Desvendando o mistério de como, quando o DNA replica

segunda-feira, dezembro 31, 2018

Identifying cis Elements for Spatiotemporal Control of Mammalian DNA Replication

Jiao Sima Abhijit Chakraborty Vishnu Dileep Marco Michalski Kyle N. Klein Nicolas P. Holcomb Jesse L. Turner Michelle T. Paulsen Juan Carlos Rivera-Mulia Claudia Trevilla-Garcia Daniel A. Bartlett Peiyao A. Zhao Brian K. Washburn Elphège P. Nora Katerina Kraft Stefan Mundlos Benoit G. Bruneau Mats Ljungman Peter Fraser Ferhat Ay David M. Gilbert 11

Published: December 27, 2018 DOI:

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• Early replicating control elements (ERCEs) regulate replication timing

• ERCEs regulate A/B compartmentalization and TAD architecture

• ERCEs form CTCF-independent loops and have features of enhancer/promoters

• ERCEs enable genetic dissection of large-scale chromosome structure and function


The temporal order of DNA replication (replication timing [RT]) is highly coupled with genome architecture, but cis-elements regulating either remain elusive. We created a series of CRISPR-mediated deletions and inversions of a pluripotency-associated topologically associating domain (TAD) in mouse ESCs. CTCF-associated domain boundaries were dispensable for RT. CTCF protein depletion weakened most TAD boundaries but had no effect on RT or A/B compartmentalization genome-wide. By contrast, deletion of three intra-TAD CTCF-independent 3D contact sites caused a domain-wide early-to-late RT shift, an A-to-B compartment switch, weakening of TAD architecture, and loss of transcription. The dispensability of TAD boundaries and the necessity of these “early replication control elements” (ERCEs) was validated by deletions and inversions at additional domains. Our results demonstrate that discrete cis-regulatory elements orchestrate domain-wide RT, A/B compartmentalization, TAD architecture, and transcription, revealing fundamental principles linking genome structure and function.

Keywords replication timing sub-nuclear compartment topologically associating domain ERCEs CTCF chromatin interactions genome architecture super-enhancer


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Reconstrução do genoma ancestral metazoário revela um aumento na novidade genômica

domingo, dezembro 30, 2018

Reconstruction of the ancestral metazoan genome reveals an increase in genomic novelty

Jordi Paps & Peter W. H. Holland 

Nature Communications volume 9, Article number: 1730 (2018) 

Reconstruction of ancestral genomes. Evolutionary relationships of the major groups included in his study


Understanding the emergence of the Animal Kingdom is one of the major challenges of modern evolutionary biology. Many genomic changes took place along the evolutionary lineage that gave rise to the Metazoa. Recent research has revealed the role that co-option of old genes played during this transition, but the contribution of genomic novelty has not been fully assessed. Here, using extensive genome comparisons between metazoans and multiple outgroups, we infer the minimal protein-coding genome of the first animal, in addition to other eukaryotic ancestors, and estimate the proportion of novelties in these ancient genomes. Contrary to the prevailing view, this uncovers an unprecedented increase in the extent of genomic novelty during the origin of metazoans, and identifies 25 groups of metazoan-specific genes that are essential across the Animal Kingdom. We argue that internal genomic changes were as important as external factors in the emergence of animals.


We thank Ignacio Maeso, Ferdinand Marlétaz, Sebastian M. Shimeld, Patrick Gemmell, and Thomas L. Dunwell for feedback during this project. Iñaki Ruiz-Trillo kindly provided genome data for different holozoan species. The authors are grateful to friends and colleagues who provided feedback on the manuscript. P.W.H.H. and J.P. acknowledge support from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013)/ERC grant [268513].

Author information


School of Biological Sciences, University of Essex, Colchester, Essex, CO4 3SQ, UK

Jordi Paps

Department of Zoology, University of Oxford, Oxford, OX1 3PS, UK

Jordi Paps & Peter W. H. Holland


J.P. and P.W.H.H. designed the study and analyses. J.P. performed the analyses. J.P. and P.W.H.H. wrote the manuscript.

Competing interests

The authors declare no competing interests.

Corresponding author

Correspondence to Jordi Paps.

Origem da vida: quando não dá por aqui...vamos de fora mesmo!

quinta-feira, dezembro 20, 2018

Deoxyribose and deoxysugar derivatives from photoprocessed astrophysical ice analogues and comparison to meteorites

Michel Nuevo, George Cooper & Scott A. Sandford

Nature Communications volume 9, Article number: 5276 (2018)


Sugars and their derivatives are essential to all terrestrial life. Their presence in meteorites, together with amino acids, nucleobases, amphiphiles, and other compounds of biological importance, may have contributed to the inventory of organics that played a role in the emergence of life on Earth. Sugars, including ribose (the sugar of RNA), and other sugar derivatives have been identified in laboratory experiments simulating photoprocessing of ices under astrophysical conditions. In this work, we report the detection of 2-deoxyribose (the sugar of DNA) and several deoxysugar derivatives in residues produced from the ultraviolet irradiation of ice mixtures consisting of H2O and CH3OH. The detection of deoxysugar derivatives adds to the inventory of compounds of biological interest that can form under astrophysical conditions and puts constraints on their abiotic formation pathway. Finally, we report that some of the deoxysugar derivatives found in our residues are also newly identified in carbonaceous meteorites.


We thank R.L. Walker (NASA Ames, retired) for technical support and A.C. Rios (NASA Ames) for useful comments on the manuscript. This work was supported by the National Aeronautics and Space Administration through the NASA Exobiology Program and the NASA Astrobiology Institute under Cooperative Agreement Notice NNH13ZDA017C issued through the Science Mission Directorate.

Author information


NASA Ames Research Center, MS 245-6, Moffett Field, CA, 94035, USA
Michel Nuevo
& Scott A. Sandford

BAER Institute, NASA Research Park, MS 18-4, Moffett Field, CA, 94035, USA
Michel Nuevo

NASA Ames Research Center, MS 239-4, Moffett Field, CA, 94035, USA
George Cooper

M.N. prepared the laboratory samples (residues) and performed GC-MS analyses with BSTFA derivatization. G.C. performed GC-MS analysis of the residues with (+)-butanol/TFAA and MTBSTFA derivatizations. M.N. and G.C. analyzed the data to identify the compounds in the residues. S.A.S. helped for the interpretation of the results and their astrobiological implications. M.N. wrote the paper with inputs from G.C. and S.A.S.
Competing interests

The authors declare no competing interests.
Corresponding author

Correspondence to Michel Nuevo.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit

About this article

Publication history

Received 30 May 2018 Accepted 14 November 2018

Published 18 December 2018


Subjects Interstellar medium Laboratory astrophysics Mass spectrometry

Darwin não consegue explicar a história abreviada da evolução humana!!!

quarta-feira, dezembro 19, 2018

International Journal of Anthropology and Ethnology

December 2018, 2:6 | Cite as

A brief history of human evolution: challenging Darwin’s claim

Authors and affiliations

Sarah Umer

Sarah Umer
1Email authorView author's OrcID profile
1.Department of Visual Arts & Graphic Design, Institute of Visual Arts & DesignLahore College for Women UniversityLahorePakistan

Open AccessResearch
First Online: 29 October 2018


There is a consensus among evolutionists today that man first appeared in Africa approximately four million years ago. Others counter this theory saying, “...when shall we speak of man as man”? The timeline they give is approximately one million years and to fully understand one million years is still a difficult task.

However, another even better way to understand time and man is to study it in terms of generations. So, keeping in mind that primitive people married and had children early, twenty years will make an average generation. According to this there would be 50,000 generations in a million years. Keeping this in mind if we calculate generations we find that 250 generations back take us to the time when written history began. While, another 250 generations back would take us to the time (10,000 years ago), when cultivation began, and man started settled life. Now we are left with 49,500 generations of men, plus a time span of 990,000 years. Keeping these statistics in mind let us ask the question once more, when should we speak of man as man?

Therefore, this paper attempts not only to understand the timeframe “when we can really call Man? – Man” in light of the so-called history of human evolution but also to understand that if the specie roaming the earth for a million years was truly man’s ancestor, as is claimed by Charles Darwin. Then what took man’s ancestor so long to show signs of development that we only witness in the last 12000 years.

Moreover, while keeping man’s progress under consideration of the last 12000 years, it will further shed light on why there are serious reservations about Charles Darwin theory of human evolution. As many scientists, evolutionists, archeologist and different religious scriptures strongly claim that man came to the earth fully developed and did not evolve from a lesser specie.

KeywordsHuman Evolution Darwin Specie Neanderthals 



Este artigo com revisão por pares vai dar uma dor de cabeça para os evolucionistas ortodoxos fundamentalistas!!!

Pano rápido! Darwin kaput desde 1859!!!

Explicando as diferenças nas taxas de evolução

Closing the gap between palaeontological and neontological speciation and extinction rate estimates

Daniele Silvestro, Rachel C. M. Warnock, Alexandra Gavryushkina & Tanja Stadler

Nature Communications volume 9, Article number: 5237 (2018)
Speciation modes reflecting the difference in phylogenetic and stratigraphic interpretations of speciation and extinction rates.


Measuring the pace at which speciation and extinction occur is fundamental to understanding the origin and evolution of biodiversity. Both the fossil record and molecular phylogenies of living species can provide independent estimates of speciation and extinction rates, but often produce strikingly divergent results. Despite its implications, the theoretical reasons for this discrepancy remain unknown. Here, we reveal a conceptual and methodological basis able to reconcile palaeontological and molecular evidence: discrepancies are driven by different implicit assumptions about the processes of speciation and species evolution in palaeontological and neontological analyses. We present the “birth-death chronospecies” model that clarifies the definition of speciation and extinction processes allowing for a coherent joint analysis of fossil and phylogenetic data. Using simulations and empirical analyses we demonstrate not only that this model explains much of the apparent incongruence between fossils and phylogenies, but that differences in rate estimates are actually informative about the prevalence of different speciation modes.


We thank David Bapst and Charles Marshall for providing valuable feedback on the manuscript. In addition, we thank Ziheng Yang, Andreas Steingötter and the ETH Seminar for Statistics group for providing advice on model testing and Carl Simpson for providing data. D.S. received funding from the Swedish Research Council (2015-04748) and from the Swedish Foundation for Strategic Research. R.C.M.W. was funded by the ETH Zürich Postdoctoral Fellowship and Marie Curie Actions for People COFUND programme. T.S. is supported in part by the European Research Council under the Seventh Framework Programme of the European Commission (PhyPD: grant agreement number 335529). A.G. was funded by the Bioprotection Research Centre. Part of the analyses were run at the high-performance computing centre Vital-IT of the Swiss Institute of Bioinformatics (Lausanne, Switzerland).

Author information

Author notes

These authors contributed equally: Daniele Silvestro, Rachel C. M. Warnock.

Department of Biological and Environmental Sciences, University of Gothenburg, 41319, Gothenburg, Sweden
Daniele Silvestro

Global Gothenburg Biodiversity Centre, 41319, Gothenburg, Sweden
Daniele Silvestro

Department of Computational Biology, University of Lausanne, Lausanne, 1015, Switzerland
Daniele Silvestro

Swiss Institute of Bioinformatics (SIB), 1015, Lausanne, Switzerland
Daniele Silvestro
, Rachel C. M. Warnock
& Tanja Stadler

Department of Biosystems Science & Engineering, Eidgenössische Technische Hochschule Zürich, 4058, Basel, Switzerland
Rachel C. M. Warnock
& Tanja Stadler

Department of Biochemistry, University of Otago, Dunedin, 9054, New Zealand
Alexandra Gavryushkina

D.S., R.C.M.W., A.G., and T.S. designed the study and developed the methods. D.S. and R.C.M.W. wrote the manuscript with contributions from all authors. R.C.M.W. implemented the maximum likelihood tests and ran the simulations. D.S. implemented the Bayesian version of the BDC model and analysed the empirical data sets. 

Competing interests

The authors declare no competing interests. 

Corresponding author

Correspondence to Daniele Silvestro.

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit

About this article

Publication history

Received 19 December 2017 Accepted 13 November 2018

Published 07 December 2018

Um modelo matematizado unificado da Informação Complexa Especificada

segunda-feira, dezembro 17, 2018

A Unified Model of Complex Specified Information

George D Montañez

Source/Fonte: Internet


A mathematical theory of complex specified information is introduced which unifies several prior methods of computing specified complexity. Similar to how the exponential family of probability distributions have dissimilar surface forms yet share a common underlying mathematical identity, we define a model that allows us to cast Dembski’s semiotic specified complexity, Ewert et al.’s algorithmic specified complexity, Hazen et al.’s functional information, and Behe’s irreducible complexity into a common mathematical form. Adding additional constraints, we introduce canonical specified complexity models, for which one-sided conservation bounds are given, showing that large specified complexity values are unlikely under any given continuous or discrete distribution and that canonical models can be used to form statistical hypothesis tests, by bounding tail probabilities for arbitrary distributions.

FREE PDF GRATIS: Bio-Complexity

O DNA mitocondrial é inadequado para testar o isolamento por distância

sexta-feira, dezembro 14, 2018

Mitochondrial DNA is unsuitable to test for isolation by distance

Peter R. Teske, Tirupathi Rao Golla, Jonathan Sandoval-Castillo, Arsalan Emami-Khoyi, Carl D. van der Lingen, Sophie von der Heyden, Brent Chiazzari, Bettine Jansen van Vuuren & Luciano B. Beheregaray 

Scientific Reports volume 8, Article number: 8448 (2018) 


Tests for isolation by distance (IBD) are the most commonly used method of assessing spatial genetic structure. Many studies have exclusively used mitochondrial DNA (mtDNA) sequences to test for IBD, but this marker is often in conflict with multilocus markers. Here, we report a review of the literature on IBD, with the aims of determining (a) whether significant IBD is primarily a result of lumping spatially discrete populations, and (b) whether microsatellite datasets are more likely to detect IBD when mtDNA does not. We also provide empirical data from four species in which mtDNA failed to detect IBD by comparing these with microsatellite and SNP data. Our results confirm that IBD is mostly found when distinct regional populations are pooled, and this trend disappears when each is analysed separately. Discrepancies between markers were found in almost half of the studies reviewed, and microsatellites were more likely to detect IBD when mtDNA did not. Our empirical data rejected the lack of IBD in the four species studied, and support for IBD was particularly strong for the SNP data. We conclude that mtDNA sequence data are often not suitable to test for IBD, and can be misleading about species’ true dispersal potential. The observed failure of mtDNA to reliably detect IBD, in addition to being a single-locus marker, is likely a result of a selection-driven reduction in genetic diversity obscuring spatial genetic differentiation.


This study was funded by the National Research Foundation (CSUR Grant No. 87702 to P.R.T.), the University of Johannesburg (URC/FRC grant to P.R.T) and the Australian Research Council (FT130101068 and DP110101275 to L.B.B.). T.R.G. and A.E.-K. acknowledge the University of Johannesburg for Global Excellence and Stature (GES) fellowships for doctoral and postdoctoral study, respectively. We are grateful to two anonymous reviewers whose comments improved the quality of this manuscript.

Author information

Author notes

Peter R. Teske and Tirupathi Rao Golla contributed equally to this work.


Centre for Ecological Genomics and Wildlife Conservation, Department of Zoology, University of Johannesburg, Auckland Park, 2006, South Africa

Peter R. Teske, Tirupathi Rao Golla, Arsalan Emami-Khoyi & Bettine Jansen van Vuuren

Molecular Ecology Lab, College of Science and Engineering, Flinders University, Adelaide, SA, 5001, Australia

Jonathan Sandoval-Castillo & Luciano B. Beheregaray

Branch: Fisheries Management, Department of Agriculture, Forestry and Fisheries, Private Bag X2, Vlaeberg, 8012, South Africa

Carl D. van der Lingen

Department of Biological Sciences and Marine Research Institute, University of Cape Town, Private Bag X3, Rondebosch, 7700, South Africa

Carl D. van der Lingen

Evolutionary Genomics Group, Department of Botany and Zoology, University of Stellenbosch, Private Bag X1, 7602, Matieland, South Africa

Sophie von der Heyden

School of Life Sciences, University of KwaZulu-Natal, Westville, Durban, 4001, South Africa

Brent Chiazzari


P.R.T. and L.B.B. designed the study; C.v.d.L., P.R.T., S.v.d.H., B.C. and J.S.-C. collected the samples; P.R.T. and T.R.G. conducted the literature review; P.R.T., J.S.-C., T.R.G. and A.E.-K. analysed the data; P.R.T., L.B.B., T.R.G. and S.v.d.H. wrote the paper, with input from C.v.d.L., J.S.-C., B.v.V. and B.C.

Competing Interests

The authors declare no competing interests.

Corresponding author

Correspondence to Peter R. Teske.

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Relatório anual de Inteligência Artificial 2018

quinta-feira, dezembro 13, 2018

A "reincarnação" explica o transgenerismo???

Childhood Gender Nonconformity and Children’s Past-Life Memories

Marieta Pehlivanova, Monica J. Janke, Jack Lee & Jim B. Tucker

Received 30 May 2018, Accepted 04 Sep 2018, Published online: 15 Nov 2018


Objectives: This study examines childhood gender nonconformity (GNC) in conjunction with the phenomenon in which young children describe memories of a purported previous life. Methods: In a case-control study of 469 children reporting past-life memories, we used logistic regression to examine predictors of GNC, measured by documented gender nonconforming behaviors. Results: Children who remembered a life involving a different natal sex were much more likely to exhibit GNC than children who remembered a same-sex life. Conclusions: After exploring potential explanations, we conclude that past-life memories represent a novel factor that may be associated with the development of GNC.

Keywords: Gender nonconformity, gender identity, children, adolescents, reincarnation memories

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International Journal of Sexual Health



Essencialmente os pesquisadores estão dizendo que as experiências de "vidas passadas" relatadas por seus sujeitos de pesquisa (crianças) indicam a reencarnação. Isso levanta a questão do que, exatamente, está sendo reencarnado? Uma alma? Um espírito? Uma mente? Seja lá o que for, tem de ser imaterial. Mas isso vai de encontro ao que os biólogos evolucionistas vêm nos dizendo sobre o estado do universo e da biologia há décadas. Simplesmente não pode haver algo imaterial.  

O status científico desta pesquisa está na balança! Razão? Os pesquisadores são da Escola de Medicina da Universidade da Virgínia, Estados Unidos… não exatamente de uma universidade qualquer. E a publicação científica é uma das mais  prestigiadas na área de sexualidade humana.  

Este blogger queria ver a reação dos biólogos evolucionistas...

A química prebiótica e a intervenção humana: Maradona que o diga!

quarta-feira, dezembro 12, 2018

Prebiotic chemistry and human intervention

Clemens Richert 

Nature Communications volume 9, Article number: 5177 (2018) | Download Citation


Experimentalists in the field of prebiotic chemistry strive to re-enact what may have happened when life arose from inanimate material. How often human intervention was needed to obtain a specific result in their studies is worth reporting.


When Diego Maradona was asked about having used his hand to score a goal in the quarter-finals of the 1986 soccer World Cup, he initially claimed that there had been divine intervention, and the term “Hand of God Goal” was coined.—There had been manual intervention, and there had been an understandable interest of the player not to admit it.—Organic chemists, if not all experimentalists in the field of prebiotic chemistry, are faced with a similar dilemma. We do our best to perform experiments that we believe re-enact possible steps of prebiotic evolution, but we know that we need to intervene manually to obtain meaningful results. Simply mixing chemicals and watching for a living system to appear from the broth seems unreasonable to me. This approach has never worked, and it is not expected to work, at least not if one is limited to the lifetime of a human, let alone the duration of a funding period or a Ph.D. thesis. So, what is a reasonable level of intervention by the experimentalist in prebiotic chemistry, and what are “plausible prebiotic conditions” in this context?

FREE PDF GRATIS: Nature Communications

O que diferencia os primatas de outros mamíferos? Somente um gene?

segunda-feira, dezembro 10, 2018

A Primate-Specific Isoform of PLEKHG6 Regulates Neurogenesis and Neuronal Migration

Adam C. O’Neill Christina Kyrousi Johannes Klaus Richard J. Leventer Edwin P. Kirk Andrew Fry Daniela T. Pilz Tim Morgan Zandra A. Jenkins Micha Drukker  Samuel F. Berkovic Ingrid E. Scheffer Renzo Guerrini David M. Markie Magdalena Götz Silvia Cappello 16, 17 Stephen P. Robertson 16

Open AccessPublished: December 4, 2018  

Graphical Abstract:

Figure thumbnail fx1


• Excess variants within basal radial glia transcriptomic signatures in cases of PH

• PLEKHG6 primate-specific isoform mutated in a case of PH functions via RhoA

• PLEKHG6 isoforms regulate features of neurogenesis

• Modulation of the PLEKHG6 primate isoform reproduces features of PH in organoids


The mammalian neocortex has undergone remarkable changes through evolution. A consequence of such rapid evolutionary events could be a trade-off that has rendered the brain susceptible to certain neurodevelopmental and neuropsychiatric conditions. We analyzed the exomes of 65 patients with the structural brain malformation periventricular nodular heterotopia (PH). De novo coding variants were observed in excess in genes defining a transcriptomic signature of basal radial glia, a cell type linked to brain evolution. In addition, we located two variants in human isoforms of two genes that have no ortholog in mice. Modulating the levels of one of these isoforms for the gene PLEKHG6 demonstrated its role in regulating neuroprogenitor differentiation and neuronal migration via RhoA, with phenotypic recapitulation of PH in human cerebral organoids. This suggests that this PLEKHG6 isoform is an example of a primate-specific genomic element supporting brain development.


O cérebro no piloto automático: mero acaso, fortuita necessidade ou design inteligente?

Brain on Autopilot

How the architecture of the brain shapes its functioning.

By Max Planck Institute for Human Development

Lead image: Default Mode Network Credit: © Max Planck Institute for Human Development

The structure of the human brain is complex, reminiscent of a circuit diagram with countless connections. But what role does this architecture play in the functioning of the brain? To answer this question, researchers at the Max Planck Institute for Human Development in Berlin, in cooperation with colleagues at the Free University of Berlin and University Hospital Freiburg, have for the first time analyzed 1.6 billion connections within the brain simultaneously. They found the highest agreement between structure and information flow in the “default mode network,” which is responsible for inward-focused thinking such as daydreaming.

Everybody’s been there: You’re sitting at your desk, staring out the window, your thoughts wandering. Instead of getting on with what you’re supposed to be doing, you start mentally planning your next holiday or find yourself lost in a thought or a memory. It’s only later that you realize what has happened: Your brain has simply “changed channels”—and switched to autopilot.

For some time now, experts have been interested in the competition among different networks of the brain, which are able to suppress one another’s activity. If one of these approximately 20 networks is active, the others remain more or less silent. So if you’re thinking about your next holiday, it is almost impossible to follow the content of a text at the same time.

To find out how the anatomical structure of the brain impacts its functional networks, a team of researchers at the Max Planck Institute for Human Development in Berlin, in cooperation with colleagues at the Free University of Berlin and the University Hospital Freiburg, have analyzed the connections between a total of 40,000 tiny areas of the brain. Using functional magnetic resonance imaging, they examined a total of 1.6 billion possible anatomical connections between these different regions in 19 participants aged between 21 and 31 years. The research team compared these connections with the brain signals actually generated by the nerve cells.

Their results showed the highest agreement between brain structure and brain function in areas forming part of the “default mode network,” which is associated with daydreaming, imagination, and self-referential thought. “In comparison to other networks, the default mode network uses the most direct anatomical connections. We think that neuronal activity is automatically directed to level off at this network whenever there are no external influences on the brain,” says Andreas Horn, lead author of the study and researcher in the Center for Adaptive Rationality at the Max Planck Institute for Human Development in Berlin.

Living up to its name, the default mode network seems to become active in the absence of external influences. In other words, the anatomical structure of the brain seems to have a built-in autopilot setting. It should not, however, be confused with an idle state. On the contrary, daydreaming, imagination, and self-referential thought are complex tasks for the brain.


Read more here: Nautilus

Os acadêmicos são covardes? A força das pesquisas de queixas e os custos irrecuperáveis da carreira acadêmica

quarta-feira, dezembro 05, 2018

Are Academics Cowards? The Grip of Grievance Studies and the Sunk Costs of Academic Pursuit

Image result for cowardice
Source/Fonte: Times Higher Education

Posted on December 4, 2018 14 minute read by James A. Lindsay

There is much that should be said about the ways in which the dominant Social Justice ideology has negative impacts upon the university, free expression, academic freedom and, especially, the sciences. Like all rigid ideologies, Social Justice is inimical to science—not because of what it claims or concludes but because of how it goes about reaching its conclusions. Social Justice, like all rigid ideologies, is only interested in science that supports its predetermined theoretical conclusions and holds all other science suspect.

Of course, the accusation that the sciences are susceptible to the forces of Social Justice and its endless politicking may come as some surprise to those in the sciences, because they are duly confident in their own rigor. They are right to realize that, even if the Social Justice educational reformers go too far or have a frightening amount of institutional control, they cannot really influence science directly because they don’t do science. The assumption held by many, which is plausible, is that scientists will keep doing science according to rigorous scientific methodologies and needn’t worry much about the influence of politics from the more ideological sectors of the academy—including the administration.

This attitude is both laudable and quaintly naive. It is likely to underestimate the degree to which the sciences, like all disciplines, are susceptible to the influences and whims of a dominant orthodoxy. We should note that this exact concern is also what we hear from proponents of Social Justice when they attempt to encroach upon science—it’s perhaps the chorus of the siren song of feminist studies of science and technology to insist that the sciences are already biased and that their activism is a necessary corrective. These criticisms of science insist that science is already prejudiced towards the ideological assumptions of white, Western men and therefore needs to be made more inclusive. This argument, however, goes against the core and essential nature of science, which is universality. Whatever is true about the world should be discoverable by the same methods, regardless of who or what does the experiment.

Another core part of the scientific process is skepticism. This means that science, as a process, is already geared to minimize and correct for potential biases and errors, be they ideological or otherwise. Input into ways to do this more efficiently are always welcome, but Social Justice approaches do not seek to further improve the objectivity of science. Instead, they aim to introduce opposing biases, which they see as effectively counteracting existing ones. Far from being a novel or useful insight, however, concerns about the lack of objectivity on the part of any given observer or theoretician aren’t lost on any serious scientist or philosopher of science and haven’t been in decades (and appropriating Thomas Kuhn’s work here doesn’t work on the Social Justice side).

For these reasons, scientists should be deeply concerned with the possibility that people with strongly ideological and political motives, many of which are ambivalent at best and hostile at worst to the core values of scientific inquiry, might establish themselves as the body of working scientists and arbiters of what science can and should be done and for what reasons. Rigorous epistemology and a certain willingness to let the cards fall where they may and to have one’s ideas proven wrong will suffice.

The thing is, it is extremely likely that a majority of working scientists, at least outside of the social sciences, are keenly aware of the ways in which Social Justice can corrupt science, its conflict with the core values of science and science education, and its potential costs and implications. Nevertheless, it appears that they are letting it happen. Why would they do this?

There’s no real mystery in this question. Most of the scientists who see the writing on the wall and wish they could do something about it will eagerly tell you precisely why they don’t speak and act against the creeping woke hegemony they know will eventually corrupt their disciplines, possibly for generations. They’re afraid. They’re afraid they’ll be fired. They’re afraid they’ll be blacklisted from jobs, tenure and research funding opportunities. They’re afraid they’ll become thorns in the sides of the administration, especially the Grand Wizards of their institutions’ Offices of Diversity and Inclusion, and targets of the newly minted campus inquisition Bias Response Teams, and never have another peaceful day to get real work done. They’re afraid they’ll be done like Tim Hunt was done.

Outside of the academy, this attitude often gets them branded cowards. In fact, the insistence that academics are cowardly, and that’s how we got into this mess in the first place, is one that seems to have a worrying level of support lately. It’s probably true that significant numbers of academics are cowards. In the main, however, it is only true in the sense in which a person is a coward for knowing that the first few to speak out in a revolt against any hegemonic regime are going to be its first martyrs. Speaking game theoretically, she who speaks out first should always be somebody else.

On those grounds, it’s probably not correct to say that academics are cowards. We hear exhortations that they should have the courage to risk their positions by speaking out because they have options. They have PhDs for God’s sake—surely they can get another job somewhere. This is a popular myth, but the opposite is nearer to the truth. Getting a PhD often locks a person into very few options other than to toe whatever line is needed to stay in academia. If we’re going to solve many of the institutional problems facing the academic working environment, not least the creep of Social Justice ideology into these institutions, the reality of the PhD job market is going to have to be taken into account.

To understand and find a workable path forward, we need to empathize.

Imagine yourself as a relatively new PhD. Chances are that you have spent anywhere between the last three and twelve years dedicated to higher education, and you have been following a path of increasing difficulty, paired with increasingly specific and narrow focus. By definition, supposing your committee and institution were up to the task and you’re not a rather extreme outlier, you should be for about eighteen months the world’s foremost authority on some exceptionally narrow topic within a subfield of whatever field you tell people that you got your doctorate in. You’re going to be competent in other aspects of that field, of course, but it’s important to remember that you’ve spent at least the last two or three years of your program (or the entire program, depending on the country where you studied) going right to the bottom of some fairly deep rabbit hole.

Why did you do this? Passion. Love. Interest. Enthusiasm. To pursue the simple dream of doing something you genuinely love doing.

It’s virtually impossible to push yourself through a PhD program unless you truly love the subject you’re studying and want to devote your working life to researching it and teaching it—which means getting an academic job. And earning a PhD isn’t exactly a picnic. (When I did my master’s degree, my reaction was that it was a bit surprising how easy it was to earn compared to my expectations going into the program. When I finished my Ph.D., the only thing I could say was, “they don’t give those away!”) In nearly every case, it takes a great deal of dedication, interest and passion to earn a PhD, to say nothing of luck and talent.

The phrase grad student is misleading. It seems to many kind of like Easy Street. But many PhD students and postdocs work obscene hours—often in excess of eighty hours a week—to keep up with their educational, research and job duties, especially if they want to do well enough to score a tenure-track job later. They usually get summers off from coursework so that they can work even harder on their research, so there’s no real break there. They also usually do this out of passion and grit because there’s hardly any money in graduate assistantship stipends in the wide majority of fields.

And don’t get this wrong. This isn’t a poor PhD candidate story: it’s a tale of investment. A PhD program isn’t just school (or college); it is just another kind of apprenticeship like that any master tradesperson has to go through, except that it takes about a decade of insanely hard work to get through the first stage of it. To earn a PhD requires an enormous investment of time, energy, talent and resources. And what do you get in return (besides your degree and a set of wizard’s robes, complete with a hooded cape and a goofy hat)? (Note: You have to buy the robes and hat, and they’re expensive. Further, you’ll never wear them again unless you go into academia professionally.)

Pause to consider this. Chances are, if you’re looking for academic jobs, especially in the sciences, you’re coming off a postdoc or two, so you’ve literally spent the last decade or more in training for the job you hope to get. You’ve made incredible sacrifices for it. You’ve invested more into getting past the first hurdle of a future career than almost anyone else. Just imagine training at double full time, paid less than minimum wage, for a decade for a job and then being able to think it’s worth risking the career you’re working for to make a political point, even a really important or necessary one.

It’s not easy to call that cowardice when you see what it’s really about.

Read more here: Aero

No mundo RNA, a vida tem mais um ingrediente... Próximo!

Inosine, but none of the 8-oxo-purines, is a plausible component of a primordial version of RNA

Seohyun Chris Kim, Derek K. O’Flaherty, Lijun Zhou, Victor S. Lelyveld, and Jack W. Szostak

PNAS published ahead of print December 3, 2018

Edited by Gerald F. Joyce, The Salk Institute, La Jolla, CA, and approved October 26, 2018 (received for review August 21, 2018)

An artist's rendition of early Earth's hostile environment


The RNA world hypothesis assumes the abiotic synthesis of nucleotides, as well as their participation in nonenzymatic RNA replication. Whereas prebiotic syntheses of the canonical purine nucleotides remain inefficient, a prebiotically plausible route to the 8-oxo-purines has been reported. Although these noncanonical purine nucleotides are known to engage in non-Watson–Crick pairing with their canonical purine counterparts, their behavior in nonenzymatic RNA copying has not been evaluated. Our study indicates that none of the 8-oxo-purines behaves as a suitable substrate for nonenzymatic RNA copying. However, inosine turns out to exhibit reasonable rates and fidelities in RNA copying reactions. We propose that inosine could have served as a surrogate for guanosine in the early emergence of life.


The emergence of primordial RNA-based life would have required the abiotic synthesis of nucleotides, and their participation in nonenzymatic RNA replication. Although considerable progress has been made toward potentially prebiotic syntheses of the pyrimidine nucleotides (C and U) and their 2-thio variants, efficient routes to the canonical purine nucleotides (A and G) remain elusive. Reported syntheses are low yielding and generate a large number of undesired side products. Recently, a potentially prebiotic pathway to 8-oxo-adenosine and 8-oxo-inosine has been demonstrated, raising the question of the suitability of the 8-oxo-purines as substrates for prebiotic RNA replication. Here we show that the 8-oxo-purine nucleotides are poor substrates for nonenzymatic RNA primer extension, both as activated monomers and when present in the template strand; their presence at the end of a primer also strongly reduces the rate and fidelity of primer extension. To provide a proper comparison with 8-oxo-inosine, we also examined primer extension reactions with inosine, and found that inosine exhibits surprisingly rapid and accurate nonenzymatic RNA copying. We propose that inosine, which can be derived from adenosine by deamination, could have acted as a surrogate for G in the earliest stages of the emergence of life.

origin of life RNA replication primordial RNA