Differential Regulation of NAPDH Oxidases in Salt-Tolerant Eutrema salsugineum and Salt-Sensitive Arabidopsis thaliana

Reactive oxygen species (ROS) signalling is crucial in modulating stress responses in plants, and NADPH oxidases (NOXs) are an important component of signal transduction under salt stress. The goal of this research was to investigate whether the regulation of NOX-dependent signalling during mild and severe salinity differs between the halophyte Eutrema salsugineum and the glycophyte Arabidopsis thaliana. Gene expression analyses showed that salt-induced expression patterns of two NOX genes, RBOHD and RBOHF, varied between the halophyte and the glycophyte. Five days of salinity stimulated the expression of both genes in E. salsugineum leaves, while their expression in A. thaliana decreased. This was not accompanied by changes in the total NOX activity in E. salsugineum, while the activity in A. thaliana was reduced. The expression of the RBOHD and RBOHF genes in E. salsugineum leaves was induced by abscisic acid (ABA) and ethephon spraying. The in silico analyses of promoter sequences of RBOHD and RBOHF revealed multiple cis-acting elements related to hormone responses, and their distribution varied between E. salsugineum and A. thaliana. Our results indicate that, in the halophyte E. salsugineum, the maintenance of the basal activity of NOXs in leaves plays a role during acclimation responses to salt stress. The different expression patterns of the RBOHD and RBOHF genes under salinity in E. salsugineum and A. thaliana point to a modified regulation of these genes in the halophyte, possibly through ABA- and/or ethylene-dependent pathways.     

Properties of a single-chain antibody containing different linker peptides

Single-chain antibodies were constructed using six differentlinker peptides to join the V_H and V_L domains of an anti-2-phenyloxazolone(Ox) antibody. Four of the linker peptides originated from theinterdomain linker region of the fungal cellulase CBHI and consistedof 28, 11, six and two amino acid residues. The two other linkerpeptides used were the (GGGGS)₃ linker with 15 amino acid residuesand a modified IgG2b hinge peptide with 22 residues. Proteolyticstability and Ox binding properties of the six different scFvderivatives produced in Escherichia coli were investigated andcompared with those of the corresponding Fv fragment containingno joining peptide between the V domains. The hapten bindingproperties of different antibody fragments were studied by ELISAand BIAcore^TM. The interdomain linker peptide improved the haptenbinding properties of the antibody fragment when compared withFv fragment, but slightly increased its susceptibility to proteases.Single-chain antibodies with short CBHI linkers of 11, six andtwo residues had a tendency to form multimers which led to ahigher apparent affinity. The fragments with linkers longerthan 11 residues remained monomeric.     

Historical contamination of Yukon Lake sediments by PCBs and organochlorine pesticides: influence of local sources and watershed characteristics

PCBs and other persistent organochlorine (OC) pesticides were analyzed in sediment cores collected from six lakes in Yukon Territory and one in northern British Columbia, Canada, with the objective of establishing sources and historical trends of these contaminants. DDT was found to be the most prominent OC in the sediment profiles of most of the lakes. Maximum sigmaDDT levels (3.47-2680 ng g(-1) dw) were observed in sediment slices dated to the 1950s from lakes near populated areas. In contrast, in more remote lakes (Hanson, Kusawa and Lindeman), the maximum sigmaDDT concentrations were observed in the sediments dated to the 1970s. Highest sigmaPCB and sigmaDDT concentrations were measured in sediments from Watson Lake, near a suspected PCB waste disposal site and in a region where DDT was heavily applied in the 1950s and 1960s. Elevated sigmaPCB concentrations [16.1-93.6 ng g(-1) dry weight (dw)] were also observed in sediments from lakes situated near populated areas, relative to Kusawa and Lindeman (11.1 and 12.7 ng g(-1) dw, respectively). Recent sigmaPCB fluxes ranged from 621 ng m(-2) y(-1) in Kusawa Lake to 16400 ng m(-2) y(-1) in Little Atlin Lake. The extremely high sedimentation rate (2050 g m(-2) y(-1)) in glacial fed Lindeman Lake gave rise to elevated fluxes of sigmaPCB (2410 ng m(-2) y(-1)) and other OCs, despite much lower concentrations in the sediment. Levels of hexachlorocyclohexanes (sigmaHCH), chlordane-related compounds (sigmaCHL), and chlorobenzenes (sigmaCBz) were in the low ng g(-1) (dw) range in all lake sediments, similar to concentrations previously reported for Arctic lakes in Canada, indicating that their major source was long range atmospheric transport. Contamination of the lakes with PCBs and DDT near populated areas of the Yukon Territory appears to be a result of regional activities rather than long range transport and deposition. The results also point to glacial runoff as a significant source of OCs to small, high elevation lakes (Lindeman), but not to larger lakes within the Yukon River drainage basin that are also affected by glacial sources (Kusawa, Laberge).     

Influence of Human Jaw Periosteal Cells Seeded β-Tricalcium Phosphate Scaffolds on Blood Coagulation

Tissue engineering offers auspicious opportunities in oral and maxillofacial surgery to heal bone defects. For this purpose, the combination of cells with stability-providing scaffolds is required. Jaw periosteal cells (JPCs) are well suited for regenerative therapies, as they are easily accessible and show strong osteogenic potential. In this study, we analyzed the influence of uncoated and polylactic-co-glycolic acid (PLGA)-coated β-tricalcium phosphate (β-TCP) scaffolds on JPC colonization and subsequent osteogenic differentiation. Furthermore, interaction with the human blood was investigated. This study demonstrated that PLGA-coated and uncoated β-TCP scaffolds can be colonized with JPCs and further differentiated into osteogenic cells. On day 15, after cell seeding, JPCs with and without osteogenic differentiation were incubated with fresh human whole blood under dynamic conditions. The activation of coagulation, complement system, inflammation, and blood cells were analyzed using ELISA and scanning electron microscopy (SEM). JPC-seeded scaffolds showed a dense cell layer and osteogenic differentiation capacity on both PLGA-coated and uncoated β-TCP scaffolds. SEM analyses showed no relevant blood cell attachment and ELISA results revealed no significant increase in most of the analyzed cell activation markers (β-thromboglobulin, Sc5B-9, polymorphonuclear (PMN)-elastase). However, a notable increase in thrombin-antithrombin III (TAT) complex levels, as well as fibrin fiber accumulation on JPC-seeded β-TCP scaffolds, was detected compared to the scaffolds without JPCs. Thus, this study demonstrated that besides the scaffold material the cells colonizing the scaffolds can also influence hemostasis, which can influence the regeneration of bone tissue.     

The Determinants of Debt and (Private) Equity Financing: The Case of Young, Innovative SMEs from Germany

Financial theory creates a puzzle. Some authors argue that high-risk entrepreneurs choose debt contracts instead of equity contracts since risky but high returns are of relatively more value for a loan-financed firm. Conversely, authors who focus explicitly on start-up finance predict that entrepreneurs are the more likely to seek equity-like venture capital contracts, the more risky their projects are. Our paper is an initial step towards resolving this puzzle empirically. We present microeconometric evidence on the determinants of debt and equity financing in young and innovative SMEs. We pay special attention to the role of risk for the choice of the method of financing. Since risk is not directly observable we use different indicators for financial and project risk. It turns out that our data generally confirms the hypothesis that the probability that a young high-tech firm receives equity financing is an increasing function of the financial risk. With regard to the intrinsic project risk, our results are less conclusive, as some of our indicators of a risky project are found to have a negative effect on the likelihood to be financed by private equity.     

Spray-Coating of Superhydrophobic Coatings for Advanced Applications

Superhydrophobic coatings are widely applicable, e.g., as self-cleaning surfaces or water–oil separation membranes, yet their wider usage is impeded due to costs of fabrication, size, or substrate limitation. Spray-coating is a versatile coating procedures and might offer a good solution for the fabrication of these superhydrophobic coatings, due to the fact that coatings can be fabricated on various materials in a simple, fast, and inexpensive manner. Most procedures rely on hybrid coatings of hydrophobized nanoparticles and a polymeric matrix, which have several drawbacks including the easy loss of nanoparticles and difficult waste handling. Here, the fabrication of the superhydrophobic material, called Fluoropor, for the first time, by spray-coating on various substrates including metals, tissues, concrete, and glass is presented. It is fabricated by spray-coating a mixture of a highly fluorinated monomer blended with porogens followed by photopolymerization. The superhydrophobicity of the material relies on the porous structure on the micro-/nanoscale across the bulk material and does not require any nanoparticles. Excellent self-cleaning ability of these coatings, resistance against thermal and abrasive impact, and their application as oil–water separation membranes are shown. This versatile applicability is highly promising for real-world application as self-cleaning coatings or oil–water separating membranes.     

Short time creep behaviour of Invar steel

During processing of so‐called true flat shadow/masks made of Invar steel for large size TV screens the mask is stretched onto a solid frame. Mask and frame are submitted to a final heat treatment (blackening treatment) in order to enhance the emissivity of the material. Elevated temperatures and pretension makes the mask material prone to plastic straining, resulting in disutility of the unit for the application. From a technological point of view, the material behaviour under these conditions has been defined as short time creep behaviour. The mechanisms causing creep in this special case are not fully understood. Focus of the present work was the examination of the effect of cube twins on the short time creep behaviour of the investigated Invar steel by texture analysis using EBSD technology. This investigation was conducted under four different material conditions covering a whole set of production steps during shadowmask processing. Detailed information about the change of the volume fractions and the orientation of characteristic texture components, most of all the cube twins, could be gained. The observations revealed that during the creep test two types of cube twins make an orientation change, thus plastic deformation takes place, causing relaxation of the material. The observation of cube twin rotation during the creep test is partly confirmed by the simulation of the respective Taylor factors.     

Review of Revitalizng retirement: Reshaping your identity, relationships, and purpose.

Reviews the book, Revitalizng retirement: Reshaping your identity, relationships, and purpose by Nancy K. Schlossberg (2009). Therapists, counsellors, and life coaches working with older middle-age adults will find this handbook to happiness in retirement a useful working tool. The author introduces the book by stating that some content resembles notes she resurrected from a freshman undergraduate lecture on personal development; accordingly, both the format and the issues discussed in this book generalise to life span motivational needs, but the intended focus is on the transition to retirement. As a result, this book would make a useful tool for a support group or workshop on psychosocial transitions in postemployment life, with some limitations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)