Antimicrobial and antibiofilm activities of 1-alkylquinolinium bromide ionic liquids

Quinoline derivatives are known to possess a range of bioactive and medicinal activities, which have been exploited in the design of antibacterial, antifungal and antimalarial compounds. In this study, we report on the microbiological toxicity of a series of 1-alkylquinolinium bromides against a range of clinically relevant microorganisms, in both planktonic and sessile (biofilm) cultures. A comparison of antimicrobial activity against planktonic bacteria and established biofilms is presented. In general, 1-alkylquinolinium ionic liquids possess excellent, broad spectrum antimicrobial activity against microorganisms grown in both the planktonic and sessile, or biofilm, mode of growth. Importantly, these compounds are potent against Gram positive and Gram negative bacteria, as well as fungi, with a clear dependency on length of the alkyl substituent for activity, with compounds containing twelve and fourteen carbons in the alkyl group exhibiting highest antimicrobial and antibiofilm activity. © 2010 The Royal Society of Chemistry.

Male morph predicts investment in larval immune function in the dung beetle, Onthophagus taurus

Investment in immunity is costly, so that resource-based trade-offs between immunity and sexually selected ornaments might be expected. The amount of resources that an individual can invest in each trait will be limited by the total resources available to them. It would therefore be informative to investigate how investment in immune function changes during growth or production of the sexual trait as resources are diverted to it. Using the dung beetle, Onthophagus taurus, which displays both sexual and male dimorphism in horn size, we examined changes in one measure of immune function, phenoloxidase (PO) activity, in the hemolymph of larvae prior to and during horn growth. We found that PO levels differed between small- and large-horned males throughout the final instar prior to the point where investment in horn growth was taking place. PO levels in females were intermediate to the 2 male morphs. These differences could not be accounted for by differences in condition, measured as hemolymph protein levels and weight. We suggest that the observed differences might be associated with sex- and morph-specific variation in juvenile hormone levels.

Characterization of bafinivirus main protease autoprocessing activities

The production of functional nidovirus replication-transcription complexes involves extensive proteolytic processing by virus-encoded proteases. In this study, we characterized the viral main protease (Mpro) of the type species, White bream virus (WBV), of the newly established genus Bafinivirus (order Nidovirales, family Coronaviridae, subfamily Torovirinae). Comparative sequence analysis and mutagenesis data confirmed that the WBV Mpro is a picornavirus 3C-like serine protease that uses a Ser-His-Asp catalytic triad embedded in a predicted two-ß-barrel fold, which is extended by a third domain at its C terminus. Bacterially expressed WBV Mpro autocatalytically released itself from flanking sequences and was able to mediate proteolytic processing in trans. Using N-terminal sequencing of autoproteolytic processing products we tentatively identified Gln?(Ala, Thr) as a substrate consensus sequence. Mutagenesis data provided evidence to suggest that two conserved His and Thr residues are part of the S1 subsite of the enzyme's substrate-binding pocket. Interestingly, we observed two N-proximal and two C-proximal autoprocessing sites in the bacterial expression system. The detection of two major forms of Mpro, resulting from processing at two different N-proximal and one C-proximal site, in WBV-infected epithelioma papulosum cyprini cells confirmed the biological relevance of the biochemical data obtained in heterologous expression systems. To our knowledge, the use of alternative Mpro autoprocessing sites has not been described previously for other nidovirus Mpro domains. The data presented in this study lend further support to our previous conclusion that bafiniviruses represent a distinct group of viruses that significantly diverged from other phylogenetic clusters of the order Nidovirales.

Age-specific reproductive investment in female burying beetles: independent effects of state and risk of death

1.How much should an individual invest in reproduction as it grows older? Answering this question involves determining whether individuals measure their age as the time left for future reproduction or as the rate of deterioration in their state. Theory suggests that in the former case individuals should increase their allocation of resources to reproduction as opportunities for future breeding dwindle, and terminally invest when they breed for the last time. In the latter case they should reduce their investment in reproduction with age, either through adaptive reproductive restraint or as a passive by-product of senescence.
2.Here we present the results of experiments on female burying beetles, Nicrophorus vespilloides, in which we independently manipulated the perceived risk of death (by activating the immune system) and the extent of deterioration in state (by changing age of first reproduction and/or prior investment in reproduction).
3.We found that the risk of death and state each independently influenced the extent of reproductive investment. Specifically, we found a state-dependent decline in reproductive investment as females grew older that could be attributed to both adaptive reproductive restraint and senescence. A perceived increase in the risk of death, induced by activation of the immune system, caused females to switch from a strategy of reproductive restraint to terminal investment. Nevertheless, absolute reproductive investment was lower in older females, indicating constraints of senescence.
4.Our results show that a decline in reproductive investment with age does not necessarily constitute evidence of reproductive senescence but can also result from adaptive reproductive restraint.
5.Our results further suggest that the extent of reproductive investment is dependent on several different intrinsic cues and that the particular blend of cues available at any given age can yield very different patterns of investment. Perhaps this explains why age-related reproductive investment patterns seen in nature are so diverse.

Sense and sensibility: The role of business incubator client advisors in assisting high-technology entrepreneurs to make sense of investment readiness status

For high-technology entrepreneurs, attaining an appropriate level of investment to support new ventures is challenging as substantial investment is usually required prior to revenue generation. Consequently, entrepreneurs must present their firms as investment ready in the context of an uncertain market response and an absence of any trading history. Gaining tenancy within a business incubator can be advantageous to this process given that placement enhances entrepreneurial contact with potential investors whilst professional client advisors (CAs) use their expertise to assist in the development of a credible business plan. However, for the investment proposal to be successful, it must make sense to fund managers despite their lack of technological expertise and product knowledge. Thus, this article explores how incubator CAs and entrepreneurs act in concert to mould innovative ideas into plausible business plans that make sense to venture fund investors. To illustrate this process, we draw upon empirical evidence which suggests that CAs act as sense makers between venture fund managers (VFMs) and high-technology entrepreneurs, yet their role and influence appears undervalued. These findings have implications for entrepreneurial access to much needed funding and also for the identification of investment opportunities for VFMs. © 2011 Taylor & Francis.

Home Confined Consumers’ Freedom through Surrogate Activities: the Role of Personal Communities

This article explores the nature of surrogate consumption activity with three cases of non-institutionalised home confined consumers. The role played by personal communities in their daily lives is explored from the constrained rural contexts in which they consume. Despite the barriers to achieving normalcy in the marketplace, home confined consumers are able to realise freedom and agency, and express identity through engagement in surrogate consumption activity. Surrogate consumption activity also provides home confined consumers with opportunities to reinforce and challenge traditional family practices (discourses of care) through the ability for relationship culture development and social capital creation. Findings in this study show that home confined consumers, labeled as 'limited-choice' (Gabel, 2005) have the ability to display power, make choices, and find their voice despite non-interaction in the marketplace.