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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

Ethnobiology as a discipline has evolved increasingly to embrace theory‐inspired and hypothesis‐driven approaches to study why and how local people choose plants and animals they interact with and use for their livelihood. However, testing complex hypotheses or a network of ethnobiological hypotheses is challenging, particularly for data sets with non‐independent observations due to species phylogenetic relatedness or socio‐relational links between participants. Further, to account fully for the dynamics of local ecological knowledge, it is important to include the spatially explicit distribution of knowledge, changes in knowledge, and knowledge transmission and use. To promote the use of advanced statistical modelling approaches that address these limitations, we synthesize methodological advances for hypothesis‐driven research in ethnobiology while highlighting the need for more figures than tables and more tables than text in ethnobiological literature. We present the ethnobiological motivations for conducting generalized linear mixed‐effect modelling, structural equation modelling, phylogenetic generalized least squares, social network analysis, species distribution modelling, and predictive modelling. For each element of the proposed ethnobiologists quantitative toolbox, we present practical applications along with scripts for a widespread implementation. Because these statistical modelling approaches are rarely taught in most ethnobiological programs but are essential for careers in academia or industry, it is critical to promote workshops and short courses focused on these advanced methods. By embracing these quantitative modelling techniques without sacrificing qualitative approaches which provide essential context, ethnobiology will progress further towards an expansive interaction with other disciplines. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity is predicted to evolve in more variable environments, conferring an advantage on individual lifetime fitness. It is less clear what the potential consequences of that plasticity will have on ecological population dynamics. Here, we use an invertebrate model system to examine the effects of environmental variation (resource availability) on the evolution of phenotypic plasticity in two life history traits—age and size at maturation—in long‐running, experimental density‐dependent environments. Specifically, we then explore the feedback from evolution of life history plasticity to subsequent ecological dynamics in novel conditions. Plasticity in both traits initially declined in all microcosm environments, but then evolved increased plasticity for age‐at‐maturation, significantly so in more environmentally variable environments. We also demonstrate how plasticity affects ecological dynamics by creating founder populations of different plastic phenotypes into new microcosms that had either familiar or novel environments. Populations originating from periodically variable environments that had evolved greatest plasticity had lowest variability in population size when introduced to novel environments than those from constant or random environments. This suggests that while plasticity may be costly it can confer benefits by reducing the likelihood that offspring will experience low survival through competitive bottlenecks in variable environments. In this study, we demonstrate how plasticity evolves in response to environmental variation and can alter population dynamics—demonstrating an eco‐evolutionary feedback loop in a complex animal moderated by plasticity in growth. [ABSTRACT FROM AUTHOR]

Bacteriophages can be trapped in the matrix of bacterial biofilms, such that the cells inside them are protected. It is not known whether these phages are still infectious and whether they pose a threat to newly arriving bacteria. Here, we address these questions using Escherichia coli and its lytic phage T7. Prior work has demonstrated that T7 phages are bound in the outermost curli polymer layers of the E. coli biofilm matrix. We show that these phages do remain viable and can kill colonizing cells that are T7-susceptible. If cells colonize a resident biofilm before phages do, we find that they can still be killed by phage exposure if it occurs soon thereafter. However, if colonizing cells are present on the biofilm long enough before phage exposure, they gain phage protection via envelopment within curli-producing clusters of the resident biofilm cells. [ABSTRACT FROM AUTHOR]

Human subsistence societies have thrived in environmental extremes while maintaining biodiversity through social learning of ecological knowledge, such as techniques to prepare food and medicine from local resources. However, there is limited understanding of which processes shape social learning patterns and configuration in ecological knowledge networks, or how these processes apply to resource management and biological conservation. In this study, we test the hypothesis that the prestige (rarity or exclusivity) of knowledge shapes social learning networks. In addition, we test whether people tend to select who to learn from based on prestige (knowledge or reputation), and homophily (e.g., people of the same age or gender). We used interviews to assess five types of medicinal plant knowledge and how 303 people share this knowledge across four villages in Solomon Islands. We developed exponential random graph models (ERGMs) to test whether hypothesized patterns of knowledge sharing based on prestige and homophily are more common in the observed network than in randomly simulated networks of the same size. We found that prestige predicts five hypothesized network configurations and all three hypothesized learning patterns, while homophily predicts one of three hypothesized network configurations and five of the seven hypothesized learning patterns. These results compare the strength of different prestige and homophily effects on social learning and show how cultural practices such as intermarriage can affect certain aspects of prestige and homophily. By advancing our understanding of how prestige and homophily affect ecological knowledge networks, we identify which social learning patterns have the largest effects on biocultural conservation of ecological knowledge. [ABSTRACT FROM AUTHOR]

Rising atmospheric carbon dioxide levels are driving decreases in aquatic pH. As a result, there has been a surge in the number of studies examining the impact of acidification on aquatic fauna over the past decade. Thus far, both positive and negative impacts on the growth of fish have been reported, creating a disparity in results. Food availability and single‐generation exposure have been proposed as some of the reasons for these variable results, where unrealistically high food treatments lead to fish overcoming the energetic costs associated with acclimating to decreased pH. Likewise, exposure of fish to lower pH for only one generation may not capture the likely ecological response to acidification that wild populations might experience over two or more generations. Here we compare somatic growth rates of laboratory populations of the Trinidadian guppy (Poecilia reticulata) exposed to pH levels that represent the average and lowest levels observed in streams in its native range. Specifically, we test the role of maternal acclimation and resource availability on the response of freshwater fishes to acidification. Acidification had a negative impact on growth at more natural, low food treatments. With high food availability, fish whose mothers were acclimated to the acidified treatment showed no reduction in growth, compared to controls. Compensatory growth was observed in both control–acidified (maternal–natal environment) and acidified–control groups, where fish that did not experience intergenerational effects achieved the same size in response to acidification as those that did, after an initial period of stunted growth. These results suggest that future studies on the effects of shifting mean of aquatic pH on fishes should take account of intergenerational effects and compensatory growth, as otherwise effects of acidification may be overestimated. [ABSTRACT FROM AUTHOR]

Through semi-structured interviews with 11 practising referees registered to one English County Football Association (FA), this article examines their experiences of officiating since the English FA implemented a Respect Campaign in 2008. Despite this high-profile public information campaign focusing on the role of the referee, the results outline that little has changed for those officiating at the youth and adult grassroots level. Referees highlight continuing verbal and physical abuse and argue that County FAs need to demonstrate greater levels of support towards them when dealing with cases of misconduct. Overall, the article illustrates that whilst the Respect Campaign remains a relatively new initiative, it requires further proactive development and improvements due to the unwelcome experiences that remain for referees when officiating matches. [ABSTRACT FROM PUBLISHER]

Abstract: In Bateman and Volberg (2008) , it was shown that the n-th partial 1/4 Cantor in the plane set decays in Favard length no faster than . In Bond and Volberg (2008) , the so-called circular Favard length of the same set is studied, and the same estimate is shown to persist when the circle has radius . By considering characteristic functions, the result of Bond and Volberg (2008) naturally leads to a conjecture which (if true) would imply the sharpness of the boundedness of the circular maximal operator proved by Seeger, Tao and Wright (2005) . [ABSTRACT FROM AUTHOR]

Abstract: In recent years, relatively sharp quantitative results in the spirit of the Besicovitch projection theorem have been obtained for self-similar sets by studying the norms of the “projection multiplicity” functions, , where is the number of connected components of the partial fractal set that orthogonally project in the θ direction to cover x. In Nazarov et al. (2008) , it was shown that n-th partial 4-corner Cantor set with self-similar scaling factor 1/4 decays in Favard length at least as fast as , for . In Bond and Volberg (2009) , this same estimate was proved for the 1-dimensional Sierpinski gasket for some . A few observations were needed to adapt the approach of Nazarov et al. (2008) to the gasket: we sketch them here. We also formulate a result about all self-similar sets of dimension 1. [Copyright &y& Elsevier]

Elite theory critiques of corporate political action rest on the claim that it advances the political interests of elite status groups. This article examines that claim by investigating the relationship between a British corporation's propensity to make donations to the Conservative party and its directors' educational backgrounds and social club affiliations. Using a structural equivalence blockmodel, it is shown that among the largest 250 British corporations in 1995 there was a set with directors who came from elite educational backgrounds and were members of elite social clubs. These corporations made a disproportionate number of donations. I argue that these results support the elite theory critique. [ABSTRACT FROM AUTHOR]