Robust zero-energy modes in an electronic higher-order topological insulator: the dimerized Kagome lattice

Quantum simulators are an essential tool for understanding complex quantum materials. Platforms based on ultracold atoms in optical lattices and photonic devices led the field so far, but electronic quantum simulators are proving to be equally relevant. Simulating topological states of matter is one of the holy grails in the field. Here, we experimentally realize a higher-order electronic topological insulator (HOTI). Specifically, we create a dimerized Kagome lattice by manipulating carbon-monoxide (CO) molecules on a Cu(111) surface using a scanning tunneling microscope (STM). We engineer alternating weak and strong bonds to show that a topological state emerges at the corner of the non-trivial configuration, while it is absent in the trivial one. Contrarily to conventional topological insulators (TIs), the topological state has two dimensions less than the bulk, denoting a HOTI. The corner mode is protected by a generalized chiral symmetry, which leads to a particular robustness against perturbations. Our versatile approach to quantum simulation with artificial lattices holds promises of revealing unexpected quantum phases of matter

Het Nieuwe Telen bij chrysant: Verkenning van energiebesparingsopties voor de chrysantenteelt

Het Nieuwe Telen (HNT) is een verzamelnaam voor verschillende methoden om energie te besparen in de glastuinbouw. In dit rapport is onderzocht welke methoden voor de chrysantenteelt interessant zijn. Er is gebruik gemaakt van een expertpanel en de rekenmodellen Kaspro en QMS

Epstein-Barr virus nuclear antigen 3A protein regulates CDKN2B transcription via interaction with MIZ-1

The Epstein-Barr virus (EBV) nuclear antigen 3 family of protein is critical for the EBV-induced primary B-cell growth transformation process. Using a yeast two-hybrid screen we identified 22 novel cellular partners of the EBNA3s. Most importantly, among the newly identified partners, five are known to play direct and important roles in transcriptional regulation. Of these, the Myc-interacting zinc finger protein-1 (MIZ-1) is a transcription factor initially characterized as a binding partner of MYC. MIZ-1 activates the transcription of a number of target genes including the cell cycle inhibitor CDKN2B. Focusing on the EBNA3A/MIZ-1 interaction we demonstrate that binding occurs in EBV-infected cells expressing both proteins at endogenous physiological levels and that in the presence of EBNA3A, a significant fraction of MIZ-1 translocates from the cytoplasm to the nucleus. Moreover, we show that a trimeric complex composed of a MIZ-1 recognition DNA element, MIZ-1 and EBNA3A can be formed, and that interaction of MIZ-1 with nucleophosmin (NPM), one of its coactivator, is prevented by EBNA3A. Finally, we show that, in the presence of EBNA3A, expression of the MIZ-1 target gene, CDKN2B, is downregulated and repressive H3K27 marks are established on its promoter region suggesting that EBNA3A directly counteracts the growth inhibitory action of MIZ-1

Enhancing environmental quality in agricultural systems

Greenhouses have been extremely successful in providing abundant, cheap and high-quality produce, by using resources (water, minerals, pesticides) with a very high economic efficiency. Marginal agricultural land is being rapidly converted into protected cultivation in many (semi-arid) regions of the world, hoping to pros-per both from primary and secondary activities. Water use efficiency of greenhouse production is about five times as high as field production of vegetables. However, in spite of using resources more efficiently, greenhouse areas have an enormous visual and environmental impact: diversion of limited good water resources; contamina-tion due to pollutants released with over-abundant irrigation; production of plastic and mineral waste and biological by-products; contamination due to plant protec-tion chemicals and emission of ¿greenhouse¿ gases (CO2) by heating with fossil fuels in Northern countries. In addition, greenhouse production has an ¿image¿ problem: there is a general perception among European consumers that such an ¿industrial¿ production of food is non-natural and unhealthy, although in the Americas, for instance, the ¿cleanliness¿ of the production process is considered an advantage. Since, the ¿polluter pays¿ very seldom, environment-friendly production is more expensive. Therefore a large market in ¿eco-labels¿ has developed in response to consumers¿ misgivings and in the hope of recovering (part of) the costs through higher prices. However, there is little clarity about agricultural practices associated to each label and there are doubts about enforcement. This paper analyses advan-tages and draw-backs of greenhouse production, and attempts to review the items where improvement is necessary in order to ensure that greenhouse production is sustainable, yet profitable also in the future

Coupling of Gab1 to C-Met, Grb2, and Shp2 Mediates Biological Responses

Gab1 is a substrate of the receptor tyrosine kinase c-Met and involved in c-Met–specific branching morphogenesis. It associates directly with c-Met via the c-Met–binding domain, which is not related to known phosphotyrosine-binding domains. In addition, Gab1 is engaged in a constitutive complex with the adaptor protein Grb2. We have now mapped the c-Met and Grb2 interaction sites using reverse yeast two-hybrid technology. The c-Met–binding site is localized to a 13–amino acid region unique to Gab1. Insertion of this site into the Gab1-related protein p97/Gab2 was sufficient to confer c-Met–binding activity. Association with Grb2 was mapped to two sites: a classical SH3-binding site (PXXP) and a novel Grb2 SH3 consensus-binding motif (PX(V/I)(D/N)RXXKP). To detect phosphorylation-dependent interactions of Gab1 with downstream substrates, we developed a modified yeast two-hybrid assay and identified PI(3)K, Shc, Shp2, and CRKL as interaction partners of Gab1. In a trk-met-Gab1–specific branching morphogenesis assay, association of Gab1 with Shp2, but not PI(3)K, CRKL, or Shc was essential to induce a biological response in MDCK cells. Overexpression of a Gab1 mutant deficient in Shp2 interaction could also block HGF/SF-induced activation of the MAPK pathway, suggesting that Shp2 is critical for c-Met/Gab1-specific signaling

Het nieuwe telen van aardbeien : topkwaliteit aardbeien telen met 14 kuub gas

Op een glasbedrijf in Limburg heeft tussen begin augustus 2009 en medio juni 2010 energieonderzoek bij aardbeien plaatsgevonden. Het doel van het project is om minimaal 20% energie te besparen en de vruchtkwaliteit te verbeteren. De hypothese is, dat energie kan worden bespaard door vroeg te planten in augustus, aanpassing van kasklimaat in nazomer en herfst waardoor in januari er minder warmtevraag is. Ondanks de grote verschillen in klimaat waren de uiteindelijke verschillen in plantontwikkeling, productie en vruchtkwaliteit erg klein. Doordat in de gekoelde afdelingen een lagere temperatuur werd gerealiseerd ontwikkelden de planten zich in die afdelingen trage

Herkennen en Spiegelen: Barrieres en kennishiaten bij energiebesparing in de glastuinbouw.

In dit rapport wordt verslag gedaan van een dieptestudie naar barrières en kennishiaten die glastuinders ervaren bij hun streven naar het besparen van energie. Glastuinders hebben in de loop der jaren een 'persoonlijk optimum' van produceren ontwikkeld dat een (kwetsbaar) evenwicht is tussen de inzet van productiemiddelen en de opbrengst. Besparing op alleen energie brengt dit evenwicht in gevaar. Een nieuw evenwicht kan pas gevonden worden wanneer de inzet van alle productiemiddelen simultaan wordt aangepast. De teler ontbeert de noodzakelijke teeltkundige kennis om zonder grote risico's te lopen zelfstandig op zoek te gaan naar het nieuwe evenwicht, en wordt in zijn mogelijkheden begrensd door de investeringscyclus. In this report, results are described of an in-depth study into barriers and knowledge gaps experienced by greenhouse growers saving energy. In the course of years, growers have found a balance between inputs and production. Merely saving energy endangers this balance. A new balance can only be found if all inputs are adjusted simultaneously. The grower lacks the necessary cultivation knowledge to search independently for a new balance without running huge risks, and is limited in his possibilities by the investment cycle