Peptide dendrimer/lipid hybrid systems are efficient DNA transfection reagents: structure--activity relationships highlight the role of charge distribution across dendrimer generations.

Efficient DNA delivery into cells is the prerequisite of the genetic manipulation of organisms in molecular and cellular biology as well as, ultimately, in nonviral gene therapy. Current reagents, however, are relatively inefficient, and structure-activity relationships to guide their improvement are hard to come by. We now explore peptide dendrimers as a new type of transfection reagent and provide a quantitative framework for their evaluation. A collection of dendrimers with cationic and hydrophobic amino acid motifs (such as KK, KA, KH, KL, and LL) distributed across three dendrimer generations was synthesized by a solid-phase protocol that provides ready access to dendrimers in milligram quantities. In conjunction with a lipid component (DOTMA/DOPE), the best reagent, G1,2,3-KL ((LysLeu)8(LysLysLeu)4(LysLysLeu)2LysGlySerCys-NH2), improves transfection by 6-10-fold over commercial reagents under their respective optimal conditions. Emerging structure-activity relationships show that dendrimers with cationic and hydrophobic residues distributed in each generation are transfecting most efficiently. The trigenerational dendritic structure has an advantage over a linear analogue worth up to an order of magnitude. The success of placing the decisive cationic charge patterns in inner shells rather than previously on the surface of macromolecules suggests that this class of dendrimers significantly differs from existing transfection reagents. In the future, this platform may be tuned further and coupled to cell-targeting moieties to enhance transfection and cell specificity

Life cycle approaches for conservation agriculture. Part I: a definition study for data analysis, Part II: Report of the special symposium on life cycle approaches for conservation agriculture on 8 May 2006 at the SETAC-Europe 16th Annual Meeting at The Hague

VakpublicatieInstitute of Environmental Science

Direito digital: Uma análise da Responsabilidade Civil e das implicações da proteção de dados pessoais à luz da Lei 13.709/2018 / Digital Law: An analysis of Civil Liability and the implications of personal data protection in light of Law 13.709/2018

A utilização de cadastros de dados para o acesso a diversos recursos disponibilizados na rede mundial de computadores é cada vez mais crescente na sociedade atual. Juntamente a esta expansão do acesso à tecnologia, surgiram também problemas relacionados à proteção de dados pessoais de usuários da internet. Neste contexto, no mês de agosto do ano de 2018, foi publicada a Lei 13.709/2018, que trata justamente da proteção a estes dados pessoais. Assim, o presente artigo pretende fazer uma análise das mudanças trazidas por essa recente legislação no âmbito da Responsabilidade Civil e do Direito Digital, especialmente no que diz respeito à responsabilidade civil dos agentes responsáveis pelo tratamento de dados dos usuários

Thauera aminoaromatica MZ1T Identified as a Polyhydroxyalkanoate-Producing Bacterium within a Mixed Microbial Consortium

Polyhydroxyalkanoates (PHAs) form a highly promising class of bioplastics for the transition from fossil fuel-based plastics to bio-renewable and biodegradable plastics. Mixed microbial consortia (MMC) are known to be able to produce PHAs from organic waste streams. Knowledge of key-microbes and their characteristics in PHA-producing consortia is necessary for further process optimization and direction towards synthesis of specific types of PHAs. In this study, a PHA-producing mixed microbial consortium (MMC) from an industrial pilot plant was characterized and further enriched on acetate in a laboratory-scale selector with a working volume of 5 L, and 16S-rDNA microbiological population analysis of both the industrial pilot plant and the 5 L selector revealed that the most dominant species within the population is Thauera aminoaromatica MZ1T, a Gram-negative beta-proteobacterium belonging to the order of the Rhodocyclales. The relative abundance of this Thauera species increased from 24 to 40% after two months of enrichment in the selector-system, indicating a competitive advantage, possibly due to the storage of a reserve material such as PHA. First experiments with T. aminoaromatica MZ1T showed multiple intracellular granules when grown in pure culture on a growth medium with a C:N ratio of 10:1 and acetate as a carbon source. Nuclear magnetic resonance (NMR) analyses upon extraction of PHA from the pure culture confirmed polyhydroxybutyrate production by T. aminoaromatica MZ1T

Life cycle approaches for Conservation Agriculture

Industrial Ecolog

Review of incidents with wildlife related to paraquat

VakpublicatieInstitute of Environmental Science

Uitbreiding van de Bestrijdingsmiddelenatlas voor de Tweede nota duurzame gewasbescherming 2013-2023

Conservation Biolog

Structure, sequon recognition and mechanism of tryptophan C-mannosyltransferase.

C-linked glycosylation is essential for the trafficking, folding and function of secretory and transmembrane proteins involved in cellular communication processes. The tryptophan C-mannosyltransferase (CMT) enzymes that install the modification attach a mannose to the first tryptophan of WxxW/C sequons in nascent polypeptide chains by an unknown mechanism. Here, we report cryogenic-electron microscopy structures of Caenorhabditis elegans CMT in four key states: apo, acceptor peptide-bound, donor-substrate analog-bound and as a trapped ternary complex with both peptide and a donor-substrate mimic bound. The structures indicate how the C-mannosylation sequon is recognized by this CMT and its paralogs, and how sequon binding triggers conformational activation of the donor substrate: a process relevant to all glycosyltransferase C superfamily enzymes. Our structural data further indicate that the CMTs adopt an unprecedented electrophilic aromatic substitution mechanism to enable the C-glycosylation of proteins. These results afford opportunities for understanding human disease and therapeutic targeting of specific CMT paralogs

Mothers' beliefs about children's learning in Hong Kong and the United States: Implications for mothers' child-based worth

Chinese and American mothers’ beliefs about children’s learning and parents’ role in it were examined using notions salient in Chinese culture. Mothers from Hong Kong (n = 66) and the United States (n = 69) indicated their endorsement of the ideas that children’s learning reflects children’s morality, and parents’ support of children’s learning reflects parents’ love and duty. Mothers also reported on the extent to which their worth is based on children’s performance. Chinese (vs. American) mothers believed more that children’s learning reflects morality and parents’ support of children’s learning reflects love; these differences accounted for their feelings of worth being more dependent on children’s performance. Chinese (vs. American) mothers believed less that parents’ support is a duty.postprin