Mould growth on kiln-dried and air-dried timber

The problem with discoloration, due to fungal growth, of wooden outdoor constructions seems to have increased in recent years. One reason for this increase might be an impact of new drying methods of timber. Modern kiln drying methods use high temperatures in an effort to shorten the drying process, which leads to fast capillary water transport and subsequently redistribution and accumulation of dissolved substances at the surface. These can then be used as nutrients by fungi. In this study, wood was dried according to different simulated drying schedules. The mould resistance of the timber was then tested. Wood dried at room temperature was used as a reference. No differences could be confirmed at the end of the test; mould growth was extensive on all the samples. However, mould growth started earlier on the kiln-dried samples than on air-dried timber. As for the discolouring fungus, there was a clear difference between wood dried at room temperature and kiln-dried wood, though no difference could be established between the two artificial methods.     

Two novel cyclodextrin-degrading enzymes isolated from thermophilic bacteria have similar domain structures but differ in oligomeric state and activity profile

In this paper, we present the expression and characterization of two novel enzymes from the alpha-amylase family exhibiting cyclomaltodextrinase specificity. The nucleotide sequences encoding the enzymes were isolated from the genomic DNA of two thermophilic bacterial strains originating from Icelandic hot springs and belonging to the genera Anoxybacillus (AfCda13) and Laceyella (LsCda13). The genes were amplified using a consensus primer strategy utilizing two of the four conserved regions present in glycoside hydrolase family 13. No identifiable signal peptides were present in open reading frames encoding the enzymes, indicating an intracellular location of both enzymes, and their physiological function to be intracellular cyclodextrin degradation. The domain structures of both enzymes were also similar, including an N-terminal domain, the catalytic module composed of the A- and B-domains, and a C-terminal domain. Despite the similarity in domain composition, the two enzymes displayed differences in the oligomeric state with AfCda13 being a dimeric protein, whereas LsCda13 was monomeric. The two enzymes also displayed significantly different activity profiles, despite being active on the same range of substrates. It was shown that the enzyme displaying the highest activity on cyclodextrin was dimeric (AfCda13). Moreover, a fraction of the dimeric enzyme could be converted to a monomeric state in the presence of KCl and this fraction retained only 23% of its activity on alpha-cyclodextrin while its activity on starch was not significantly affected, indicating that the oligomeric state is an important factor for a high activity on cyclodextrin substrates.     

Interactional perspective on environmental communication in construction projects

Drawing on theories of social interaction, a critical discourse analysis approach is used to examine the resources and constraints on environmental-communication practices in four construction projects in Sweden. The assumption is that talk and action work together to construct, maintain and change organizational structure, social practices, and contractual arrangements. The empirical data were collected through in-depth interviews and field observations where photo documentation was extensively used. The study showed mismatches between information and action, both within the project and between the project and its stakeholders. The mismatches were not caused by a lack of information, but rather by inconsistencies between the communication cultures, the status of the communicator, and the tools used to mediate the information, e.g. the media, discourses and genres used. These discrepancies resulted in a lack of engagement in environmental work in the projects. If environmental and other performances in construction projects are to be improved, more effort needs to be exerted on understanding the dynamics of the social context, human interaction, and the mediating tools used to communicate. This paper suggests an approach that can enhance such an understanding.

S'appuyant sur les théories de l'interaction sociale, les auteurs procède à une analyse du discours critique pour examiner les ressources et les contraintes liées aux pratiques en matière d'environnement et de communication dans le cadre de quatre projets de construction en Suède. On suppose que la parole et l'action fonctionnent ensemble pour construire, entretenir et modifier la structure organisationnelle, les pratiques sociales et les dispositions contractuelles. Les données empiriques ont été recueillies au cours d'interviews approfondies et d'observations sur le terrain où la documentation photographique a été largement utilisée. L'étude a montrer des décalages entre l'information et l'action, à la fois dans le cadre de projets et entre projets et parties intéressées. Ces décalages ne sont pas dus à un manque d'information mais plutôt à des incohérences entre cultures de la communication, état du communicateur et les outils utilisés pour médiatiser les informations comme, par exemple, les média, les discours et les genres. Ces différences se sont traduites par un manque d'engagement dans les travaux environnementaux des projets. Si les performances environnementales et d'autres dans le cadre de projets de construction doivent être améliorées, il faut faire davantage d'efforts pour mieux comprendre la dynamique du contexte social, les interactions humaines et les outils de médiatisation utilisés pour communiquer. Cet article suggère une approche qui pourrait améliorer une telle compréhension.

Mots clés: communication, projets de construction, engagement, information sur l'environnement, médiateur, contexte social, efficacité du lieu de travail     

A Copper Story: From Protein Folding and Metal Transport to Cancer

Enzymes need to fold into unique three-dimensional structures in order to function. Copper ions are cofactors in many essential enzymes. Such enzymes need to couple polypeptide folding with metal incorporation, as the metal sites are often integrated within the folded structure. Since free copper ions are toxic, most organisms have highly specialized copper transport systems. The human cytoplasmic copper chaperone Atox1 delivers copper to P_1B-type ATPases in the Golgi, for incorporation into copper-dependent enzymes following the secretory path. Copper plays key roles in cancer development, as copper-dependent enzymes are needed for tumor growth and metastasis. In addition, platinum-based drugs are exported out of cells by the copper transport machinery. Recent findings also imply that some copper transport proteins regulate cell growth and development. In this brief journey of my later career, I will discuss the roles of copper in protein folding, mechanisms of copper ion transport, and cisplatin hitchhiking. The identification of new partners for Atox1 underscore the importance of further research in this area for combating cancer.     

Influence of molecular weight and rheological behavior on electrospinning cellulose nanofibers from ionic liquids

Dissolving pulp was depolymerized with 2.5M HCl into cellulose fractions with decreasing molecular weight relative to acid treatment time. The cellulose fractions were dissolved at various concentrations in the ionic liquid 1‐ethyl‐3‐methylimidazolium acetate (EmimAc) with co‐solvent DMSO at ratio 1 : 1 (w/w) and electrospun. Size exclusion chromatography was used to evaluate the molecular weight distributions and the rheological properties were characterized with a cone‐and‐plate rheometer. Scanning electron microscope was used to evaluate the fiber morphology, and thereby spinnability. Zero shear viscosity as a function of cellulose concentration show that all the solutions in this study are in the entangled semi‐dilute regime; where the polymer concentration is large enough for significant overlap necessary for chain entanglement. However, within the intervals studied, neither cellulose concentration nor molecular weight seems to be decisive for if a solution can be electrospun into fibers or not. It is rather the viscosity of the solution that is decisive for electrospinnability, even though the solution is in the entangled semi‐dilute regime. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2303–2310, 2013     

Sustainable homes,or simply energy-efficient buildings?

Environmental consideration within the Swedish construction sector can no longer be considered marginal. It is here discussed whether the same commitment is extended to facilitate deeper dimensions of sustainability in the provision of housing, beyond simply energy-efficient residential buildings? The paper presents the case of a multi-family ‘green’ residential area being developed in Göteborg, Sweden. An interview study with the seven housing developers building in the area provides primary empirical insights, further complemented by findings from a workshop with architects involved in the project. Conceptualizations of sustainability in housing are explored, based in discourses among these market actors. Issues identified in the inductive data analysis relate to the ambitions set and measures taken in new ‘green’ building, as well as market perceptions of housing standards, lifestyles and household configurations that are reproduced in the built environment. The paper shows that interpretations of sustainability in market-led housing development do not radically challenge the normative and resource intense contemporary ideals surrounding the urban home and that the realization of goals undertaken in the case of Kvillebäcken is generally dependent on economic considerations and market assessments. In conclusion, the paper emphasizes the need to formulate an integrative approach to more holistic sustainable residential environments.     

Formation of carbonated apatite particles from a supersaturated inorganic blood serum model

Pathological calcification is common among for instance dialysis patients, and this causes an increase in mortality risk. An elevated serum phosphate concentration among those patients strongly correlates to this increase. In this work investigations of the conditions, composition, crystallinity and morphology of in vitro calcification are performed and related to results from in vivo studies. The study was performed under conditions mimicking physiological ones, i.e. a pH around 7.40, a temperature of 37°C, an ionic strength of 150 mM and ion concentrations close to those in human serum including the effects of elevated phosphate concentrations. The course of precipitation involves an initial precipitate that subsequently re-dissolves to give another precipitate, in accordance with the well-known Ostwald ripening theory. The final bulk precipitate consists of a macroscopically amorphous carbonated apatite. The amorphous apatite is formed from assemblies of spherical particles in the μm range, in turn composed of nano-crystalline needles of about 10 × 100 nm. Even the initially formed precipitate, as well as a small amount of precipitate that occurs on the liquid surface, consist of a carbonated calcium phosphate. The in vitro observed carbonated apatite bears strong resemblance to in vivo cardiovascular calcification known from literature.     

Indoor levels of polycyclic aromatic hydrocarbons in homes with or without wood burning for heating

The aim of this study was to investigate the impact of domestic wood burning on indoor levels of polycyclic aromatic hydrocarbons (PAHs). Indoor and outdoor concentrations of 27 PAHs were measured during wintertime in homes with (n= 13) or without (n 0) wood-burning appliances and at an ambient site in a Swedish residential area where wood burning for space heating is common. Twenty-four hour indoor levels of anthracene, benzo(ghi)fluoranthene, cyclopenta(cd)pyrene, benz(a)anthracene, chrysene/triphenylene, benzo(a)pyrene (BaP), indeno(1,2,3-cd)pyrene, benzo(ghi)perylene, and coronene were significantly (about 3- to 5-fold) higher in homes with, compared with homes without, wood-burning appliances. The outdoor levels of PAHs were generally higher than the indoor levelsfor all PAHs exceptforthe methylated phenanthrenes. The total PAH cancer potency (sum of BaP equivalents) was significantly higher (about 4 times) in the wood-burning homes compared with the reference homes, with BaP being the largest contributor, while phenanthrene made the largest contribution to the total PAH concentration in indoor and outdoor air. The median indoor BaP level in the wood-burning homes (0.52 ng/m3) was 5 times higher than the Swedish health-based guideline of 0.1 ng/m3, which was also exceeded outdoors on all days (median 0.37 ng/m3).     

Work functions shaping the ability to innovate: insights from the case of the safety engineer

Cognition, Technology & Work - To perform as intended, firms are divided into work functions that contribute to the behaviour-shaping constraints under which individuals build their skills,...