Modeling population dynamics of online communities

Online communities are more dynamic in terms of composition compared to traditional physical communities. This can affect the conditions for cooperation. We discuss empirical results from online communities and extend the evolution of firms model of Axtell to discover the conditions of cooperation in groups

Internal noise estimates correlate with autistic traits

Previous neuroimaging research has reported increased internal (neural) noise in sensory systems of autistic individuals. However, it is unclear if this difference has behavioural or perceptual consequences, as previous attempts at measuring internal noise in ASD psychophysically have been indirect. Here we use a ‘gold standard’ psychophysical double-pass paradigm to investigate the relationship between internal noise and autistic traits in the neurotypical population (n=43). We measured internal noise in three tasks (contrast perception, facial expression intensity perception and number summation) to estimate a global internal noise factor using principal components analysis. This global internal noise was positively correlated with autistic traits (rs=0.32, p=0.035). This suggests that increased internal noise is associated with the ASD phenotype even in subclinical populations. The finding is discussed in relation to the neural and genetic basis of internal noise in ASD

Old World megadroughts and pluvials during the Common Era

Climate model projections suggest widespread drying in the Mediterranean Basin and wetting in Fennoscandia in the coming decades largely as a consequence of greenhouse gas forcing of climate. To place these and other “Old World” climate projections into historical perspective based on more complete estimates of natural hydroclimatic variability, we have developed the “Old World Drought Atlas” (OWDA), a set of year-to-year maps of tree-ring reconstructed summer wetness and dryness over Europe and the Mediterranean Basin during the Common Era. The OWDA matches historical accounts of severe drought and wetness with a spatial completeness not previously available. In addition, megadroughts reconstructed over north-central Europe in the 11th and mid-15th centuries reinforce other evidence from North America and Asia that droughts were more severe, extensive, and prolonged over Northern Hemisphere land areas before the 20th century, with an inadequate understanding of their causes. The OWDA provides new data to determine the causes of Old World drought and wetness and attribute past climate variability to forced and/or internal variability

Natural micropolymorphism in human leukocyte antigens provides a basis for genetic control of antigen recognition

Human leukocyte antigen (HLA) gene polymorphism plays a critical role in protective immunity, disease susceptibility, autoimmunity, and drug hypersensitivity, yet the basis of how HLA polymorphism influences T cell receptor (TCR) recognition is unclear. We examined how a natural micropolymorphism in HLA-B44, an important and large HLA allelic family, affected antigen recognition. T cell–mediated immunity to an Epstein-Barr virus determinant (EENLLDFVRF) is enhanced when HLA-B*4405 was the presenting allotype compared with HLA-B*4402 or HLA-B*4403, each of which differ by just one amino acid. The micropolymorphism in these HLA-B44 allotypes altered the mode of binding and dynamics of the bound viral epitope. The structure of the TCR–HLA-B*4405EENLLDFVRF complex revealed that peptide flexibility was a critical parameter in enabling preferential engagement with HLA-B*4405 in comparison to HLA-B*4402/03. Accordingly, major histocompatibility complex (MHC) polymorphism can alter the dynamics of the peptide-MHC landscape, resulting in fine-tuning of T cell responses between closely related allotypes

A contingency analysis of precarious organizational temporariness

This paper extends our current understanding of organizational temporariness. The life of a temporary British trade union branch established to recruit Eastern European migrant workers reveals ‘precarious temporariness’, which is less predictable than the ‘planned temporariness’ typically portrayed in the literature. This different type of temporariness was associated with four key contingencies affecting the branch: dispersed governance, bottom-up initiatives, uncertain resourcing, and an effectuation logic. Analysis of the case extends our existing understanding of organizational temporariness and points to an extension of existing theorizing by highlighting the contingent nature of temporariness. The broader managerial implication of the findings is that for projects facing contingencies of the kind studied, the conventional linear approach of target setting and performance management will be less effective than an ongoing process of communication and consultation

Decoupled diversity dynamics in green and brown webs during primary succession in a salt marsh

1.Terrestrial ecosystems are characterised by a strong functional connection between the green (plant-herbivore-based) and brown (detritus-detritivore-based) parts of the food web, which both develop over successional time. However, the interlinked changes in green and brown food web diversity patterns in relation to key ecosystem processes are rarely studied. 2.Here, we demonstrate changes in species richness, diversity and evenness over a wide range of invertebrate green and brown trophic groups during 100 years of primary succession in a salt marsh ecosystem, using a well-calibrated chronosequence. 3.We contrast two hypotheses on the relationship between green and brown food web diversity across succession: i) ‘coupled diversity hypothesis’, which predicts that all trophic groups covary similarly with the main drivers of successional ecosystem assembly versus ii) the ‘decoupled diversity hypothesis’, where green and brown trophic groups diversity respond to different drivers during succession. 4.We found that, while species richness for plants and invertebrate herbivores (green web groups) both peaked at intermediate productivity and successional age, the diversity of macro-detritivores, microarthropod microbivores and secondary consumers (brown web groups) continuously increased towards the latest successional stages. These results suggest that green web trophic groups are mainly driven by vegetation parameters, such as the amount of bare soil, vegetation biomass production, and vegetation height, while brown web trophic groups are mostly driven by the production and standing stock of dead organic material and soil development. 5.Our results show that plant diversity cannot simply be used as a proxy for the diversity of all other species groups that drive ecosystem functioning, as brown and green diversity components in our ecosystem responded differently to successional gradients

Mutation analysis of the NSD1 gene in patients with autism spectrum disorders and macrocephaly

<p>Abstract</p> <p>Background</p> <p>Sotos syndrome is an overgrowth syndrome characterized by macrocephaly, advanced bone age, characteristic facial features, and learning disabilities, caused by mutations or deletions of the <it>NSD1 </it>gene, located at 5q35. Sotos syndrome has been described in a number of patients with autism spectrum disorders, suggesting that <it>NSD1 </it>could be involved in other cases of autism and macrocephaly.</p> <p>Methods</p> <p>We screened the <it>NSD1 </it>gene for mutations and deletions in 88 patients with autism spectrum disorders and macrocephaly (head circumference 2 standard deviations or more above the mean). Mutation analysis was performed by direct sequencing of all exons and flanking regions. Dosage analysis of <it>NSD1 </it>was carried out using multiplex ligation-dependent probe amplification.</p> <p>Results</p> <p>We identified three missense variants (R604L, S822C and E1499G) in one patient each, but none is within a functional domain. In addition, segregation analysis showed that all variants were inherited from healthy parents and in two cases were also present in unaffected siblings, indicating that they are probably nonpathogenic. No partial or whole gene deletions/duplications were observed.</p> <p>Conclusion</p> <p>Our findings suggest that Sotos syndrome is a rare cause of autism spectrum disorders and that screening for <it>NSD1 </it>mutations and deletions in patients with autism and macrocephaly is not warranted in the absence of other features of Sotos syndrome.</p

An International Urogynecological Association (IUGA)/International Continence Society (ICS) joint report on the terminology for female anorectal dysfunction.

INTRODUCTION: The terminology for anorectal dysfunction in women has long been in need of a specific clinically-based Consensus Report. METHODS: This Report combines the input of members of the Standardization and Terminology Committees of two International Organizations, the International Urogynecological Association (IUGA) and the International Continence Society (ICS), assisted on Committee by experts in their fields to form a Joint IUGA/ICS Working Group on Female Anorectal Terminology. Appropriate core clinical categories and sub classifications were developed to give an alphanumeric coding to each definition. An extensive process of twenty rounds of internal and external review was developed to exhaustively examine each definition, with decision-making by collective opinion (consensus). RESULTS: A Terminology Report for anorectal dysfunction, encompassing over 130 separate definitions, has been developed. It is clinically based with the most common diagnoses defined. Clarity and user-friendliness have been key aims to make it interpretable by practitioners and trainees in all the different specialty groups involved in female pelvic floor dysfunction. Female-specific anorectal investigations and imaging (ultrasound, radiology and MRI) has been included whilst appropriate figures have been included to supplement and help clarify the text. Interval review (5-10 years) is anticipated to keep the document updated and as widely acceptable as possible. CONCLUSION: A consensus-based Terminology Report for female anorectal dysfunction terminology has been produced aimed at being a significant aid to clinical practice and a stimulus for research. Neurourol. Urodynam. 36:10-34, 2017. © 2016 Wiley Periodicals, Inc., and The International Urogynecological Association

Tales of migration from the global south. The civilized and uncivilized migrant in the narratives of La Tercera and El Mercurio

Migration is not a new phenomenon in Chile as the country has long seen migrants coming from Europe, the Middle East and Asia. Colonial views about race and ethnicity adopted by Latin Americans as part of their class structure (Quijano 2000) established an early differentiation between the “civilized migrant” and the “uncivilized migrant” among groups that arrived on Latin America shores. Chilean news media has echoes of this binary vision between the “civilized = good” migrant and the “uncivilized = bad” migrant. The chapter aims to uncover the narratives of the civilized and uncivilized migrant within the printed news media, particularly in the two major newspapers El Mercurio and La Tercera, by focusing on how these ideas frame the way in which they cover migration.Published versio