Relationships among foliar chemistry, foliar polyamines, and soil chemistry in red spruce trees growing across the northeastern United States

Forest trees are constantly exposed to various types of natural and anthropogenic stressors. A major long-term goal of our research is to develop a set of early physiological and biochemical markers of stress in trees before the appearance of visual symptoms. Six red spruce (t Picea rubens Sarg.) stands from the northeastern United States were selected for collection of soil and foliage samples. All of the chosen sites had soil solution pH values below 4.0 in the Oa horizon but varied in their geochemistry. Some of these sites were apparently under some form of environmental stress as indicated by a large number of dead and dying red spruce trees. Samples of soil and needles (from apparently healthy red spruce trees) were collected from these sites four times during a two-year period. The needles were analyzed for perchloric acid-soluble polyamines and exchangeable inorganic ions. Soil and soil solution samples from the Oa and B horizons were analyzed for their exchange chemistry. The data showed a strong positive correlation between Ca and Mg concentrations in the needles and in the Oa horizon of the soil. However, needles from trees growing on relatively Ca-rich soils with a low exchangeable Al concentration and a low Al:Ca soil solution ratio had significantly lower concentrations of putrescine and spermidine than those growing on Ca-poor soils with a high exchangeable Al concentration and a high Al:Ca soil solution in the Oa horizon. The magnitude of this change was several fold higher for putrescine concentrations than for spermidine concentrations. Neither putrescine nor spermidine were correlated with soil solution Ca, Mg, and Al concentrations in the B horizon. The putrescine concentrations of the needles always correlated significantly with exchangeable Al (r²=0.73, t p0.05) and soil solution Al:Ca ratios (r²=0.91, t p0.01) of the Oa horizon. This suggests that in conjunction with soil chemistry, putrescine and/or spermidine may be used as a potential early indicator of Al stress before the appearance of visual symptoms in red spruce trees.     

Regulation to Create Environments Conducive to Physical Activity: Understanding the Barriers and Facilitators at the Australian State Government Level

Introduction

Policy and regulatory interventions aimed at creating environments more conducive to physical activity (PA) are an important component of strategies to improve population levels of PA. However, many potentially effective policies are not being broadly implemented. This study sought to identify potential policy/regulatory interventions targeting PA environments, and barriers/facilitators to their implementation at the Australian state/territory government level.

Methods

In-depth interviews were conducted with senior representatives from state/territory governments, statutory authorities and non-government organisations (n = 40) to examine participants'': 1) suggestions for regulatory interventions to create environments more conducive to PA; 2) support for preselected regulatory interventions derived from a literature review. Thematic and constant comparative analyses were conducted.

Results

Policy interventions most commonly suggested by participants fell into two areas: 1) urban planning and provision of infrastructure to promote active travel; 2) discouraging the use of private motorised vehicles. Of the eleven preselected interventions presented to participants, interventions relating to walkability/cycling and PA facilities received greatest support. Interventions involving subsidisation (of public transport, PA-equipment) and the provision of more public transport infrastructure received least support. These were perceived as not economically viable or unlikely to increase PA levels. Dominant barriers were: the powerful ‘road lobby’, weaknesses in the planning system and the cost of potential interventions. Facilitators were: the provision of evidence, collaboration across sectors, and synergies with climate change/environment agendas.

Conclusion

This study points to how difficult it will be to achieve policy change when there is a powerful ‘road lobby’ and government investment prioritises road infrastructure over PA-promoting infrastructure. It highlights the pivotal role of the planning and transport sectors in implementing PA-promoting policy, however suggests the need for clearer guidelines and responsibilities for state and local government levels in these areas. Health outcomes need to be given more direct consideration and greater priority within non-health sectors.     

Gamma-Ray Mutagenesis in Bacteriophage T4

137Cs-gamma irradiation of bacteriophage T4 induces large deletions plus a variety of types of point mutations. All mutations arise with single-hit kinetics, and all by a misrepair process. The estimated point mutation rate is 1.5 X 10(-9) per locus per rad.     

Cycling of Etk and Etp phosphorylation states is involved in formation of group 4 capsule by Escherichia coli

Capsules frequently play a key role in bacterial interactions with their environment. Escherichia coli capsules were categorized as groups 1 through 4, each produced by a distinct mechanism. Etk and Etp are members of protein families required for the production of group 1 and group 4 capsules. These members function as a protein tyrosine kinase and protein tyrosine phosphatase, respectively. We show that Etp dephosphorylates Etk in vivo, and mutations rendering Etk or Etp catalytically inactive result in loss of group 4 capsule production, supporting the notion that cyclic phosphorylation and dephosphorylation of Etk is required for capsule formation. Notably, Etp also becomes tyrosine phosphorylated in vivo and catalyzes rapid auto-dephosphorylation. Further analysis identified Tyr121 as the phosphorylated residue of Etp. Etp containing Phe, Glu or Ala in place of Tyr121 retained phosphatase activity and catalyzed dephosphorylation of Etp and Etk. Although EtpY121E and EtpY121A still supported capsule formation, EtpY121F failed to do so. These results suggest that cycles of phosphorylation and dephosphorylation of Etp, as well as Etk, are involved in the formation of group 4 capsule, providing an additional regulatory layer to the complex control of capsule production.     

Ectoparasites of northern fulmars Fulmarus glacialis (Procellariiformes: Procellariidae) from the Canadian Arctic

We studied the prevalence and intensity of infestation of ectoparasites on northern fulmars (Fulmarus glacialis L.) from a breeding colony in Arctic Canada in June–August 2003. No fleas or ticks were found on any fulmars, but three species of chewing lice (Phthiraptera) were recorded: Ischnocera: Perineus nigrolimbatus (Giebel 1874), Ischnocera: Saemundssonia occidentalis (Kellogg 1896), and Amblycera: Ancistrona vagelli (Fabricius 1787). Non-breeding birds had a higher prevalence of lice than breeding birds, and prevalence varied markedly among louse species. Our study is an important baseline for the occurrence of ectoparasites on northern fulmars in the high Arctic, a region undergoing extensive environmental change due to global warming, and an area where parasites are expected to extend ranges or increase in prevalence under changing annual temperature regimes.     

A functional gene array for detection of bacterial virulence elements

Emerging known and unknown pathogens create profound threats to public health. Platforms for rapid detection and characterization of microbial agents are critically needed to prevent and respond to disease outbreaks. Available detection technologies cannot provide broad functional information about known or novel organisms. As a step toward developing such a system, we have produced and tested a series of high-density functional gene arrays to detect elements of virulence and antibiotic resistance mechanisms. Our first generation array targets genes from Escherichia coli strains K12 and CFT073, Enterococcus faecalis and Staphylococcus aureus. We determined optimal probe design parameters for gene family detection and discrimination. When tested with organisms at varying phylogenetic distances from the four target strains, the array detected orthologs for the majority of targeted gene families present in bacteria belonging to the same taxonomic family. In combination with whole-genome amplification, the array detects femtogram concentrations of purified DNA, either spiked in to an aerosol sample background, or in combinations from one or more of the four target organisms. This is the first report of a high density NimbleGen microarray system targeting microbial antibiotic resistance and virulence mechanisms. By targeting virulence gene families as well as genes unique to specific biothreat agents, these arrays will provide important data about the pathogenic potential and drug resistance profiles of unknown organisms in environmental samples.     

Role of extracellular charged amino acids in the yeast alpha-factor receptor

The yeast pheromone receptor, Ste2p, is a G protein coupled receptor that initiates cellular responses to alpha-mating pheromone, a 13 residue peptide that carries a net positive charge at physiological pH. We have examined the role of extracellular charged groups on the receptor in response to the pheromone. Substitutions of Asn or Ala for one extracellular residue, Asp275, affected both pheromone binding and signaling, suggesting that this position interacts directly with ligand. The other seven extracellular acidic residues could be individually replaced by polar residues with no detectable effects on receptor function. However, substitution of Ala for each of these seven residues resulted in impairment of signaling without affecting pheromone binding, implying that the polar nature of these residues promotes receptor activation. In contrast, substitution of Ala for each of the six positively charged residues at the extracellular surface of Ste2p did not affect signaling.     

Examining disruption of pheromone communication in Choristoneura rosaceana and Pandemis limitata using microencapsulated (Z)-11-tetradecenyl acetate applied in a laboratory flight tunnel

Pheromone‐based mating disruption of lepidopteran pests (Tortricidae) of pome fruits using hand‐applied dispensing systems has become standard management practice for many producers in western North America. Sprayable microencapsulated (MEC) pheromone formulations that enable the application of pheromone controls with other orchard sprays and assist in the development of multispecies mating‐disruption systems are currently under development. Responses of male Choristoneura rosaceana (Harris) and Pandemis limitata (Robinson) (Lepidoptera: Tortricidae) to calling females in clean air, and air treated with their major pheromone component (Z)‐11‐tetradecenyl acetate (Z11‐14:OAc), released from a 3M sprayable pheromone formulation containing proprietary 3M Phase I microcapsules, applied at doses of 1, 10, and 100 mg of active ingredient (ai) m^?2 to the upwind end of a flight tunnel (equivalent to field rates of 10, 100, and 1000 g ai ha^?1) were compared in laboratory flight tunnels. In both species, disorientation was found to be dose‐dependent, because relative to male orientation to calling females in clean air, the orientation of male P. limitata was disrupted 23.3, 46.3, and 71.3%, and orientation by male C. rosaceana was disrupted 31.6, 37.7, and 45.8% by treatment doses of 1, 10, and 100 mg m^?2, respectively. Latency of male responses to calling females in a background of Z11‐14:OAc relative to responses in clean air was also dose‐dependent. Albeit short, the disruption lasted 26, 74, and 218 h in P. limitata and 30, 54, and 174 h in C. rosaceana at each application rate, respectively. Disruption by pheromone treatment was greater in P. limitata than in C. rosaceana. This difference may be correlated with species’ differences in the pheromone release rates of females. Mechanisms of disruption invoked by this 3M MEC pheromone formulation are discussed in relation to issues of its longevity and observed differences in the effects against the two species. It appears possible to evaluate relative activity of MEC pheromones in a laboratory setting which may aid in development of new formulations for mating disruption.     

The Burden of Research on Trauma for Respondents: A Prospective and Comparative Study on Respondents Evaluations and Predictors

The possible burden of participating in trauma research is an important topic for Ethical Committees (EC''s), Review Boards (RB''s) and researchers. However, to what extent research on trauma is more burdensome than non-trauma research is unknown. Little is known about which factors explain respondents evaluations on the burden: to what extent are they trauma-related or dependent on other factors such as personality and how respondents evaluate research in general? Data of a large probability based multi-wave internet panel, with surveys on politics and values, personality and health in 2009 and 2011, and a survey on trauma in 2012 provided the unique opportunity to address these questions. Results among respondents confronted with these events in the past 2 years (N = 950) showed that questions on trauma were significantly and systematically evaluated as less pleasant (enjoyed less), more difficult, but also stimulated respondents to think about things more than almost all previous non-trauma surveys. Yet, the computed effect sizes indicated that the differences were (very) small and often meaningless. No differences were found between users and non-users of mental services, in contrast to posttraumatic stress symptoms. Evaluations of the burden of previous surveys in 2011 on politics and values, personality and health most strongly, systematically and independently predicted the burden of questions on trauma, and not posttraumatic stress symptoms, event-related coping self-efficacy and personality factors. For instance, multiple linear regression analyses showed that 30% of the variance of how (un)pleasant questions on trauma and life-events were evaluated, was explained by how (un)pleasant the 3 surveys in 2011 were evaluated, in contrast to posttraumatic stress symptoms (not significant) and coping self-efficacy (5%). Findings question why EC''s, RB''s and researchers should be more critical of the possible burden of trauma research than of the possible burden of other non-trauma research.