A Predator from East Africa that Chooses Malaria Vectors as Preferred Prey

BACKGROUND: All vectors of human malaria, a disease responsible for more than one million deaths per year, are female mosquitoes from the genus Anopheles. Evarcha culicivora is an East African jumping spider (Salticidae) that feeds indirectly on vertebrate blood by selecting blood-carrying female mosquitoes as preferred prey. METHODOLOGY/PRINCIPAL FINDINGS: By testing with motionless lures made from mounting dead insects in lifelike posture on cork discs, we show that E. culicivora selects Anopheles mosquitoes in preference to other mosquitoes and that this predator can identify Anopheles by static appearance alone. Tests using active (grooming) virtual mosquitoes rendered in 3-D animation show that Anopheles' characteristic resting posture is an important prey-choice cue for E. culicivora. Expression of the spider's preference for Anopheles varies with the spider's size, varies with its prior feeding condition and is independent of the spider gaining a blood meal. CONCLUSIONS/SIGNIFICANCE: This is the first experimental study to show that a predator of any type actively chooses Anopheles as preferred prey, suggesting that specialized predators having a role in the biological control of disease vectors is a realistic possibility

Gene co-regulation by Fezf2 selects neurotransmitter identity and connectivity of corticospinal neurons

The neocortex contains an unparalleled diversity of neuronal subtypes, each defined by distinct traits that are developmentally acquired under the control of subtype-specific and pan-neuronal genes. The regulatory logic that orchestrates the expression of these unique combinations of genes is unknown for any class of cortical neuron. Here, we report that Fezf2 is a selector gene able to regulate the expression of gene sets that collectively define mouse corticospinal motor neurons (CSMN). We find that Fezf2 directly induces the glutamatergic identity of CSMN via activation of Vglut1 (Slc17a7) and inhibits a GABAergic fate by repressing transcription of Gad1. In addition, we identify the axon guidance receptor EphB1 as a target of Fezf2 necessary to execute the ipsilateral extension of the corticospinal tract. Our data indicate that co-regulated expression of neuron subtype–specific and pan-neuronal gene batteries by a single transcription factor is one component of the regulatory logic responsible for the establishment of CSMN identity

Novel insights from Fe-isotopes into the lithological heterogeneity of Ocean Island Basalts and plume-influenced MORBs

The extent of lithological heterogeneity in the Earth’s convecting mantle is highly debated. Whilst the presence of pyroxenite in the mantle source regions of Ocean Island Basalts (OIBs) has traditionally been constrained using the minor-element chemistry of olivine phenocrysts, recent studies have shown that the Ni and Mn contents of primitive olivines are influenced by the conditions of mantle melting, as well as magma chamber processes. Nevertheless, constraining the lithological properties of the mantle is important due to it’s influence on the P-T path followed by solid mantle material during adiabatic ascent, as well as the density of upwelling mantle plumes. We have therefore explored the use of Fe-isotopes as a novel method of tracing lithological heterogeneity in the mantle source regions beneath plume-influenced segments of the global Mid-Ocean Ridge system as well as OIBs. We present new Fe-isotope (δ56Fe) and trace-element data for 26 basaltic glasses from the plume-influenced Galápagos Spreading Centre to investigate the relative roles of pyroxenite and peridotite in the mantle source region of oceanic basalts. Our data reveals significant heterogeneity in the Fe-isotope composition of the Galápagos Spreading Centre basalts (+0.05 - +0.25‰ δ56Fe), which correlates with key major- and trace-element parameters (e.g. CaO(8)/Al2O3(8), [La/Sm]n). Application of new models developed to calculate Fe-isotope fractionation during mantle melting, alongside Monte Carlo simulations for melting of a 2-component peridotite mantle, show that this variation cannot be caused by changes in melting processes and/or oxygen fugacity of a peridotitic mantle. Instead, our new δ56Fe data is best explained by variations in the proportion of isotopically-heavy pyroxenite-derived melt that contributes to the GSC basalts, and conclusively shows that lithological heterogeneity exists in the Galápagos mantle plume. Our findings have implications for the moderately-heavy δ56Fe compositions measured in plume-influenced basalts from the Society Islands, Rochambeau Ridges of the Lau back-arc basin, and the FAMOUS segment of the Mid-Atlantic Ridge, which we suggest may also represent contribution from pyroxenite-derived melts.This study was supported by a NERC (Natural Environmental Research Council) Research Training Student Grant (NE/L002507/1) awarded to M.L.M.G as well as NERC grants RG57434 (S.A.G) and NE/M00427/1 and NE/M010848/1 (H.M.W) and ERC Habitable Planet consolidator grant (306655; H.M.W)

Factors controlling soil development in sand dunes: evidence from a coastal dune soil cronosequence

Aerial photographs, maps and optically stimulated luminescence dates were combined with existing soil data to construct high resolution chronosequences of soil development over 140 years at a temperate Atlantic UK dune system. Since soil formation had progressed for varying duration under different climate and nitrogen deposition regimes, it was possible to infer their relative influence on soil development compared with location-specific variables such as soil pH, slope and distance to the sea. Results suggest that soil development followed a sigmoid curve. Soil development was faster in wet than in dry dune habitats. In dry dunes, rates were greater than in the literature: they increased with increasing temperature and nitrogen deposition and decreased with increasing summer gales. The combination explained 62% of the variation. Co-correlation meant that effects of nitrogen deposition could not be differentiated from temperature. In wet dune habitats rates increased with temperature and decreased with gales. The combination explained only 23% of the variation; surprisingly, rainfall was not significant. Effects of location-specific variables were not significant in either habitat type. Nitrogen accumulation was faster in wet than dry dune habitats, averaging 43 kg N ha−1 per year overall. Nitrogen accumulation greatly exceeded inputs from atmospheric deposition, suggesting rates of input for biological N fixation are 10–60 kg N ha−1 per year. Recent climate and/or nitrogen deposition regimes may have accelerated soil development compared with past rates. These data suggest the importance of changing climate on soil development rates and highlight the contribution of biological N fixation in early successional systems

Os inquéritos domiciliares e o Sistema Nacional de Informações em Saúde The household surveys and the National Health Information System

Neste artigo apresenta-se um breve histórico dos inquéritos domiciliares em saúde de abrangência nacional, que foram desenvolvidos no Brasil ao longo dos últimos 20 anos. Discutem-se alguns problemas metodológicos importantes envolvidos na concepção e no desenho amostral dos inquéritos de base populacional e faz-se uma breve revisão dos aspectos contemplados pelos suplementos de saúde da Pesquisa Nacional por Amostra de Domicílios (PNAD), que foram a campo em 1981, 1986, 1998 e 2003. Tendo em vista o compromisso já assumido pelo Ministério da Saúde e pelo IBGE quanto à inclusão de um novo suplemento na PNAD de 2008, abre-se um debate sobre as vantagens e as limitações da PNAD como instrumento capaz de gerar dados de base populacional sobre morbidade, acesso e utilização de serviços de saúde. Finalmente destaca-se a necessidade de formulação de política para a geração de informações a partir de inquéritos de base populacional e sua incorporação ao Sistema Nacional de Informações em Saúde. Os inquéritos devem ser realizados periodicamente e os recursos financeiros para sua realização garantidos.<br>In this article the authors present a brief review of the household health surveys developed in Brazil in the last 20 years. Some important methodological problems related to their conception and sample design are discussed, and a brief review of the National Household Survey Health supplements conducted in 1981, 1986, 1998 and 2003 is presented. Given the already established agreement between the Ministry of Health and the Brazilian Institute of Geography and Statistics as to inclusion of a Health supplement in the 2008 National Household Survey, the authors propose a debate on the advantages and limitations of this instrument for the collection of data on morbidity, access to and utilization of health services. Finally, the authors stress the need for a policy towards generation of population-based information and its incorporation in the National Health Information System. Surveys must be periodically conducted and their financing must be guaranteed