the same species may shed light on the underlying evolutionary processes. Here, we examine transcriptome-wide divergence and polymorphism in the marine copepod Tigriopus californicus, a species where allopatric evolution has led to replicate sets of populations with varying degrees of divergence and hybrid incompatibility. Our analyses suggest that relatively small effective population sizes have resulted in an exponential decline of shared polymorphisms during population divergence and also facilitated the fixation of slightly deleterious mutations within allopatric populations. Five interpopulation comparisons at three different stages of divergence show that nonsynonymous mutations tend to accumulate in a specific set of proteins. These include proteins with central roles in cellular metabolism, such as those encoded in mtDNA, but also include an additional set of proteins that repeatedly show signatures of positive selection during allopatric divergence. Although our results are consistent with a contribution of nonadaptive processes, such as genetic drift and gene expression levels, generating repeatable patterns of genomic divergence in closely related taxa, they also indicate that adaptive evolution targeting a specific set of genes contributes to this pattern. Our results yield insights into the predictability of evolution at the gene level. © 2016 John Wiley & Sons Ltd.

Cooperation in an evolutionary prisoner’s dilemma game with probabilistic strategies

International Nuclear Information System (INIS)

Li Haihong; Dai Qionglin; Cheng Hongyan; Yang Junzhong

2012-01-01

Highlights: ► Introducing probabilistic strategies instead of the pure C/D in the PDG. ► The strategies patterns depends on interaction structures and updating rules. ► There exists an optimal increment of the probabilistic strategy. - Abstract: In this work, we investigate an evolutionary prisoner’s dilemma game in structured populations with probabilistic strategies instead of the pure strategies of cooperation and defection. We explore the model in details by considering different strategy update rules and different population structures. We find that the distribution of probabilistic strategies patterns is dependent on both the interaction structures and the updating rules. We also find that, when an individual updates her strategy by increasing or decreasing her probabilistic strategy a certain amount towards that of her opponent, there exists an optimal increment of the probabilistic strategy at which the cooperator frequency reaches its maximum.

Evolutionary biology of bacterial and fungal pathogens

National Research Council Canada - National Science Library

Baquero, F

2008-01-01

... and Evolutionary Dynamics of Pathogens * 21 Keith A. Crandall and Marcos Pérez-Losada II. Evolutionary Genetics of Microbial Pathogens 4. Environmental and Social Influences on Infectious Disea...

Diversification of defensins and NLRs in Arabidopsis species by different evolutionary mechanisms.

Science.gov (United States)

Mondragón-Palomino, Mariana; Stam, Remco; John-Arputharaj, Ajay; Dresselhaus, Thomas

2017-12-15

Genes encoding proteins underlying host-pathogen co-evolution and which are selected for new resistance specificities frequently are under positive selection, a process that maintains diversity. Here, we tested the contribution of natural selection, recombination and transcriptional divergence to the evolutionary diversification of the plant defensins superfamily in three Arabidopsis species. The intracellular NOD-like receptor (NLR) family was used for comparison because positive selection has been well documented in its members. Similar to defensins, NLRs are encoded by a large and polymorphic gene family and many of their members are involved in the immune response. Gene trees of Arabidopsis defensins (DEFLs) show a high prevalence of clades containing orthologs. This indicates that their diversity dates back to a common ancestor and species-specific duplications did not significantly contribute to gene family expansion. DEFLs are characterized by a pervasive pattern of neutral evolution with infrequent positive and negative selection as well as recombination. In comparison, most NLR alignment groups are characterized by frequent occurrence of positive selection and recombination in their leucine-rich repeat (LRR) domain as well negative selection in their nucleotide-binding (NB-ARC) domain. While major NLR subgroups are expressed in pistils and leaves both in presence or absence of pathogen infection, the members of DEFL alignment groups are predominantly transcribed in pistils. Furthermore, conserved groups of NLRs and DEFLs are differentially expressed in response to Fusarium graminearum regardless of whether these genes are under positive selection or not. The present analyses of NLRs expands previous studies in Arabidopsis thaliana and highlights contrasting patterns of purifying and diversifying selection affecting different gene regions. DEFL genes show a different evolutionary trend, with fewer recombination events and significantly fewer instances of

Regional systems of innovation: an evolutionary perspective

OpenAIRE

P Cooke; M G Uranga; G Etxebarria

1998-01-01

The authors develop the concept of regional systems of innovation and relate it to preexisting research on national systems of innovation. They argue that work conducted in the 'new regional science' field is complementary to systems of innovation approaches. They seek to link new regional work to evolutionary economics, and argue for the development of evolutionary regional science. Common elements of interest to evolutionary innovation research and new regional science are important in unde...

Evolution in the block: common elements of 5S rDNA organization and evolutionary patterns in distant fish genera.

Science.gov (United States)

Campo, Daniel; García-Vázquez, Eva

2012-01-01

The 5S rDNA is organized in the genome as tandemly repeated copies of a structural unit composed of a coding sequence plus a nontranscribed spacer (NTS). The coding region is highly conserved in the evolution, whereas the NTS vary in both length and sequence. It has been proposed that 5S rRNA genes are members of a gene family that have arisen through concerted evolution. In this study, we describe the molecular organization and evolution of the 5S rDNA in the genera Lepidorhombus and Scophthalmus (Scophthalmidae) and compared it with already known 5S rDNA of the very different genera Merluccius (Merluccidae) and Salmo (Salmoninae), to identify common structural elements or patterns for understanding 5S rDNA evolution in fish. High intra- and interspecific diversity within the 5S rDNA family in all the genera can be explained by a combination of duplications, deletions, and transposition events. Sequence blocks with high similarity in all the 5S rDNA members across species were identified for the four studied genera, with evidences of intense gene conversion within noncoding regions. We propose a model to explain the evolution of the 5S rDNA, in which the evolutionary units are blocks of nucleotides rather than the entire sequences or single nucleotides. This model implies a "two-speed" evolution: slow within blocks (homogenized by recombination) and fast within the gene family (diversified by duplications and deletions).

A Multi Agent System for Flow-Based Intrusion Detection Using Reputation and Evolutionary Computation

Science.gov (United States)

2011-03-01

pertinent example of the application of Evolutionary Algorithms to pattern recognition comes from Radtke et al. [130]. The authors apply Multi- Objective...J., T. Zseby, and B. Claise. S. Zander,” Requirements for IP Flow Information Export (IPFIX). Technical report, RFC 3917, October 2004. [130] Radtke ...hal.inria.fr/inria-00104200/en/. [131] Radtke , P.V.W., T. Wong, and R. Sabourin. “A multi-objective memetic al- gorithm for intelligent feature extraction

Evolutionary robotics

Indian Academy of Sciences (India)

In evolutionary robotics, a suitable robot control system is developed automatically through evolution due to the interactions between the robot and its environment. It is a complicated task, as the robot and the environment constitute a highly dynamical system. Several methods have been tried by various investigators to ...

Normal and abnormal aging in bilinguals

Directory of Open Access Journals (Sweden)

Alfredo Ardila

Full Text Available Abstract Bilinguals use two different language systems to mediate not only social communication, but also cognitive processes. Potential differences between bilinguals and monolinguals in task-solving strategies and patterns of cognitive decline during normal and abnormal aging have been suggested. Main contribution: A research review of the area suggests that normal aging is associated with increased interference between the two languages and tendency to retreat to a single language. General cognitive functioning has been found to be higher in demented bilingual patients if communication is carried out in L1 rather than in L2. Recent research has reported that bilingualism can have a protective effect during aging, attenuating the normal cognitive decline associated with aging, and delaying the onset of dementia. Conclusions: Regardless of the significant heterogeneity of bilingualism and the diversity of patterns in language use during life-span, current research suggests that bilingualism is associated with preserved cognitive test performance during aging, and potentially can have some protective effect in dementia.

Evolutionary mysteries in meiosis.

Science.gov (United States)

Lenormand, Thomas; Engelstädter, Jan; Johnston, Susan E; Wijnker, Erik; Haag, Christoph R

2016-10-19

Meiosis is a key event of sexual life cycles in eukaryotes. Its mechanistic details have been uncovered in several model organisms, and most of its essential features have received various and often contradictory evolutionary interpretations. In this perspective, we present an overview of these often 'weird' features. We discuss the origin of meiosis (origin of ploidy reduction and recombination, two-step meiosis), its secondary modifications (in polyploids or asexuals, inverted meiosis), its importance in punctuating life cycles (meiotic arrests, epigenetic resetting, meiotic asymmetry, meiotic fairness) and features associated with recombination (disjunction constraints, heterochiasmy, crossover interference and hotspots). We present the various evolutionary scenarios and selective pressures that have been proposed to account for these features, and we highlight that their evolutionary significance often remains largely mysterious. Resolving these mysteries will likely provide decisive steps towards understanding why sex and recombination are found in the majority of eukaryotes.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'. © 2016 The Author(s).

Blink patterns and lid-contact times in dry-eye and normal subjects

Directory of Open Access Journals (Sweden)

Ousler GW 3rd

2014-05-01

Full Text Available George W Ousler 3rd,1 Mark B Abelson,1,2 Patrick R Johnston,1 John Rodriguez,1 Keith Lane,1 Lisa M Smith11Ora, Andover, MA, USA; 2Department of Ophthalmology, Harvard Medical School, Boston, MA, USAPurpose: To classify blinks in dry eye and normal subjects into six subtypes, and to define the blink rate and duration within each type of blink, as well as the total lid-contact time/minute.Materials and methods: This was a single-centered, prospective, double-blind study of eleven dry-eye and ten normal subjects. Predefined subjects watched a video while blinks were recorded for 10 minutes. Partial blinks were classified by percentage closure of maximal palpebral fissure opening: 25%, 50%, 75%. Complete blinks were characterized as full (>0 seconds, extended (>0.1 seconds, or superextended (>0.5 seconds. The mean duration of each type of blink was determined and standardized per minute as total lid-contact time.Results: Total blinks observed were 4,990 (1,414 normal, 3,756 dry eye: 1,809 (50.59% partial and 1,767 (49.41% complete blinks among dry-eye subjects versus 741 (52.90% partial and 673 (47.60% complete blinks among normal subjects. Only superextended blinks of ≥0.5-second duration were significantly more frequent in dry-eye subjects than normals (2.3% versus 0.2%, respectively; P=0.023. Total contact time was seven times higher in dry-eye subjects than normals (0.565 versus 0.080 seconds, respectively; P<0.001. Isolating only extended blinks (>0.1 second, the average contact time (seconds was four times longer in dry-eye versus normal subjects (2.459 in dry eye, 0.575 in normals; P=0.003. Isolating only superextended blinks (>0.5 seconds, average contact time was also significantly different (7.134 in dry eye, 1.589 in normals; P<0.001. The contact rate for all full closures was 6.4 times longer in dry-eye (0.045 versus 0.007, P<0.001 than normal subjects.Conclusion: Dry-eye subjects spent 4.5% of a

Automatic classification of liver scintigram patterns by computer

International Nuclear Information System (INIS)

Csernay, L.; Csirik, J.

1976-01-01

The pattern recognition of projection is one of the problems in the automatic evaluation of scintigrams. An algorythm and a computerized programme with the ability to classify the shapes of liver scintigrams has been elaborated by the authors. The programme differentiates not only normal and pathologic basic forms, but performs the identification of nine normal forms described by the literature. To pattern recognition structural and local parameters of the picture were defined. A detailed mechanism of the programme is given in their reports. The programme can classify 55 out of 60 actual liver scintigrams, a result different from subjective definition obtained in 5 cases. These were normal pattern of liver scans. No wrong definition was obtained when classifying normal and pathologic patterns

Phylomedicine: An evolutionary telescope to explore and diagnose the universe of disease mutations

Science.gov (United States)

Kumar, Sudhir; Dudley, Joel T.; Filipski, Alan; Liu, Li

2011-01-01

Modern technologies have made the sequencing of personal genomes routine. They have revealed thousands of nonsynonymous (amino-acid altering) single nucleotide variants (nSNVs) of protein coding DNA per genome. What do these variants foretell about an individual’s predisposition to diseases? The experimental technologies required to carry out such evaluations at a genomic scale are not yet available. Fortunately, the process of natural selection has lent us an almost infinite set of tests in nature. During the long-term evolution, new mutations and existing variations have been evaluated for their biological consequences in countless species, and outcomes were readily revealed by multispecies genome comparisons. We review studies that have investigated evolutionary characteristics and in silico functional diagnoses of nSNVs found in thousands of disease-associated genes. We conclude that the patterns of long-term evolutionary conservation and permissible divergence are essential and instructive modalities for functional assessment of human genetic variations. PMID:21764165

Evolutionary morphology of the hemolymph vascular system of basal araneomorph spiders (Araneae: Araneomorphae).

Science.gov (United States)

Huckstorf, Katarina; Michalik, Peter; Ramírez, Martín; Wirkner, Christian S

2015-11-01

The superfamily Austrochiloidea (Austrochilidae and Gradungulidae) take a pivotal position in araneomorph spider phylogeny. In this discussion crevice weaver spiders (Filistatidae) are of equal interest. Especially data from these phylogenetically uncertain yet basal off branching groups can enlighten our understanding on the evolution of organ systems. In the course of a survey on the evolutionary morphology of the circulatory system in spiders we therefore investigated the hemolymph vascular system in two austrochiloid and one filistatid species. Additionally some data on a hypochilid and a gradungulid species are included. Using up-to-date morphological methods, the vascular systems in these spiders are visualized three dimensionally. Ground pattern features of the circulatory systems in austrochiloid spiders are presented and the data discussed along recent lines of phylogenetic hypotheses. Special topics highlighted are the intraspecific variability of the origins of some prosomal arteries and the evolutionary correlation of respiratory and circulatory systems in spiders. Copyright © 2015 Elsevier Ltd. All rights reserved.

MR of normal pancreas : comparison of five pulse sequences and enhancing patterns on dynamic imaging

International Nuclear Information System (INIS)

Jang, Hyun Jung; Kim, Tae Kyoung; Hong, Sung Hwan; Han, Joon Koo; Choi, Byung Ihn

1997-01-01

To compare T1-weighted FLASH and turbo spin echo (SE) T2-weighted sequences with conventional T1- and T2-weighted sequences in imaging normal pancreas and to describe the enhancing patterns on dynamic MR imging. Forty-four patients with presumed hepatic hemangiomas were studied at 1.0T or 1.5T by using conventional SE sequences (T1-weighted, T2-weighted, and heavily T2-weighted), turbo-SE T2-weighted sequences, and breath-hold T1-weighted FLASH sequences acquired before, immediately on, and at 1, 2, 3, and 5 or 10 minutes after injection of a bolus of gadopentetate dimeglumine. No patients had either a history or its clinical features of pancreatic disease. Images were quantitatively analyzed for signal-difference-to noise ratios (SD/Ns) between the pancreas and peripancreatic fat. Percentage enhancement of the pancreas was measured on each dynamic MR image. Conspicuity of the pancreatic border was qualitatively evaluated according to a consensus, reached by three radiologists. Turbo-SE T2-weighted images had a significantly higher SD/N ratio (p<0.001) and better conspicuity of the pancreatic border (p<0.001) than SE T2- and heavily T2-weighted images;T1-weighted SE images had a significantly higher SD/N ratio than T1-weighted FLASH images (p<0.001), but there was no significant difference between tham in qualitative analysis (p=0.346). Percentage enhancement immediately on and at 1, 2, 3, 5, and 10 minutes after administration of contrast material was 39.9%, 44.5%, 42.9%, 40.8%, 36.3%, 29.9%, respectively, with peak enhancement at 1 minute. In MR imaging of normal pancreas, turbo-SE T2-weighted imaging is superior to SE T2- and heavily T2- weighted imaging, and SE T1-weighted imaging is superior to T1-weighted FLASH imaging. On serial gadolinium-enhanced FLASH imaging, normal pancreas shows peak enhancement at 1 minute

Solution of Fractional Order System of Bagley-Torvik Equation Using Evolutionary Computational Intelligence

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Muhammad Asif Zahoor Raja

2011-01-01

Full Text Available A stochastic technique has been developed for the solution of fractional order system represented by Bagley-Torvik equation. The mathematical model of the equation was developed with the help of feed-forward artificial neural networks. The training of the networks was made with evolutionary computational intelligence based on genetic algorithm hybrid with pattern search technique. Designed scheme was successfully applied to different forms of the equation. Results are compared with standard approximate analytic, stochastic numerical solvers and exact solutions.

Evolutionary advantages of adaptive rewarding

International Nuclear Information System (INIS)

Szolnoki, Attila; Perc, Matjaž

2012-01-01

Our well-being depends on both our personal success and the success of our society. The realization of this fact makes cooperation an essential trait. Experiments have shown that rewards can elevate our readiness to cooperate, but since giving a reward inevitably entails paying a cost for it, the emergence and stability of such behavior remains elusive. Here we show that allowing for the act of rewarding to self-organize in dependence on the success of cooperation creates several evolutionary advantages that instill new ways through which collaborative efforts are promoted. Ranging from indirect territorial battle to the spontaneous emergence and destruction of coexistence, phase diagrams and the underlying spatial patterns reveal fascinatingly rich social dynamics that explain why this costly behavior has evolved and persevered. Comparisons with adaptive punishment, however, uncover an Achilles heel of adaptive rewarding, coming from over-aggression, which in turn hinders optimal utilization of network reciprocity. This may explain why, despite its success, rewarding is not as firmly embedded into our societal organization as punishment. (paper)

Evolutionary impact assessment: accounting for evolutionary consequences of fishing in an ecosystem approach to fisheries management.

Science.gov (United States)

Laugen, Ane T; Engelhard, Georg H; Whitlock, Rebecca; Arlinghaus, Robert; Dankel, Dorothy J; Dunlop, Erin S; Eikeset, Anne M; Enberg, Katja; Jørgensen, Christian; Matsumura, Shuichi; Nusslé, Sébastien; Urbach, Davnah; Baulier, Loїc; Boukal, David S; Ernande, Bruno; Johnston, Fiona D; Mollet, Fabian; Pardoe, Heidi; Therkildsen, Nina O; Uusi-Heikkilä, Silva; Vainikka, Anssi; Heino, Mikko; Rijnsdorp, Adriaan D; Dieckmann, Ulf

2014-03-01

Managing fisheries resources to maintain healthy ecosystems is one of the main goals of the ecosystem approach to fisheries (EAF). While a number of international treaties call for the implementation of EAF, there are still gaps in the underlying methodology. One aspect that has received substantial scientific attention recently is fisheries-induced evolution (FIE). Increasing evidence indicates that intensive fishing has the potential to exert strong directional selection on life-history traits, behaviour, physiology, and morphology of exploited fish. Of particular concern is that reversing evolutionary responses to fishing can be much more difficult than reversing demographic or phenotypically plastic responses. Furthermore, like climate change, multiple agents cause FIE, with effects accumulating over time. Consequently, FIE may alter the utility derived from fish stocks, which in turn can modify the monetary value living aquatic resources provide to society. Quantifying and predicting the evolutionary effects of fishing is therefore important for both ecological and economic reasons. An important reason this is not happening is the lack of an appropriate assessment framework. We therefore describe the evolutionary impact assessment (EvoIA) as a structured approach for assessing the evolutionary consequences of fishing and evaluating the predicted evolutionary outcomes of alternative management options. EvoIA can contribute to EAF by clarifying how evolution may alter stock properties and ecological relations, support the precautionary approach to fisheries management by addressing a previously overlooked source of uncertainty and risk, and thus contribute to sustainable fisheries.

Evolutionary Genomics of Life in (and from) the Sea

Energy Technology Data Exchange (ETDEWEB)

Boore, Jeffrey L.; Dehal, Paramvir; Fuerstenberg, Susan I.

2006-01-09

High throughput genome sequencing centers that were originally built for the Human Genome Project (Lander et al., 2001; Venter et al., 2001) have now become an engine for comparative genomics. The six largest centers alone are now producing over 150 billion nucleotides per year, more than 50 times the amount of DNA in the human genome, and nearly all of this is directed at projects that promise great insights into the pattern and processes of evolution. Unfortunately, this data is being produced at a pace far exceeding the capacity of the scientific community to provide insightful analysis, and few scientists with training and experience in evolutionary biology have played prominent roles to date. One of the consequences is that poor quality analyses are typical; for example, orthology among genes is generally determined by simple measures of sequence similarity, when this has been discredited by molecular evolutionary biologists decades ago. Here we discuss the how genomes are chosen for sequencing and how the scientific community can have input. We describe the PhIGs database and web tools (Dehal and Boore 2005a; http://PhIGs.org), which provide phylogenetic analysis of all gene families for all completely sequenced genomes and the associated 'Synteny Viewer', which allows comparisons of the relative positions of orthologous genes. This is the best tool available for inferring gene function across multiple genomes. We also describe how we have used the PhIGs methods with the whole genome sequences of a tunicate, fish, mouse, and human to conclusively demonstrate that two rounds of whole genome duplication occurred at the base of vertebrates (Dehal and Boore 2005b). This evidence is found in the large scale structure of the positions of paralogous genes that arose from duplications inferred by evolutionary analysis to have occurred at the base of vertebrates.

Freud: the first evolutionary psychologist?

Science.gov (United States)

LeCroy, D

2000-04-01

An evolutionary perspective on attachment theory and psychoanalytic theory brings these two fields together in interesting ways. Application of the evolutionary principle of parent-offspring conflict to attachment theory suggests that attachment styles represent context-sensitive, evolved (adaptive) behaviors. In addition, an emphasis on offspring counter-strategies to adult reproductive strategies leads to consideration of attachment styles as overt manifestations of psychodynamic mediating processes, including the defense mechanisms of repression and reaction formation.

Citizen science reveals unexpected continental-scale evolutionary change in a model organism.

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Jonathan Silvertown

2011-04-01

Full Text Available Organisms provide some of the most sensitive indicators of climate change and evolutionary responses are becoming apparent in species with short generation times. Large datasets on genetic polymorphism that can provide an historical benchmark against which to test for recent evolutionary responses are very rare, but an exception is found in the brown-lipped banded snail (Cepaea nemoralis. This species is sensitive to its thermal environment and exhibits several polymorphisms of shell colour and banding pattern affecting shell albedo in the majority of populations within its native range in Europe. We tested for evolutionary changes in shell albedo that might have been driven by the warming of the climate in Europe over the last half century by compiling an historical dataset for 6,515 native populations of C. nemoralis and comparing this with new data on nearly 3,000 populations. The new data were sampled mainly in 2009 through the Evolution MegaLab, a citizen science project that engaged thousands of volunteers in 15 countries throughout Europe in the biggest such exercise ever undertaken. A known geographic cline in the frequency of the colour phenotype with the highest albedo (yellow was shown to have persisted and a difference in colour frequency between woodland and more open habitats was confirmed, but there was no general increase in the frequency of yellow shells. This may have been because snails adapted to a warming climate through behavioural thermoregulation. By contrast, we detected an unexpected decrease in the frequency of Unbanded shells and an increase in the Mid-banded morph. Neither of these evolutionary changes appears to be a direct response to climate change, indicating that the influence of other selective agents, possibly related to changing predation pressure and habitat change with effects on micro-climate.

Sustainability and the anthropogenic alteration of evolutionary processes

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John Cairns, Jr.

2004-08-01

Full Text Available Persuasive evidence indicates that Earth is now experiencing a major biotic crisis. Even if humankind ceases severe stress on natural systems, the crisis will probably disrupt the basic evolutionary processes that characterized the period preceding the agricultural and industrial revolutions.Proliferation of drug and pesticide resistant species and opportunistic species that thrive in human-dominated ecosystems will become increasingly common. The effect on humankind of altering basic evolutionary processes is uncertain because the understanding of these processes is not robust. The probable result will not be an environment as favorable to humans as the one that has existed for most of human history. Humans probably have altered the environment since Homo sapiens first appeared. However, only in the last two centuries has the degree and rate of change reached levels now considered by many people to be ‘normal’, even though the record shows they are not.Greatly improved technology has facilitated increased exploitation of natural resources to unsustainablelevels. This exploitation, in turn, has led to exponential human population growth, which has depleted natural capital (living systems and the services they provide. Economic globalization has ensured that ecosystems far distant from consumers can be and are profitably exploited. Economicgrowth has become a universal mantra that is coupled with a conviction that such growth can continue indefinitely on a finite planet. A major paradigm shift is essential if sustainable use of the planet is to become a reality.

Circadian pattern of blood pressure in normal pregnancy and preeclampsia.

Science.gov (United States)

Gupta, Hem Prabha; Singh, R K; Singh, Urmila; Mehrotra, Seema; Verma, N S; Baranwal, Neelam

2011-08-01

AIMS #ENTITYSTARTX00026; To find out the circadian pattern of blood pressure in normotensive pregnant women and in women with preeclampsia. A cross-sectional prospective observational case control study. Blood pressure was sampled in thirty-five normotensive pregnant women (control) and thirty five preeclamptic women (study group) by using non-invasive automatic ambulatory blood pressure monitoring machine for 72 h. Blood pressure (BP) was not constant over 24 h period and it oscillated from time to time in control group. BP was maximum during early part of afternoon. However, in preeclampsia besides quantitative increase in BP, circadian BP oscillations were less pronounced and in around 50% subjects BP was maximum during evening and night hours. Both systolic and diastolic BP showed definite reproducible circadian pattern in both preeclamptic and normotensive pregnant women. This pattern both quantitatively and qualitatively was different in preeclamptic women. Standardized 24 h BP monitoring allows quantitative and qualitative evaluation of hypertensive status and is important for timing and dosing of antihypertensive medications.

SVD identifies transcript length distribution functions from DNA microarray data and reveals evolutionary forces globally affecting GBM metabolism.

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Nicolas M Bertagnolli

Full Text Available To search for evolutionary forces that might act upon transcript length, we use the singular value decomposition (SVD to identify the length distribution functions of sets and subsets of human and yeast transcripts from profiles of mRNA abundance levels across gel electrophoresis migration distances that were previously measured by DNA microarrays. We show that the SVD identifies the transcript length distribution functions as "asymmetric generalized coherent states" from the DNA microarray data and with no a-priori assumptions. Comparing subsets of human and yeast transcripts of the same gene ontology annotations, we find that in both disparate eukaryotes, transcripts involved in protein synthesis or mitochondrial metabolism are significantly shorter than typical, and in particular, significantly shorter than those involved in glucose metabolism. Comparing the subsets of human transcripts that are overexpressed in glioblastoma multiforme (GBM or normal brain tissue samples from The Cancer Genome Atlas, we find that GBM maintains normal brain overexpression of significantly short transcripts, enriched in transcripts that are involved in protein synthesis or mitochondrial metabolism, but suppresses normal overexpression of significantly longer transcripts, enriched in transcripts that are involved in glucose metabolism and brain activity. These global relations among transcript length, cellular metabolism and tumor development suggest a previously unrecognized physical mode for tumor and normal cells to differentially regulate metabolism in a transcript length-dependent manner. The identified distribution functions support a previous hypothesis from mathematical modeling of evolutionary forces that act upon transcript length in the manner of the restoring force of the harmonic oscillator.

Evolutionary trends of the pharyngeal dentition in Cypriniformes (Actinopterygii: Ostariophysi.

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Emmanuel Pasco-Viel

Full Text Available BACKGROUND: The fish order Cypriniformes is one of the most diverse ray-finned fish groups in the world with more than 3000 recognized species. Cypriniformes are characterized by a striking distribution of their dentition: namely the absence of oral teeth and presence of pharyngeal teeth on the last gill arch (fifth ceratobranchial. Despite this limited localisation, the diversity of tooth patterns in Cypriniformes is astonishing. Here we provide a further description of this diversity using X-ray microtomography and we map the resulting dental characters on a phylogenetic tree to explore evolutionary trends. RESULTS: We performed a pilot survey of dental formulae and individual tooth shapes in 34 adult species of Cypriniformes by X-ray microtomography (using either conventional X-ray machine, or synchrotron microtomography when necessary or by dissecting. By mapping morphological results in a phylogenetic tree, it emerges that the two super-families Cobitoidea and Cyprinoidea have followed two distinct evolutionary pathways. Furthermore, our analysis supports the hypothesis of a three-row dentition as ancestral for Cyprinoidea and a general trend in tooth row reduction in most derived lineages. Yet, this general scheme must be considered with caution as several events of tooth row gain and loss have occurred during evolutionary history of Cyprinoidea. SIGNIFICANCE: Dentition diversity in Cypriniformes constitutes an excellent model to study the evolution of complex morphological structures. This morphological survey clearly advocates for extending the use of X-ray microtomography to study tooth morphology in Cypriniformes. Yet, our survey also underlines that improved knowledge of Cypriniformes life traits, such as feeding habits, is required as current knowledge is not sufficient to conclude on the link between diet and dental morphology.

[Evolutionary medicine: an introduction. Evolutionary biology, a missing element in medical teaching].

Science.gov (United States)

Swynghedauw, Bernard

2009-05-01

The aim of this brief review article is to help to reconcile medicine with evolutionary biology, a subject that should be taught in medical school. Evolutionary medicine takes the view that contemporary ills are related to an incompatibility between the environment in which humans currently live and their genomes, which have been shaped by diferent environmental conditions during biological evolution. Human activity has recently induced acute environmental modifications that have profoundly changed the medical landscape. Evolutionary biology is an irreversible, ongoing and discontinuous process characterized by periods of stasis followed by accelerations. Evolutionary biology is determined by genetic mutations, which are selected either by Darwinian selective pressure or randomly by genetic drift. Most medical events result from a genome/environment conflict. Some may be purely genetic, as in monogenic diseases, and others purely environmental, such as traffic accidents. Nevertheless, in most common diseases the clinical landscape is determined by the conflict between these two factors, the genetic elements of which are gradually being unraveled Three examples are examined in depth:--The medical consequences of the greenhouse effect. The absence of excess mortality during recent heat waves suggests that the main determinant of mortality in the 2003 heatwave was heatstroke and old age. The projected long-term effects of global warming call for research on thermolysis, a forgotten branch of physiology.--The hygiene hypothesis postulates that the exponential rise in autoimmune and allergic diseases is linked to lesser exposure to infectious agents, possibly involving counter-regulatory factors such as IL-10.--The recent rise in the incidence of obesity and type 2 diabetes in rich countries can be considered to result from a conflict between a calorie-rich environment and gene variants that control appetite. These variants are currently being identified by genome

Language Patterns Discriminate Mild Depression From Normal Sadness and Euthymic State.

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Smirnova, Daria; Cumming, Paul; Sloeva, Elena; Kuvshinova, Natalia; Romanov, Dmitry; Nosachev, Gennadii

2018-01-01

Deviations from typical word use have been previously reported in clinical depression, but language patterns of mild depression (MD), as distinct from normal sadness (NS) and euthymic state, are unknown. In this study, we aimed to apply the linguistic approach as an additional diagnostic key for understanding clinical variability along the continuum of affective states. We studied 402 written reports from 124 Russian-speaking patients and 77 healthy controls (HC), including 35 cases of NS, using hand-coding procedures. The focus of our psycholinguistic methods was on lexico-semantic [e.g., rhetorical figures (metaphors, similes)], syntactic [e.g., predominant sentence type (single-clause and multi-clause)], and lexico-grammatical [e.g., pronouns (indefinite, personal)] variables. Statistical evaluations included Cohen's kappa for inter-rater reliability measures, a non-parametric approach (Mann-Whitney U -test and Pearson chi-square test), one-way ANOVA for between-group differences, Spearman's and point-biserial correlations to analyze relationships between linguistic and gender variables, discriminant analysis (Wilks' λ) of linguistic variables in relation to the affective diagnostic types, all using SPSS-22 (significant, p  language, single-clause sentences domination over multi-clause, atypical word order, increased use of personal and indefinite pronouns, and verb use in continuous/imperfective and past tenses. In NS, as compared with HC, we found greater use of lexical repetitions, omission of words, and verbs in continuous and present tenses. MD was significantly differentiated from NS and euthymic state by linguistic variables [98.6%; Wilks' λ(40) = 0.009; p  language use distinguishing depression from NS and euthymic state, which points to a potential role of linguistic indicators in diagnosing affective states.

A Hybrid Chaotic Quantum Evolutionary Algorithm

DEFF Research Database (Denmark)

Cai, Y.; Zhang, M.; Cai, H.

2010-01-01

A hybrid chaotic quantum evolutionary algorithm is proposed to reduce amount of computation, speed up convergence and restrain premature phenomena of quantum evolutionary algorithm. The proposed algorithm adopts the chaotic initialization method to generate initial population which will form a pe...... tests. The presented algorithm is applied to urban traffic signal timing optimization and the effect is satisfied....

Evaluation of CD307a expression patterns during normal B-cell maturation and in B-cell malignancies by flow cytometry.

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Auat, Mariangeles; Cardoso, Chandra Chiappin; Santos-Pirath, Iris Mattos; Rudolf-Oliveira, Renata Cristina Messores; Matiollo, Camila; Lange, Bárbara Gil; da Silva, Jessica Pires; Dametto, Gisele Cristina; Pirolli, Mayara Marin; Colombo, Maria Daniela Holthausen Perico; Santos-Silva, Maria Claudia

2018-02-24

Flow cytometric immunophenotyping is deemed a fundamental tool for the diagnosis of B-cell neoplasms. Currently, the investigation of novel immunophenotypic markers has gained importance, as they can assist in the precise subclassification of B-cell malignancies by flow cytometry. Therefore, the purpose of the present study was to evaluate the expression of CD307a during normal B-cell maturation and in B-cell malignancies as well as to investigate its potential role in the differential diagnosis of these entities. CD307a expression was assessed by flow cytometry in normal precursor and mature B cells and in 115 samples collected from patients diagnosed with precursor and mature B-cell neoplasms. CD307a expression was compared between neoplastic and normal B cells. B-acute lymphoblastic leukemia cases exhibited minimal expression of CD307a, displaying a similar expression pattern to that of normal B-cell precursors. Mantle cell lymphoma (MCL) cases showed the lowest levels of CD307a among mature B-cell neoplasms. CD307a expression was statistically lower in MCL cases than in chronic B lymphocytic leukemia (CLL) and marginal zone lymphoma (MZL) cases. No statistical differences were observed between CD307a expression in neoplastic and normal plasma cells. These results indicate that the assessment of CD307a expression by flow cytometry could be helpful to distinguish CLL from MCL, and the latter from MZL. Although these results are not entirely conclusive, they provide a basis for further studies in a larger cohort of patients. © 2018 International Clinical Cytometry Society. © 2018 International Clinical Cytometry Society.

Evolutionary medicine: its scope, interest and potential.

Science.gov (United States)

Stearns, Stephen C

2012-11-07

This review is aimed at readers seeking an introductory overview, teaching courses and interested in visionary ideas. It first describes the range of topics covered by evolutionary medicine, which include human genetic variation, mismatches to modernity, reproductive medicine, degenerative disease, host-pathogen interactions and insights from comparisons with other species. It then discusses priorities for translational research, basic research and health management. Its conclusions are that evolutionary thinking should not displace other approaches to medical science, such as molecular medicine and cell and developmental biology, but that evolutionary insights can combine with and complement established approaches to reduce suffering and save lives. Because we are on the cusp of so much new research and innovative insights, it is hard to estimate how much impact evolutionary thinking will have on medicine, but it is already clear that its potential is enormous.

Temporal knowledge and autobiographical memory: an evolutionary perspective

OpenAIRE

Skowronski, John J.; Sedikides, Constantine

2007-01-01

Section I: Philosophical issues 1. Evolutionary pyschology in the round , Robin Dunbar & Louise Barrett 2. The power of culture , Henry Plotkin 3. Evolution and psychology in philosophical perspective , Matteo Mameli 4. Niche construction, human behavioural ecology and evolutionary psychology , Kevin N Laland 5. Group level evolutionary processes , David Sloan Wilson Section II: The comparative Approach 6. Homologizing the mind , Drew Rendall, Hugh Nottman & John ...

The ABCs of an evolutionary education science: The academic, behavioral, and cultural implications of an evolutionary approach to education theory and practice

Science.gov (United States)

Kauffman, Rick, Jr.

Calls for improving research-informed policy in education are everywhere. Yet, while there is an increasing trend towards science-based practice, there remains little agreement over which of the sciences to consult and how to organize a collective effort between them. What Education lacks is a general theoretical framework through which policies can be constructed, implemented, and assessed. This dissertation submits that evolutionary theory can provide a suitable framework for coordinating educational policies and practice, and can provide the entire field of education with a clearer sense of how to better manage the learning environment. This dissertation explores two broad paths that outline the conceptual foundations for an Evolutionary Education Science: "Teaching Evolution" and "Using Evolution to Teach." Chapter 1 introduces both of these themes. After describing why evolutionary science is best suited for organizing education research and practice, Chapter 1 proceeds to "teach" an overview of the "evolutionary toolkit"---the mechanisms and principles that underlie the modern evolutionary perspective. The chapter then employs the "toolkit" in examining education from an evolutionary perspective, outlining the evolutionary precepts that can guide theorizing and research in education, describing how educators can "use evolution to teach.". Chapters 2-4 expand on this second theme. Chapters 2 and 3 describe an education program for at-risk 9th and 10th grade students, the Regents Academy, designed entirely with evolutionary principles in mind. The program was rigorously assessed in a randomized control design and has demonstrated success at improving students' academic performance (Chapter 2) and social & behavioral development (Chapter 3). Chapter 4 examines current teaching strategies that underlie effective curriculum-instruction-assessment practices and proposes a framework for organizing successful, evidence-based strategies for neural

Language Patterns Discriminate Mild Depression From Normal Sadness and Euthymic State

Directory of Open Access Journals (Sweden)

Daria Smirnova

2018-04-01

Full Text Available ObjectivesDeviations from typical word use have been previously reported in clinical depression, but language patterns of mild depression (MD, as distinct from normal sadness (NS and euthymic state, are unknown. In this study, we aimed to apply the linguistic approach as an additional diagnostic key for understanding clinical variability along the continuum of affective states.MethodsWe studied 402 written reports from 124 Russian-speaking patients and 77 healthy controls (HC, including 35 cases of NS, using hand-coding procedures. The focus of our psycholinguistic methods was on lexico-semantic [e.g., rhetorical figures (metaphors, similes], syntactic [e.g., predominant sentence type (single-clause and multi-clause], and lexico-grammatical [e.g., pronouns (indefinite, personal] variables. Statistical evaluations included Cohen’s kappa for inter-rater reliability measures, a non-parametric approach (Mann–Whitney U-test and Pearson chi-square test, one-way ANOVA for between-group differences, Spearman’s and point-biserial correlations to analyze relationships between linguistic and gender variables, discriminant analysis (Wilks’ λ of linguistic variables in relation to the affective diagnostic types, all using SPSS-22 (significant, p < 0.05.ResultsIn MD, as compared with healthy individuals, written responses were longer, demonstrated descriptive rather than analytic style, showed signs of spoken and figurative language, single-clause sentences domination over multi-clause, atypical word order, increased use of personal and indefinite pronouns, and verb use in continuous/imperfective and past tenses. In NS, as compared with HC, we found greater use of lexical repetitions, omission of words, and verbs in continuous and present tenses. MD was significantly differentiated from NS and euthymic state by linguistic variables [98.6%; Wilks’ λ(40 = 0.009; p < 0.001; r = 0.992]. The highest predictors in discrimination between

Evolutionary Game Theory: A Renaissance

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Jonathan Newton

2018-05-01

Full Text Available Economic agents are not always rational or farsighted and can make decisions according to simple behavioral rules that vary according to situation and can be studied using the tools of evolutionary game theory. Furthermore, such behavioral rules are themselves subject to evolutionary forces. Paying particular attention to the work of young researchers, this essay surveys the progress made over the last decade towards understanding these phenomena, and discusses open research topics of importance to economics and the broader social sciences.

Erythropoietin improves place learning in fimbria-fornix-transected rats and modifies the search pattern of normal rats

DEFF Research Database (Denmark)

Mogensen, Jesper; Miskowiak, Kamilla; Sørensen, Thomas Alrik

2004-01-01

administration of EPO significantly improves the posttraumatic functional recovery of the presently studied place learning task after transections of the fimbria-fornix. Additionally, administration of EPO influences the strategy, although not quality, of task solution in normal (sham-operated) rats.......The acquisition of a water-maze-based allocentric place learning task was studied in four groups of rats: two groups subjected to bilateral transections of the fimbria-fornix and two groups undergoing a sham control operation. At the moment of surgery all animals were given one systemic......-associated impairment. The two sham-operated groups did not differ with respect to the proficiency of task acquisition. But administration of EPO to intact animals caused a significant modification of swim patterns-apparently reflecting a somewhat modified strategy of task solution. It is concluded that systemic...

Evolutionary constrained optimization

CERN Document Server

Deb, Kalyanmoy

2015-01-01

This book makes available a self-contained collection of modern research addressing the general constrained optimization problems using evolutionary algorithms. Broadly the topics covered include constraint handling for single and multi-objective optimizations; penalty function based methodology; multi-objective based methodology; new constraint handling mechanism; hybrid methodology; scaling issues in constrained optimization; design of scalable test problems; parameter adaptation in constrained optimization; handling of integer, discrete and mix variables in addition to continuous variables; application of constraint handling techniques to real-world problems; and constrained optimization in dynamic environment. There is also a separate chapter on hybrid optimization, which is gaining lots of popularity nowadays due to its capability of bridging the gap between evolutionary and classical optimization. The material in the book is useful to researchers, novice, and experts alike. The book will also be useful...

Principal component analysis of normalized full spectrum mass spectrometry data in multiMS-toolbox: An effective tool to identify important factors for classification of different metabolic patterns and bacterial strains.

Science.gov (United States)

Cejnar, Pavel; Kuckova, Stepanka; Prochazka, Ales; Karamonova, Ludmila; Svobodova, Barbora

2018-06-15

Explorative statistical analysis of mass spectrometry data is still a time-consuming step. We analyzed critical factors for application of principal component analysis (PCA) in mass spectrometry and focused on two whole spectrum based normalization techniques and their application in the analysis of registered peak data and, in comparison, in full spectrum data analysis. We used this technique to identify different metabolic patterns in the bacterial culture of Cronobacter sakazakii, an important foodborne pathogen. Two software utilities, the ms-alone, a python-based utility for mass spectrometry data preprocessing and peak extraction, and the multiMS-toolbox, an R software tool for advanced peak registration and detailed explorative statistical analysis, were implemented. The bacterial culture of Cronobacter sakazakii was cultivated on Enterobacter sakazakii Isolation Agar, Blood Agar Base and Tryptone Soya Agar for 24 h and 48 h and applied by the smear method on an Autoflex speed MALDI-TOF mass spectrometer. For three tested cultivation media only two different metabolic patterns of Cronobacter sakazakii were identified using PCA applied on data normalized by two different normalization techniques. Results from matched peak data and subsequent detailed full spectrum analysis identified only two different metabolic patterns - a cultivation on Enterobacter sakazakii Isolation Agar showed significant differences to the cultivation on the other two tested media. The metabolic patterns for all tested cultivation media also proved the dependence on cultivation time. Both whole spectrum based normalization techniques together with the full spectrum PCA allow identification of important discriminative factors in experiments with several variable condition factors avoiding any problems with improper identification of peaks or emphasis on bellow threshold peak data. The amounts of processed data remain still manageable. Both implemented software utilities are available

Evolution of microgastropods (Ellobioidea, Carychiidae): integrating taxonomic, phylogenetic and evolutionary hypotheses

Science.gov (United States)

2013-01-01

Background Current biodiversity patterns are considered largely the result of past climatic and tectonic changes. In an integrative approach, we combine taxonomic and phylogenetic hypotheses to analyze temporal and geographic diversification of epigean (Carychium) and subterranean (Zospeum) evolutionary lineages in Carychiidae (Eupulmonata, Ellobioidea). We explicitly test three hypotheses: 1) morphospecies encompass unrecognized evolutionary lineages, 2) limited dispersal results in a close genetic relationship of geographical proximally distributed taxa and 3) major climatic and tectonic events had an impact on lineage diversification within Carychiidae. Results Initial morphospecies assignments were investigated by different molecular delimitation approaches (threshold, ABGD, GMYC and SP). Despite a conservative delimitation strategy, carychiid morphospecies comprise a great number of unrecognized evolutionary lineages. We attribute this phenomenon to historic underestimation of morphological stasis and phenotypic variability amongst lineages. The first molecular phylogenetic hypothesis for the Carychiidae (based on COI, 16S and H3) reveals Carychium and Zospeum to be reciprocally monophyletic. Geographical proximally distributed lineages are often closely related. The temporal diversification of Carychiidae is best described by a constant rate model of diversification. The evolution of Carychiidae is characterized by relatively few (long distance) colonization events. We find support for an Asian origin of Carychium. Zospeum may have arrived in Europe before extant members of Carychium. Distantly related Carychium clades inhabit a wide spectrum of the available bioclimatic niche and demonstrate considerable niche overlap. Conclusions Carychiid taxonomy is in dire need of revision. An inferred wide distribution and variable phenotype suggest underestimated diversity in Zospeum. Several Carychium morphospecies are results of past taxonomic lumping. By collecting

Evolutionary Computation and Its Applications in Neural and Fuzzy Systems

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Biaobiao Zhang

2011-01-01

Full Text Available Neural networks and fuzzy systems are two soft-computing paradigms for system modelling. Adapting a neural or fuzzy system requires to solve two optimization problems: structural optimization and parametric optimization. Structural optimization is a discrete optimization problem which is very hard to solve using conventional optimization techniques. Parametric optimization can be solved using conventional optimization techniques, but the solution may be easily trapped at a bad local optimum. Evolutionary computation is a general-purpose stochastic global optimization approach under the universally accepted neo-Darwinian paradigm, which is a combination of the classical Darwinian evolutionary theory, the selectionism of Weismann, and the genetics of Mendel. Evolutionary algorithms are a major approach to adaptation and optimization. In this paper, we first introduce evolutionary algorithms with emphasis on genetic algorithms and evolutionary strategies. Other evolutionary algorithms such as genetic programming, evolutionary programming, particle swarm optimization, immune algorithm, and ant colony optimization are also described. Some topics pertaining to evolutionary algorithms are also discussed, and a comparison between evolutionary algorithms and simulated annealing is made. Finally, the application of EAs to the learning of neural networks as well as to the structural and parametric adaptations of fuzzy systems is also detailed.

The integration of Darwinism and evolutionary morphology: Alexej Nikolajevich Sewertzoff (1866-1936) and the developmental basis of evolutionary change.

Science.gov (United States)

Levit, George S; Hossfeld, Uwe; Olsson, Lennart

2004-07-15

The growth of evolutionary morphology in the late 19th and early 20th centuries was inspired by the work of Carl Gegenbaur (1826-1903) and his protégé and friend Ernst Haeckel (1834-1919). However, neither of them succeeded in creating and applying a strictly Darwinian (selectionist) methodology. This task was left to the next generation of evolutionary morphologists. In this paper we present a relatively unknown researcher, Alexej Nikolajevich Sewertzoff (1866-1936) who made important contributions towards a synthesis of Darwinism and evolutionary morphology. Copyright 2004 Wiley-Liss, Inc.

Evolutionary dynamics with fluctuating population sizes and strong mutualism

Science.gov (United States)

Chotibut, Thiparat; Nelson, David R.

2015-08-01

Game theory ideas provide a useful framework for studying evolutionary dynamics in a well-mixed environment. This approach, however, typically enforces a strictly fixed overall population size, deemphasizing natural growth processes. We study a competitive Lotka-Volterra model, with number fluctuations, that accounts for natural population growth and encompasses interaction scenarios typical of evolutionary games. We show that, in an appropriate limit, the model describes standard evolutionary games with both genetic drift and overall population size fluctuations. However, there are also regimes where a varying population size can strongly influence the evolutionary dynamics. We focus on the strong mutualism scenario and demonstrate that standard evolutionary game theory fails to describe our simulation results. We then analytically and numerically determine fixation probabilities as well as mean fixation times using matched asymptotic expansions, taking into account the population size degree of freedom. These results elucidate the interplay between population dynamics and evolutionary dynamics in well-mixed systems.

Evolutionary dynamics with fluctuating population sizes and strong mutualism.

Science.gov (United States)

Chotibut, Thiparat; Nelson, David R

2015-08-01

Game theory ideas provide a useful framework for studying evolutionary dynamics in a well-mixed environment. This approach, however, typically enforces a strictly fixed overall population size, deemphasizing natural growth processes. We study a competitive Lotka-Volterra model, with number fluctuations, that accounts for natural population growth and encompasses interaction scenarios typical of evolutionary games. We show that, in an appropriate limit, the model describes standard evolutionary games with both genetic drift and overall population size fluctuations. However, there are also regimes where a varying population size can strongly influence the evolutionary dynamics. We focus on the strong mutualism scenario and demonstrate that standard evolutionary game theory fails to describe our simulation results. We then analytically and numerically determine fixation probabilities as well as mean fixation times using matched asymptotic expansions, taking into account the population size degree of freedom. These results elucidate the interplay between population dynamics and evolutionary dynamics in well-mixed systems.

Islamic medicine and evolutionary medicine: a comparative analysis.

Science.gov (United States)

Saniotis, Arthur

2012-01-01

The advent of evolutionary medicine in the last two decades has provided new insights into the causes of human disease and possible preventative strategies. One of the strengths of evolutionary medicine is that it follows a multi-disciplinary approach. Such an approach is vital to future biomedicine as it enables for the infiltration of new ideas. Although evolutionary medicine uses Darwinian evolution as a heuristic for understanding human beings' susceptibility to disease, this is not necessarily in conflict with Islamic medicine. It should be noted that current evolutionary theory was first expounded by various Muslim scientists such as al-Jāḥiẓ, al-Ṭūsī, Ibn Khaldūn and Ibn Maskawayh centuries before Darwin and Wallace. In this way, evolution should not be viewed as being totally antithetical to Islam. This article provides a comparative overview of Islamic medicine and Evolutionary medicine as well as drawing points of comparison between the two approaches which enables their possible future integration.

[Evolutionary perspective in precocious puberty].

Science.gov (United States)

Hochberg, Ze'ev

2014-10-01

Pubertal development is subject to substantial heritability, but much variation remains to be explained, including fast changes over the last 150 years, that cannot be explained by changes of gene frequency in the population. This article discusses the influence of environmental factors to adjust maturational tempo in the service of fitness goals. Utilizing evolutionary development thinking (evo-devo), the author examines adolescence as an evolutionary life-history stage in its developmental context. The transition from the preceding stage of juvenility entails adaptive plasticity in response to energy resources, social needs of adolescence and maturation toward youth and adulthood. Using Belsky's evolutionary theory of socialization, I show that familial psychosocial environment during the infancy-childhood and childhood-juvenility transitions foster a fast life-history and reproductive strategy rather than early maturation being just a risk factor for aggression and delinquency. The implications of the evo-devo framework for theory building, illuminates new directions in the understanding of precocious puberty other than a diagnosis of a disease.

Evolutionary engineering for industrial microbiology.

Science.gov (United States)

Vanee, Niti; Fisher, Adam B; Fong, Stephen S

2012-01-01

Superficially, evolutionary engineering is a paradoxical field that balances competing interests. In natural settings, evolution iteratively selects and enriches subpopulations that are best adapted to a particular ecological niche using random processes such as genetic mutation. In engineering desired approaches utilize rational prospective design to address targeted problems. When considering details of evolutionary and engineering processes, more commonality can be found. Engineering relies on detailed knowledge of the problem parameters and design properties in order to predict design outcomes that would be an optimized solution. When detailed knowledge of a system is lacking, engineers often employ algorithmic search strategies to identify empirical solutions. Evolution epitomizes this iterative optimization by continuously diversifying design options from a parental design, and then selecting the progeny designs that represent satisfactory solutions. In this chapter, the technique of applying the natural principles of evolution to engineer microbes for industrial applications is discussed to highlight the challenges and principles of evolutionary engineering.

Handbook of differential equations evolutionary equations

CERN Document Server

Dafermos, CM

2008-01-01

The material collected in this volume discusses the present as well as expected future directions of development of the field with particular emphasis on applications. The seven survey articles present different topics in Evolutionary PDE's, written by leading experts.- Review of new results in the area- Continuation of previous volumes in the handbook series covering Evolutionary PDEs- Written by leading experts

The evolutionary rates of HCV estimated with subtype 1a and 1b sequences over the ORF length and in different genomic regions.

Directory of Open Access Journals (Sweden)

Manqiong Yuan

Full Text Available Considerable progress has been made in the HCV evolutionary analysis, since the software BEAST was released. However, prior information, especially the prior evolutionary rate, which plays a critical role in BEAST analysis, is always difficult to ascertain due to various uncertainties. Providing a proper prior HCV evolutionary rate is thus of great importance.176 full-length sequences of HCV subtype 1a and 144 of 1b were assembled by taking into consideration the balance of the sampling dates and the even dispersion in phylogenetic trees. According to the HCV genomic organization and biological functions, each dataset was partitioned into nine genomic regions and two routinely amplified regions. A uniform prior rate was applied to the BEAST analysis for each region and also the entire ORF. All the obtained posterior rates for 1a are of a magnitude of 10(-3 substitutions/site/year and in a bell-shaped distribution. Significantly lower rates were estimated for 1b and some of the rate distribution curves resulted in a one-sided truncation, particularly under the exponential model. This indicates that some of the rates for subtype 1b are less accurate, so they were adjusted by including more sequences to improve the temporal structure.Among the various HCV subtypes and genomic regions, the evolutionary patterns are dissimilar. Therefore, an applied estimation of the HCV epidemic history requires the proper selection of the rate priors, which should match the actual dataset so that they can fit for the subtype, the genomic region and even the length. By referencing the findings here, future evolutionary analysis of the HCV subtype 1a and 1b datasets may become more accurate and hence prove useful for tracing their patterns.

Sixty-Five Million Years of Change in Temperature and Topography Explain Evolutionary History in Eastern North American Plethodontid Salamanders.

Science.gov (United States)

Barnes, Richard; Clark, Adam Thomas

2017-07-01

For many taxa and systems, species richness peaks at midelevations. One potential explanation for this pattern is that large-scale changes in climate and geography have, over evolutionary time, selected for traits that are favored under conditions found in contemporary midelevation regions. To test this hypothesis, we use records of historical temperature and topographic changes over the past 65 Myr to construct a general simulation model of plethodontid salamander evolution in eastern North America. We then explore possible mechanisms constraining species to midelevation bands by using the model to predict plethodontid evolutionary history and contemporary geographic distributions. Our results show that models that incorporate both temperature and topographic changes are better able to predict these patterns, suggesting that both processes may have played an important role in driving plethodontid evolution in the region. Additionally, our model (whose annotated source code is included as a supplement) represents a proof of concept to encourage future work that takes advantage of recent advances in computing power to combine models of ecology, evolution, and earth history to better explain the abundance and distribution of species over time.

Evo-devo of novel traits : the genetic basis of butterfly colour patterns

NARCIS (Netherlands)

Saenko, Suzanne Viatcheslavovna

2010-01-01

The origin and diversification of novel morphological traits is a major research theme in evolutionary developmental biology, or evo-devo. Wing patterns of butterflies, in particular eyespots, are lineage-specific novelties crucial for visual communication. This thesis explores different aspects of

Evolutionary algorithms for mobile ad hoc networks

CERN Document Server

Dorronsoro, Bernabé; Danoy, Grégoire; Pigné, Yoann; Bouvry, Pascal

2014-01-01

Describes how evolutionary algorithms (EAs) can be used to identify, model, and minimize day-to-day problems that arise for researchers in optimization and mobile networking. Mobile ad hoc networks (MANETs), vehicular networks (VANETs), sensor networks (SNs), and hybrid networks—each of these require a designer’s keen sense and knowledge of evolutionary algorithms in order to help with the common issues that plague professionals involved in optimization and mobile networking. This book introduces readers to both mobile ad hoc networks and evolutionary algorithms, presenting basic concepts as well as detailed descriptions of each. It demonstrates how metaheuristics and evolutionary algorithms (EAs) can be used to help provide low-cost operations in the optimization process—allowing designers to put some “intelligence” or sophistication into the design. It also offers efficient and accurate information on dissemination algorithms topology management, and mobility models to address challenges in the ...

Physical Activity Patterns in Normal-Weight and Overweight/Obese Pregnant Women.

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Elisabetta Bacchi

Full Text Available The aims of the present study were to assess the volume of physical activity (PA throughout pregnancy in normal-weight vs overweight/obese women, and to investigate which factors may predict compliance to PA recommendations in these women throughout gestation. In 236 pregnant women, 177 normal-weight and 59 overweight/obese (median[IQR] BMI 21.2[19.9-22.8] vs 26.5[25.5-29.0] kg/m2, respectively, medical history, anthropometry and clinical data, including glucose tolerance, were recorded. In addition, pre-pregnancy PA was estimated by the Kaiser questionnaire, while total, walking and fitness/sport PA during pregnancy were assessed by the Physical Activity Scale for the Elderly (PASE modified questionnaire, at 14-16, 24-28 and 30-32 weeks of gestation. PA volume was very low in the first trimester of pregnancy in both groups of women. However, it increased in the second and third trimester in normal-weight, but not in overweight/obese subjects. Higher pre-pregnancy PA was a statistically significant predictor of being physically active (>150 minutes of PA per week during all trimesters of gestation. In conclusion, physical activity volume is low in pregnant women, especially in overweight/obese subjects. PA volume increases during pregnancy only in normal-weight women. Pre-pregnancy PA is an independent predictor of achieving a PA volume of at least 150 min per week during pregnancy.

Stochastic win-stay-lose-shift strategy with dynamic aspirations in evolutionary social dilemmas

Science.gov (United States)

Amaral, Marco A.; Wardil, Lucas; Perc, Matjaž; da Silva, Jafferson K. L.

2016-09-01

In times of plenty expectations rise, just as in times of crisis they fall. This can be mathematically described as a win-stay-lose-shift strategy with dynamic aspiration levels, where individuals aspire to be as wealthy as their average neighbor. Here we investigate this model in the realm of evolutionary social dilemmas on the square lattice and scale-free networks. By using the master equation and Monte Carlo simulations, we find that cooperators coexist with defectors in the whole phase diagram, even at high temptations to defect. We study the microscopic mechanism that is responsible for the striking persistence of cooperative behavior and find that cooperation spreads through second-order neighbors, rather than by means of network reciprocity that dominates in imitation-based models. For the square lattice the master equation can be solved analytically in the large temperature limit of the Fermi function, while for other cases the resulting differential equations must be solved numerically. Either way, we find good qualitative agreement with the Monte Carlo simulation results. Our analysis also reveals that the evolutionary outcomes are to a large degree independent of the network topology, including the number of neighbors that are considered for payoff determination on lattices, which further corroborates the local character of the microscopic dynamics. Unlike large-scale spatial patterns that typically emerge due to network reciprocity, here local checkerboard-like patterns remain virtually unaffected by differences in the macroscopic properties of the interaction network.

Evolutionary change in physiological phenotypes along the human lineage.

Science.gov (United States)

Vining, Alexander Q; Nunn, Charles L

2016-01-01

Research in evolutionary medicine provides many examples of how evolution has shaped human susceptibility to disease. Traits undergoing rapid evolutionary change may result in associated costs or reduce the energy available to other traits. We hypothesize that humans have experienced more such changes than other primates as a result of major evolutionary change along the human lineage. We investigated 41 physiological traits across 50 primate species to identify traits that have undergone marked evolutionary change along the human lineage. We analysed the data using two Bayesian phylogenetic comparative methods. One approach models trait covariation in non-human primates and predicts human phenotypes to identify whether humans are evolutionary outliers. The other approach models adaptive shifts under an Ornstein-Uhlenbeck model of evolution to assess whether inferred shifts are more common on the human branch than on other primate lineages. We identified four traits with strong evidence for an evolutionary increase on the human lineage (amylase, haematocrit, phosphorus and monocytes) and one trait with strong evidence for decrease (neutrophilic bands). Humans exhibited more cases of distinct evolutionary change than other primates. Human physiology has undergone increased evolutionary change compared to other primates. Long distance running may have contributed to increases in haematocrit and mean corpuscular haemoglobin concentration, while dietary changes are likely related to increases in amylase. In accordance with the pathogen load hypothesis, human monocyte levels were increased, but many other immune-related measures were not. Determining the mechanisms underlying conspicuous evolutionary change in these traits may provide new insights into human disease. The Author(s) 2016. Published by Oxford University Press on behalf of the Foundation for Evolution, Medicine, and Public Health.

Ectocranial suture fusion in primates: pattern and phylogeny.

Science.gov (United States)

Cray, James; Cooper, Gregory M; Mooney, Mark P; Siegel, Michael I

2014-03-01

Patterns of ectocranial suture fusion among Primates are subject to species-specific variation. In this study, we used Guttman Scaling to compare modal progression of ectocranial suture fusion among Hominidae (Homo, Pan, Gorilla, and Pongo), Hylobates, and Cercopithecidae (Macaca and Papio) groups. Our hypothesis is that suture fusion patterns should reflect their evolutionary relationship. For the lateral-anterior suture sites there appear to be three major patterns of fusion, one shared by Homo-Pan-Gorilla, anterior to posterior; one shared by Pongo and Hylobates, superior to inferior; and one shared by Cercopithecidae, posterior to anterior. For the vault suture pattern, the Hominidae groups reflect the known phylogeny. The data for Hylobates and Cercopithecidae groups is less clear. The vault suture site termination pattern of Papio is similar to that reported for Gorilla and Pongo. Thus, it may be that some suture sites are under larger genetic influence for patterns of fusion, while others are influenced by environmental/biomechanic influences. Copyright © 2013 Wiley Periodicals, Inc.

Comparing Evolutionary Strategies on a Biobjective Cultural Algorithm

Directory of Open Access Journals (Sweden)

Carolina Lagos

2014-01-01

Full Text Available Evolutionary algorithms have been widely used to solve large and complex optimisation problems. Cultural algorithms (CAs are evolutionary algorithms that have been used to solve both single and, to a less extent, multiobjective optimisation problems. In order to solve these optimisation problems, CAs make use of different strategies such as normative knowledge, historical knowledge, circumstantial knowledge, and among others. In this paper we present a comparison among CAs that make use of different evolutionary strategies; the first one implements a historical knowledge, the second one considers a circumstantial knowledge, and the third one implements a normative knowledge. These CAs are applied on a biobjective uncapacitated facility location problem (BOUFLP, the biobjective version of the well-known uncapacitated facility location problem. To the best of our knowledge, only few articles have applied evolutionary multiobjective algorithms on the BOUFLP and none of those has focused on the impact of the evolutionary strategy on the algorithm performance. Our biobjective cultural algorithm, called BOCA, obtains important improvements when compared to other well-known evolutionary biobjective optimisation algorithms such as PAES and NSGA-II. The conflicting objective functions considered in this study are cost minimisation and coverage maximisation. Solutions obtained by each algorithm are compared using a hypervolume S metric.

A comparative study of deficit pattern in theory of mind and emotion regulation methods in evaluating patients with bipolar disorder and normal individuals

OpenAIRE

Ali Fakhari; Khalegh Minashiri; Abolfazl Fallahi; Mohammad Taher Panah

2013-01-01

BACKGROUND: This study compared patterns of deficit in "theory of mind" and "emotion regulation" in patientswith bipolar disorder and normal individuals. METHODS: In this causal-comparative study, subjects were 20 patients with bipolar disorder and 20 normalindividuals. Patients were selected via convenience sampling method among hospitalized patients at Razi hospital ofTabriz, Iran. The data was collected through two scales: Reading the Mind in the Eyes Test and Emotion RegulationQuestionnai...

Marrow pattern in the proximal femoral metaphysis of patients with osteonecrosis of femoral head and normal subjects: comparison on MR images

International Nuclear Information System (INIS)

Chun, Ho Jong; Park, Jeong Mi; Kim, Jee Young; Lim, Gye Yeon; Yang, Po Song; Kim, Euy Neyong; Kim, Choon Yul; Shinn, Kyung Sub

1996-01-01

To predict early risk of osteonecrosis of the femoral head by comparison of the bone marrow pattern of the proximal femoral metaphysis(PFM) in normal subjects and patients with osteonecrosis of the femoral head on T1-weighted magnetic resonance(MR) images. The authors retrospectively reviewed T1(TR 525/TE 25 msec) weighted coronal MR images of 67 hips with osteonecrosis and 65 normal hips in 39 patients with osteonecrosis of the femoral head and in 27 normal subjects. On the basis of bright signal intensity of fat, the proportion of remaining hematopoietic marrow in PFM was subdivided into 4 grades (0 to 3) by two radiologists. No evidence of remaining hematopoietic marrow was assigned grade 0, and grades 1, 2 and 3 represented scanty, moderate, and prominent hematopoietic marrow, respectively. Grades 0 and 1 were collectively defined as 'predominantly fatty', grades 2 and 3 as 'predominantly hematopoietic'. The frequency of the predominantly fatty marrow in PFM was analyzed in relation to three age groups (<25, 25-50, 50<) and both sexes. The overall frequency of predominantly fatty marrow in PFM was higher in hips with osteonecrosis than in normal hips (p<0.001). Especially in the male population under the age of 50, the frequency was apparently higher in hips with osteonecrosis, compared with normal hips (p<0.0001). However, the male population aged over 50 or female population showed no statistically significant difference in our series. In proximal femoral metaphysis with osteonecrosis of the femoral head, fatty marrow conversion occurs apparently earlier than in normal subject. T1-weighted MR imaging could therefore be useful in predicting early risk of osteonecrosis of the femoral head because of early fatty marrow conversion of the proximal femoral metaphysis

MultiSeq: unifying sequence and structure data for evolutionary analysis

Directory of Open Access Journals (Sweden)

Wright Dan

2006-08-01

Full Text Available Abstract Background Since the publication of the first draft of the human genome in 2000, bioinformatic data have been accumulating at an overwhelming pace. Currently, more than 3 million sequences and 35 thousand structures of proteins and nucleic acids are available in public databases. Finding correlations in and between these data to answer critical research questions is extremely challenging. This problem needs to be approached from several directions: information science to organize and search the data; information visualization to assist in recognizing correlations; mathematics to formulate statistical inferences; and biology to analyze chemical and physical properties in terms of sequence and structure changes. Results Here we present MultiSeq, a unified bioinformatics analysis environment that allows one to organize, display, align and analyze both sequence and structure data for proteins and nucleic acids. While special emphasis is placed on analyzing the data within the framework of evolutionary biology, the environment is also flexible enough to accommodate other usage patterns. The evolutionary approach is supported by the use of predefined metadata, adherence to standard ontological mappings, and the ability for the user to adjust these classifications using an electronic notebook. MultiSeq contains a new algorithm to generate complete evolutionary profiles that represent the topology of the molecular phylogenetic tree of a homologous group of distantly related proteins. The method, based on the multidimensional QR factorization of multiple sequence and structure alignments, removes redundancy from the alignments and orders the protein sequences by increasing linear dependence, resulting in the identification of a minimal basis set of sequences that spans the evolutionary space of the homologous group of proteins. Conclusion MultiSeq is a major extension of the Multiple Alignment tool that is provided as part of VMD, a structural

On economic applications of evolutionary game theory

OpenAIRE

Daniel Friedman

1998-01-01

Evolutionary games have considerable unrealized potential for modeling substantive economic issues. They promise richer predictions than orthodox game models but often require more extensive specifications. This paper exposits the specification of evolutionary game models and classifies the possible asymptotic behavior for one and two dimensional models.

On the Evolutionary Stability of Bargaining Inefficiency

DEFF Research Database (Denmark)

Poulsen, Anders

This paper investigates whether 'tough' bargaining behavior, which gives rise to inefficiency, can be evolutionary stable. We show that in a two-stage Nash Demand Game tough behavior survives. Indeed, almost all the surplus may be wasted. We also study the Ultimatum Game. Here evolutionary select...

Evolutionary Robotics: What, Why, and Where to

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Stephane eDoncieux

2015-03-01

Full Text Available Evolutionary robotics applies the selection, variation, and heredity principles of natural evolution to the design of robots with embodied intelligence. It can be considered as a subfield of robotics that aims to create more robust and adaptive robots. A pivotal feature of the evolutionary approach is that it considers the whole robot at once, and enables the exploitation of robot features in a holistic manner. Evolutionary robotics can also be seen as an innovative approach to the study of evolution based on a new kind of experimentalism. The use of robots as a substrate can help address questions that are difficult, if not impossible, to investigate through computer simulations or biological studies. In this paper we consider the main achievements of evolutionary robotics, focusing particularly on its contributions to both engineering and biology. We briefly elaborate on methodological issues, review some of the most interesting findings, and discuss important open issues and promising avenues for future work.

Evolutionary ethics from Darwin to Moore.

Science.gov (United States)

Allhoff, Fritz

2003-01-01

Evolutionary ethics has a long history, dating all the way back to Charles Darwin. Almost immediately after the publication of the Origin, an immense interest arose in the moral implications of Darwinism and whether the truth of Darwinism would undermine traditional ethics. Though the biological thesis was certainly exciting, nobody suspected that the impact of the Origin would be confined to the scientific arena. As one historian wrote, 'whether or not ancient populations of armadillos were transformed into the species that currently inhabit the new world was certainly a topic about which zoologists could disagree. But it was in discussing the broader implications of the theory...that tempers flared and statements were made which could transform what otherwise would have been a quiet scholarly meeting into a social scandal' (Farber 1994, 22). Some resistance to the biological thesis of Darwinism sprung from the thought that it was incompatible with traditional morality and, since one of them had to go, many thought that Darwinism should be rejected. However, some people did realize that a secular ethics was possible so, even if Darwinism did undermine traditional religious beliefs, it need not have any effects on moral thought. Before I begin my discussion of evolutionary ethics from Darwin to Moore, I would like to make some more general remarks about its development. There are three key events during this history of evolutionary ethics. First, Charles Darwin published On the Origin of the Species (Darwin 1859). Since one did not have a fully developed theory of evolution until 1859, there exists little work on evolutionary ethics until then. Shortly thereafter, Herbert Spencer (1898) penned the first systematic theory of evolutionary ethics, which was promptly attacked by T.H. Huxley (Huxley 1894). Second, at about the turn of the century, moral philosophers entered the fray and attempted to demonstrate logical errors in Spencer's work; such errors were alluded

Evolutionary adaptations: theoretical and practical implications for visual ergonomics.

Science.gov (United States)

Fostervold, Knut Inge; Watten, Reidulf G; Volden, Frode

2014-01-01

The literature discussing visual ergonomics often mention that human vision is adapted to light emitted by the sun. However, theoretical and practical implications of this viewpoint is seldom discussed or taken into account. The paper discusses some of the main theoretical implications of an evolutionary approach to visual ergonomics. Based on interactional theory and ideas from ecological psychology an evolutionary stress model is proposed as a theoretical framework for future research in ergonomics and human factors. The model stresses the importance of developing work environments that fits with our evolutionary adaptations. In accordance with evolutionary psychology, the environment of evolutionary adaptedness (EEA) and evolutionarily-novel environments (EN) are used as key concepts. Using work with visual display units (VDU) as an example, the paper discusses how this knowledge can be utilized in an ergonomic analysis of risk factors in the work environment. The paper emphasises the importance of incorporating evolutionary theory in the field of ergonomics. Further, the paper encourages scientific practices that further our understanding of any phenomena beyond the borders of traditional proximal explanations.

Semantic error patterns on the Boston Naming Test in normal aging, amnestic mild cognitive impairment, and mild Alzheimer's disease: is there semantic disruption?

Science.gov (United States)

Balthazar, Marcio Luiz Figueredo; Cendes, Fernando; Damasceno, Benito Pereira

2008-11-01

Naming difficulty is common in Alzheimer's disease (AD), but the nature of this problem is not well established. The authors investigated the presence of semantic breakdown and the pattern of general and semantic errors in patients with mild AD, patients with amnestic mild cognitive impairment (aMCI), and normal controls by examining their spontaneous answers on the Boston Naming Test (BNT) and verifying whether they needed or were benefited by semantic and phonemic cues. The errors in spontaneous answers were classified in four mutually exclusive categories (semantic errors, visual paragnosia, phonological errors, and omission errors), and the semantic errors were further subclassified as coordinate, superordinate, and circumlocutory. Patients with aMCI performed normally on the BNT and needed fewer semantic and phonemic cues than patients with mild AD. After semantic cues, subjects with aMCI and control subjects gave more correct answers than patients with mild AD, but after phonemic cues, there was no difference between the three groups, suggesting that the low performance of patients with AD cannot be completely explained by semantic breakdown. Patterns of spontaneous naming errors and subtypes of semantic errors were similar in the three groups, with decreasing error frequency from coordinate to superordinate to circumlocutory subtypes.

3D computational mechanics elucidate the evolutionary implications of orbit position and size diversity of early amphibians.

Directory of Open Access Journals (Sweden)

Jordi Marcé-Nogué

Full Text Available For the first time in vertebrate palaeontology, the potential of joining Finite Element Analysis (FEA and Parametrical Analysis (PA is used to shed new light on two different cranial parameters from the orbits to evaluate their biomechanical role and evolutionary patterns. The early tetrapod group of Stereospondyls, one of the largest groups of Temnospondyls is used as a case study because its orbits position and size vary hugely within the members of this group. An adult skull of Edingerella madagascariensis was analysed using two different cases of boundary and loading conditions in order to quantify stress and deformation response under a bilateral bite and during skull raising. Firstly, the variation of the original geometry of its orbits was introduced in the models producing new FEA results, allowing the exploration of the ecomorphology, feeding strategy and evolutionary patterns of these top predators. Secondly, the quantitative results were analysed in order to check if the orbit size and position were correlated with different stress patterns. These results revealed that in most of the cases the stress distribution is not affected by changes in the size and position of the orbit. This finding supports the high mechanical plasticity of this group during the Triassic period. The absence of mechanical constraints regarding the orbit probably promoted the ecomorphological diversity acknowledged for this group, as well as its ecological niche differentiation in the terrestrial Triassic ecosystems in clades as lydekkerinids, trematosaurs, capitosaurs or metoposaurs.

3D Computational Mechanics Elucidate the Evolutionary Implications of Orbit Position and Size Diversity of Early Amphibians

Science.gov (United States)

Marcé-Nogué, Jordi; Fortuny, Josep; De Esteban-Trivigno, Soledad; Sánchez, Montserrat; Gil, Lluís; Galobart, Àngel

2015-01-01

For the first time in vertebrate palaeontology, the potential of joining Finite Element Analysis (FEA) and Parametrical Analysis (PA) is used to shed new light on two different cranial parameters from the orbits to evaluate their biomechanical role and evolutionary patterns. The early tetrapod group of Stereospondyls, one of the largest groups of Temnospondyls is used as a case study because its orbits position and size vary hugely within the members of this group. An adult skull of Edingerella madagascariensis was analysed using two different cases of boundary and loading conditions in order to quantify stress and deformation response under a bilateral bite and during skull raising. Firstly, the variation of the original geometry of its orbits was introduced in the models producing new FEA results, allowing the exploration of the ecomorphology, feeding strategy and evolutionary patterns of these top predators. Secondly, the quantitative results were analysed in order to check if the orbit size and position were correlated with different stress patterns. These results revealed that in most of the cases the stress distribution is not affected by changes in the size and position of the orbit. This finding supports the high mechanical plasticity of this group during the Triassic period. The absence of mechanical constraints regarding the orbit probably promoted the ecomorphological diversity acknowledged for this group, as well as its ecological niche differentiation in the terrestrial Triassic ecosystems in clades as lydekkerinids, trematosaurs, capitosaurs or metoposaurs. PMID:26107295

High-technology exports of EEC countries: Persistence and diversity of specialization patterns

International Nuclear Information System (INIS)

Papagni, E.

1992-01-01

This analysis of the persistence and diversity of specialization patterns in EEC high technology exports is based on a package of products selected from the Eurostat database, COMEXT. High technology goods are considered as an innovative output indicator. A test of hypotheses of hysteresis and diversity of trade patterns at a national level is performed to verify some claims made by the 'evolutionary' theory of innovation and trade. The three-mode principal component analysis carried out confirms the persistence of specialization patterns of each EEC country in high technology exports, and highlights their sharp differences

Evolutionary Biology Today

Indian Academy of Sciences (India)

Hindi and English. Port 1. Resonance, Vo1.7 ... they use. Of course, many evolutionary biologists do work with fossils or DNA, or both, but there are also large numbers of ... The first major division that I like to make is between studies focussed ...

Large-Scale Portfolio Optimization Using Multiobjective Evolutionary Algorithms and Preselection Methods

Directory of Open Access Journals (Sweden)

B. Y. Qu

2017-01-01

Full Text Available Portfolio optimization problems involve selection of different assets to invest in order to maximize the overall return and minimize the overall risk simultaneously. The complexity of the optimal asset allocation problem increases with an increase in the number of assets available to select from for investing. The optimization problem becomes computationally challenging when there are more than a few hundreds of assets to select from. To reduce the complexity of large-scale portfolio optimization, two asset preselection procedures that consider return and risk of individual asset and pairwise correlation to remove assets that may not potentially be selected into any portfolio are proposed in this paper. With these asset preselection methods, the number of assets considered to be included in a portfolio can be increased to thousands. To test the effectiveness of the proposed methods, a Normalized Multiobjective Evolutionary Algorithm based on Decomposition (NMOEA/D algorithm and several other commonly used multiobjective evolutionary algorithms are applied and compared. Six experiments with different settings are carried out. The experimental results show that with the proposed methods the simulation time is reduced while return-risk trade-off performances are significantly improved. Meanwhile, the NMOEA/D is able to outperform other compared algorithms on all experiments according to the comparative analysis.

Signatures of selection acting on the innate immunity gene Toll-like receptor 2 (TLR2) during the evolutionary history of rodents.

Science.gov (United States)

Tschirren, B; Råberg, L; Westerdahl, H

2011-06-01

Patterns of selection acting on immune defence genes have recently been the focus of considerable interest. Yet, when it comes to vertebrates, studies have mainly focused on the acquired branch of the immune system. Consequently, the direction and strength of selection acting on genes of the vertebrate innate immune defence remain poorly understood. Here, we present a molecular analysis of selection on an important receptor of the innate immune system of vertebrates, the Toll-like receptor 2 (TLR2), across 17 rodent species. Although purifying selection was the prevalent evolutionary force acting on most parts of the rodent TLR2, we found that codons in close proximity to pathogen-binding and TLR2-TLR1 heterodimerization sites have been subject to positive selection. This indicates that parasite-mediated selection is not restricted to acquired immune system genes like the major histocompatibility complex, but also affects innate defence genes. To obtain a comprehensive understanding of evolutionary processes in host-parasite systems, both innate and acquired immunity thus need to be considered. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

The evolutionary rate dynamically tracks changes in HIV-1 epidemics

Energy Technology Data Exchange (ETDEWEB)

Maljkovic-berry, Irina [Los Alamos National Laboratory; Athreya, Gayathri [Los Alamos National Laboratory; Daniels, Marcus [Los Alamos National Laboratory; Bruno, William [Los Alamos National Laboratory; Korber, Bette [Los Alamos National Laboratory; Kuiken, Carla [Los Alamos National Laboratory; Ribeiro, Ruy M [Los Alamos National Laboratory

2009-01-01

Large-sequence datasets provide an opportunity to investigate the dynamics of pathogen epidemics. Thus, a fast method to estimate the evolutionary rate from large and numerous phylogenetic trees becomes necessary. Based on minimizing tip height variances, we optimize the root in a given phylogenetic tree to estimate the most homogenous evolutionary rate between samples from at least two different time points. Simulations showed that the method had no bias in the estimation of evolutionary rates and that it was robust to tree rooting and topological errors. We show that the evolutionary rates of HIV-1 subtype B and C epidemics have changed over time, with the rate of evolution inversely correlated to the rate of virus spread. For subtype B, the evolutionary rate slowed down and tracked the start of the HAART era in 1996. Subtype C in Ethiopia showed an increase in the evolutionary rate when the prevalence increase markedly slowed down in 1995. Thus, we show that the evolutionary rate of HIV-1 on the population level dynamically tracks epidemic events.

The First Joke: Exploring the Evolutionary Origins of Humor

Directory of Open Access Journals (Sweden)

Joseph Polimeni

2006-01-01

Full Text Available Humor is a complex cognitive function which often leads to laughter. Contemporary humor theorists have begun to formulate hypotheses outlining the possible innate cognitive structures underlying humor. Humor's conspicuous presence in the behavioral repertoire of humankind invites adaptive explanations. This article explores the possible adaptive features of humor and ponders its evolutionary path through hominid history. Current humor theories and previous evolutionary ideas on humor are reviewed. In addition, scientific fields germane to the evolutionary study of humor are examined: animal models, genetics, children's humor, humor in pathological conditions, neurobiology, humor in traditional societies and cognitive archeology. Candidate selection pressures and associated evolutionary mechanisms are considered. The authors conclude that several evolutionary-related topics such as the origins of language, cognition underlying spiritual feelings, hominid group size, and primate teasing could have special relevance to the origins of humor.

Predicting loss of evolutionary history: Where are we?

Science.gov (United States)

Veron, Simon; Davies, T Jonathan; Cadotte, Marc W; Clergeau, Philippe; Pavoine, Sandrine

2017-02-01

The Earth's evolutionary history is threatened by species loss in the current sixth mass extinction event in Earth's history. Such extinction events not only eliminate species but also their unique evolutionary histories. Here we review the expected loss of Earth's evolutionary history quantified by phylogenetic diversity (PD) and evolutionary distinctiveness (ED) at risk. Due to the general paucity of data, global evolutionary history losses have been predicted for only a few groups, such as mammals, birds, amphibians, plants, corals and fishes. Among these groups, there is now empirical support that extinction threats are clustered on the phylogeny; however this is not always a sufficient condition to cause higher loss of phylogenetic diversity in comparison to a scenario of random extinctions. Extinctions of the most evolutionarily distinct species and the shape of phylogenetic trees are additional factors that can elevate losses of evolutionary history. Consequently, impacts of species extinctions differ among groups and regions, and even if global losses are low within large groups, losses can be high among subgroups or within some regions. Further, we show that PD and ED are poorly protected by current conservation practices. While evolutionary history can be indirectly protected by current conservation schemes, optimizing its preservation requires integrating phylogenetic indices with those that capture rarity and extinction risk. Measures based on PD and ED could bring solutions to conservation issues, however they are still rarely used in practice, probably because the reasons to protect evolutionary history are not clear for practitioners or due to a lack of data. However, important advances have been made in the availability of phylogenetic trees and methods for their construction, as well as assessments of extinction risk. Some challenges remain, and looking forward, research should prioritize the assessment of expected PD and ED loss for more taxonomic

How evolutionary principles improve the understanding of human health and disease.

Science.gov (United States)

Gluckman, Peter D; Low, Felicia M; Buklijas, Tatjana; Hanson, Mark A; Beedle, Alan S

2011-03-01

An appreciation of the fundamental principles of evolutionary biology provides new insights into major diseases and enables an integrated understanding of human biology and medicine. However, there is a lack of awareness of their importance amongst physicians, medical researchers, and educators, all of whom tend to focus on the mechanistic (proximate) basis for disease, excluding consideration of evolutionary (ultimate) reasons. The key principles of evolutionary medicine are that selection acts on fitness, not health or longevity; that our evolutionary history does not cause disease, but rather impacts on our risk of disease in particular environments; and that we are now living in novel environments compared to those in which we evolved. We consider these evolutionary principles in conjunction with population genetics and describe several pathways by which evolutionary processes can affect disease risk. These perspectives provide a more cohesive framework for gaining insights into the determinants of health and disease. Coupled with complementary insights offered by advances in genomic, epigenetic, and developmental biology research, evolutionary perspectives offer an important addition to understanding disease. Further, there are a number of aspects of evolutionary medicine that can add considerably to studies in other domains of contemporary evolutionary studies.

Theoretical Approaches in Evolutionary Ecology: Environmental Feedback as a Unifying Perspective.

Science.gov (United States)

Lion, Sébastien

2018-01-01

Evolutionary biology and ecology have a strong theoretical underpinning, and this has fostered a variety of modeling approaches. A major challenge of this theoretical work has been to unravel the tangled feedback loop between ecology and evolution. This has prompted the development of two main classes of models. While quantitative genetics models jointly consider the ecological and evolutionary dynamics of a focal population, a separation of timescales between ecology and evolution is assumed by evolutionary game theory, adaptive dynamics, and inclusive fitness theory. As a result, theoretical evolutionary ecology tends to be divided among different schools of thought, with different toolboxes and motivations. My aim in this synthesis is to highlight the connections between these different approaches and clarify the current state of theory in evolutionary ecology. Central to this approach is to make explicit the dependence on environmental dynamics of the population and evolutionary dynamics, thereby materializing the eco-evolutionary feedback loop. This perspective sheds light on the interplay between environmental feedback and the timescales of ecological and evolutionary processes. I conclude by discussing some potential extensions and challenges to our current theoretical understanding of eco-evolutionary dynamics.

What Is Sexual Orientation All About? Explaining an Evolutionary Paradox

OpenAIRE

Brad Bowins

2015-01-01

Numerous psychological, biological, and evolutionary theories have been proposed to explain sexual orientation. For a theory to be valid it must account for the evolutionary or Darwinian paradox of how homosexual behavior seemingly blocking evolutionary fitness could have evolved. Typically it is only evolutionary based theories that attempt to address this issue. All theories proposed to date have limitations, a major one being that they tend to be specific for male or female sexual orientat...

Basic emotions and adaptation. A computational and evolutionary model.

Directory of Open Access Journals (Sweden)

Daniela Pacella

Full Text Available The core principles of the evolutionary theories of emotions declare that affective states represent crucial drives for action selection in the environment and regulated the behavior and adaptation of natural agents in ancestrally recurrent situations. While many different studies used autonomous artificial agents to simulate emotional responses and the way these patterns can affect decision-making, few are the approaches that tried to analyze the evolutionary emergence of affective behaviors directly from the specific adaptive problems posed by the ancestral environment. A model of the evolution of affective behaviors is presented using simulated artificial agents equipped with neural networks and physically inspired on the architecture of the iCub humanoid robot. We use genetic algorithms to train populations of virtual robots across generations, and investigate the spontaneous emergence of basic emotional behaviors in different experimental conditions. In particular, we focus on studying the emotion of fear, therefore the environment explored by the artificial agents can contain stimuli that are safe or dangerous to pick. The simulated task is based on classical conditioning and the agents are asked to learn a strategy to recognize whether the environment is safe or represents a threat to their lives and select the correct action to perform in absence of any visual cues. The simulated agents have special input units in their neural structure whose activation keep track of their actual "sensations" based on the outcome of past behavior. We train five different neural network architectures and then test the best ranked individuals comparing their performances and analyzing the unit activations in each individual's life cycle. We show that the agents, regardless of the presence of recurrent connections, spontaneously evolved the ability to cope with potentially dangerous environment by collecting information about the environment and then

Basic emotions and adaptation. A computational and evolutionary model.

Science.gov (United States)

Pacella, Daniela; Ponticorvo, Michela; Gigliotta, Onofrio; Miglino, Orazio

2017-01-01

The core principles of the evolutionary theories of emotions declare that affective states represent crucial drives for action selection in the environment and regulated the behavior and adaptation of natural agents in ancestrally recurrent situations. While many different studies used autonomous artificial agents to simulate emotional responses and the way these patterns can affect decision-making, few are the approaches that tried to analyze the evolutionary emergence of affective behaviors directly from the specific adaptive problems posed by the ancestral environment. A model of the evolution of affective behaviors is presented using simulated artificial agents equipped with neural networks and physically inspired on the architecture of the iCub humanoid robot. We use genetic algorithms to train populations of virtual robots across generations, and investigate the spontaneous emergence of basic emotional behaviors in different experimental conditions. In particular, we focus on studying the emotion of fear, therefore the environment explored by the artificial agents can contain stimuli that are safe or dangerous to pick. The simulated task is based on classical conditioning and the agents are asked to learn a strategy to recognize whether the environment is safe or represents a threat to their lives and select the correct action to perform in absence of any visual cues. The simulated agents have special input units in their neural structure whose activation keep track of their actual "sensations" based on the outcome of past behavior. We train five different neural network architectures and then test the best ranked individuals comparing their performances and analyzing the unit activations in each individual's life cycle. We show that the agents, regardless of the presence of recurrent connections, spontaneously evolved the ability to cope with potentially dangerous environment by collecting information about the environment and then switching their behavior

The evolutionary portrait of metazoan NAD salvage.

Science.gov (United States)

Carneiro, João; Duarte-Pereira, Sara; Azevedo, Luísa; Castro, L Filipe C; Aguiar, Paulo; Moreira, Irina S; Amorim, António; Silva, Raquel M

2013-01-01

Nicotinamide Adenine Dinucleotide (NAD) levels are essential for cellular homeostasis and survival. Main sources of intracellular NAD are the salvage pathways from nicotinamide, where Nicotinamide phosphoribosyltransferases (NAMPTs) and Nicotinamidases (PNCs) have a key role. NAMPTs and PNCs are important in aging, infection and disease conditions such as diabetes and cancer. These enzymes have been considered redundant since either one or the other exists in each individual genome. The co-occurrence of NAMPT and PNC was only recently detected in invertebrates though no structural or functional characterization exists for them. Here, using expression and evolutionary analysis combined with homology modeling and protein-ligand docking, we show that both genes are expressed simultaneously in key species of major invertebrate branches and emphasize sequence and structural conservation patterns in metazoan NAMPT and PNC homologues. The results anticipate that NAMPTs and PNCs are simultaneously active, raising the possibility that NAD salvage pathways are not redundant as both are maintained to fulfill the requirement for NAD production in some species.

A glimpse on the pattern of rodent diversification

DEFF Research Database (Denmark)

Fabre, Pierre-Henri Fréderic; Hautier, Lionel; Dimitrov, Dimitar Stefanov

2012-01-01

BACKGROUND:Development of phylogenetic methods that do not rely on fossils for the study of evolutionary processes through time have revolutionized the field of evolutionary biology and resulted in an unprecedented expansion of our knowledge about the tree of life. These methods have helped to shed...... molecular works. A relaxed molecular clock dating approach provided a time framework for speciation events. We found that the Myomorpha clade shows a greater degree of variation in diversification rates than Sciuroidea, Caviomorpha, Castorimorpha and Anomaluromorpha. We identified a number of shifts...... imbalances and the time line we discuss the potential role of different diversification factors that might have shaped the rodents radiation. CONCLUSIONS:The present glimpse on the diversification pattern of rodents can be used for further comparative meta-analyses. Muroid lineages have a greater degree...

The evolutionary implications of epigenetic inheritance.

Science.gov (United States)

Jablonka, Eva

2017-10-06

The Modern Evolutionary Synthesis (MS) forged in the mid-twentieth century was built on a notion of heredity that excluded soft inheritance, the inheritance of the effects of developmental modifications. However, the discovery of molecular mechanisms that generate random and developmentally induced epigenetic variations is leading to a broadening of the notion of biological heredity that has consequences for ideas about evolution. After presenting some old challenges to the MS that were raised, among others, by Karl Popper, I discuss recent research on epigenetic inheritance, which provides experimental and theoretical support for these challenges. There is now good evidence that epigenetic inheritance is ubiquitous and is involved in adaptive evolution and macroevolution. I argue that the many evolutionary consequences of epigenetic inheritance open up new research areas and require the extension of the evolutionary synthesis beyond the current neo-Darwinian model.

Variation in recombination frequency and distribution across eukaryotes: patterns and processes

Science.gov (United States)

Feulner, Philine G. D.; Johnston, Susan E.; Santure, Anna W.; Smadja, Carole M.

2017-01-01

Recombination, the exchange of DNA between maternal and paternal chromosomes during meiosis, is an essential feature of sexual reproduction in nearly all multicellular organisms. While the role of recombination in the evolution of sex has received theoretical and empirical attention, less is known about how recombination rate itself evolves and what influence this has on evolutionary processes within sexually reproducing organisms. Here, we explore the patterns of, and processes governing recombination in eukaryotes. We summarize patterns of variation, integrating current knowledge with an analysis of linkage map data in 353 organisms. We then discuss proximate and ultimate processes governing recombination rate variation and consider how these influence evolutionary processes. Genome-wide recombination rates (cM/Mb) can vary more than tenfold across eukaryotes, and there is large variation in the distribution of recombination events across closely related taxa, populations and individuals. We discuss how variation in rate and distribution relates to genome architecture, genetic and epigenetic mechanisms, sex, environmental perturbations and variable selective pressures. There has been great progress in determining the molecular mechanisms governing recombination, and with the continued development of new modelling and empirical approaches, there is now also great opportunity to further our understanding of how and why recombination rate varies. This article is part of the themed issue ‘Evolutionary causes and consequences of recombination rate variation in sexual organisms’. PMID:29109219

Evolutionary Computing for Intelligent Power System Optimization and Control

DEFF Research Database (Denmark)

This new book focuses on how evolutionary computing techniques benefit engineering research and development tasks by converting practical problems of growing complexities into simple formulations, thus largely reducing development efforts. This book begins with an overview of the optimization the...... theory and modern evolutionary computing techniques, and goes on to cover specific applications of evolutionary computing to power system optimization and control problems....

Patterns of bone-marrow scintigraphy

International Nuclear Information System (INIS)

Touya, J.J.; Lee, G.S.; Narvaez, M.; Marciano, D.

1977-01-01

111 In-transferrin, radiocolloid and bone scans were performed within one week on 105 from more than 250 scanned patients with different haematological disorders. All patients had complete haematological workups and confirmed final diagnoses. From the comparison of the 111 In-transferrin marrow scan with the radiocolloid marrow scan and bone scan, eight basic patterns of localized or generalized disorders in the bone marrow cell production were delineated. The first pattern was called a cold area and two sub-patterns were distinguished in it. A cold area in the erythropoietic and reticuloendothelial scans associated with cold or normal areas in the bone scan corresponded to radiation damage of the marrow or multiple myeloma; a cold area in both marrow scans with a hot area in the bone scan to tumour, infarct and bone trauma. The second pattern was called a hot area. A hot area in the two marrow scans with a normal bone scan was observed in islands of active bone-marrow. Hot areas in both 111 In-transferrin and bone scan associated with a cold area in the radiocolloid scan were observed in tumours growing in bones with or without little active bone marrow. Hot areas on the three scans were observed in osteomyelitis of bones of the extremities. The third pattern was bone-marrow expansion, which was observed in hereditary haemolytic anaemias, in myeloproliferative disorders and in patients with bone-marrow damage following irradiation. The fourth pattern was saturation of the serum iron-binding capacity and it was manifested by increased activity in the kidneys in the 111 In-transferrin scan. The fifth pattern was bone-marrow failure which consists of decreased accumulation in the marrow and increased accumulation in the liver of marrow-seeking agents associated with normal bone scan. The sixth pattern, pure red cell aplasia, was characterized by less accumulation of 111 In-transferrin than radiocolloid in the bone marrow. The seventh pattern, bone-marrow siderosis

Apoptosis patterns in eutopic and ectopic endometrium, adhesions and normal-looking peritoneum from women with or without endometriosis.

Science.gov (United States)

Hassa, H; Tanir, H Mete; Tekin, B; Artan, S; Dundar, E; Kirilmaz, S D; Sahin Mutlu, F

2009-08-01

To assess the apoptosis rate in eutopic and ectopic endometrial stromal and glandular cells, normal peritoneum and adhesions in women with endometriosis. A total number of 97 women with (n:60) and without (n:37) histopathologically confirmed endometriosis who underwent laparoscopy or laparotomy in the early follicular phase of the menstrual cycles for pain and infertility were included in this study. Stage I/II and stage III/IV were categorized as early staged and late-staged endometriosis. The endometrial samples were obtained with a Novack cannula from the corpus of the uterus. Normal-looking peritoneum, peritoneal implants and adhesions were sampled and fixed in formaldehyde for immunohistochemical staining with Bcl-2 and Bax. Tissue samples were fixed in formaldehyde for the assessment of apoptosis via terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) and M30 cytoDEATH antibody. The intensity of Bax staining of normal-looking peritoneum in early staged endometriosis was higher, compared to women with late-staged and women without endometriosis (P = 0.03). However, degree of Bcl-2 staining did not differ among early and late-staged endometriosis and women without endometriosis (P = 0.1). In terms of Bcl-2 and Bax staining in the stromal and glandular parts of the eutopic endometria, no significant differences were detected among three groups. In cases with early- and late-staged endometriosis the intensity of Bax and Bcl-2 stainings did not differ in both stromal and glandular parts of ectopic endometria. Number of cells with positive apoptotic signals assessed via TUNEL (P = 1.0) and M30 cytoDEATH antibody (P = 0.59) in normal-looking peritoneum did not differ between three groups. In addition, no difference in term of numbers of apoptotic cells obtained from adhesions was observed between three groups (for TUNEL, P = 0.29, for M30, P = 0.19). Apoptosis patterns did not differ in the eutopic and ectopic

The great opportunity: Evolutionary applications to medicine and public health.

Science.gov (United States)

Nesse, Randolph M; Stearns, Stephen C

2008-02-01

Evolutionary biology is an essential basic science for medicine, but few doctors and medical researchers are familiar with its most relevant principles. Most medical schools have geneticists who understand evolution, but few have even one evolutionary biologist to suggest other possible applications. The canyon between evolutionary biology and medicine is wide. The question is whether they offer each other enough to make bridge building worthwhile. What benefits could be expected if evolution were brought fully to bear on the problems of medicine? How would studying medical problems advance evolutionary research? Do doctors need to learn evolution, or is it valuable mainly for researchers? What practical steps will promote the application of evolutionary biology in the areas of medicine where it offers the most? To address these questions, we review current and potential applications of evolutionary biology to medicine and public health. Some evolutionary technologies, such as population genetics, serial transfer production of live vaccines, and phylogenetic analysis, have been widely applied. Other areas, such as infectious disease and aging research, illustrate the dramatic recent progress made possible by evolutionary insights. In still other areas, such as epidemiology, psychiatry, and understanding the regulation of bodily defenses, applying evolutionary principles remains an open opportunity. In addition to the utility of specific applications, an evolutionary perspective fundamentally challenges the prevalent but fundamentally incorrect metaphor of the body as a machine designed by an engineer. Bodies are vulnerable to disease - and remarkably resilient - precisely because they are not machines built from a plan. They are, instead, bundles of compromises shaped by natural selection in small increments to maximize reproduction, not health. Understanding the body as a product of natural selection, not design, offers new research questions and a framework for

Study on Evolutionary Path of University Students’ Entrepreneurship Training

Directory of Open Access Journals (Sweden)

Daojian Yang

2014-01-01

Full Text Available Aiming at studying the evolution pattern of cultivating the ability of university students’ entrepreneurship, this paper established the payoff matrix between the university and students agent with the evolutionary economics method. The analysis of the evolution of the communication process model reveals how the choice strategy of individuals influences that of groups. Numerical simulation also demonstrates the influences of different values of decision-making parameters and the change of initial conditions on the result of evolution. It is found that the evolution path system of university students’ entrepreneurial ability has two kinds of modes: one is the ideal state; and the other one is the bad “lock” state. By adjusting parameters, we can jump out of the bad “lock” state, thus optimizing cultivation path.

Prey preference follows phylogeny: evolutionary dietary patterns within the marine gastropod group Cladobranchia (Gastropoda: Heterobranchia: Nudibranchia).

Science.gov (United States)

Goodheart, Jessica A; Bazinet, Adam L; Valdés, Ángel; Collins, Allen G; Cummings, Michael P

2017-10-26

The impact of predator-prey interactions on the evolution of many marine invertebrates is poorly understood. Since barriers to genetic exchange are less obvious in the marine realm than in terrestrial or freshwater systems, non-allopatric divergence may play a fundamental role in the generation of biodiversity. In this context, shifts between major prey types could constitute important factors explaining the biodiversity of marine taxa, particularly in groups with highly specialized diets. However, the scarcity of marine specialized consumers for which reliable phylogenies exist hampers attempts to test the role of trophic specialization in evolution. In this study, RNA-Seq data is used to produce a phylogeny of Cladobranchia, a group of marine invertebrates that feed on a diverse array of prey taxa but mostly specialize on cnidarians. The broad range of prey type preferences allegedly present in two major groups within Cladobranchia suggest that prey type shifts are relatively common over evolutionary timescales. In the present study, we generated a well-supported phylogeny of the major lineages within Cladobranchia using RNA-Seq data, and used ancestral state reconstruction analyses to better understand the evolution of prey preference. These analyses answered several fundamental questions regarding the evolutionary relationships within Cladobranchia, including support for a clade of species from Arminidae as sister to Tritoniidae (which both preferentially prey on Octocorallia). Ancestral state reconstruction analyses supported a cladobranchian ancestor with a preference for Hydrozoa and show that the few transitions identified only occur from lineages that prey on Hydrozoa to those that feed on other types of prey. There is strong phylogenetic correlation with prey preference within Cladobranchia, suggesting that prey type specialization within this group has inertia. Shifts between different types of prey have occurred rarely throughout the evolution of

Universal scaling for the dilemma strength in evolutionary games

Science.gov (United States)

Wang, Zhen; Kokubo, Satoshi; Jusup, Marko; Tanimoto, Jun

2015-09-01

Why would natural selection favor the prevalence of cooperation within the groups of selfish individuals? A fruitful framework to address this question is evolutionary game theory, the essence of which is captured in the so-called social dilemmas. Such dilemmas have sparked the development of a variety of mathematical approaches to assess the conditions under which cooperation evolves. Furthermore, borrowing from statistical physics and network science, the research of the evolutionary game dynamics has been enriched with phenomena such as pattern formation, equilibrium selection, and self-organization. Numerous advances in understanding the evolution of cooperative behavior over the last few decades have recently been distilled into five reciprocity mechanisms: direct reciprocity, indirect reciprocity, kin selection, group selection, and network reciprocity. However, when social viscosity is introduced into a population via any of the reciprocity mechanisms, the existing scaling parameters for the dilemma strength do not yield a unique answer as to how the evolutionary dynamics should unfold. Motivated by this problem, we review the developments that led to the present state of affairs, highlight the accompanying pitfalls, and propose new universal scaling parameters for the dilemma strength. We prove universality by showing that the conditions for an ESS and the expressions for the internal equilibriums in an infinite, well-mixed population subjected to any of the five reciprocity mechanisms depend only on the new scaling parameters. A similar result is shown to hold for the fixation probability of the different strategies in a finite, well-mixed population. Furthermore, by means of numerical simulations, the same scaling parameters are shown to be effective even if the evolution of cooperation is considered on the spatial networks (with the exception of highly heterogeneous setups). We close the discussion by suggesting promising directions for future research

A quantitative evolutionary theory of adaptive behavior dynamics.

Science.gov (United States)

McDowell, J J

2013-10-01

The idea that behavior is selected by its consequences in a process analogous to organic evolution has been discussed for over 100 years. A recently proposed theory instantiates this idea by means of a genetic algorithm that operates on a population of potential behaviors. Behaviors in the population are represented by numbers in decimal integer (phenotypic) and binary bit string (genotypic) forms. One behavior from the population is emitted at random each time tick, after which a new population of potential behaviors is constructed by recombining parent behavior bit strings. If the emitted behavior produced a benefit to the organism, then parents are chosen on the basis of their phenotypic similarity to the emitted behavior; otherwise, they are chosen at random. After parent behavior recombination, the population is subjected to a small amount of mutation by flipping random bits in the population's bit strings. The behavior generated by this process of selection, reproduction, and mutation reaches equilibrium states that conform to every empirically valid equation of matching theory, exactly and without systematic error. These equations are known to describe the behavior of many vertebrate species, including humans, in a variety of experimental, naturalistic, natural, and social environments. The evolutionary theory also generates instantaneous dynamics and patterns of preference change in constantly changing environments that are consistent with the dynamics of live-organism behavior. These findings support the assertion that the world of behavior we observe and measure is generated by evolutionary dynamics. PsycINFO Database Record (c) 2013 APA, all rights reserved

On Reciprocal Causation in the Evolutionary Process.

Science.gov (United States)

Svensson, Erik I

2018-01-01

Recent calls for a revision of standard evolutionary theory (SET) are based partly on arguments about the reciprocal causation. Reciprocal causation means that cause-effect relationships are bi-directional, as a cause could later become an effect and vice versa. Such dynamic cause-effect relationships raise questions about the distinction between proximate and ultimate causes, as originally formulated by Ernst Mayr. They have also motivated some biologists and philosophers to argue for an Extended Evolutionary Synthesis (EES). The EES will supposedly expand the scope of the Modern Synthesis (MS) and SET, which has been characterized as gene-centred, relying primarily on natural selection and largely neglecting reciprocal causation. Here, I critically examine these claims, with a special focus on the last conjecture. I conclude that reciprocal causation has long been recognized as important by naturalists, ecologists and evolutionary biologists working in the in the MS tradition, although it it could be explored even further. Numerous empirical examples of reciprocal causation in the form of positive and negative feedback are now well known from both natural and laboratory systems. Reciprocal causation have also been explicitly incorporated in mathematical models of coevolutionary arms races, frequency-dependent selection, eco-evolutionary dynamics and sexual selection. Such dynamic feedback were already recognized by Richard Levins and Richard Lewontin in their bok The Dialectical Biologist . Reciprocal causation and dynamic feedback might also be one of the few contributions of dialectical thinking and Marxist philosophy in evolutionary theory. I discuss some promising empirical and analytical tools to study reciprocal causation and the implications for the EES. Finally, I briefly discuss how quantitative genetics can be adapated to studies of reciprocal causation, constructive inheritance and phenotypic plasticity and suggest that the flexibility of this approach

The Riddle of a Human Being: A Human Singularity of Co-evolutionary Processes

Directory of Open Access Journals (Sweden)

Helena N. Knyazeva

2008-10-01

Full Text Available span style="font-size: 10pt; font-family: #39;Times New Roman#39;"The theory of self-organization of complex systems studies laws of sustainable co-evolutionary development of structures having different speeds of development as well as laws of assembling of a complex evolutionary whole from parts when some elements of ldquo;memoryrdquo; (the biological memory, i.e. DNA, the memory of culture, i.e. the cultural and historical traditions, etc. must be included. The theory reveals general rules of nonlinear synthesis of complex evolutionary structures. The most important and paradoxical consequences of the holistic view, including an approach to solving the riddle of human personality, are as follows: 1 the explanation why and under what conditions a part (a human can be more complex than a whole (society; 2 in order to reconstruct society it is necessary to change an individual but not by cutting off the supposed undesirable past, since a human being as a microcosm is the synthesis of all previous stages of evolution, and as a result of repression of, it would seem, the wild past one can extinguish a ldquo;divine sparkrdquo; in his soul; 3 in the physical sense, singularity denotes a moment of instability, phase transition; one can talk about the human singularity of co-evolutionary processes, since in such a moment of instability individual actions of a human can play a key role in determining a channel of further development as well as in appearance of a new pattern of collective behavior in society; 4 as the models of nonlinear dynamics, elaborated at the Keldysh Institute of Applied Mathematics of the Russian Academy of Sciences in Moscow, show, there is a possibility of a direct influence of the future and even a touch of an infinitely remote future in certain evolutionary regimes and under rigorously definite conditions, more over, it turns out that such a possibility exists only for a human (admittedly, through a specific state of being

Right thoracic curvature in the normal spine

Directory of Open Access Journals (Sweden)

Masuda Keigo

2011-01-01

Full Text Available Abstract Background Trunk asymmetry and vertebral rotation, at times observed in the normal spine, resemble the characteristics of adolescent idiopathic scoliosis (AIS. Right thoracic curvature has also been reported in the normal spine. If it is determined that the features of right thoracic side curvature in the normal spine are the same as those observed in AIS, these findings might provide a basis for elucidating the etiology of this condition. For this reason, we investigated right thoracic curvature in the normal spine. Methods For normal spinal measurements, 1,200 patients who underwent a posteroanterior chest radiographs were evaluated. These consisted of 400 children (ages 4-9, 400 adolescents (ages 10-19 and 400 adults (ages 20-29, with each group comprised of both genders. The exclusion criteria were obvious chest and spinal diseases. As side curvature is minimal in normal spines and the range at which curvature is measured is difficult to ascertain, first the typical curvature range in scoliosis patients was determined and then the Cobb angle in normal spines was measured using the same range as the scoliosis curve, from T5 to T12. Right thoracic curvature was given a positive value. The curve pattern was organized in each collective three groups: neutral (from -1 degree to 1 degree, right (> +1 degree, and left ( Results In child group, Cobb angle in left was 120, in neutral was 125 and in right was 155. In adolescent group, Cobb angle in left was 70, in neutral was 114 and in right was 216. In adult group, Cobb angle in left was 46, in neutral was 102 and in right was 252. The curvature pattern shifts to the right side in the adolescent group (p Conclusions Based on standing chest radiographic measurements, a right thoracic curvature was observed in normal spines after adolescence.

Evolutionary convergence of the patterns of international research collaborations across scientific fields

NARCIS (Netherlands)

Wang, L.; Coccia, M.

2015-01-01

Frame and Carpenter (1979) analysed the pattern of international research collaboration among scientific fields in 1970s. Starting from this pioneering work, this paper investigates international collaborations over 1997-2012 and compares the critical results with earlier studies to detect the

Comparison of normal adult and children brain SPECT imaging using statistical parametric mapping(SPM)

Energy Technology Data Exchange (ETDEWEB)

Lee, Myoung Hoon; Yoon, Seok Nam; Joh, Chul Woo; Lee, Dong Soo [Ajou University School of Medicine, Suwon (Korea, Republic of); Lee, Jae Sung [Seoul national University College of Medicine, Seoul (Korea, Republic of)

2002-07-01

This study compared rCBF pattern in normal adult and normal children using statistical parametric mapping (SPM). The purpose of this study was to determine distribution pattern not seen visual analysis in both groups. Tc-99m ECD brain SPECT was performed in 12 normal adults (M:F=11:1, average age 35 year old) and 6 normal control children (M:F=4:2, 10.5{+-}3.1y) who visited psychiatry clinic to evaluate ADHD. Their brain SPECT revealed normal rCBF pattern in visual analysis and they were diagnosed clinically normal. Using SPM method, we compared normal adult group's SPECT images with those of 6 normal children subjects and measured the extent of the area with significant hypoperfusion and hyperperfusion (p<0.001, extent threshold=16). The areas of both angnlar gyrus, both postcentral gyrus, both superior frontal gyrus, and both superior parietal lobe showed significant hyperperfusion in normal adult group compared with normal children group. The areas of left amygdala gyrus, brain stem, both cerebellum, left globus pallidus, both hippocampal formations, both parahippocampal gyrus, both thalamus, both uncus, both lateral and medial occipitotemporal gyrus revealed significantly hyperperfusion in the children. These results demonstrated that SPM can say more precise anatomical area difference not seen visual analysis.

Comparison of normal adult and children brain SPECT imaging using statistical parametric mapping(SPM)

International Nuclear Information System (INIS)

Lee, Myoung Hoon; Yoon, Seok Nam; Joh, Chul Woo; Lee, Dong Soo; Lee, Jae Sung

2002-01-01

This study compared rCBF pattern in normal adult and normal children using statistical parametric mapping (SPM). The purpose of this study was to determine distribution pattern not seen visual analysis in both groups. Tc-99m ECD brain SPECT was performed in 12 normal adults (M:F=11:1, average age 35 year old) and 6 normal control children (M:F=4:2, 10.5±3.1y) who visited psychiatry clinic to evaluate ADHD. Their brain SPECT revealed normal rCBF pattern in visual analysis and they were diagnosed clinically normal. Using SPM method, we compared normal adult group's SPECT images with those of 6 normal children subjects and measured the extent of the area with significant hypoperfusion and hyperperfusion (p<0.001, extent threshold=16). The areas of both angnlar gyrus, both postcentral gyrus, both superior frontal gyrus, and both superior parietal lobe showed significant hyperperfusion in normal adult group compared with normal children group. The areas of left amygdala gyrus, brain stem, both cerebellum, left globus pallidus, both hippocampal formations, both parahippocampal gyrus, both thalamus, both uncus, both lateral and medial occipitotemporal gyrus revealed significantly hyperperfusion in the children. These results demonstrated that SPM can say more precise anatomical area difference not seen visual analysis

EVOLUTIONARY THEORY AND THE MARKET COMPETITION

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SIRGHI Nicoleta

2014-12-01

Full Text Available Evolutionary theory study of processes that transform economy for firms, institutions, industries, employment, production, trade and growth within, through the actions of diverse agents from experience and interactions, using evolutionary methodology. Evolutionary theory analyses the unleashing of a process of technological and institutional innovation by generating and testing a diversity of ideas which discover and accumulate more survival value for the costs incurred than competing alternatives.This paper presents study the behavior of the firms on the market used the evolutionary theory.The paper is to present in full the developments that have led to the re-assessment of theories of firms starting from the criticism on Coase's theory based on the lack of testable hypotheses and on non-operative definition of transaction costs. In the literature in the field studies on firms were allotted a secondary place for a long period of time, to date the new theories of the firm hold a dominant place in the firms’ economic analysis. In an article, published in 1937, Ronald H. Coase identified the main sources of the cost of using the market mechanism. The firms theory represent a issue intensively studied in the literature in the field, regarding the survival, competitiveness and innovation of firm on the market. The research of Nelson and Winter, “An Evolutionary Theory of Economic Change” (1982 is the starting point for a modern literature in the field which considers the approach of the theory of the firm from an evolutionary perspective. Nelson and Winter have shown that the “orthodox” theory, is objectionable primarily by the fact that the hypothesis regarding profit maximization has a normative character and is not valid in any situation. Nelson and Winter reconsidered their microeconomic analysis showing that excessive attention should not be paid to market equilibrium but rather to dynamic processes resulting from irreversible

Characterization of the avian Trojan gene family reveals contrasting evolutionary constraints.

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Petrov, Petar; Syrjänen, Riikka; Smith, Jacqueline; Gutowska, Maria Weronika; Uchida, Tatsuya; Vainio, Olli; Burt, David W

2015-01-01

"Trojan" is a leukocyte-specific, cell surface protein originally identified in the chicken. Its molecular function has been hypothesized to be related to anti-apoptosis and the proliferation of immune cells. The Trojan gene has been localized onto the Z sex chromosome. The adjacent two genes also show significant homology to Trojan, suggesting the existence of a novel gene/protein family. Here, we characterize this Trojan family, identify homologues in other species and predict evolutionary constraints on these genes. The two Trojan-related proteins in chicken were predicted as a receptor-type tyrosine phosphatase and a transmembrane protein, bearing a cytoplasmic immuno-receptor tyrosine-based activation motif. We identified the Trojan gene family in ten other bird species and found related genes in three reptiles and a fish species. The phylogenetic analysis of the homologues revealed a gradual diversification among the family members. Evolutionary analyzes of the avian genes predicted that the extracellular regions of the proteins have been subjected to positive selection. Such selection was possibly a response to evolving interacting partners or to pathogen challenges. We also observed an almost complete lack of intracellular positively selected sites, suggesting a conserved signaling mechanism of the molecules. Therefore, the contrasting patterns of selection likely correlate with the interaction and signaling potential of the molecules.

The evolutionary role of modularity and integration in the hominoid cranium.

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Mitteroecker, Philipp; Bookstein, Fred

2008-04-01

Patterns of morphological integration and modularity among shape features emerge from genetic and developmental factors with varying pleiotropic effects. Factors or processes affecting morphology only locally may respond to selection more easily than common factors that may lead to deleterious side effects and hence are expected to be more conserved. We briefly review evidence for such global factors in primate cranial development as well as for local factors constrained to either the face or the neurocranium. In a sample comprising 157 crania of Homo sapiens, Pan troglodytes, and Gorilla gorilla, we statistically estimated common and local factors of shape variation from Procrustes coordinates of 347 landmarks and semilandmarks. Common factors with pleiotropic effects on both the face and the neurocranium account for a large amount of shape variation, but mainly by extension or truncation of otherwise conserved developmental pathways. Local factors (modular shape characteristics) have more degrees of freedom for evolutionary change than mere ontogenetic scaling. Cranial shape is similarly integrated during development in all three species, but human evolution involves dissociation among several characteristics. The dissociation has probably been achieved by evolutionary alterations and by the novel emergence of local factors affecting characteristics that are controlled at the same time by the common factors.

Evolutionary epistemology, rationality, and the sociology of knowledge

CERN Document Server

Bartley, W W

1993-01-01

This collection of essays in support of the theory of evolutionary epistemology includes articles by Karl Popper, Peter Munz and Gerhard Vollmer. This volume attempts to show how an evolutionary and non-justificational approach affects the sociology of knowledge.

Phylodynamics and evolutionary epidemiology of African swine fever p72-CVR genes in Eurasia and Africa.

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Alkhamis, Moh A; Gallardo, Carmina; Jurado, Cristina; Soler, Alejandro; Arias, Marisa; Sánchez-Vizcaíno, José M

2018-01-01

African swine fever (ASF) is a complex infectious disease of swine that constitutes devastating impacts on animal health and the world economy. Here, we investigated the evolutionary epidemiology of ASF virus (ASFV) in Eurasia and Africa using the concatenated gene sequences of the viral protein 72 and the central variable region of isolates collected between 1960 and 2015. We used Bayesian phylodynamic models to reconstruct the evolutionary history of the virus, to identify virus population demographics and to quantify dispersal patterns between host species. Results suggest that ASFV exhibited a significantly high evolutionary rate and population growth through time since its divergence in the 18th century from East Africa, with no signs of decline till recent years. This increase corresponds to the growing pig trade activities between continents during the 19th century, and may be attributed to an evolutionary drift that resulted from either continuous circulation or maintenance of the virus within Africa and Eurasia. Furthermore, results implicate wild suids as the ancestral host species (root state posterior probability = 0.87) for ASFV in the early 1700s in Africa. Moreover, results indicate the transmission cycle between wild suids and pigs is an important cycle for ASFV spread and maintenance in pig populations, while ticks are an important natural reservoir that can facilitate ASFV spread and maintenance in wild swine populations. We illustrated the prospects of phylodynamic methods in improving risk-based surveillance, support of effective animal health policies, and epidemic preparedness in countries at high risk of ASFV incursion.

Molluscan Evolutionary Development

DEFF Research Database (Denmark)

Wanninger, Andreas Wilhelm Georg; Koop, Damien; Moshel-Lynch, Sharon

2008-01-01

Brought together by Winston F. Ponder and David R. Lindberg, thirty-six experts on the evolution of the Mollusca provide an up-to-date review of its evolutionary history. The Mollusca are the second largest animal phylum and boast a fossil record of over 540 million years. They exhibit remarkable...

Gene evolutionary trajectories and GC patterns driven by recombination in Zea mays

Science.gov (United States)

Recombination occurring during meiosis is critical for creating genetic variation and plays an essential role in plant evolution. In addition to creating novel gene combinations, recombination can affect genome structure through altering GC patterns. In maize (Zea mays) and other grasses, another in...

Observational and evolutionary aspects of Wolf-Rayet stars

International Nuclear Information System (INIS)

Vanbeveren, D.

1980-01-01

The author considers (i) the binary status of Wolf-Rayet stars, (ii) the evolutionary status of Wolf-Rayet stars, (iii) the chemical abundances of Wolf-Rayet stars and (iv) evolutionary models for some known Wolf-Rayet systems. (G.T.H.)

Hepatoscintiangiography of normal liver and its alteration in hepatomas and liver abscess

International Nuclear Information System (INIS)

Bahk, Y.W.; Chung, S.K.

1984-01-01

This study was performed to establish normal hepatoscintiangiographic (HSA) pattern of hepatic blood flow and to investigate differential HSA findings of primary and metastatic carcinomas and abscess of the liver. HSA was carried out after intravenous bolus injection of l0 mCi of Tc-99m-phytate by obtaining sequential anterior images of 1-second exposure for 16 seconds. Observations included (1) baseline study of normal hepatic blood flow patterns by correlating with contrast angiogram, (2) time-sequence phasing of normal HSA, and (3) analysis of altered patterns in primary and metastatic carcinomas and abscess of the liver. Results were: (1) Normal HSA demonstrated 3 distinct phases of arterialization (AP), arterial hepatrogram (AHP), and portal venous hepatogram (PVHP). The means of each phase were 5.3, 6.3, and 8.3 seconds, respectively. Portal vein could be seen in all but one of 20 normal subjects. (2) Pattern changes in disease groups were early start of AP in carcinomas and very early start of AP in abscess. AP became prolonged in all disease groups. (3) Distinction between AHP and PVHP was sharp in metastasis and abscess but was unsharp in primary hepatoma. Cold area or areas became vascularized in primary hepatoma but not in abscess. Cold areas of metastasis were inhomogenously vascularized in late AP and throughout AHP and became relatively avascular as PVHP began. The cold area of abscess showed rim enhancement during AH and APH. These differences in HSA pattern were very useful in differential diagnosis of the diseases studied

The non-random clustering of non-synonymous substitutions and its relationship to evolutionary rate

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Stone Eric A

2011-08-01

Full Text Available Abstract Background Protein sequences are subject to a mosaic of constraint. Changes to functional domains and buried residues, for example, are more apt to disrupt protein structure and function than are changes to residues participating in loops or exposed to solvent. Regions of constraint on the tertiary structure of a protein often result in loose segmentation of its primary structure into stretches of slowly- and rapidly-evolving amino acids. This clustering can be exploited, and existing methods have done so by relying on local sequence conservation as a signature of selection to help identify functionally important regions within proteins. We invert this paradigm by leveraging the regional nature of protein structure and function to both illuminate and make use of genome-wide patterns of local sequence conservation. Results Our hypothesis is that the regional nature of structural and functional constraints will assert a positive autocorrelation on the evolutionary rates of neighboring sites, which, in a pairwise comparison of orthologous proteins, will manifest itself as the clustering of non-synonymous changes across the amino acid sequence. We introduce a dispersion ratio statistic to test this and related hypotheses. Using genome-wide interspecific comparisons of orthologous protein pairs, we reveal a strong log-linear relationship between the degree of clustering and the intensity of constraint. We further demonstrate how this relationship varies with the evolutionary distance between the species being compared. We provide some evidence that proteins with a history of positive selection deviate from genome-wide trends. Conclusions We find a significant association between the evolutionary rate of a protein and the degree to which non-synonymous changes cluster along its primary sequence. We show that clustering is a non-redundant predictor of evolutionary rate, and we speculate that conflicting signals of clustering and constraint may

Trophic phylogenetics: evolutionary influences on body size, feeding, and species associations in grassland arthropods.

Science.gov (United States)

Lind, Eric M; Vincent, John B; Weiblen, George D; Cavender-Bares, Jeannine; Borer, Elizabeth T

2015-04-01

Contemporary animal-plant interactions such as herbivory are widely understood to be shaped by evolutionary history. Yet questions remain about the role of plant phylogenetic diversity in generating and maintaining herbivore diversity, and whether evolutionary relatedness of producers might predict the composition of consumer communities. We tested for evidence of evolutionary associations among arthropods and the plants on which they were found, using phylogenetic analysis of naturally occurring arthropod assemblages sampled from a plant-diversity manipulation experiment. Considering phylogenetic relationships among more than 900 arthropod consumer taxa and 29 plant species in the experiment, we addressed several interrelated questions. First, our results support the hypothesis that arthropod functional traits such as body size and trophic role are phylogenetically conserved in community ecological samples. Second, herbivores tended to cooccur with closer phylogenetic relatives than would be expected at random, whereas predators and parasitoids did not show phylogenetic association patterns. Consumer specialization, as measured by association through time with monocultures of particular host plant species, showed significant phylogenetic signal, although the. strength of this association varied among plant species. Polycultures of phylogenetically dissimilar plant species supported more phylogenetically dissimilar consumer communities than did phylogenetically similar polycultures. Finally, we separated the effects of plant species richness and relatedness in predicting the phylogenetic distribution of the arthropod assemblages in this experiment. The phylogenetic diversity of plant communities predicted the phylogenetic diversity of herbivore communities even after accounting for plant species richness. The phylogenetic diversity of secondary consumers differed by guild, with predator phylogenetic diversity responding to herbivore relatedness, while parasitoid

Evolutionary conservation and changes in insect TRP channels.

Science.gov (United States)

Matsuura, Hironori; Sokabe, Takaaki; Kohno, Keigo; Tominaga, Makoto; Kadowaki, Tatsuhiko

2009-09-10

TRP (Transient Receptor Potential) channels respond to diverse stimuli and thus function as the primary integrators of varied sensory information. They are also activated by various compounds and secondary messengers to mediate cell-cell interactions as well as to detect changes in the local environment. Their physiological roles have been primarily characterized only in mice and fruit flies, and evolutionary studies are limited. To understand the evolution of insect TRP channels and the mechanisms of integrating sensory inputs in insects, we have identified and compared TRP channel genes in Drosophila melanogaster, Bombyx mori, Tribolium castaneum, Apis mellifera, Nasonia vitripennis, and Pediculus humanus genomes as part of genome sequencing efforts. All the insects examined have 2 TRPV, 1 TRPN, 1 TRPM, 3 TRPC, and 1 TRPML subfamily members, demonstrating that these channels have the ancient origins in insects. The common pattern also suggests that the mechanisms for detecting mechanical and visual stimuli and maintaining lysosomal functions may be evolutionarily well conserved in insects. However, a TRPP channel, the most ancient TRP channel, is missing in B. mori, A. mellifera, and N. vitripennis. Although P. humanus and D. melanogaster contain 4 TRPA subfamily members, the other insects have 5 TRPA subfamily members. T. castaneum, A. mellifera, and N. vitripennis contain TRPA5 channels, which have been specifically retained or gained in Coleoptera and Hymenoptera. Furthermore, TRPA1, which functions for thermotaxis in Drosophila, is missing in A. mellifera and N. vitripennis; however, they have other Hymenoptera-specific TRPA channels (AmHsTRPA and NvHsTRPA). NvHsTRPA expressed in HEK293 cells is activated by temperature increase, demonstrating that HsTRPAs function as novel thermal sensors in Hymenoptera. The total number of insect TRP family members is 13-14, approximately half that of mammalian TRP family members. As shown for mammalian TRP channels, this

Evolutionary conservation and changes in insect TRP channels

Directory of Open Access Journals (Sweden)