Turning it inside out: The organization of human septin heterooligomers.

Septin family proteins are quite similar to each other both within and between eukaryotic species. Typically, multiple discrete septins co-assemble into linear heterooligomers (usually hexameric or octameric rods) with a variety of cellular functions. We know little about how incorporation of different septins confers different properties to such complexes. This issue is especially acute in human cells where 13 separate septin gene products (often produced in multiple forms arising from alternative start codons and differential splicing) are expressed in a tissue-specific manner. Based on sequence alignments and phylogenetic criteria, human septins fall into four distinct groups predictive of their interactions, that is, members of the same group appear to occupy the same position within oligomeric septin protomers, which are "palindromic" (have twofold rotational symmetry about a central homodimeric pair). Many such protomers are capable of end-to-end polymerization, generating filaments. Over a decade ago, a study using X-ray crystallography and single-particle electron microscopy deduced the arrangement within recombinant heterohexamers comprising representatives of three human septin groups-SEPT2, SEPT6, and SEPT7. This model greatly influenced subsequent studies of human and other septin complexes, including how incorporating a septin from a fourth group forms heterooctamers, as first observed in budding yeast. Two recent studies, including one in this issue of Cytoskeleton, provide clear evidence that, in fact, the organization of subunits within human septin heterohexamers and heterooctamers is inverted relative to the original model. These findings are discussed here in a broader context, including possible causes for the initial confusion

Generalized soldering of ±2\pm 2 helicity states in D=2+1D=2+1

The direct sum of a couple of Maxwell-Chern-Simons (MCS) gauge theories of opposite helicities $\pm 1$ does not lead to a Proca theory in $D=2+1$, although both theories share the same spectrum. However, it is known that by adding an interference term between both helicities we can join the complementary pieces together and obtain the physically expected result. A generalized soldering procedure can be defined to generate the missing interference term. Here we show that the same procedure can be applied to join together $\pm 2$ helicity states in a full off-shell manner. In particular, by using second-order (in derivatives) self-dual models of helicities $\pm 2$ (spin two analogues of MCS models) the Fierz-Pauli theory is obtained after soldering. Remarkably, if we replace the second-order models by third-order self-dual models (linearized topologically massive gravity) of opposite helicities we end up after soldering exactly with the new massive gravity theory of Bergshoeff, Hohm and Townsend in its linearized approximation.Comment: 12 pages, to appear in Phys. Rev.

Temperatura-base inferior e estacionalidade de produção de gramíneas forrageiras tropicais.

bitstream/item/37266/1/Circular45.pd

Ex-Convicts Face Multiple Labor Market Punishments: Estimates of Peer-Group and Stigma Effects Using Equations of Returns to Schooling

We produced a data set from a survey of a population of convicts in probation. We combined this new data set with an official data set from the Brazilian government to study labor market discrimination faced by ex-convicts. We were interested in estimating two potential effects of discrimination, statistical (stigma) and behavioral (peer-group) effects. Our econometric results suggest that stigmatization leads to a 39% reduction in the wage earned by ex-convicts relative to the wage earned by non-convicts. They also suggest that the peer-group effect accounts for a reduction in the relative earnings of ex-convicts of 1.1% per year of study. In addition, we also show that ex-convicts earn 3.1% less per year of experience than non-convicts.Stigma Effect, Peer Effect, Crime Rate, Returns to Schooling, Wage Discrimination

Disadvantaged youths’ subjective well-being: the role of gender, age, and multiple social support attunement

This paper explores the relationship between gender, age, Multiple Social Support Attunement (MSSA), and disadvantaged youths’ Subjective Well-Being (SWB). MSSA is defined as social support patterns regarding multiple sources. In this study, MSSA patterns included closest family member, mentor, and best friend support. SWB was measured in terms of quality-of-life, social anxiety, and depression. Two hundred and thirty-six adolescents aged between 12 and 18 years old (M = 14.10; SD = 1.78; 60.20% boys) participated in this study. A three-class solution was retained after Latent Class Analysis (LCA) was conducted, guaranteeing a more balanced participant distribution and a more feasible comparison between MSSA patterns. Further analyses showed that MSSA patterns were associated with disadvantaged youths’ quality-of-life, social anxiety and depression, regardless of age and gender effects. These associations were more generalized and systematic than those between gender or age and the selected well-being indicators. High MSSA also emerged as an optimal pattern to improve disadvantaged youths’ SWB, especially among early adolescents. Recommendations are made to improve MSSA assessment in social interventions, as well as to promote cross-generational activities that may help to activate high MSSA shared by peers and significant adults.info:eu-repo/semantics/acceptedVersio

Water diffusion in rough carbon nanotubes

We use molecular dynamics simulations to study the diffusion of water inside deformed carbon nanotubes with different degrees of deformation at 300 K. We found that the number of hydrogen bonds that water forms depends on nanotube topology, leading to enhancement or suppression of water diffusion. The simulation results reveal that more realistic nanotubes should be considered to understand the confined water diffusion behavior, at least for the narrowest nanotubes, when the interaction between water molecules and carbon atoms is relevant.Comment: 17 pages, 8 figure

Product line architecture recovery with outlier filtering in software families: the Apo-Games case study

Software product line (SPL) approach has been widely adopted to achieve systematic reuse in families of software products. Despite its benefits, developing an SPL from scratch requires high up-front investment. Because of that, organizations commonly create product variants with opportunistic reuse approaches (e.g., copy-and-paste or clone-and-own). However, maintenance and evolution of a large number of product variants is a challenging task. In this context, a family of products developed opportunistically is a good starting point to adopt SPLs, known as extractive approach for SPL adoption. One of the initial phases of the extractive approach is the recovery and definition of a product line architecture (PLA) based on existing software variants, to support variant derivation and also to allow the customization according to customers’ needs. The problem of defining a PLA from existing system variants is that some variants can become highly unrelated to their predecessors, known as outlier variants. The inclusion of outlier variants in the PLA recovery leads to additional effort and noise in the common structure and complicates architectural decisions. In this work, we present an automatic approach to identify and filter outlier variants during the recovery and definition of PLAs. Our approach identifies the minimum subset of cross-product architectural information for an effective PLA recovery. To evaluate our approach, we focus on real-world variants of the Apo-Games family. We recover a PLA taking as input 34 Apo-Game variants developed by using opportunistic reuse. The results provided evidence that our automatic approach is able to identify and filter outlier variants, allowing to eliminate exclusive packages and classes without removing the whole variant. We consider that the recovered PLA can help domain experts to take informed decisions to support SPL adoption.This research was partially funded by INES 2.0; CNPq grants 465614/2014-0 and 408356/2018-9; and FAPESB grants JCB0060/2016 and BOL2443/201

Rossby waves in rapidly rotating Bose-Einstein condensates

We predict and describe a new collective mode in rotating Bose-Einstein condensates, which is very similar to the Rossby waves in geophysics. In the regime of fast rotation, the Coriolis force dominates the dynamics and acts as a restoring force for acoustic-drift waves along the condensate. We derive a nonlinear equation that includes the effects of both the zero-point pressure and the anharmonicity of the trap. It is shown that such waves have negative phase speed, propagating in the opposite sense of the rotation. We discuss different equilibrium configurations and compare with those resulting from the Thomas-Fermi approximation.Comment: 4 pages, 2 figures (submitted to PRL