So far, yet so close: α-Catenin dimers help migrating cells get together

Epithelial cells in tissues use their actin cytoskeletons to stick together, whereas unattached cells make active plasma membrane protrusions to migrate. In this issue, Wood et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201612006) show that the junction component α-catenin is critical in freely moving cells to promote adhesion and migration

Symplectic Quantization of Open Strings and Noncommutativity in Branes

We show how to translate boundary conditions into constraints in the symplectic quantization method by an appropriate choice of generalized variables. This way the symplectic quantization of an open string attached to a brane in the presence of an antisymmetric background field reproduces the non commutativity of the brane coordinates.Comment: We included a comparison with previous results obtained from Dirac quantization, emphasizing the fact that in the symplectic case the boundary conditions, that lead to the non commutativity, show up from the direct application of the standard method. Version to appear in Phys. Rev.

Green manure in coffee systems in the region of Zona da Mata, Minas Gerais: characteristics and kinetics of carbon and nitrogen mineralization.

The use of green manure may contribute to reduce soil erosion and increase the soil organic matter content and N availability in coffee plantations in the Zona da Mata, State of Minas Gerais, in Southeastern Brazil. The potential of four legumes (A. pintoi, C. mucunoides, S. aterrimum and S. guianensis)to produce above-ground biomass, accumulate nutrients and mineralize N was studied in two coffee plantations of subsistence farmers under different climate conditions. The biomass production of C. mucunoides was influenced by the shade of the coffee plantation.C. mucunoides tended to mineralize more N than the other legumes due to the low polyphenol content and polyphenol/N ratio. In the first year, the crop establishment of A. pintoi in the area took longer than of the other legumes, resulting in lower biomass production and N2 fixation. In the long term, cellulose was the main factor controlling N mineralization. The biochemical characteristics, nutrient accumulation and biomass production of the legumes were greatly influenced by the altitude and position of the area relative to the sun

Impact of a Tutored Theoretical-Practical Training to Develop Undergraduate Students’ Skills for the Detection of Caries Lesions: Study Protocol for a Multicenter Controlled Randomized Study

Background: Tutored laboratorial activities could be a manner of improving the competency development of students. However, its impact over conventional theoretical classes has not yet been tested. Additionally, different university contexts could influence this issue and should be explored. Objective: To assess the impact of a tutored theoretical-practical training for teaching undergraduate students to detect caries lesions as compared with theoretical teaching activities. The impact of these teaching/learning activities will be assessed in terms of efficacy, cost/benefit, retention of knowledge/acquired competences, and student acceptability. Methods: Sixteen centers (7 centers from Brazil and 9 centers from other countries throughout the world) are involved in the inclusion of subjects for this protocol. A randomized controlled study with parallel groups will be conducted. One group (control) will be exposed to a 60- to 90-minute conventional theoretical class and the other group (test) will be exposed to the same theoretical class and also a 90-minute laboratory class, including exercises and discussions based on the evaluation of a pool of images and extracted teeth. The mentioned outcomes will be evaluated immediately after the teaching activities and also in medium- and long-term analyses. To compare the long-term outcomes, students who enrolled in the university before the participating students will be interviewed for data collection and these data will be used as a control and compared with the trained group. This stage will be a nonrandomized phase of this study, nested in the main study. Appropriate statistical analysis will be performed according to the aims of this study. Variables related to the centers will also be analyzed and used to model adjustment as possible sources of variability among results. Results: This ongoing study is funded by a Brazilian national funding agency (CNPq- 400736/2014-4). We expect that the tutored theoretical-practical training will improve the undergraduate students’ performance in the detection of caries lesions and subsequent treatment decisions, mainly in terms of long-term retention of knowledge. Our hypothesis is that tutored theoretical-practical training is a more cost-effective option for teaching undergraduate students to detect caries lesions. Conclusions: If our hypothesis is confirmed, the use of laboratory training in conjunction with theoretical classes could be used as an educational strategy in Cariology to improve the development of undergraduate students’ skills in the detection of caries lesions and clinical decision-making

Ajuba is required for Rac activation and maintenance of E-cadherin adhesion

A Rac–PAK1–Ajuba feedback loop stabilizes cadherin complexes via coordination of spatiotemporal signaling with actin remodeling at cell–cell contacts

Clinical Relevance of Studies on the Accuracy of Visual Inspection for Detecting Caries Lesions: A Systematic Review

Although visual inspection is the most commonly used method for caries detection, and consequently the most investigated, studies have not been concerned about the clinical relevance of this procedure. Therefore, we conducted a systematic review in order to perform a critical evaluation considering the clinical relevance and methodological quality of studies on the accuracy of visual inspection for assessing caries lesions. Two independent reviewers searched several databases through July 2013 to identify papers/articles published in English. Other sources were checked to identify unpublished literature. The eligible studies were those which (1) assessed the accuracy of the visual method for detecting caries lesions on occlusal, approximal or smooth surfaces, in primary or permanent teeth, (2) used a reference standard, and (3) reported data about sample size and accuracy of the methods. Aspects related to clinical relevance and the methodological quality of the studies were evaluated. 96 of the 5,578 articles initially identified met the inclusion criteria. In general, most studies failed in considering some clinically relevant aspects: only 1 included study validated activity status of lesions, no study considered its prognosis, 79 studies did not consider a clinically relevant outcome, and only 1 evaluated a patient-centred outcome. Concerning methodological quality, the majority of the studies presented a high risk of bias in sample selection. In conclusion, studies on the accuracy of the visual method for caries detection should consider clinically relevant outcomes besides accuracy; moreover, they should be conducted with higher methodological quality, mainly regarding sample selection

Soluble sugars and germination of Annona emarginata (Schltdl.) H. Rainer seeds submitted to immersion in GA3 up to different water contents

The objective of this study was to evaluate the effect of different water contents achieved by Annona emarginata (Schltdl.) H. Rainer seeds during immersion in GA3 solutions, in variation of soluble sugars levels and germination. Seeds with 10% of initial water content were submitted to imbibition in GA3 solutions with concentrations of 0; 250; 500; 750 and 1000 mg L-1 and when they reached the water content of 15%, 20%, 25%, 30% and 35%, the quantification of soluble sugars levels and germination test were performed. Seeds immersed up to they reach 15% of water with GA3 and immersed up to the water acquisition of 20% without GA3, presented higher soluble sugars levels and germination percentage, which were decreased when the seeds reached 30% and 35% of water, independently of the presence of the plant growth regulator. It was conclude that different water contents reached by the seeds in immersion treatments with GA3 affect the soluble sugars levels and germination percentage of Annona emarginata seeds. Thus, in treatments with Annona emarginata, the seeds must remain immersed in water without GA3 up to they reach 20% of water, as higher water contents (35%) reduce the soluble sugars levels and the seed germination percentage.O objetivo deste trabalho foi avaliar o efeito de diferentes teores de água atingidos pelas sementes de Annona emarginata (Schltdl.) H. Rainer durante a imersão em soluções de GA3, na variação dos teores de açúcares solúveis e na germinação. Sementes com teor de água inicial de 10% foram colocadas para embeber em soluções com as concentrações de 0; 250; 500; 750 e 1.000 mg L-1 de GA3, e ao atingirem os teores de 15%, 20%, 25%, 30% e 35% de água, procedeu-se à quantificação dos teores de açúcares solúveis e ao teste de germinação. As sementes imersas até atingirem 15% de água com a adição de GA3 e imersas até a aquisição de 20% de água sem a adição de GA3 apresentaram maiores teores de açúcares solúveis e porcentagens de germinação, os quais foram reduzidos à medida que as sementes atingiram 30% e 35% de água, independentemente do uso do regulador vegetal. Conclui-se que os diferentes teores de água alcançados pelas sementes nos tratamentos de imersão afetam os teores de açúcares solúveis e a germinação de sementes de Annona emarginata. Assim, em tratamentos com Annona emarginata, as sementes devem permancer imersas na água sem a adição de GA3 até a aquisição de 20% de água, uma vez que elevados teores de água (35%) reduzem os teores de açúcares solúveis totais e a porcentagem de germinação das sementes.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNESP Biosciences Institute Graduation Program on Biological SciencesUNESP Biosciences Institute Botany DepartmentUNESP Biosciences Institute Graduation Program on Biological SciencesUNESP Biosciences Institute Botany DepartmentCNPq: 553428/2010-

Ecological distribution and population structure of Acantholobulus schmitti (Rathbun, 1930) (Crustacea, Decapoda, Xanthoidea) on the southeastern Brazilian coast

This investigation analyzed the ecological distribution and population structure of A. schmitti on the southeastern coast of Brazil. Crabs were sampled monthly from January 1998 to December 1999 at the following bays: Ubatumirim (UBM), Ubatuba (UBA) and Mar Virado (MV). Water and sediment samples were also collected from all sampling sites for an analysis of environmental factors. Acantholobus schmitti was most abundant at UBM (224), followed by UBA (154) and MV (23) but its abundance showed no association with the environmental factors analyzed. The low abundance of these crabs in MV may be due to the high wave action that moved biodetritic material accumulated on the bottom and frequently removed small crabs from their sheltered positions among the shell fragments. The individuals captured included 269 males and 132 females, of which only 4 specimens were brooding females. Juvenile recruitment occurred throughout the year, but was less intense in the spring. The major abundance of individuals as well as of ovigerous females occurred during 1999, when the entrance of the South Atlantic Central Waters (SACW) was stronger than in previous year. This environmental influence could be the main factor modulating this population