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Encounters among bacteria and their viral predators (bacteriophages) are among the most common ecological interactions on Earth. These encounters are likely to occur with regularity inside surface-bound communities that microbes most often occupy in natural environments. Such communities, termed biofilms, are spatially constrained: interactions become limited to near neighbors, diffusion of solutes and particulates can be reduced, and there is pronounced heterogeneity in nutrient access and physiological state. It is appreciated from prior theoretical work that phage-bacteria interactions are fundamentally different in spatially structured contexts, as opposed to well-mixed liquid culture. Spatially structured communities are predicted to promote the protection of susceptible host cells from phage exposure, and thus weaken selection for phage resistance. The details and generality of this prediction in realistic biofilm environments, however, are not known. Here, we explore phage-host interactions using experiments and simulations that are tuned to represent the essential elements of biofilm communities. Our simulations show that in biofilms, phage-resistant cells-as their relative abundance increases-can protect clusters of susceptible cells from phage exposure, promoting the coexistence of susceptible and phage-resistant bacteria under a large array of conditions. We characterize the population dynamics underlying this coexistence, and we show that coexistence is recapitulated in an experimental model of biofilm growth measured with confocal microscopy. Our results provide a clear view into the dynamics of phage resistance in biofilms with single-cell resolution of the underlying cell-virion interactions, linking the predictions of canonical theory to realistic models and in vitro experiments of biofilm growth.IMPORTANCE In the natural environment, bacteria most often live in communities bound to one another by secreted adhesives. These communities, or biofilms, play a central role in biogeochemical cycling, microbiome functioning, wastewater treatment, and disease. Wherever there are bacteria, there are also viruses that attack them, called phages. Interactions between bacteria and phages are likely to occur ubiquitously in biofilms. We show here, using simulations and experiments, that biofilms will in most conditions allow phage-susceptible bacteria to be protected from phage exposure, if they are growing alongside other cells that are phage resistant. This result has implications for the fundamental ecology of phage-bacteria interactions, as well as the development of phage-based antimicrobial therapeutics.

Microbial populations form intricate macroscopic colonies with diverse morphologies whose functions remain to be fully understood. Despite fungal colonies isolated from environmental and clinical samples revealing abundant intraspecies morphological diversity, it is unclear how this diversity affects fungal fitness and disease progression. Here we observe a notable effect of oxygen tension on the macroscopic and biofilm morphotypes of the human fungal pathogen Aspergillus fumigatus. A hypoxia-typic morphotype is generated through the expression of a subtelomeric gene cluster containing genes that alter the hyphal surface and perturb interhyphal interactions to disrupt in vivo biofilm and infection site morphologies. Consequently, this morphotype leads to increased host inflammation, rapid disease progression and mortality in a murine model of invasive aspergillosis. Taken together, these data suggest that filamentous fungal biofilm morphology affects fungal-host interactions and should be taken into consideration when assessing virulence and host disease progression of an isolated strain.

Historical accounts of the British aristocracy argue its economic decline was owed to anachronistic characteristics, declining land values, and inheritance taxes. We find disconfirming evidence based on the hereditary peerage's probates 1858 to 2018, showing: decline only began after World War I; no links between aristocratic wealth and farmland prices; and a greater role for tax avoidance with respect to inheritance taxes. Aristocrats also followed the rich with their share of wealth dwindling over the 20th century. Together, these arguments suggest the British aristocracy detached economic interests from status characteristics enabling them to persist more effectively than previously thought. [ABSTRACT FROM AUTHOR]

A new sensitive method to determine polonium-210 (210Po) and lead-210 (210Pb) in a diversity of environmental samples was developed. For fresh and marine waters, Po was pre-concentrated using a titanium (III) hydroxide (Ti(OH)3) co-precipitation. Solid environmental samples were digested with nitric acid (HNO3) and hydrogen peroxide (H2O2). The alpha thin layer source was prepared using CuS micro-precipitation and 210Po was measured by alpha spectrometry. Lead-210 was left to decay for up to a year and indirectly measured via its progeny, 210Po. The chemical recoveries for 210Po and 210Pb were high, 90% and 97%, respectively, for a large variety of samples and a very low minimum detectable activity (MDA) was obtained. The method was validated using standardized solutions and certified reference materials. [ABSTRACT FROM AUTHOR]

To authenticate to the full-text of this article, please visit this link: http://dx.doi.org/10.1111/j.1468-4446.2010.01314.x Byline: Matthew Bond (1), Siana Glouharova ([dagger]), Nicholas Harrigan ([double dagger]) Keywords: Business politics; social clubs; elite schools; super-wealthy; collective action; boards of directors Abstract: Abstract Business has played a central role in the debate over Britain's place in the European Union. This paper examines the socio-economic characteristics of directors of Britain's largest corporations who affiliated either to Business for Sterling or Britain in Europe. It reports associations between directors' social backgrounds and their probabilities of affiliation. Elite university education, club membership, wealth and multiple directorships were all associated with higher propensities to affiliate. The associations are consistent with the idea that directors' social resources allow them to overcome collective action problems as well as supplying them with the motivations to affiliate. They also indicated that directors form a privileged group in that they have a number of very powerful actors who can take unilateral political actions. Author Affiliation: (*)Social and Policy Studies, London South Bank University. ([dagger])Department of Sociology, University of Oxford ([double dagger])Department of Sociology, Singapore Management University Article History: (Date accepted: February 2010) Article note: email: bondm3@lsbu.ac.uk

It is argued that institutional features of the British state create collective action problems for the mobilization of corporations as donors to the Conservative Party. Social factors are necessary for overcoming these problems. Using social network analyses, the effect that interlocking directorates have on 250 large British corporations' decisions to donate are analysed. Instead of the central mobilizing factor being diffuse inner circle mechanisms positively influencing the decision to make a donation, the results show that more particularistic mechanisms such as information bias and control are equally important. Keywords: British corporate political donations; interlocking directorates; political mobilization; social networks; social idilemmas; inner circle theories