Dominant negative phenotype of Bacillus thuringiensis Cry1Ab, Cry11Aa and Cry4Ba mutants suggest hetero-oligomer formation among different Cry toxins.

Background - Bacillus thuringiensis Cry toxins are used worldwide in the control of different insect pests important in agriculture or in human health. The Cry proteins are pore-forming toxins that affect the midgut cell of target insects. It was shown that non-toxic Cry1Ab helix a-4 mutants had a dominant negative (DN) phenotype inhibiting the toxicity of wildtype Cry1Ab when used in equimolar or sub-stoichiometric ratios (1:1, 0.5:1, mutant:wt) indicating that oligomer formation is a key step in toxicity of Cry toxins. Methodology/Principal Findings - The DN Cry1Ab-D136N/T143D mutant that is able to block toxicity of Cry1Ab toxin, was used to analyze its capacity to block the activity against Manduca sexta larvae of other Cry1 toxins, such as Cry1Aa, Cry1Ac, Cry1Ca, Cry1Da, Cry1Ea and Cry1Fa. Cry1Ab-DN mutant inhibited toxicity of Cry1Aa, Cry1Ac and Cry1Fa. In addition, we isolated mutants in helix a-4 of Cry4Ba and Cry11Aa, and demonstrate that Cry4Ba-E159K and Cry11Aa-V142D are inactive and completely block the toxicity against Aedes aegypti of both wildtype toxins, when used at sub-stoichiometric ratios, confirming a DN phenotype. As controls we analyzed Cry1Ab-R99A or Cry11Aa-E97A mutants that are located in helix a-3 and are affected in toxin oligomerization. These mutants do not show a DN phenotype but were able to block toxicity when used in 10:1 or 100:1 ratios (mutant:wt) probably by competition of binding with toxin receptors. Conclusions/Significance - We show that DN phenotype can be observed among different Cry toxins suggesting that may interact in vivo forming hetero-oligomers. The DN phenotype cannot be observed in mutants affected in oligomerization, suggesting that this step is important to inhibit toxicity of other toxin

Portuguese colonial architectural archives at the Arquivo Histórico Ultramarino, mid 19th century - 1975

The Arquivo Histórico Ultramarino (AHU - Overseas Historical Archive) holds Portuguese architectural and also engineering archival records created and managed by the Colonial Public Offices seated in Lisbon, dating back to the end of the 16th century to 1975. The archives from the offices that performed duties in the Portuguese colonies remained there, even after their independence from Portugal. Until recently, records dated from the mid 19th century onwards were poorly identified, a panorama that changed over the last decade. These records are related to Angola, Cabo Verde, Guinea-Bissao, São Tomé and Príncipe, Mozambique, previous Portugese possessions in India, Macao and East Timor. The AHU hosted two funded projects by the Portuguese Foundation to Science and Technology (FCT) submitted by the Centre for Socioeconomic and Territorial Studies from the Lisbon University Institute (DINÂMIA'CET-IUL). The participation of the AHU in both projects allowed processing these records bulk. The first one was “The Colonial Urbanization Offices”, a three year project which benefited from the collaboration of five archival fellowships during nearly two years. The second project is the “Coast to Coast”, has a similar duration to the previous and will be ongoing until December 2019, with the contribution of an archival fellowship. Two archivists of the AHU participated in these projects as well, supervising the archival processing as researchers.info:eu-repo/semantics/publishedVersio

Colheita de girassol com plataforma de milho adaptada.

Adaptações feitas na plataforma de milho; Funcionamento da plataforma de milho adaptada; Vantagens da plataforma de milho adaptada; Indicações técnicas para a colheita de girassol.bitstream/item/60603/1/Folder-06-2005.pdf1 folder

P2X receptors as targets for the treatment of status epilepticus.

Prolonged seizures are amongst the most common neurological emergencies. Status epilepticus is a state of continuous seizures that is life-threatening and prompt termination of status epilepticus is critical to protect the brain from permanent damage. Frontline treatment comprises parenteral administration of anticonvulsants such as lorazepam that facilitate γ-amino butyric acid (GABA) transmission. Because status epilepticus can become refractory to anticonvulsants in a significant proportion of patients, drugs which act on different neurotransmitter systems may represent potential adjunctive treatments. P2X receptors are a class of ligand-gated ion channel activated by ATP that contributes to neuro- and glio-transmission. P2X receptors are expressed by both neurons and glia in various brain regions, including the hippocampus. Electrophysiology, pharmacology and genetic studies suggest certain P2X receptors are activated during pathologic brain activity. Expression of several members of the family including P2X2, P2X4, and P2X7 receptors has been reported to be altered in the hippocampus following status epilepticus. Recent studies have shown that ligands of the P2X7 receptor can have potent effects on seizure severity during status epilepticus and mice lacking this receptor display altered seizures in response to chemoconvulsants. Antagonists of the P2X7 receptor also modulate neuronal death, microglial responses and neuroinflammatory signaling. Recent work also found altered neuronal injury and inflammation after status epilepticus in mice lacking the P2X4 receptor. In summary, members of the P2X receptor family may serve important roles in the pathophysiology of status epilepticus and represent novel targets for seizure control and neuroprotection

Magnetic stimulation of the angiogenic potential of mesenchymal stromal cells in vascular tissue engineering

The authors acknowledge the financial support from Fundação para a Ciência e a Tecnologia (FCT-MEC), Portugal, through the dedicated project [PTDC/EDM-EDM/30828/2017] (BeLive) and PhD grant [SFRH/BD/114043/2015] and  through the project [EXPL/CTM-POL/1117/1135/2012] Moreover, the authors thanks POR Lisboa 2020 for the research project [PRECISE, Project N. 16394]. We acknowledge Dr. Marta Teixeira and the IPATIMUP facilities for the development of the ex vivo CAM experiments. The authors acknowledge Prof. Reyes Mallada (University of Zaragoza, Spain) for the use of the vibrating sample magnetometer (VSM) equipment and Dr. Pavel Strichovanec (University of Zaragoza, Spain) for the technical assistance provided during the experiments. We also acknowledge the Instituto de Medicina Molecular (IMM, Lisboa) for the services provided concerning the use of the Confocal Scanning Microscopy (Zeiss LSM 710). Publisher Copyright: © 2021 The Author(s). Published by National Institute for Materials Science in partnership with Taylor & Francis Group.The growing prevalence of vascular diseases worldwide has emphasized the need for novel tissue-engineered options concerning the development of vascularized 3D constructs. This study reports, for the first time, the use of external magnetic fields to stimulate mesenchymal stromal cells (MSCs) to increase the production of vascular endothelial growth factor-A (VEGF-A). Polyvinylalcohol and gelatin-based scaffolds, containing iron oxide nanoparticles, were designed for optimal cell magnetic stimulation. While the application of static magnetic fields over 24 h did not impact on MSCs proliferation, viability and phenotypic identity, it significantly increased the production of VEGF-A and guided MSCs morphology and alignment. The ability to enhance MSCs angiogenic potential was demonstrated by the increase in the number of new vessels formed in the presence of MSCs conditioned media through in vitro and in vivo models. Ultimately, this study uncovers the potential to manipulate cellular processes through short-term magnetic stimulation.publishersversionpublishe

A Ni hyperaccumulator and a congeneric non-accumulator reveal equally effective defenses against herbivory

The defense hypothesis is commonly used to explain the adaptive role ofmetal hyperaccumulation. We tested this hypothesis using two Brassicaceae congeneric species: Alyssum pintodasilvae, a Ni hyperaccumulator, and the non-accumulator Alyssum simplex both growing on serpentine soils in Portugal. Artificial diet disks amended with powdered leaves from each plant species were used to compare the performance (mortality, biomass change) and feeding behavior of Tribolium castaneum in no-choice and choice tests. The performance of T. castaneum was not affected at several concentrations of A. pintodasilvae or A. simplex in no-choice tests. However, the consumption of plant-amended disks was significantly lower than that of control disks, irrespectively of the species fed. Accordingly, when insects were given an alternative food choice, disks of both plant species were significantly less consumed than control disks. Moreover, insects did not discriminate between disks in the combination “A. pintodasilvae + A. simplex”. Contrary to our expectations, these results suggest that both plant species have equally effective defenses against herbivory. While Ni is believed to be part of the deterrence mechanism in the hyperaccumulator A. pintodasilvae, it seems likely that organic compounds, possibly glucosinolates, play an important role in the defense of A. simplex or in both species.This study was fully supported by the Centre for Functional Ecology, University of Coimbra

Staggered Quantum Walks With Hamiltonians

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Quantum walks are recognizably useful for the development of new quantum algorithms, as well as for the investigation of several physical phenomena in quantum systems. Actual implementations of quantum walks face technological difficulties similar to the ones for quantum computers, though. Therefore, there is a strong motivation to develop new quantum-walk models which might be easier to implement. In this work we present an extension of the staggered quantum walk model that is fitted for physical implementations in terms of time-independent Hamiltonians. We demonstrate that this class of quantum walk includes the entire class of staggered quantum walk model, Szegedy's model, and an important subset of the coined model.951Faperj [E-26/102.350/2013]CNPq [303406/20151, 474143/2013-9, PDJ 165941/2014-6]FAPESP through the Research Center in Optics and Photonics (CePOF)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP