Feedback control of chromosome separation by a midzone Aurora B gradient

Accurate chromosome segregation during mitosis requires the physical separation of sister chromatids before nuclear envelope reassembly (NER). However, how these two processes are coordinated remains unknown. Here, we identified a conserved feedback control mechanism that delays chromosome decondensation and NER in response to incomplete chromosome separation during anaphase. A midzone-associated Aurora B gradient was found to monitor chromosome position along the division axis and to prevent premature chromosome decondensation by retaining Condensin I. PP1/PP2A phosphatases counteracted this gradient and promoted chromosome decondensation and NER. Thus, an Aurora B gradient appears to mediate a surveillance mechanism that prevents chromosome decondensation and NER until effective separation of sister chromatids is achieved. This allows the correction and reintegration of lagging chromosomes in the main nuclei before completion of NER.We thank all colleagues who provided reagents and P. Sampaio for technical help with FRET. H. M. is funded by FCOMP-01-0124-FEDER-015941 (PTDC/SAU-ONC/112917/2009) through COMPETE and Fundacao para a Ciencia e a Tecnologia of Portugal, the Human Frontier Science Program, and PRECISE grant from the European Research Council. Data described can be found in the main figures and supplementary materials. The authors declare no conflict of interests

Computational Models Development and Demand Response Application for Smart Grids

This paper focuses on computational models development and its applications on demand response, within smart grid scope. A prosumer model is presented and the corresponding economic dispatch problem solution is analyzed. The prosumer solar radiation production and energy consumption are forecasted by artificial neural networks. The existing demand response models are studied and a computational tool based on fuzzy clustering algorithm is developed and the results discussed. Consumer energy management applications within the InovGrid pilot project are presented. Computation systems are developed for the acquisition, monitoring, control and supervision of consumption data provided by smart meters, allowing the incorporation of consumer actions on their electrical energy management. An energy management system with integration of smart meters for energy consumers in a smart grid is developed

Relationship between self-declared ethnicity, mitochondrial haplogroup and genomic ancestry in individuals from southeast of Brazil

Em populações onde há um alto grau de miscigenação, como no Brasil, o uso exclusivo de informações da etnia auto-declarada não é um bom método de classifi cação étnica. Neste trabalho, nós avaliamos a relação entre as etnias auto-declaradas com ancestralidade genômica e haplogrupos mitocondriais em 492 indivíduos do Sudeste Brasileiro. Haplogrupos mitocondriais foram obtidos pela análise das regiões hipervariáveis do DNA mitocondrial (mtDNA) e a ancestralidade genômica foi obtida utilizando 48 marcadores autossômicos informativos de ancestralidade (AIM). Dos 492 indivíduos, 74,6% se auto-declararam brancos, 13,8% pardos e 10,4% pretos. Em relação aos haplogrupos mitocondriais, 46,3% apresentaram mtDNA Africano e a maior contribuição de ancestralidade genômica foi Europeia (57,4%). Quando realizamos a distribuição do mtDNA e ancestralidade genômica de acordo com as etnias auto-declaradas, dos 367 indivíduos auto-declarados brancos, encontramos 37,6% com mtDNA Africano, sendo observado maior contribuição de ancestralidade Europeia (63,3%). Dos 68 indivíduos auto-declarados pardos, 25% apresentaram mtDNA Ameríndio e pouca diferen-ça na contribuição de ancestralidade Europeia e Africana. Dos 51 indivíduos auto-declarados pretos, 80,4% apresentaram mtDNA Africano e maior contribuição de ancestralidade Africana (55,6%). A população brasileira apresenta uma uniformidade de ancestralidade genômica Ameríndia, e apenas o uso de marcadores genéticos (autossômico e mitocondrial) foi capaz de capturar essa informação. Sugerimos que estudos epidemiológicos façam o uso associado destes métodos, pois poderiam fornecer informações complementares.In populations where there is a high degree of admixture, as in Brazil, the sole use of ethnicity self-declaration information is not a good method of ethnic classifi cation. We evaluate the relationship between self-declared ethnicities with genomic ancestry and mitochondrial haplogroups in 492 individuals from Southeastern Brazil. Mitochondrial haplogroups were obtained by analyzing the hypervariable regions of mitochondrial DNA (mtDNA) and genomic ancestry was obtained using 48 autosomal ancestry informative markers (AIM). Of the 492 individuals, 74.6% self-declared as white, 13.8% as Brown and 10.4% as Black. In relation of mtDNA haplogroups, 46.3% presented African mtDNA and the major genomic ancestry was European (57.4%). When we performed the distribution of mtDNA and genomic ancestry according to the self-declared ethnicities, from 367 individuals self-declared white, 37.6% showed African mtDNA, and had a higher contribution of European ancestry (63.3%). The 68 individuals self-declared brown, 25% showed Amerindian mtDNA and few differences in the averages contribution of European and African ancestries. Those 51 subjects self-declared black, 80.4% had African mtDNA and the main contribution of African ancestry (55.6%). The Brazilian population had a very uniform degree of Amerindian genomic ancestry, and only by using genetic markers (autosomal and mitochondrial) we were able to capture this information. Epidemiological studies should use the association of these methods to provide complementary information

Combination light-based therapies to treat pancreatic cancer: A proof of concept

Pancreatic ductal adenocarcinoma remains one of the worst types of cancers mainly due to its late diagnosis, lack of effective therapies for advance disease and high chemoresistance. Novel therapeutic options that could improve patient quality of life and overall survival are therefore imperative. In this study, we describe the use of an original strategy based on photochemical internalisation (PCI) technology for pancreatic cancer treatment. Subcellular localisation of the photosensitiser meso-tetraphenylporphine-disulfonate (TPPS2a) was performed in PANC-1 cells, showing its preferential accumulation in lysosomes. Treatments with increasing concentrations of the ribosome-inactivating protein saporin or TPPS2a alone were compared with PCI-saporin. Metabolic activity and cell viability of PANC-1 cells were determined 96h post-illumination by MTT and trypan blue assays, respectively. Our results show that PCI using the photosensitiser TPPS2a, synergistically enhances the cytotoxic effects of saporin in PANC-1 cells and could offer more effective treatment options for pancreatic cancer

Robust gap repair in the contractile ring ensures timely completion of cytokinesis.

Cytokinesis in animal cells requires the constriction of an actomyosin contractile ring, whose architecture and mechanism remain poorly understood. We use laser microsurgery to explore the biophysical properties of constricting rings in Caenorhabditis elegans embryos. Laser cutting causes rings to snap open. However, instead of disintegrating, ring topology recovers and constriction proceeds. In response to severing, a finite gap forms and is repaired by recruitment of new material in an actin polymerization-dependent manner. An open ring is able to constrict, and rings repair from successive cuts. After gap repair, an increase in constriction velocity allows cytokinesis to complete at the same time as controls. Our analysis demonstrates that tension in the ring increases while net cortical tension at the site of ingression decreases throughout constriction and suggests that cytokinesis is accomplished by contractile modules that assemble and contract autonomously, enabling local repair of the actomyosin network. Consequently, cytokinesis is a highly robust process impervious to discontinuities in contractile ring structure.This project has received funding from the European Research Council (grants 640553, 260892, and 338410), Fundo Europeu de Desenvolvimento Regional (FED ER) funds through the Operational Competitiveness Program (COM PETE), national funds through Fundação para a Ciência e a Tecnologia (FCT) under the project FCO MP-01-0124-FED ER-028255 (PTDC/BEX-BCM/0654/2012), Fundação Luso-Americana para o Desenvolvimento Life Science 2020, and the Louis-Jeantet Young Investigator Award to H. Maiato. A.X. Carvalho, R. Gassmann, and I.A. Telley have FCT Investigator positions funded by FCT and cofunded by the European Social Fund through Programa Operacional Temático Potencial Type 4.2 promotion of scientific employment. A.M. Silva holds an FCT fellowship (SFRH/BPD/95707/2013). D.S. Osório was cofunded by the Programa Operacional Regional do Norte under the Quadro de Downloaded from jcb.rupress.org on February 27, 2018 Laser microsurgery in the contractile ring • Silva et al. 799 Referência Estratégico Nacional through FED ER and by FCT grant NOR TE-07-0124-FED ER-000003 (Cell Homeostasis Tissue Organization and Organism Biology)

Temperature dependence of the refractive index near the reentrant-isotropic-calamitic-nematic phase transition

The laser-induced nonlinear optical response of a lyotropic liquid crystal system in the reentrant-isotropic and calamitic-nematic phases is investigated by the use of the thermal lens technique. The occurrence of an inversion in the temperature coefficient of the ordinary refractive index, dn(perpendicular to)/dT, near the reentrant-isotropic-calamitic-nematic phase transition, is discussed. This effect is attributed to the behavior of the electronic polarizability due to the change in micelle shape near the isotropic-nematic transition, and correlated with the results obtained near the nematic-isotropic transition, previously reported.641

The enigmatic monotypic crab plover Dromas ardeola is closely related to pratincoles and coursers (Aves, Charadriiformes, Glareolidae)

The phylogenetic placement of the monotypic crab plover Dromasardeola (Aves, Charadriiformes) remains controversial. Phylogenetic analysis of anatomical and behavioral traits using phenetic and cladistic methods of tree inference have resulted in conflicting tree topologies, suggesting a close association of Dromas to members of different suborders and lineages within Charadriiformes. Here, we revisited the issue by applying Bayesian and parsimony methods of tree inference to 2,012 anatomical and 5,183 molecular characters to a set of 22 shorebird genera (including Turnix). Our results suggest that Bayesian analysis of anatomical characters does not resolve the phylogenetic relationship of shorebirds with strong statistical support. In contrast, Bayesian and parsimony tree inference from molecular data provided much stronger support for the phylogenetic relationships within shorebirds, and support a sister relationship of Dromas to Glareolidae (pratincoles and coursers), in agreement with previously published DNA-DNA hybridization studies