1,463 research outputs found
The Trypanosomatid Pr77-hallmark contains a downstream core promoter element essential for transcription activity of the Trypanosoma cruzi L1Tc retrotransposon
Background: Trypanosomatid genomes are highly colonized by non-LTR retroelements that make up to 5% of the nuclear genome. These elements are mainly accumulated in the strand switch regions (SSRs) where polycistronic transcription is initiated and have a 77nt-long sequence - Pr77 - at their 5' ends. L1Tc is the best represented retrotransposon in the Trypanosoma cruzi genome and is a potentially functional autonomous element that encodes its own retrotransposition machinery. The Pr77of the T. cruzi L1Tc element activates gene transcription via RNA polymerase II, generating abundant, unspliced transcripts which are translated. Results: The present manuscript describes the identification of a downstream core promoter element (DPE) in the L1Tc Pr77sequence. Just four nucleotides long (CGTG), it covers in Pr77positions +25 to +28 of the described L1Tc transcription start site. The Pr77-DPE motif is conserved in terms of sequence composition and position in the Pr77of most trypanosomatid non-LTR retrotransposons, independent of the coding or non-coding capacity of these retroelements. Transcription assays in T. cruzi stable transfectants with vector containing point mutations at 17locations of the Pr77nucleotide sequence evidence that the DPE motif is essential for the promoter function of Pr77. Furthermore, the obtained data show that other nucleotides also contributed to the promoter function of Pr77. In addition, the presented results indicate that parasite nuclear proteins specifically bind to different regions of the Pr77sequence although the strongest binding is to the DPE motif. Moreover, it is shown that the DPE sense single-stranded sequence is being required in DNA-protein recognition of nuclear factors. Conclusions: The Pr77sequence present in most of non-LTR retrotransposons of trypanosomatids contains a downstream core promoter element (DPE) which is conserved in terms of nucleotide composition and location. The Pr77-DPE motif is essential for the transcriptional activity of Pr77although other nucleotides are also involved. DPE has a high affinity binding for nuclear proteins in T. cruzi. The wide retroelement-mediated distribution of Pr77suggests that it may represent an important tool for regulating gene expression in trypanosomatids. © 2016 Macías et al.This work was supported by the Programa Estatal I+D+i (MINECO) via grants SAF2012-35777, SAF2013-48527-R and RTC-2014-2130, by the RICET Tropical Diseases Research Network via grant RD12/0018/0021, and via FEDER funds.Peer reviewe
Mechanical–biological treatment: Performance and potentials. An LCA of 8 MBT plants including waste characterization
Methodology for the identification, evaluation and prioritization of market handicaps which prevent the implementation of Demand Response: Application to European electricity markets
This paper presents a methodology for the identification, analysis and comparative assessment of the handicaps which nowadays prevent the higher implementation of Demand Response (DR) in the electricity market. Its application provides a hierarchical organization of handicaps from the most critical to the less critical and then, from the easiest to the most difficult to overcome. This makes possible to determine which barriers would be a priority, which may indicate the direction of regulatory changes to properly address these handicaps and so, stimulating a higher participation of the demand side in electricity markets. After applying the methodology to three European countries, 34 handicaps have been identified, analysing which of these handicaps affect such stakeholders as grid operators, retailers and customers and how these stakeholders are affected. For each handicap, the criticality and difficulty to overcome the different handicaps have been studied, based on detailed information coming from personal interviews to experts representing the different stakeholders in the electricity trading chain. Regulatory barriers have been identified as the most critical and difficult to overcome. Together with regulatory changes, the promotion of aggregators and the training of customers on DR applications are some of the most significant initiatives.This work was completed in the framework of the DRIP project (11ENV/DE/340) co-funded by the European Commission through the LIFE Environment Programme. The authors deeply thank all the participants in the project for their help and support that made possible this work.Alcázar-Ortega, M.; Calpe Esteve, CM.; Theisen, T.; Carbonell-Carretero, J. (2015). Methodology for the identification, evaluation and prioritization of market handicaps which prevent the implementation of Demand Response: Application to European electricity markets. Energy Policy. 86:529-543. doi:10.1016/j.enpol.2015.08.006S5295438
Deformaciones pliocenas y cuaternarias en la plataforma continental oriental del Algarve, Golfo de Cádiz
The eastern Algarve continental shelf in the northern margin of
the Gulf of Cadiz has been investigated by analysing a set of high-resolution seismic reflection profiles. We examine the major structural
elements affecting the upper sedimentary units. A seismo-stratigraphic interpretation and regional correlation allowed the identification of a major discontinuity that separates two main intervals,
pre-Middle Pleistocene (MP) and post-MP. In addition, a number of
deformation features such as ENE-WSW to NE-SW thrusts, kilometric-scale N-S to NW-SE folds and NNE-SSW to NNW-SSE sub-vertical normal faults were identified affecting the Pliocene-Quaternary
sedimentary record, indicating neotectonic activity. The structures
pre-dating MP are in agreement with a dominant transpressive regime along the continental shelf, under the Late Cenozoic NW-SE
oblique convergence and related to the reactivation of Mesozoic diapiric structures. The structures post-dating MP induce a lower deformation of the sedimentary cover but were still active during the last
glacial maximum, in agreement with the low uplift recognized in the
Portuguese mainlandLa plataforma continental del Algarve en el margen septentrional del Golfo de Cádiz ha sido investigada mediante el análisis de
una red de perfiles sísmicos de alta resolución. Se presentan las principales estructuras que afectan a la cobertera sedimentaria superficial. Una interpretación sismoestratigráfica y correlaciones a nivel
regional han permitido diferenciar dos intervalos separados por una
discontinuidad principal, anterior y posterior al Pleistoceno Medio
(PM). Los depósitos del Plioceno y Cuaternario están deformados
por estructuras de deformación tales como cabalgamientos ENEOSO a NE-SO, pliegues N-S a NO-SE de escala kilométrica y fallas
subverticales NNE-SSO a NNO-SSE, que indican actividad neotectónica. Las estructuras anteriores al PM se generan en relación con el
régimen transpresivo (NO-SE) dominante a fInales del Cenozoico en
esta región y la reactivación de las estructuras diapíricas mesozoicas
observadas en el margen. En cambio, las estructuras posteriores al
PM producen una ligera deformación de la cobertera sedimentaria
y actividad durante el último máximo glaciar, lo que concuerda con
un moderado levantamiento tectónico observado en la zona continental del margen portugué
A putative Leishmania DNA polymerase theta protects the parasite against oxidative damage
Leishmania infantum is a protozoan parasite that is phagocytized by human macrophages. The host macrophages kill the parasite by generating oxidative compounds that induce DNA damage. We have identified, purified and biochemically characterized a DNA polymerase θ from L. infantum (LiPolθ), demonstrating that it is a DNA-dependent DNA polymerase involved in translesion synthesis of 8oxoG, abasic sites and thymine glycol lesions. Stably transfected L. infantum parasites expressing LiPolθ were significantly more resistant to oxidative and interstrand cross-linking agents, e.g. hydrogen peroxide, cisplatin and mitomycin C. Moreover, LiPolθ-overexpressing parasites showed an increased infectivity toward its natural macrophage host. Therefore, we propose that LiPolθ is a translesion synthesis polymerase involved in parasite DNA damage tolerance, to confer resistance against macrophage aggression.Spanish Ministry of Science and Innovation [AGL2010-21806-C02-01 to V.L., BFU2012-37969 to L.B.]; Comunidad deMadrid [S2010/BMD-2361 to L.B.]; Ramón Areces Foundation [050204100014 to V.L.]Peer Reviewe
Production of Docosahexaenoic Acid and Odd-Chain Fatty Acids by Microalgae Schizochytrium limacinum Grown on Waste-Derived Volatile Fatty Acids
Heterotrophic microalgae are recognized as a source of bioactive compounds. However, there are still some drawbacks for their use at an industrial scale associated with the high cost of glucose, the main carbon source in heterotrophic cultures. In recent years, significant efforts have been made to investigate more sustainable carbon sources to produce biomass. In this study, the capacity of Schizochytrium limacinum to grow on waste-derived volatile fatty acids and the effect that their use produces on biomass and fatty acids profiles were investigated. Acetic, propionic, butyric, valeric and caproic acid were evaluated independently, as well as in a synthetic mixture (VFA). The use of acetic and butyric resulted in a good biomass productivity, while the use of valeric and propionic acid resulted in higher content of odd-chain fatty acids (OCFA), increasingly investigated due to their potential benefits for human health. The use of industrial waste-derived VFA as a potential carbon source was validated through the utilization of biowaste derived effluents from a volatile fatty acid platform. The biomass produced was of 18.5 g/L, 54.0% lipids, 46.3% docosahexaenoic acid (DHA) and 25.0% OCFA, concluding that waste derived VFA can produce DHA and OCFA in a suitable ratio of DHA/OCFA with potential industrial applications.The authors would like to thank the European project VOLATILE. The project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 720777
Cryptic speciation of the zoogonid digenean Diphterostomum flavum n. sp. demonstrated by morphological and molecular data
Diphterostomum brusinae (Zoogonidae) is a digenean species that has been recorded worldwide parasitizing marine fishes. Several species have been synonymized with D. brusinae because they lack conspicuous morphological differences. However, due to the breadth of its geographic distribution and the variety of hosts involved in the life cycles, it is likely to be an assemblage of cryptic species. Diphterostomum flavum n. sp. is described here as a morphologically cryptic relative of D. brusinae, in the fish Pinguipes brasilianus (Pinguipedidae) off the Patagonian coast, Southwestern Atlantic Ocean, and its life cycle is elucidated through morphology and molecular analysis. This species uses the gastropod Buccinanops deformis (Nassariidae) as first and second intermediate host with metacercariae encysting within sporocysts. They also, however, use the polychaete Kinbergonuphis dorsalis (Onuphidae) as second intermediate host. No morphological differences were found between adults of D. flavum n. sp. and D. brusinae; however, the number of penetration glands of the cercariae, a diagnostic feature, differed (9 vs. 3 pairs), as well as the ITS2 sequences for the two species. This work provides morphological and molecular evidence of cryptic diversification among species described as D. brusinae, in which the only clear differences are in larval morphology and host spectrum. The strict specificity to the snail acting as the first intermediate host and the variety of fishes with different feeding habits acting as definitive hosts support the likely existence of multiple cryptic species around the world.Fil: Gilardoni, Carmen Mariangel. Instituto de Biología de Organismos Marinos (cct Conicet-cenpat); ArgentinaFil: Etchegoin, Jorge Alejandro. Universidad Nacional de Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Instituto de Investigaciones En Sanidad Produccion y Ambiente. - Comision de Investigaciones Cientificas de la Provincia de Buenos Aires. Instituto de Investigaciones En Sanidad Produccion y Ambiente.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Cribb, Thomas. The University of Queensland; Australia. University of Queensland; AustraliaFil: Pina, Susana. Universidad de Porto; PortugalFil: Rodrigues, Pedro. I3s - Instituto de Investigação E Inovação Em Saúde, Universidade Do Porto, Portugal; Portugal. Universidad de Porto; PortugalFil: Diez, María Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Cremonte, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; Argentin
Atheists on the Santiago way : examining motivations to go on pilgrimage
In the past 30 years, the camino to Santiago de Compostela has been recreated as an eclectic pilgrimage, open to both religious and atheist travelers. Following previous work on motivational orientations and religion, we conducted a study examining atheist versus religious pilgrims' motivations to walk the Santiago way. We assessed pilgrims (N = 360) at various parts of the northern Spanish camino using a questionnaire that measured motivations to go on pilgrimage. In addition, we measured levels of positive and negative affect, physical exertion, and emotional problems. Atheists scored significantly lower on community and religious types of motivations. However, in several measures no differences were found between groups. We suggest that both atheist and religious pilgrims are exploring forms of horizontal and vertical transcendence characterized by a desire to connect to nature and one's deeper sel
GRIDMAT—A Sustainable Material Combining Mat and Geogrid Concept for Ballasted Railways
Under ballast mats (UBM) have demonstrated their capacity to reduce section stiffness
and ballast degradation. However, UBM can cause ballast destabilisation under some circumstances
due to excessive vertical track deflections, requiring the installation of geogrids over the mat which
increases costs and time. As alternative to this solution, this paper shows the design of GridMat:
a sustainable technology for ballasted railways that combines the concepts of geogrids and under
ballast mats (UBM) manufactured from recycled crumb rubber. This aims to provide damping
capacity while limiting the oscillations and settlement of ballast layer. To obtain the optimal GridMat
design, five different configurations varying the aperture size and void areas were assessed through
laboratory box tests reproducing the track section including the GridMat. Results showed that the
optimal Gridmat was of 55 mm aperture seize and 25% void area. To evaluate the sustainability
of this design, the expected number of conservation and renewal operations were calculated from
full-scale laboratory tests and a life-cycle assessment and life-cycle cost analysis were undertaken.
GridMat showed long-term reduction in ballast degradation and track settlement, reducing need for
maintenance and renewal operations in comparison with standard mats.Spanish Government RTI2018-102124-J-IO
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