A new method of preparing insects for scanning electron microscopy.

Acidified 2,2-dimethoxypropane (DMP), used as an alternative to regular fixation and dehydration methods for insects, was found to be the only successful means of preparing the sugarbeet root maggot larva, Tetanops myopaeformis (R?der) (Diptera:Otitidae), for the scanning electron microscope. No morphological changes were evident when DMP treated sugarbeet root maggot adults were compared to fresh (unfixed) adults and glutaraldehyde-osmium tetroxide fixed adults. The method has been used with success on several gropus of insects. Acidified CMP is quickly hydrolyzed by water in tissue to acetone and methanol. DMP is advantageous in that it penetrates water impermeable cuticles rapidly and saves several steps and time in the fixation and dehydration process.     

A new sorediate,fumarprotocetraric acid‐producing lichen species of Menegazzia (Parmeliaceae,Ascomycota) from New Zealand

A new sorediate lichen, Menegazzia hypernota Bjerke, is described from New Zealand. This new species is characterised by convex, crescent‐shaped to fabi‐form soralia that are occasionally associated with perforations; apothecia with 2‐spored asci; the small perforations; the numerous secondary lobules; the presence of inconspicuous, yellow spots in the internal cavity; and fumarprotocetraric acid as principal medullary constituent. Menegazzia caliginosa, a species associated with M. hypernota, is reported for the first time from the Auckland Islands.     

The RNase PARN Controls the Levels of Specific miRNAs that Contribute to p53 Regulation

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Extreme winter warming events more negatively impact small rather than large soil fauna: shift in community composition explained by traits not taxa

Extreme weather events can have negative impacts on species survival and community structure when surpassing lethal thresholds. Extreme winter warming events in the Arctic rapidly melt snow and expose ecosystems to unseasonably warm air (2–10 °C for 2–14 days), but returning to cold winter climate exposes the ecosystem to lower temperatures by the loss of insulating snow. Soil animals, which play an integral part in soil processes, may be very susceptible to such events depending on the intensity of soil warming and low temperatures following these events. We simulated week‐long extreme winter warming events – using infrared heating lamps, alone or with soil warming cables – for two consecutive years in a sub‐Arctic dwarf shrub heathland. Minimum temperatures were lower and freeze‐thaw cycles were 2–11 times more frequent in treatment plots compared with control plots. Following the second event, Acari populations decreased by 39%; primarily driven by declines of Prostigmata (69%) and the Mesostigmatic nymphs (74%). A community‐weighted vertical stratification shift occurred from smaller soil dwelling (eu‐edaphic) Collembola species dominance to larger litter dwelling (hemi‐edaphic) species dominance in the canopy‐with‐soil warming plots compared with controls. The most susceptible groups to these winter warming events were the smallest individuals (Prostigmata and eu‐edaphic Collembola). This was not apparent from abundance data at the Collembola taxon level, indicating that life forms and species traits play a major role in community assembly following extreme events. The observed shift in soil community can cascade down to the micro‐flora affecting plant productivity and mineralization rates. Short‐term extreme weather events have the potential to shift community composition through trait composition with potentially large consequences for ecosystem development.     

Factors influencing the social acceptability of large carnivore behaviours

A survey on attitudes toward large carnivores was conducted in a representative sample of the Norwegian population (n = 3134). People were asked about the acceptability of carnivores living in remote wilderness, close to where people live, killing livestock, killing pets, or threatening humans. Large differences in acceptability appeared across the five situations. Wolves and bears were less acceptable than lynx and wolverines when observed close to where people live. Negative associations were found between acceptability and lack of personal control, economic loss, and respondents' age. Acceptability was higher among males than among females, and higher among urban than among rural residents. The results showed that general measures of attitudes alone toward large carnivores were of limited value in wildlife management. The situational and social specificity of these attitudes should be given more attention.     

A novel assay for examining the molecular reactions at the eukaryotic replication fork: activities of replication protein A required during elongation.

Studies to elucidate the reactions that occur at the eukaryotic replication fork have been limited by the model systems available. We have established a method for isolating and characterizing Simian Virus 40 (SV40) replication complexes. SV40 rolling circle complexes are isolated using paramagnetic beads and then incubated under replication conditions to obtain continued elongation. In rolling circle replication, the normal mechanism for termination of SV40 replication does not occur and the elongation phase of replication is prolonged. Thus, using this assay system, elongation phase reactions can be examined in the absence of initiation or termination. We show that the protein requirements for elongation of SV40 rolling circles are equivalent to complete SV40 replication reactions. The DNA produced by SV40 rolling circles is double-stranded, unmethylated and with a much longer length than the template DNA. These properties are similar to those of physiological replication forks. We show that proteins associated with the isolated rolling circles, including SV40 T antigen, DNA polymerase alpha, replication protein A (RPA) and RF-C, are necessary for continued DNA synthesis. PCNA is also required but is not associated with the isolated complexes. We present evidence suggesting that synthesis of the leading and lagging strands are co-ordinated in SV40 rolling circle replication. We have used this system to show that both RPA-protein and RPA-DNA interactions are important for RPA's function in elongation.     

Alterations of Mitochondrial DNA in CEM Cells Selected for Resistance Toward DDC Toxicity

2 ′,3 ′-dideoxycytidine (ddC) is a nucleoside analog that has been shown to produce a delayed toxicity which may be due to the depletion of mitochondrial DNA (mtDNA). In order to gain further understanding of the events involved in mitochondrial toxicity, two different CEM cell lines were selected for resistance to the delayed ddC toxicity.     

Climatic and biotic extreme events moderate long‐term responses of above‐ and belowground sub‐Arctic heathland communities to climate change

Climate change impacts are not uniform across the Arctic region because interacting factors causes large variations in local ecosystem change. Extreme climatic events and population cycles of herbivores occur simultaneously against a background of gradual climate warming trends and can redirect ecosystem change along routes that are difficult to predict. Here, we present the results from sub‐Arctic heath vegetation and its belowground micro‐arthropod community in response to the two main drivers of vegetation damage in this region: extreme winter warming events and subsequent outbreaks of the defoliating autumnal moth caterpillar (Epirrita autumnata). Evergreen dwarf shrub biomass decreased (30%) following extreme winter warming events and again by moth caterpillar grazing. Deciduous shrubs that were previously exposed to an extreme winter warming event were not affected by the moth caterpillar grazing, while those that were not exposed to warming events (control plots) showed reduced (23%) biomass from grazing. Cryptogam cover increased irrespective of grazing or winter warming events. Micro‐arthropods declined (46%) following winter warming but did not respond to changes in plant community. Extreme winter warming and caterpillar grazing suppressed the CO₂ fluxes of the ecosystem. Evergreen dwarf shrubs are disadvantaged in a future sub‐Arctic with more stochastic climatic and biotic events. Given that summer warming may further benefit deciduous over evergreen shrubs, event and trend climate change may both act against evergreen shrubs and the ecosystem functions they provide. This is of particular concern given that Arctic heath vegetation is typically dominated by evergreen shrubs. Other components of the vegetation showed variable responses to abiotic and biotic events, and their interaction indicates that sub‐Arctic vegetation response to multiple pressures is not easy to predict from single‐factor responses. Therefore, while biotic and climatic events may have clear impacts, more work is needed to understand their net effect on Arctic ecosystems.     

Role of macrophage migration inhibitory factor (MIF) in allergic and endotoxin-induced airway inflammation in mice

Macrophage migration inhibitory factor (MIF) has recently been forwarded as a critical regulator of inflammatory conditions, and it has been hypothesized that MIF may have a role in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). Hence, we examined effects of MIF immunoneutralization on the development of allergen-induced eosinophilic inflammation as well as on lipopolysaccharide (LPS)-induced neutrophilic inflammation in lungs of mice. Anti-MIF serum validated with respect to MIF neutralizing capacity or normal rabbit serum (NRS) was administered i.p. repeatedly during allergen aerosol exposure of ovalbumin (OVA)-immunized mice in an established model of allergic asthma, or once before instillation of a minimal dose of LPS into the airways of mice, a tentative model of COPD. Anti-MIF treatment did not affect the induced lung tissue eosinophilia or the cellular composition of bronchoalveolar lavage fluid (BALF) in the asthma model. Likewise, anti-MIF treatment did not affect the LPS-induced neutrophilia in lung tissue, BALF, or blood, nor did it reduce BALF levels of tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein-1alpha (MIP-1alpha). The present data suggest that MIF is not critically important for allergen-induced eosinophilic, and LPS-induced neutrophilic responses in lungs of mice. These findings do not support a role of MIF inhibition in the treatment of inflammatory respiratory diseases.