Interacting forces of predation and fishing affect species’ maturation size

1. Fishing is a strong selective force and is supposed to select for earlier maturation at smaller body size. However, the extent to which fishing‐induced evolution is shaping ecosystems remains debated. This is in part because it is challenging to disentangle fishing from other selective forces (e.g., size‐structured predation and cannibalism) in complex ecosystems undergoing rapid change.
2. Changes in maturation size from fishing and predation have previously been explored with multi‐species physiologically structured models but assumed separation of ecological and evolutionary timescales. To assess the eco‐evolutionary impact of fishing and predation at the same timescale, we developed a stochastic physiologically size‐structured food‐web model, where new phenotypes are introduced randomly through time enabling dynamic simulation of species'' relative maturation sizes under different types of selection pressures.
3. Using the model, we carried out a fully factorial in silico experiment to assess how maturation size would change in the absence and presence of both fishing and predation (including cannibalism). We carried out ten replicate stochastic simulations exposed to all combinations of fishing and predation in a model community of nine interacting fish species ranging in their maximum sizes from 10 g to 100 kg. We visualized and statistically analyzed the results using linear models.
4. The effects of fishing on maturation size depended on whether or not predation was enabled and differed substantially across species. Fishing consistently reduced the maturation sizes of two largest species whether or not predation was enabled and this decrease was seen even at low fishing intensities (F = 0.2 per year). In contrast, the maturation sizes of the three smallest species evolved to become smaller through time but this happened regardless of the levels of predation or fishing. For the four medium‐size species, the effect of fishing was highly variable with more species showing significant and larger fishing effects in the presence of predation.
5. Ultimately our results suggest that the interactive effects of predation and fishing can have marked effects on species'' maturation sizes, but that, at least for the largest species, predation does not counterbalance the evolutionary effect of fishing. Our model also produced relative maturation sizes that are broadly consistent with empirical estimates for many fish species.

     

An efficient chemical approach to bispecific antibodies and antibodies of high valency

Irreversible chemical programming of monoclonal aldolase antibody (mAb) 38C2 has been accomplished with β-lactam equipped mono- and bifunctional targeting modules, including a cyclic-RGD peptide linked to either the peptide (d-Lys⁶)-LHRH or another cyclic RGD unit and a small-molecule integrin inhibitor SCS-873 conjugated to (d-Lys⁶)LHRH. We also prepared monofunctional targeting modules containing either cyclic RGD or (d-Lys⁶)-LHRH peptides. Binding of the chemically programmed antibodies to integrin receptors α(v)β(3) and α(v)β(5) and to the luteinizing hormone releasing hormone receptor were evaluated. The bifunctional and bivalent c-RGD/LHRH and SCS-783/LHRH, the monofunctional and tetravalent c-RGD/c-RGD, and the monofunctional bivalent c-RGD chemically programmed antibodies bound specifically to the isolated integrin receptor proteins as well as to integrins expressed on human melanoma M-21 cells. c-RGD/LHRH, SCS-783/LHRH, and LHRH chemically programmed antibodies bound specifically to the LHRH receptors expressed on human ovarian cancer cells. This approach provides an efficient, versatile, and economically viable route to high-valency therapeutic antibodies that target defined combinations of specific receptors. Additionally, this approach should be applicable to chemically programmed vaccines.     

Analysis and visualization of H7 influenza using genomic,evolutionary and geographic information in a modular web service

We have reported previously on use of a web‐based application, Supramap ( http://supramap.org ) for the study of biogeographic, genotypic, and phenotypic evolution. Using Supramap we have developed maps of the spread of drug‐resistant influenza and host shifts in H1N1 and H5N1 influenza and coronaviruses such as SARS. Here we report on another zoonotic pathogen, H7 influenza, and provide an update on the implementation of Supramap as a web service. We find that the emergence of pathogenic strains of H7 is labile with many transitions from high to low pathogenicity, and from low to high pathogenicity. We use Supramap to put these events in a temporal and geospatial context. We identify several lineages of H7 influenza with biomarkers of high pathogenicity in regions that have not been reported in the scientific literature. The original implementation of Supramap was built with tightly coupled client and server software. Now we have decoupled the components to provide a modular web service for POY ( http://poyws.org ) that can be consumed by a data provider to create a novel application. To demonstrate the web service, we have produced an application, Geogenes ( http://geogenes.org ). Unlike in Supramap, in which the user is required to create and upload data files, in Geogenes the user works from a graphical interface to query an underlying dataset. Geogenes demonstrates how the web service can provide underlying processing for any sequence and metadata database. © The Willi Hennig Society 2012.     

Narratives of success among Irish and African Caribbean migrants

This paper compares the narratives of two men in midlife who migrated to the UK from Ireland and from the Caribbean as children, in the middle of the last century. We examine how success is narrated over the life course to show how migrants’ positioning of themselves differs from the ways in which they are positioned by outsiders, including in policy and public discourse. We conclude that while outsider narratives often polarise success and failure, insider understandings of success are dynamic and culturally and historically situated.     

Isotopically sensitive branching in the formation of cyclic monoterpenes: proof that (-)-alpha-pinene and (-)-beta-pinene are synthesized by the same monoterpene cyclase via deprotonation of a common intermediate

To determine whether the bicyclic monoterpene olefins (-)-alpha-pinene and (-)-beta-pinene arise biosynthetically from the same monoterpene cyclase by alternate deprotonations of a common carbocationic intermediate, the product distributions arising from the acyclic precursor [10-2H3,1-3H]geranyl pyrophosphate were compared with those resulting from incubation of [1-3H]geranyl pyrophosphate with (-)-pinene cyclase from Salvia officinalis. Alteration in proportions of the olefinic products generated by the partially purified pinene cyclase resulted from the suppression of the formation of (-)-beta-pinene (C10 deprotonation) by a primary deuterium isotope effect with a compensating stimulation of the formation of (-)-alpha-pinene (C4 deprotonation). (-)-Pinene cyclase as well as (+)-pinene cyclase also exhibited a decrease in the proportion of the acyclic olefin myrcene generated from the deuteriated substrate, accompanied by a corresponding increase in the commitment to cyclized products. The observation of isotopically sensitive branching, in conjunction with quantitation of the magnitude of the secondary deuterium isotope effect on the overall rate of product formation by the (+)- and (-)-pinene cyclases as well as two other monoterpene cyclases from the same tissue, supports the biosynthetic origin of (-)-alpha-pinene and (-)-beta-pinene by alternative deprotonations of a common enzymatic intermediate. A biogenetic scheme consistent with these results is presented, and alternate proposals for the origin of the pinenes are addressed.     

Analysis of Human RSV Immunity at the Molecular Level: Learning from the Past and Present

Human RSV is one of the most prevalent viral pathogens of early childhood for which no vaccine is available. Herein we provide an analysis of RSV epitope data to examine its application to vaccine design and development. Our objective was to provide an overview of antigenic coverage, identify critical antibody and T cell determinants, and then analyze the cumulative RSV epitope data from the standpoint of functional responses using a combinational approach to characterize antigenic structure and epitope location. A review of the cumulative data revealed, not surprisingly, that the vast majority of epitopes have been defined for the two major surface antigens, F and G. Antibody and T cell determinants have been reported from multiple hosts, including those from human subjects following natural infection, however human data represent a minority of the data. A structural analysis of the major surface antigen, F, showed that the majority of epitopes defined for functional antibodies (neutralizing and/or protective) were either shown to bind pre-F or to be accessible in both pre- and post-F forms. This finding may have has implications for on-going vaccine design and development. These interpretations are in agreement with previous work and can be applied in the larger context of functional epitopes on the F protein. It is our hope that this work will provide the basis for further RSV-specific epitope discovery and investigation into the nature of antigen conformation in immunogenicity.