Factorization of 3-point static structure functions in 3D Yukawa liquids

In many-body systems the convolution approximation states that the 3-point static structure function, $S^{(3)}(\textbf{k}_{1},\textbf{k}_{2})$, can approximately be "factorized" in terms of the 2-point counterpart, $S^{(2)}(\textbf{k}_{1})$. We investigate the validity of this approximation in 3-dimensional strongly-coupled Yukawa liquids: the factorization is tested for specific arrangements of the wave vectors $\textbf{k}_{1}$ and $\textbf{k}_{2}$, with molecular dynamics simulations. With the increase of the coupling parameter we find a breakdown of factorization, of which a notable example is the appearance of negative values of $S^{(3)}(\textbf{k}_{1},\textbf{k}_{2})$, whereas the approximate factorized form is restricted to positive values. These negative values -- based on the quadratic Fluctuation-Dissipation Theorem -- imply that the quadratic part of the density response of the system changes sign with wave number. Our simulations that incorporate an external potential energy perturbation clearly confirm this behavior

Building physics of a prototype water house

Japan as a highly industrialized developed country has not been able to solve flat construction in mass production yet. This demand has been existing for several decades, that is why different variants of industrialized flat construction ideas has generated interest. One of these attempts started from the Budapest University of Technology and Economics, Faculty of Architecture as an experiment leading to a specific construction technology. Experiments with prefabricated non-silicate-based assembled metal frames – like elements of car chassis – were carried out. They can be organized into modular buildings that can be quickly assembled on site. A new idea about houses with vertical transparent walls, called water houses, was developed by Gutai Matyas, graduate of the Budapest University of Technology and Economics, where the some-centimeter wide gaps between the boundary surfaces are filled with water. The first test water house has been built and completed in Kecskemet. This unusual system of building construction raises a lot of questions in the field of building physics. They include, among others, heat transmission of glazing as well as thickness and strength of glass plates. The paper elaborates the building physics and technology behind the water house

Gender, hyperandrogenism and vitamin D deficiency related functional and morphological alterations of rat cerebral arteries

Hyperandrogenism is a risk factor of cerebrovascular diseases as androgens can alter markedly the regulation of cerebrovascular tone. We examined the combined impact of androgen excess and vitamin D deficiency (VDD), a common co-morbidity in hyperandrogenic disorders, on remodeling and testosterone-induced vascular responses of anterior cerebral arteries (ACA) in order to evaluate the interplay between androgens and VDD in the cerebral vasculature. Male and female Wistar rats were either fed with vitamin D deficient or vitamin D supplemented diet. Half of the female animals from both groups received transdermal testosterone treatment. After 8 weeks, vessel lumen, wall thickness and testosterone-induced vascular tone of isolated ACA were determined using pressure microangiometry and histological examination. Androgen receptor protein expression in the wall of cerebral arteries was examined using immunohistochemistry. In female rats only combined VDD and testosterone treatment decreased the lumen and increased the wall thickness of ACA. In males, however VDD by itself was able to decrease the lumen and increase the wall thickness. Vascular reactivity showed similar alterations: in females, testosterone constricted the ACA only after combined VDD and hyperandrogenism, whereas in males VDD resulted in increased testosterone-induced contractions in spite of decreased androgen receptor expression. In conclusion, a marked interplay between hyperandrogenism and VDD results in inward remodeling and enhanced testosterone-induced constrictions of cerebral arteries, which might compromise the cerebral circulation and thus, increase the risk of stroke in the long term. In addition, the early cerebrovascular manifestation of VDD appears to require androgen excess and thus, depends on gender

Auxin-dependent cell cycle reactivation through transcriptional regulation of Arabidopsis E2Fa by lateral organ boundary proteins

Multicellular organisms depend on cell production, cell fate specification, and correct patterning to shape their adult body. In plants, auxin plays a prominent role in the timely coordination of these different cellular processes. A well-studied example is lateral root initiation, in which auxin triggers founder cell specification and cell cycle activation of xylem pole-positioned pericycle cells. Here, we report that the E2Fa transcription factor of Arabidopsis thaliana is an essential component that regulates the asymmetric cell division marking lateral root initiation. Moreover, we demonstrate that E2Fa expression is regulated by the LATERAL ORGAN BOUNDARY DOMAIN18/LATERAL ORGAN BOUNDARY DOMAIN33 (LBD18/LBD33) dimer that is, in turn, regulated by the auxin signaling pathway. LBD18/LBD33 mediates lateral root organogenesis through E2Fa transcriptional activation, whereas E2Fa expression under control of the LBD18 promoter eliminates the need for LBD18. Besides lateral root initiation, vascular patterning is disrupted in E2Fa knockout plants, similarly as it is affected in auxin signaling and lbd mutants, indicating that the transcriptional induction of E2Fa through LBDs represents a general mechanism for auxin-dependent cell cycle activation. Our data illustrate how a conserved mechanism driving cell cycle entry has been adapted evolutionarily to connect auxin signaling with control of processes determining plant architecture

Integrated energy design: education and training in cross-disciplinary teams implementing energy performance of buildings directive (EPBD)

In Europe, energy and climate policies started to take shape from the 1990s onwards culminating with the ambitious 20-20-20 climate goals and the Low-Carbon Europe roadmap 2050. The European Commission empower the importance of achieving the objective of the recast Directive on energy performance of buildings (EPBD) that new buildings built from 2021 onwards will have to be nearly zero-energy buildings. The general belief is that the energy performance optimization of buildings requires an integrated design approach and cross-disciplinary teamwork to optimize the building's energy use and quality of indoor environment while satisfying the occupants' needs.In this context, there is a substantial need for professionals such as architects and engineers specifically trained and educated in integrated design approach and trained to work in cross-disciplinary teams. To be able to push forward the development, it is essential that educational institutions foster professionals with such knowledge, skills and competences. An initiative toward this direction is the EU-project of IDES-EDU: "Master and Post-Graduate education and training in multi-disciplinary teams".The paper describes the necessity of more integrated and cross-disciplinary approaches to building design through state-of-the-art of the building sector and educational initiatives in the participating countries in the project, and through theory of design processes. The paper also communicates the results of newly developed cross-disciplinary education established by fifteen different educational institutions in Europe. Finally, the paper explains and discusses the challenges encountered during development and implementation of the education across different professions and countries. (C) 2013 Elsevier Ltd. All rights reserved.info:eu-repo/semantics/publishedVersio

IDES-EDU – new interdisciplinary education program for Integral design of built environment

Buildings fulfilling all requirements related to energy, economy and environment are necessary to be designed by interdisciplinary teams with efficient transfer of information and good knowledge base. IDES EDU is a project co-funded by the Intelligent Energy Europe program in which 15 European universities make a concerted effort to develop and implement balanced master and postgraduate courses on Sustainable Energy Design providing skills and knowledge that exceed the requirements of the EPBD. The resulting courses focus on different aspects of sustainable building design from the perspective of architecture, building construction and building technologies.European Commission - Executive Agency for Competitiveness and Innovation - IIE - Inteligent Energy Europ

Proteome-wide landscape of solubility limits in a bacterial cell

Proteins are prone to aggregate when expressed above their solubility limits. Aggregation may occur rapidly, potentially as early as proteins emerge from the ribosome, or slowly, following synthesis. However, in vivo data on aggregation rates are scarce. Here, we classified the Escherichia coli proteome into rapidly and slowly aggregating proteins using an in vivo image-based screen coupled with machine learning. We find that the majority (70%) of cytosolic proteins that become insoluble upon overexpression have relatively low rates of aggregation and are unlikely to aggregate co-translationally. Remarkably, such proteins exhibit higher folding rates compared to rapidly aggregating proteins, potentially implying that they aggregate after reaching their folded states. Furthermore, we find that a substantial fraction (similar to 35%) of the proteome remain soluble at concentrations much higher than those found naturally, indicating a large margin of safety to tolerate gene expression changes. We show that high disorder content and low surface stickiness are major determinants of high solubility and are favored in abundant bacterial proteins. Overall, our study provides a global view of aggregation rates and hence solubility limits of proteins in a bacterial cell.Peer reviewe

Arabidopsis RETINOBLASTOMA RELATED directly regulates DNA damage responses through functions beyond cell cycle control

The rapidly proliferating cells in plant meristems must be protected from genome damage. Here, we show that the regulatory role of the Arabidopsis RETINOBLASTOMA RELATED (RBR) in cell proliferation can be separated from a novel function in safeguarding genome integrity. Upon DNA damage, RBR and its binding partner E2FA are recruited to heterochromatic γH2AX-labelled DNA damage foci in an ATM- and ATR-dependent manner. These γH2AX-labelled DNA lesions are more dispersedly occupied by the conserved repair protein, AtBRCA1, which can also co-localise with RBR foci. RBR and AtBRCA1 physically interact in vitro and in planta. Genetic interaction between the RBR-silenced amiRBR and Atbrca1 mutants suggests that RBR and AtBRCA1 may function together in maintaining genome integrity. Together with E2FA, RBR is directly involved in the transcriptional DNA damage response as well as in the cell death pathway that is independent of SOG1, the plant functional analogue of p53. Thus, plant homologs and analogues of major mammalian tumour suppressor proteins form a regulatory network that coordinates cell proliferation with cell and genome integrity