An Updated Algorithm for Estimation of Pesticide Exposure Intensity in the Agricultural Health Study

An algorithm developed to estimate pesticide exposure intensity for use in epidemiologic analyses was revised based on data from two exposure monitoring studies. In the first study, we estimated relative exposure intensity based on the results of measurements taken during the application of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) (n = 88) and the insecticide chlorpyrifos (n = 17). Modifications to the algorithm weighting factors were based on geometric means (GM) of post-application urine concentrations for applicators grouped by application method and use of chemically-resistant (CR) gloves. Measurement data from a second study were also used to evaluate relative exposure levels associated with airblast as compared to hand spray application methods. Algorithm modifications included an increase in the exposure reduction factor for use of CR gloves from 40% to 60%, an increase in the application method weight for boom spray relative to in-furrow and for air blast relative to hand spray, and a decrease in the weight for mixing relative to the new weights assigned for application methods. The weighting factors for the revised algorithm now incorporate exposure measurements taken on Agricultural Health Study (AHS) participants for the application methods and personal protective equipment (PPE) commonly reported by study participants

Catch a tiger snake by its tail: Differential toxicity, co-factor dependence and antivenom efficacy in a procoagulant clade of Australian venomous snakes

A paradigm of venom research is adaptive evolution of toxins as part of a predator-prey chemical arms race. This study examined differential co-factor dependence, variations relative to dietary preference, and the impact upon relative neutralisation by antivenom of the procoagulant toxins in the venoms of a clade of Australian snakes. All genera were characterised by venoms rich in factor Xa which act upon endogenous prothrombin. Examination of toxin sequences revealed an extraordinary level of conservation, which indicates that adaptive evolution is not a feature of this toxin type. Consistent with this, the venoms did not display differences on the plasma of different taxa. Examination of the prothrombin target revealed endogenous blood proteins are under extreme negative selection pressure for diversification, this in turn puts a strong negative selection pressure upon the toxins as sequence diversification could result in a drift away from the target. Thus this study reveals that adaptive evolution is not a consistent feature in toxin evolution in cases where the target is under negative selection pressure for diversification. Consistent with this high level of toxin conservation, the antivenom showed extremely high-levels of cross-reactivity. There was however a strong statistical correlation between relative degree of phospholipid-dependence and clotting time, with the least dependent venoms producing faster clotting times than the other venoms even in the presence of phospholipid. The results of this study are not only of interest to evolutionary and ecological disciplines, but also have implications for clinical toxinology

Proteomic and functional variation within black snake venoms (Elapidae: Pseudechis )

Pseudechis (black snakes) is an Australasian elapid snake genus that inhabits much of mainland Australia, with two representatives confined to Papua New Guinea. The present study is the first to analyse the venom of all 9 described Pseudechis species (plus one undescribed species) to investigate the evolution of venom composition and functional activity. Proteomic results demonstrated that the typical Pseudechis venom profile is dominated by phospholipase A2 toxins. Strong cytotoxicity was the dominant function for most species. P. porphyriacus, the most basal member of the genus, also exhibited the most divergent venom composition, being the only species with appreciable amounts of procoagulant toxins. The relatively high presence of factor Xa recovered in P. porphyriacus venom may be related to a predominantly amphibian diet. Results of this study provide important insights to guide future ecological and toxinological investigations

Ruthenium(II) chloride complexes of the mesocyclic ligand 1,5-dithiacyclooctane 1-oxide. Preparation and structure of the "all-trans" complex

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Structure of a novel neutral lead(II) complex with dipropyldithiocarbamate

The synthesis and X-ray structure of a novel tetramer of Pb(II) with the dipropyldithiocarbamato ligand is described. The compound crystallizes in the triclinic space group P ̅1with a=9.576(2), b= 14.151(4), c=16.175(4) Å , α =104.84(2), β = 102.26(2), γ =90.62(2)ۥ , V=2065(1) Å 3. Unit cell dimensions and data collection were done at 130(1) K using graphite-monochromated Mo Kα radiation. The conventional R factor is 0.030 for 5323 unique observed reflections with the goodness- of-fit parameter = 1.35. The structure consists of a sulfur-bridged neutral tetrameric species where each Pb(II) ion is pentacoordinated

Synthesis and structure of the mesocyclic compounds, 5-phenyl-l-thia-5-phosphacyclooctane, Cis-and trans-1,5-Diphenyl-1,5-diphosphacyclooctane and their phosphine oxides

Three 1.5-disubstituted eight-membered ring meSocycles, 5-phenyl-l-thia-5-phosphacyclooctane, 2, cis-and trans-1,5-diphenyl-1,5-diphosphacyclooctane. 5a and 5b, have been synthesized. The diastereomers 5a and 5b were separated by preparative HPLC and the stereochemical assignments confirmed by an X-ray crystal structure of 5b. The X-ray crystal structures of 5-phenyl-1-thia-5-phosphacyclooctane 5-oxide, 1, and trans-l,5-diphenyl-l,5-diphosphacyclooctane 1.5-dioxide, 3b, are also reported. MeSocycles 1, 3b and 5b are in the boat-chair conformation and are devoid of any indications of transannular interactions

Dinero seguro: Desarrollo de cooperativas de ahorro y crédito eficaces en América Latina

Los responsables de la economía de América Latina están recurriendo a políticas que consiguen no sólo altas tasas de rendimiento económico sino también un impacto favorable en la distribución del ingreso. Al proporcionar servicios financieros a las pequeñas empresas y a las familias de bajos ingresos, que normalmente carecen de esos servicios, las cooperativas de ahorro crédito aseguran el crecimiento con equidad. Los desafíos que enfrentan hoy las cooperativas de ahorro y crédito en América Latina probablemente las obligarán a modernizarse y consolidarse aún más, a afinar sus ventajas intrínsecas, a mejorar los mecanismos de regulación prudencial y a ampliar su participación en los mercados de ingresos bajos y medianos. Dinero seguro presenta nuevas ideas para que las cooperativas de ahorro y crédito puedan competir eficazmente en los mercados financieros modernos sin perder su misión social.

The evolution and ecology of multiple antipredator defences

Prey seldom rely on a single type of antipredator defence, often using multiple defences to avoid predation. In many cases, selection in different contexts may favour the evolution of multiple defences in a prey. However, a prey may use multiple defences to protect itself during a single predator encounter. Such “defence portfolios” that defend prey against a single instance of predation are distributed across and within successive stages of the predation sequence (encounter, detection, identification, approach (attack), subjugation and consumption). We contend that at present, our understanding of defence portfolio evolution is incomplete, and seen from the fragmentary perspective of specific sensory systems (e.g., visual) or specific types of defences (especially aposematism). In this review, we aim to build a comprehensive framework for conceptualizing the evolution of multiple prey defences, beginning with hypotheses for the evolution of multiple defences in general, and defence portfolios in particular. We then examine idealized models of resource trade-offs and functional interactions between traits, along with evidence supporting them. We find that defence portfolios are constrained by resource allocation to other aspects of life history, as well as functional incompatibilities between different defences. We also find that selection is likely to favour combinations of defences that have synergistic effects on predator behaviour and prey survival. Next, we examine specific aspects of prey ecology, genetics and development, and predator cognition that modify the predictions of current hypotheses or introduce competing hypotheses. We outline schema for gathering data on the distribution of prey defences across species and geography, determining how multiple defences are produced, and testing the proximate mechanisms by which multiple prey defences impact predator behaviour. Adopting these approaches will strengthen our understanding of multiple defensive strategies.ISSN:1010-061XISSN:1420-910