The use of rapid prototyping techniques (RPT) to manufacture micro channels suitable for high operation pressures and uPIV

This paper aims to present a new methodology to manufacture micro-channels suitable for high operating pressures and micro particle image velocimetry (µPIV) measurements using a rapid-prototyping high-resolution 3D printer. This methodology can fabricate channels down to 250 µm and withstand pressures of up to 5 ± 0.2 MPa. The manufacturing times are much shorter than in soft lithography processes. The novel manufacturing method developed takes advantage of the recently improved resolution in 3D printers to manufacture an rapid prototyping technique part that contains the hose connections and a micro-channel useful for microfluidics. A method to assemble one wall of the micro-channel using UV curable glue with a glass slide is presented – an operation required to prepare the channel for µPIV measurements. Once built, the micro-channel has been evaluated when working under pressure and the grease flow behavior in it has been measured using µPIV. Furthermore, the minimum achievable channels have been defined using a confocal microscopy study. This technique is much faster than previous micro-manufacturing techniques where different steps were needed to obtain the micro-machined parts. However, due to current 3D printers ' resolutions (around 50 µm) and according to the experimental results, channels smaller than 250-µm2 cross-section should not be used to characterize fluid flow behaviors, as inaccuracies in the channel boundaries can deeply affect the fluid flow behavior. The present methodology is developed due to the need to validate micro-channels using µPIV to lubricate critical components (bearings and gears) in wind turbines. This novel micro-manufacturing technique overcomes current techniques, as it requires less manufacturing steps and therefore it is faster and with less associated costs to manufacture micro-channels down to 250-µm2 cross-section that can withstand pressures higher than 5 MPa that can be used to characterize microfluidic flow behavior using µPIV.Peer ReviewedPostprint (author's final draft

First record of Oligochoerus limnophilus (Acoela, Acoelomorpha) from British waters

Primer registro de Oligochoerus limnophilus (Acoela, Acoelomorpha) en aguas británicas Informamos de la existencia de poblaciones del acelo Oligochoerus limnophilus (Acoelomorpha) en la islas Británicas sobre la base de los especímenes capturados en el río Támesis (también conocido localmente como río Isis) a su paso por Oxford, Inglaterra, ampliando así considerablemente el área de distribución de la especie, restringida hasta ahora al continente europeo. La información gráfica que aportamos, imágenes de especímenes vivos y proyecciones CLSM de estructuras informativas seleccionadas por su valor sistemático, corrobora su estrecha relación con el género Convoluta Ørsted, 1843.We report the occurrence of the acoel Oligochoerus limnophilus (Acoelomorpha) from the British Islands, based on specimens captured in the river Thames (locally known as the river Isis) in Oxford, England, thereby considerably widening the distributional range of the species that had formerly been reported only from continental Europe. We further present live images and CLSM-projections of systematically informative structures that corroborate a close relationship with the genus Convoluta Ørsted, 1843.Primer registre d'Oligochoerus limnophilus (Acoela, Acoelomorpha) en aigües britàniques Informem de l'existència de poblacions de l'acel Oligochoerus limnophilus (Acoelomorpha) a les illes Britàniques sobre la base dels espècimens capturats al riu Tàmesi (també conegut localment com a riu Isis) al pas per Oxford, Anglaterra, amb la qual cosa ampliem considerablement l'àrea de distribució de l'espècie, restringida fins ara al continent europeu. La informació gràfica que aportem, imatges d'espècimens vius i projeccions CLSM d'estructures informatives seleccionades pel seu valor sistemàtic, corrobora l'estreta relació amb el gènere Convoluta Ørsted, 1843

New method for lubricating wind turbine pitch gears using embedded micro-nozzles

This is a copy of the author 's final draft version of an article published in the journal Journal of mechanical science and technology. The final publication is available at Springer via http://dx.doi.org/10.1007/s12206-017-0131-3The increase of power generated by wind turbines has increased the stresses applied in all of its components, thereby causing premature failures. Particularly, pitch and yaw gears suffer from excessive wear mainly caused by inappropriate lubrication. This paper presents a novel method to automatically lubricate the wind turbine pitch gear during operation. A micro-nozzle to inject fresh grease continuously between the teeth in contact was designed, manufactured, and installed in a test bench of a 2 MW wind turbine pitch system. The test bench was used to characterize the fatigue behavior of the gear surface using conventional wind turbine greases under real cyclic loads. Measurements of wear evolution in a pitch gear with and without micro-nozzle show a decrease of 70 % of the wear coefficient after 2×104 cycles.Peer ReviewedPostprint (author's final draft

Matroids and Quantum Secret Sharing Schemes

A secret sharing scheme is a cryptographic protocol to distribute a secret state in an encoded form among a group of players such that only authorized subsets of the players can reconstruct the secret. Classically, efficient secret sharing schemes have been shown to be induced by matroids. Furthermore, access structures of such schemes can be characterized by an excluded minor relation. No such relations are known for quantum secret sharing schemes. In this paper we take the first steps toward a matroidal characterization of quantum secret sharing schemes. In addition to providing a new perspective on quantum secret sharing schemes, this characterization has important benefits. While previous work has shown how to construct quantum secret sharing schemes for general access structures, these schemes are not claimed to be efficient. In this context the present results prove to be useful; they enable us to construct efficient quantum secret sharing schemes for many general access structures. More precisely, we show that an identically self-dual matroid that is representable over a finite field induces a pure state quantum secret sharing scheme with information rate one

Los cinípidos mexicanos no asociados a encinos (Hymenoptera : Cynipidae), perspectivas de estudio

Ésta es la segunda aportación de los autores al estado de conocimiento de los Cynipidae de México. La única especie de Aylacini citada hasta el momento de México, Aylax rufipes (Cameron, 1884), es transferida a la familia Figitidae como Myrtopsen rufipes (Cameron, 1884) n. comb. Se discute la posibilidad de encontrar especies autóctonas o invasoras de Aylacini en México. En lo que se refiere a los cinípidos inquilinos, incluidos en la tribu Synergini, la riqueza de Synergus, Saphonecrus y Ceroptres dista mucho de ser conocida, habiéndose citado solamente dos especies de Synergus; Periclistus es un género inquilino inexistente en México debido a la ausencia de las agallas huésped, pertenecientes a tribu Diplolepidini. Finalmente, aunque las tribus Diplolepidini, Eschatocerini y Pediaspidini nunca se han citado, se discute su posible presencia.This is the second contribution of the authors to the knowledge of the Cynipidae in Mexico. The only Aylacini species cited for Mexico, Aylax rufipes (Cameron, 1884), is transferred to the family Figitidae as Myrtopsen rufipes (Cameron, 1884) n. comb. The possibility of finding native or invasive species of Aylacini in Mexico is discussed. Concerning the inquiline cynipids, included in the Synergini, the species richness of Synergus, Saphonecrus and Ceroptres is far from being well known, with only two Synergus species cited; Periclistus is an inquiline genus absent in Mexico due to the absence of the host galls; which belong to the Diplolepidini. Lastly, even if the tribes Diplolepidini, Eschatocerini and Pediaspidini have never been cited, their possible presence is discussed

Overlapping and Distinct Roles of PRR7 and PRR9 in the Arabidopsis Circadian Clock

AbstractThe core mechanism of the circadian oscillators described to date rely on transcriptional negative feedback loops with a delay between the negative and the positive components [1–3]. In plants, the first suggested regulatory loop involves the transcription factors CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) and the pseudo-response regulator TIMING OF CAB EXPRESSION 1 (TOC1/PRR1)[4]. TOC1 is a member of the Arabidopsis circadian-regulated PRR gene family [5,6]. Analysis of single and double mutants in PRR7 and PRR9 indicates that these morning-expressed genes play a dual role in the circadian clock, being involved in the transmission of light signals to the clock and in the regulation of the central oscillator. Furthermore, CCA1 and LHY had a positive effect on PRR7 and PRR9 expression levels, indicating that they might form part of an additional regulatory feedback loop. We propose that the Arabidopsis circadian oscillator is composed of several interlocking positive and negative feedback loops, a feature of clock regulation that appears broadly conserved between plants, fungi, and animals

Very accurate computation of the impedance elements on the discretization of the magnetic field integral equation with the orthogonal basis functions

We show a novel integrating technique, the direct evaluation method, that provides maximum accuracy in the computation of the MFIE-interactions between neighboring noncoplanar basis functions sharing an edge or a vertex of the discretization. Unlike the previous techniques, this strategy requires no extraction of quasi-singular terms from the Kernel and accounts for both inner- and outer-integrals. We show that the recently proposed discretization of the MFIE with orthogonal facet-oriented basis functions provide best accuracy in the RCS computation of objects with small electrical dimensions when compared with other conventional basis functions sets.Peer ReviewedPostprint (published version

Actual performance of mechanical ventilators in ICU: a multicentric quality control study.

Even if the performance of a given ventilator has been evaluated in the laboratory under very well controlled conditions, inappropriate maintenance and lack of long-term stability and accuracy of the ventilator sensors may lead to ventilation errors in actual clinical practice. The aim of this study was to evaluate the actual performances of ventilators during clinical routines. A resistance (7.69 cmH(2)O/L/s) - elastance (100 mL/cmH(2)O) test lung equipped with pressure, flow, and oxygen concentration sensors was connected to the Y-piece of all the mechanical ventilators available for patients in four intensive care units (ICUs; n = 66). Ventilators were set to volume-controlled ventilation with tidal volume = 600 mL, respiratory rate = 20 breaths/minute, positive end-expiratory pressure (PEEP) = 8 cmH(2)O, and oxygen fraction = 0.5. The signals from the sensors were recorded to compute the ventilation parameters. The average ± standard deviation and range (min-max) of the ventilatory parameters were the following: inspired tidal volume = 607 ± 36 (530-723) mL, expired tidal volume = 608 ± 36 (530-728) mL, peak pressure = 20.8 ± 2.3 (17.2-25.9) cmH(2)O, respiratory rate = 20.09 ± 0.35 (19.5-21.6) breaths/minute, PEEP = 8.43 ± 0.57 (7.26-10.8) cmH(2)O, oxygen fraction = 0.49 ± 0.014 (0.41-0.53). The more error-prone parameters were the ones related to the measure of flow. In several cases, the actual delivered mechanical ventilation was considerably different from the set one, suggesting the need for improving quality control procedures for these machines

Resistance Evolution to EPSPS Inhibiting Herbicides in False Barley (Hordeum murinum) Harvested in Southern Spain

A failure of the EPSPS-inhibiting herbicide glyphosate to control several populations of Hordeum murinum subsp. leporinum (or H. murinum) occurred in southern Spain after more than fifteen applications in both crop (olive, orchards, and citrus) and non-crop (dry areas, roadsides and ditches) areas. Eight out of 18 populations studied were resistant (R) to glyphosate with R factors higher than four based on GR50. These populations also had the highest values of LD50 and the lowest levels of shikimic acid accumulation. Two adjuvants tested increased glyphosate efficacy in both susceptible (S) and R populations thanks to better spray foliar retention. Moreover, PS I-, PS II-, and ACCase-inhibiting herbicides, in pre- or post-emergence, proved to be the best chemical alternatives with different sites of action (SoA) to control both S and glyphosate-R populations. This study represents the first report worldwide of glyphosate resistance in H. murinum found in very different crop and non-crop areas from southern Spain. To design chemical strategies to implement integrated weed management programs for glyphosate-R H. murinum, both adjuvants and herbicides with alternative SoA as well as application timings should be considered.This research has also been supported by the Spanish Government, through project AGL2017-83325-C4-2-R (AEI/FEDER/UE), Asociación de Agroquímicos y Medioambiente and project ref PO 4513358935 by Bayer CropScience

Amaranthus palmeri a New Invasive Weed in Spain with Herbicide Resistant Biotypes

Amaranthus palmeri is the most prominent invasive weed in agricultural land from North America, partly due to its propensity to evolve resistance to multiple herbicide sites of action. In the last two decades, reports of this species have increased throughout the American continent and occasionally in other continents. In 2007, A. palmeri populations were found in three localities in northeastern Spain, and they are still present today. To determine whether these three populations resulted from a common or independent introduction events¿and when and from where they could have occurred¿research was carried out aiming to characterize the resistance profile and mechanisms to 5-enolpyruvylshikimate-3-phosphate synthase-and acetolactate synthase (ALS)-inhibiting herbicides and to analyze the relationship between these three populations using inter simple sequence repeat DNA fingerprinting. Dose-response trials confirmed that the three populations were susceptible to glyphosate but resistant to nicosulfuron-methyl. Resistance to ALS inhibitors was due to several amino acid substitutions in positions Pro197, Trp574 and Ser653. Moreover, the substitutions Ser653Ile and Pro197Thr are described for the first time in this species. At field-labeled rates, all populations were fully controlled with alternative herbicides with other sites of action. Amaranthus palmeri individuals were clustered in three groups based on unweighted pair group method with arithmetic mean analysis, which corresponded to the three sampled populations, with a 67% of genetic relationship among them. Considering this high genetic variability and the different positions and amino acid substations found between populations, it was hypothesized that different colonization events occurred from the American continent probably prior to the introduction of glyphosate resistant crops. Prevention from new introductions is warranted because new herbicide resistance traits could arrive, complicating the management of this invasive weed species, while managing or eradicating the already established populations.This work was funded by Spanish Government through the project AGL2017-83325-C4-2-R (AEI/FEDER/UE). Joel Torra acknowledges support from the Spanish Ministry of Science, Innovation and Universities (grant Ramon y Cajal RYC2018-023866-I)