40 research outputs found
Lack of maintenance of motorway fences works against their intended purpose with potential negative impacts on protected species
Linear infrastructure intrusions into natural ecosystems, such as motorways and high-speed railways, causes direct loss of habitat but also impacts fauna through collisions. Wildlife road mortality is well documented and extensive conservation legislation exists in many countries to minimise the negative impact of these infrastructures. However, although these measures are implemented because of legislation, these structures are often not adequately maintained. Here we present data on the functionality of perimeter fences along two motorways in Malaga province (southern Spain) erected to prevent collisions with the common chameleon (Chamaeleo chamaeleon). We sampled the fences along the 14 km of the two motorways included in the 17 1 × 1 km squares of the study area. Our results show that the reptile fence is permeable throughout at those points where the metal sheeting was absent and where the vegetation had overgrown around the fence, hence allowing chameleons to cross. Given our results, we conclude that this situation is likely to be similar in other regions of Spain and in other countries. This is because construction/concessionary companies do not consider the environmental impact of construction projects in the medium and long term, and environmental authorities do not ensure that companies comply with the legislation
Concentration Dependent Effect of Plant Root Exudates on the Chemosensory Systems of Pseudomonas putida KT2440
Plant root colonization by rhizobacteria can protect plants against pathogens and promote plant growth, and chemotaxis to root exudates was shown to be an essential prerequisite for efficient root colonization. Since many chemoattractants control the transcript levels of their cognate chemoreceptor genes, we have studied here the transcript levels of the 27 Pseudomonas putida KT2440 chemoreceptor genes in the presence of different maize root exudate (MRE) concentrations. Transcript levels were increased for 10 chemoreceptor genes at low MRE concentrations, whereas almost all receptor genes showed lower transcript levels at high MRE concentrations. The exposure of KT2440 to different MRE concentrations did not alter c-di-GMP levels, indicating that changes in chemoreceptor transcripts are not mediated by this second messenger. Data suggest that rhizosphere colonization unfolds in a temporal fashion. Whereas at a distance to the root, exudates enhance chemoreceptor gene transcript levels promoting in turn chemotaxis, this process is reversed in root vicinity, where the necessity of chemotaxis toward the root may be less important. Insight into KT2440 signaling processes were obtained by analyzing mutants defective in the three cheA paralogous genes. Whereas a mutant in cheA1 showed reduced c-di-GMP levels and impaired biofilm formation, a cheA2 mutant was entirely deficient in MRE chemotaxis, indicating the existence of homologs of the P. aeruginosawsp and che (chemotaxis) pathways. Signaling through both pathways was important for efficient maize root colonization. Future studies will show whether the MRE concentration dependent effect on chemoreceptor gene transcript levels is a feature shared by other species
Pseudomonas aeruginosa That Specifically Mediates Chemotaxis Toward α-Ketoglutarate
Pseudomonas aeruginosa is an ubiquitous pathogen able to infect humans, animals, and plants. Chemotaxis was found to be associated with the virulence of this and other pathogens. Although established as a model for chemotaxis research, the majority of the 26 P. aeruginosa chemoreceptors remain functionally un-annotated. We report here the identification of PA5072 (named McpK) as chemoreceptor for α-ketoglutarate (αKG). High-throughput thermal shift assays and isothermal titration calorimetry studies (ITC) of the recombinant McpK ligand binding domain (LBD) showed that it recognizes exclusively α-ketoglutarate. The ITC analysis indicated that the ligand bound with positive cooperativity (Kd1 = 301 μM, Kd2 = 81 μM). McpK is predicted to possess a helical bimodular (HBM) type of LBD and this and other studies suggest that this domain type may be associated with the recognition of organic acids. Analytical ultracentrifugation (AUC) studies revealed that McpK-LBD is present in monomer-dimer equilibrium. Alpha-KG binding stabilized the dimer and dimer self-dissociation constants of 55 μM and 5.9 μM were derived for ligand-free and αKG-bound forms of McpK-LBD, respectively. Ligand-induced LBD dimer stabilization has been observed for other HBM domain containing receptors and may correspond to a general mechanism of this protein family. Quantitative capillary chemotaxis assays demonstrated that P. aeruginosa showed chemotaxis to a broad range of αKG concentrations with maximal responses at 500 μM. Deletion of the mcpK gene reduced chemotaxis over the entire concentration range to close to background levels and wild type like chemotaxis was recovered following complementation. Real-time PCR studies indicated that the presence of αKG does not modulate mcpK expression. Since αKG is present in plant root exudates it was investigated whether the deletion of mcpK altered maize root colonization. However, no significant changes with respect to the wild type strain were observed. The existence of a chemoreceptor specific for αKG may be due to its central metabolic role as well as to its function as signaling molecule. This work expands the range of known chemoreceptor types and underlines the important physiological role of chemotaxis toward tricarboxylic acid cycle intermediates. [EN]FEDER funds and Fondo Social Europeo through grants from the Junta de Andalucía (grant CVI-7335) and the Spanish Ministry for Economy and Competitiveness (grant BIO2013-42297). MM was supported by the Spanish Ministry of Economy and Competitiveness Postdoctoral Research Program, Juan de la Cierva (JCI-2012-11815).Peer reviewe
SUMOylated SNF2PH promotes variant surface glycoprotein expression in bloodstream trypanosomes
SUMOylation is a post¿translational modification that positively regulates monoallelic expression of the trypanosome variant surface glycoprotein (VSG). The presence of a highly SUMOylated focus associated with the nuclear body, where the VSG gene is transcribed, further suggests an important role of SUMOylation in regulating VSG expression. Here, we show that SNF2PH, a SUMOylated plant homeodomain (PH)¿transcription factor, is upregulated in the bloodstream form of the parasite and enriched at the active VSG telomere. SUMOylation promotes the recruitment of SNF2PH to the VSG promoter, where it is required to maintain RNA polymerase I and thus to regulate VSG transcript levels. Further, ectopic overexpression of SNF2PH in insect forms, but not of a mutant lacking the PH domain, induces the expression of bloodstream stage¿specific surface proteins. These data suggest that SNF2PH SUMOylation positively regulates VSG monoallelic transcription, while the PH domain is required for the expression of bloodstream¿specific surface proteins. Thus, SNF2PH functions as a positive activator, linking expression of infective form surface proteins and VSG regulation, thereby acting as a major regulator of pathogenicity.The authors thank Dr. Alicia Barroso Del Jesus for excellent assistance and input with NSG methodology at the Genomic Unit and Dr. Laura Montosa at the Microscopy Unit (IPBLN-CSIC). This work was supported by grants from the Spanish Ministerio de Ciencia, Innovación y Universidades (RTI2018-098834-B-I00) and the Wellcome Trust (WTI 204697/Z/16/Z to MCF) and thegrant from the Argentinian National Agency for Promotion of Scientific and
Technological Research to VEA (PICT/2016/0465)
Mammalian biogeography and the Ebola virus in Africa
ABSTRACT 1. Ebola virus is responsible for the fatal Ebola virus disease (EVD). 2. Identifying the distribution area of the Ebola virus is crucial for understanding risk factors conditioning the emergence of new EVD cases. Existing distribution models have underrepresented the potential contribution that reservoir species and vulnerable species make in sustaining the presence of the virus. 3. In this paper, we map favourable areas for Ebola virus in Africa according to environmental and zoogeographic descriptors, independent of human-to-human transmissions. We combine two different biogeographic approaches: analysis of mammalian distribution types (chorotypes), and distribution modelling of the Ebola virus. 4. We first obtain a model defining the distribution of environmentally favourabl
Structural and Spectroscopic Properties of Two New Isostructural Complexes of Lapacholate with Cobalt and Copper
The molecular structures of two isostructural complexes of lapacholate (Lap) anion and dimethylformamide (DMF), M(Lap)2(DMF)2 with M: Co Cu, were determined by X-ray diffraction methods. The substances crystallize in the triclinic space group P1 with one molecule per unit cell and cell constants a = 7.7591(3), b = 10.3560(3), c = 11.2224(4) A, α = 95.110(2), β = 94.310(2), and γ = 107.704(2)◦ for the Co complex and a = 7.9308(2), b = 10.0033(4), c = 10.7508(4), α = 97.387(2), β = 93.621(2), and γ = 103.980(2)◦ for the Cu complex. The structures were solved from 2933 (Co) and 2888 (Cu) reflections with I > 2σ (I) and refined by full matrix least squares to agreement R1-factors of 0.041 (Co) and 0.033 (Cu). The metal M(II) ion is sited on a crystallographic inversion center in a MO6 distorted octahedral environment. This ion is coordinated equatorially to two lapacholate anions through their adjacent carbonyl and phenol oxygen atoms [M–O bond distances of 2.134(1) and 2.008(1) A˚ (Co) and 2.301(1) and 1.914(1) A (Cu)] and axially to two DMF molecules through oxygen atoms [M–O bond lengths of 2.143(1) ˚ A (Co) and 2.069(1) ˚ A (Cu)]. The solid state IR transmittance and solution electronic absorption spectra of both Co and Cu ˚ compounds are also reported and compared to each other and to the corresponding spectra of other members of the lapacholate metal family of complexes.Instituto de Física La Plat
Mature Andean forests as globally important carbon sinks and future carbon refuges
It is largely unknown how South America’s Andean forests affect the global carbon cycle, and thus regulate climate change. Here, we measure aboveground carbon dynamics over the past two decades in 119 monitoring plots spanning a range of >3000 m elevation across the subtropical and tropical Andes. Our results show that Andean forests act as strong sinks for aboveground carbon (0.67 ± 0.08 Mg C ha−1 y−1) and have a high potential to serve as future carbon refuges. Aboveground carbon dynamics of Andean forests are driven by abiotic and biotic factors, such as climate and size-dependent mortality of trees. The increasing aboveground carbon stocks offset the estimated C emissions due to deforestation between 2003 and 2014, resulting in a net total uptake of 0.027 Pg C y−1. Reducing deforestation will increase Andean aboveground carbon stocks, facilitate upward species migrations, and allow for recovery of biomass losses due to climate change.Fil: Duque, Alvaro. Universidad Nacional de Colombia; ColombiaFil: Peña, Miguel A.. Universidad Nacional de Colombia; ColombiaFil: Cuesta, Francisco. Universidad de Las Américas; EcuadorFil: González Caro, Sebastián. Universidad Nacional de Colombia; ColombiaFil: Kennedy, Peter. University of Minnesota; Estados UnidosFil: Phillips, Oliver L.. University of Leeds; Reino UnidoFil: Calderón Loor, Marco. Universidad de Las Américas; EcuadorFil: Blundo, Cecilia Mabel. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Carilla, Julieta. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Cayola, Leslie. Missouri Botanical Garden; Estados UnidosFil: Farfán Ríos, William. Washington University in St. Louis; Estados UnidosFil: Fuentes, Alfredo. Missouri Botanical Garden; Estados UnidosFil: Grau, Hector Ricardo. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Homeier, Jürgen. Universität Göttingen; AlemaniaFil: Loza-Rivera, María I.. Missouri Botanical Garden; Estados UnidosFil: Malhi, Yadvinder. University of Oxford; Reino UnidoFil: Malizia, Agustina. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Malizia, Lucio Ricardo. Universidad Nacional de Jujuy; ArgentinaFil: Martínez Villa, Johanna A.. Université du Québec a Montreal; CanadáFil: Myers, Jonathan A.. Washington University in St. Louis; Estados UnidosFil: Osinaga Acosta, Oriana. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Peralvo, Manuel. No especifíca;Fil: Pinto, Esteban. No especifíca;Fil: Saatchi, Sassan. Jet Propulsion Laboratory; Estados UnidosFil: Silman, Miles. Center For Energy, Environment And Sustainability; Estados UnidosFil: Tello, J. Sebastián. Missouri Botanical Garden; Estados UnidosFil: Terán Valdez, Andrea. No especifíca;Fil: Feeley, Kenneth J.. University of Miami; Estados Unido
Mature Andean forests as globally important carbon sinks and future carbon refuges
It is largely unknown how South America’s Andean forests affect the global carbon cycle, and thus regulate climate change. Here, we measure aboveground carbon dynamics over the past two decades in 119 monitoring plots spanning a range of >3000 m elevation across the subtropical and tropical Andes. Our results show that Andean forests act as strong sinks for aboveground carbon (0.67 ± 0.08 Mg C ha−1 y−1) and have a high potential to serve as future carbon refuges. Aboveground carbon dynamics of Andean forests are driven by abiotic and biotic factors, such as climate and size-dependent mortality of trees. The increasing aboveground carbon stocks offset the estimated C emissions due to deforestation between 2003 and 2014, resulting in a net total uptake of 0.027 Pg C y−1. Reducing deforestation will increase Andean aboveground carbon stocks, facilitate upward species migrations, and allow for recovery of biomass losses due to climate change.Fil: Duque, Alvaro. Universidad Nacional de Colombia; ColombiaFil: Peña, Miguel A.. Universidad Nacional de Colombia; ColombiaFil: Cuesta, Francisco. Universidad de Las Américas; EcuadorFil: González Caro, Sebastián. Universidad Nacional de Colombia; ColombiaFil: Kennedy, Peter. University of Minnesota; Estados UnidosFil: Phillips, Oliver L.. University of Leeds; Reino UnidoFil: Calderón Loor, Marco. Universidad de Las Américas; EcuadorFil: Blundo, Cecilia Mabel. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Carilla, Julieta. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Cayola, Leslie. Missouri Botanical Garden; Estados UnidosFil: Farfán Ríos, William. Washington University in St. Louis; Estados UnidosFil: Fuentes, Alfredo. Missouri Botanical Garden; Estados UnidosFil: Grau, Hector Ricardo. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Homeier, Jürgen. Universität Göttingen; AlemaniaFil: Loza-Rivera, María I.. Missouri Botanical Garden; Estados UnidosFil: Malhi, Yadvinder. University of Oxford; Reino UnidoFil: Malizia, Agustina. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Malizia, Lucio Ricardo. Universidad Nacional de Jujuy; ArgentinaFil: Martínez Villa, Johanna A.. Université du Québec a Montreal; CanadáFil: Myers, Jonathan A.. Washington University in St. Louis; Estados UnidosFil: Osinaga Acosta, Oriana. Universidad Nacional de Tucumán. Instituto de Ecología Regional. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Ecología Regional; ArgentinaFil: Peralvo, Manuel. No especifíca;Fil: Pinto, Esteban. No especifíca;Fil: Saatchi, Sassan. Jet Propulsion Laboratory; Estados UnidosFil: Silman, Miles. Center For Energy, Environment And Sustainability; Estados UnidosFil: Tello, J. Sebastián. Missouri Botanical Garden; Estados UnidosFil: Terán Valdez, Andrea. No especifíca;Fil: Feeley, Kenneth J.. University of Miami; Estados Unido
A consensus statement for trauma surgery capacity building in Latin America
Background
Trauma is a significant public health problem in Latin America (LA), contributing to substantial death and disability in the region. Several LA countries have implemented trauma registries and injury surveillance systems. However, the region lacks an integrated trauma system. The consensus conference’s goal was to integrate existing LA trauma data collection efforts into a regional trauma program and encourage the use of the data to inform health policy.
Methods
We created a consensus group of 25 experts in trauma and emergency care with previous data collection and injury surveillance experience in the LA. region. Experts participated in a consensus conference to discuss the state of trauma data collection in LA. We utilized the Delphi method to build consensus around strategic steps for trauma data management in the region. Consensus was defined as the agreement of ≥ 70% among the expert panel.
Results
The consensus conference determined that action was necessary from academic bodies, scientific societies, and ministries of health to encourage a culture of collection and use of health data in trauma. The panel developed a set of recommendations for these groups to encourage the development and use of robust trauma information systems in LA. Consensus was achieved in one Delphi round.
Conclusions
The expert group successfully reached a consensus on recommendations to key stakeholders in trauma information systems in LA. These recommendations may be used to encourage capacity building in trauma research and trauma health policy in the region
The First Post-Kepler Brightness Dips of KIC 8462852
We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in October 2015, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1-2.5% dips, named "Elsie," "Celeste," "Skara Brae," and "Angkor", which persist on timescales from several days to weeks. Our main results so far are: (i) there are no apparent changes of the stellar spectrum or polarization during the dips; (ii) the multiband photometry of the dips shows differential reddening favoring non-grey extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale <<1um, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term "secular" dimming, which may be caused by independent processes, or probe different regimes of a single process