Communicative Approaches to Restoration Ecology: a case study from Dovre Mountain and Svalbard, Norway

Extensive damage to the vegetation cover in arctic and alpine landscapes has raised the question of restoration as a possible management strategy. Restoration is a goal-oriented activity, a technological undertaking wider than its parent science of ecology. Social science and planning concepts and methods are necessary to handle the value judgements implicit in restoration. It is argued that the notion of 'desired state' is a better reference point in defining restoration goals than the notion of 'original state'. Using qualitative methods, two areas with vulnerable arctic/alpine vegetation are investigated. Based on participants' statements, four possible scenarios or desired states for future management are constructed. The main focus in the scenarios is on participants' attitudes to restoration activity, and it is shown how these are influenced by participants' attachment to the area and their view of nature.     

Diketopyrrolopyrrole Organic Thin‐Film Transistors: Impact of Alkyl Substituents and Tolerance of Ethylhexyl Stereoisomers

Bis(thiophen‐2‐yl)‐diketopyrrolopyrrole (DPP) dyes bearing various alkyl substituents at the amide positions (n‐butyl, n‐pentyl, n‐hexyl, n‐heptyl, n‐octyl, 2‐ethylhexyl) and chlorine (Cl), bromine (Br), or cyano (CN) substituents at the thiophene positions have been synthesized and investigated with regard to their molecular and semiconducting properties. Intense absorption, strong fluorescence, and reversible oxidation and reduction processes are common to all of these dyes. Their characterization as organic semiconductors in vacuum‐processed thin‐film transistors reveals p‐channel operation with field‐effect mobilities ranging from 0.01 to 0.7 cm² V^?1 s^?1. The highest mobility is found for the DPP dyes bearing the 2‐ethylhexyl substituents, which is surprising, considering that as a result of the chiral substituents, this material is a mixture of (R,R), (S,S), and (R,S) stereoisomers. The high carrier mobility in the films of the DPPs bearing stereoisomerically inhomogeneous ethylhexyl groups is rationalized here by single‐crystal X‐ray diffraction (XRD) analysis in combination with XRD and atomic force microscopy studies on thin films, which reveal the presence of slightly different 2D layer arrangements for the n‐alkyl and the 2‐ethylhexyl derivatives. For the cyano‐substituted DPPs possessing the lowest LUMO levels, ambipolar transport characteristics are observed.     

Photoluminescence and lasing from deoxyribonucleic acid (DNA) thin films doped with sulforhodamine

Thin solid films of salmon deoxyribonucleic acid (DNA) have been fabricated by treatment with a surfactant and used as host for the laser dye sulforhodamine (SRh). The DNA films have an absorption peak at approximately 260 nm owing to absorption by the nitrogenous aromatic bases. The SRh molecules in the DNA films have absorption and emission peaks at 578 and 602 nm, respectively. The maximum emission was obtained at approximately 1 wt. % SRh in DNA, equivalent to approximately 100 DNA base pairs per SRh molecule. A distributed feedback grating structure was fabricated on a SiO(2)-Si substrate using interference lithography. The grating period of 437 nm was selected, corresponding to second-order emission at the amplified spontaneous emission wavelength of 650 nm. Lasing was obtained by pumping with a doubled Nd:YAG laser at 532 nm. The lasing threshold was 3 microJ, corresponding to approximately 30 microJ/cm(2) or 4 kW/cm(2). The emission linewidth decreased from approximately 30 nm in the amplified spontaneous emission mode to <0.4 nm (instrument limited) in the lasing mode. The slope efficiency of the lasing was approximately 1.2%.     

(R)-alpha-lipoic acid-supplemented old rats have improved mitochondrial function, decreased oxidative damage, and increased metabolic rate

A diet supplemented with (R)-lipoic acid, a mitochondrial coenzyme, was fed to old rats to determine its efficacy in reversing the decline in metabolism seen with age. Young (3 to 5 months) and old (24 to 26 months) rats were fed an AIN-93M diet with or without (R)-lipoic acid (0.5% w/w) for 2 wk, killed, and their liver parenchymal cells were isolated. Hepatocytes from untreated old rats vs. young controls had significantly lower oxygen consumption (P<0. 03) and mitochondrial membrane potential. (R)-Lipoic acid supplementation reversed the age-related decline in O2 consumption and increased (P<0.03) mitochondrial membrane potential. Ambulatory activity, a measure of general metabolic activity, was almost threefold lower in untreated old rats vs. controls, but this decline was reversed (P<0.005) in old rats fed (R)-lipoic acid. The increase of oxidants with age, as measured by the fluorescence produced on oxidizing 2',7'-dichlorofluorescin, was significantly lowered in (R)-lipoic acid supplemented old rats (P<0.01). Malondialdehyde (MDA) levels, an indicator of lipid peroxidation, were increased fivefold with age in cells from unsupplemented rats. Feeding rats the (R)-lipoic acid diet reduced MDA levels markedly (P<0.01). Both glutathione and ascorbic acid levels declined in hepatocytes with age, but their loss was completely reversed with (R)-lipoic acid supplementation. Thus, (R)-lipoic acid supplementation improves indices of metabolic activity as well as lowers oxidative stress and damage evident in aging.     

Characterization of crosslinked,macroporous, monosized polymer particles

Macroporous, monosized poly(meta‐divinylbenzene) and poly(para‐divinylbenzene) beads have been prepared by the two‐step activated swelling method with toluene or 2‐ethylhexanoic acid as pore‐forming agents. The type of divinylbenzene isomer as well as the type of porogen has a large effect on both physical and chemical properties of the monodisperse beads. Large pores are obtained with 2‐ethylhexanoic acid as porogen while beads prepared in the presence of toluene consist of only small pores and exhibit a shrinking behavior upon drying. The beads have considerable amounts of residual vinyl groups at the end of polymerization, as determined by bromination and Fourier transform IR analysis. The morphology and texture of the particles have been investigated by scanning electron microscopy and atomic force microscopy. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 152–169, 2000     

Development and immunobiological evaluation of nanoparticles containing an immunodominant epitope of herpes simplex virus

Herpes simplex virus (HSV) 1 and 2 are viruses that infect individuals worldwide and for which there is no cure or vaccine available. The protective response against herpes is mostly mediated by CD8 T lymphocytes that respond to the immunodominant SSIEFARL epitope. However, there are some obstacles concerning the use of free SSIEFARL for vaccine or immunotherapy. The aim of this study was to evaluate the feasibility of nanoencapsulation of SSIEFARL and its immunostimulatory properties. Nano/SSIEFARL was produced by interfacial polymerization in methylmetacrylate, and the physico‐chemical properties, morphology and immunobiological parameters were evaluated. To evaluate the ex vivo capacity of Nano/SSIEFARL, we used splenocytes from HSV‐1‐infected mice to enhance the frequency of SSIEFARL‐specific CD8 T lymphocytes. The results indicate that Nano/SSIEFARL has a spherical shape, an average diameter of 352 ± 22 nm, the PDI was 0.361 ± 0.009 and is negatively charged (−26.30 ± 35). The stability at 4°C was 28 days. Also, Nano/SSIEFARL is not toxic for cells at low concentrations in vitro and it is taken up by JAWS II dendritic cells. No histopathological changes were observed in kidneys, liver and lymph nodes of animals treated with Nano/SSIEFARL. Nan/SSIEFARL increased the production of IL‐1β, TNF‐α and IL‐12 by the dendritic cells. Finally, Nano/SSIEFARL expanded the frequency of SSIEFARL‐specific CD8+T lymphocytes at the same rate as free SSIEFARL. In conclusion all data together indicate that SSIEFARL is suitable for nanoencapsulation, and the system produced presents some immunoadjuvant properties that can be used to improve the immune response against herpes.     

Economic analysis of earthquake retrofit options: an application to welded steel moment frames

Decisions on whether to modify the seismic performance of an existing building may depend on the comparative economic consequences of the approaches under consideration. The measures of economic consequences assessed include benefit–cost ratio, probable maximum loss, and insurance payments with different deductibles. These measures are applied to a three building complex of welded steel moment frames. Fourteen different repair schemes for the damaged buildings were evaluated for a typical Los Angeles site. The repair and retrofit approaches include: repair to former condition; modify the connections; modify the structural system with braces or shear walls; and, add dampers. The evaluation indicates that for the specific buildings some repair and modification approaches are cost–beneficial, depending on the time period and interest rate assumptions. The preferred options were then examined for PML and insurance indicators of economic impact. Many financial institutions require the probable maximum loss to be less than a threshold number and/or that insurance be purchased to be considered for financing. A PML analysis indicates that only some of the options should be considered further. The best of the near cost–beneficial options reduced the PML by a factor of two. If insurance was bought for a 5-year term, then repairing the buildings to their former condition yields a 19·5% probability of an insurance loss (damage less the amount deductible) being paid in the 5-year period, with a median payment of 6%, and a 10% probability of a payment more than 17%. Modifying the structural system in the most cost-effective manner yields a 5·2% probability of an insurance loss being paid in the 5-year period, with a median payment of 5%, and a 10% probability of a payment more than 15%. The analysis indicates that the key question in making such assessments is whether earthquake insurance is purchased or not. If insurance costs are included in the economic analysis, then more of the approaches to repair are cost effective than if not. © 1998 John Wiley & Sons, Ltd.