Methods to determine wood moisture content and their applicability in monitoring concepts.

The reaction of wood to moisture forms an integral part of any task in connection with this natural and renewable building material. Changes in wood moisture content lead to changes of virtually all physical and mechanical properties (e.g. strength and stiffness properties) of wood. Another effect of changes of the wood moisture content is the associated shrinkage or swelling of the material. The existence of high moisture content can initiate decay or growth of fungi. The correct estimation of timber moisture content and the subsequent initiation of potentially necessary measures are therefore essential tasks during the planning, execution and maintenance of buildings built with wood or wood-based products. This is supported by the high amount of damages on structural timber elements that can be attributed to ignorance of the reaction of wood to moisture. Also supported by this fact, the in situ monitoring of moisture content of structural timber elements has recently received considerable interest and growth. This paper describes common methods to determine wood moisture content and evaluates them with respect to their applicability for monitoring concepts. Keywords Wood Moisture Measurement Monitoring Temperature Relative humidity Moisture gradients Shrinkage Swellin

Moisture contents in timber roof structures of ice rinks

Moisture content in load-bearing timber elements of ice-rinks can exceed acceptable levels. High relative humidity around the load-bearing elements located over the ice surface is easily be generated. High moisture content of the wood negatively affects the load-bearing capacity and durability of the structure. Control of humidity levels is therefore a special concern for engineers designing the structure. This paper lists and compares moisture contents measured in different ice-rinks: closed and open building envelopes, with and without climate control. Moisture contents were measured above the grandstand, but also above the ice surface. The presented work provides a data-based overview of measured moisture contents and lists recommendation for future structures

Endothelial histamine H1 receptor signaling reduces blood–brain barrier permeability and susceptibility to autoimmune encephalomyelitis

Disruption of the blood–brain barrier (BBB) underlies the development of experimental autoimmune encephalomyelitis (EAE) and multiple sclerosis. Environmental factors, such as Bordetella pertussis, are thought to sensitize central endothelium to biogenic amines like histamine, thereby leading to increased BBB permeability. B. pertussis-induced histamine sensitization (Bphs) is a monogenic intermediate phenotype of EAE controlled by histamine H1 receptor (Hrh1/H1R). Here, we transgenically overexpressed H1R in endothelial cells of Hrh1-KO (H1RKO) mice to test the role of endothelial H1R directly in Bphs and EAE. Unexpectedly, transgenic H1RKO mice expressing endothelial H1R under control of the von Willebrand factor promoter (H1RKO-vWFH1R Tg) were Bphs-resistant. Moreover, H1RKO-vWFH1R Tg mice exhibited decreased BBB permeability and enhanced protection from EAE compared with H1RKO mice. Thus, contrary to prevailing assumptions, our results show that endothelial H1R expression reduces BBB permeability, suggesting that endothelial H1R signaling may be important in the maintenance of cerebrovascular integrity