Controlled delivery of membrane proteins to artificial lipid bilayers by nystatin-ergosterol modulated vesicle fusion

The study of ion channels and other membrane proteins and their potential use as biosensors and drug screening targets require their reconstitution in an artificial membrane. These applications would greatly benefit from microfabricated devices in which stable artificial lipid bilayers can be rapidly and reliably formed. However, the amount of protein delivered to the bilayer must be carefully controlled. A vesicle fusion technique is investigated where composite ion channels of the polyene antibiotic nystatin and the sterol ergosterol are employed to render protein-carrying vesicles fusogenic After fusion with an ergosterol-free artificial bilayer the nystatin-ergosterol channels do not dissociate immediately and thus cause a transient current signal that marks the vesicle fusion event. Experimental pitfalls of this method were identified, the influence of the nystatin and ergosterol concentration on the fusion rate and the shape of the fusion event marker was explored, and the number of different lipid was reduced. Under these conditions, the B-amyloid peptide could be delivered in a controlled manner to a standard planar bilayer. Additionally, the electrical recordings were obtained of vesicles fusing with a planar lipid bilayer in a microfabricated device, demonstrating the suitability of nystatin-ergosterol modulated vesicle fusion for protein delivery within microsystems

Revisiting the Female Germline and Its Expanding Toolbox

The Arabidopsis thaliana ovule arises as a female reproductive organ composed solely of somatic diploid cells. Among them, one cell will acquire a unique identity and initiate female germline development. In this review we explore the complex network that facilitates differentiation of this single cell, and consider how it becomes committed to a distinct developmental program. We highlight recent progress towards understanding the role of intercellular communication, cell competency, and cell-cycle regulation in the ovule primordium, and we discuss the possibility that distinct pathways restrict germline development at different stages. Importantly, these recent findings suggest a renaissance in plant ovule research, restoring the female germline as an attractive model to study cell communication and cell fate establishment in multicellular organs

That Should Be Left to Doctors, That's What They are There For! - Exploring the Reflexivity and Trust of Young Adults When Seeking Health Information

This paper explores the health information-seeking practices of healthy young adults and how they assess and rank sources of information through a qualitative study. The findings show that participants (a) are strongly committed to searching for information about health and lifestyle, especially via the Internet; (b) healthcare professionals were perceived as the most reliable source of health information and advice; (c) online health information, although frequently accessed and experienced as empowering, is seen as a potentially unreliable source. Findings evidence how becoming better informed about health-related topics plays a pivotal role in individuals’ lives, most notably by using the Internet. Participants were able to reflect about what it means to know about health. The construction of trust regarding health information involved a heuristic process vis-à-vis source reliability and perceived credibility that places doctors as the most trustworthy medium of medical advice and health information. We conclude that participants’ trust toward professionals suggests the preference and need for more personalized care; and it is a response to the ambiguity and uncertainty that permeates the health information landscape, particularly that which is web-based.This article draws on research conducted as part of the project “Evaluating the State of Public Knowledge on Health and Health Information in Portugal” (HMSP/IISE/SAU-ICT/0003/2009), funded by the Portuguese Foundation for Science and Technology (FCT) within the Harvard Medical School-Portugal Program on Translational Research and Health Information. Part of this work has been financed by FEDER funds through the COMPETE 2020—POCI, Portugal 2020, and by Portuguese funds through FCT/Ministério da Ciência, Tecnologia e Inovação—project “Institute for Research and Innovation in Health Sciences” (POCI-01-0145-FEDER-007274). ÁM (SFRH/BPD/88647/2012) and LA (SFRH/BD/78949/2011) are both supported by fellowships from FCT. The authors would like to thank all the participants in this study, the coordinators of the EpiTeen study, and the administrative staff of the Epidemiology department of the Faculty of Medicine of the University of Porto. The authors would also like to thank Liliana Gil and Patrícia Ferreira (Centre for Social Studies, University of Coimbra, Portugal) for their collaboration in part of the interviews, and Rute Verdade for her help in proofreading this text. The authors are also grateful to anonymous reviewers for their helpful comments and suggestions that very much improved the quality of the paper

Grupos de pesquisa em enfermagem no Brasil: comparação dos perfis de 2006 e 2016

RESUMO Objetivos Comparar o perfil dos grupos de pesquisa em Enfermagem cadastrados no Diretório do CNPq em 2006 e 2016. Métodos Estudo descritivo documental. A coleta de dados aconteceu em 2006 e 2016 a partir de consulta parametrizada com o termo Enfermagem no Diretório dos Grupos de Pesquisa, na página online do CNPq, sendo realizada a análise descritiva. Os dados foram organizados em planilha do Excel. Resultados O número de Grupos de Pesquisa aumentou de 251 em 2006 para 617 em 2016, com incremento no número de participantes. Houve redução do número de grupos sem estudantes, embora 22% permaneçam sem participação de alunos de graduação. Conclusões Os grupos de pesquisa em Enfermagem refletem avanços estruturais e políticos na geração de ciência, tecnologia e inovação da área, entretanto ainda deve ser incentivada a participação de alunos de graduação e pesquisadores estrangeiros, bem como a ampliação de recursos tecnológicos e das parcerias interinstitucionais

Advancing Tests of Relativistic Gravity via Laser Ranging to Phobos

Phobos Laser Ranging (PLR) is a concept for a space mission designed to advance tests of relativistic gravity in the solar system. PLR's primary objective is to measure the curvature of space around the Sun, represented by the Eddington parameter $\gamma$, with an accuracy of two parts in $10^7$, thereby improving today's best result by two orders of magnitude. Other mission goals include measurements of the time-rate-of-change of the gravitational constant, $G$ and of the gravitational inverse square law at 1.5 AU distances--with up to two orders-of-magnitude improvement for each. The science parameters will be estimated using laser ranging measurements of the distance between an Earth station and an active laser transponder on Phobos capable of reaching mm-level range resolution. A transponder on Phobos sending 0.25 mJ, 10 ps pulses at 1 kHz, and receiving asynchronous 1 kHz pulses from earth via a 12 cm aperture will permit links that even at maximum range will exceed a photon per second. A total measurement precision of 50 ps demands a few hundred photons to average to 1 mm (3.3 ps) range precision. Existing satellite laser ranging (SLR) facilities--with appropriate augmentation--may be able to participate in PLR. Since Phobos' orbital period is about 8 hours, each observatory is guaranteed visibility of the Phobos instrument every Earth day. Given the current technology readiness level, PLR could be started in 2011 for launch in 2016 for 3 years of science operations. We discuss the PLR's science objectives, instrument, and mission design. We also present the details of science simulations performed to support the mission's primary objectives.Comment: 25 pages, 10 figures, 9 table