Laboratory and telescope demonstration of the TP3-WFS for the adaptive optics segment of AOLI

AOLI (Adaptive Optics Lucky Imager) is a state-of-art instrument that combines adaptive optics (AO) and lucky imaging (LI) with the objective of obtaining diffraction limited images in visible wavelength at mid- and big-size ground-based telescopes. The key innovation of AOLI is the development and use of the new TP3-WFS (Two Pupil Plane PositionsWavefront Sensor). The TP3-WFS, working in visible band, represents an advance over classical wavefront sensors such as the Shack-Hartmann WFS (SH-WFS) because it can theoretically use fainter natural reference stars, which would ultimately provide better sky coverages to AO instruments using this newer sensor. This paper describes the software, algorithms and procedures that enabled AOLI to become the first astronomical instrument performing real-time adaptive optics corrections in a telescope with this new type of WFS, including the first control-related results at the William Herschel Telescope (WHT)This work was supported by the Spanish Ministry of Economy under the projects AYA2011-29024, ESP2014-56869-C2-2-P, ESP2015-69020-C2-2-R and DPI2015-66458-C2-2-R, by project 15345/PI/10 from the Fundación Séneca, by the Spanish Ministry of Education under the grant FPU12/05573, by project ST/K002368/1 from the Science and Technology Facilities Council and by ERDF funds from the European Commission. The results presented in this paper are based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. Special thanks go to Lara Monteagudo and Marcos Pellejero for their timely contributions

Native breeds conservation, sustainable economies and usefulness

In the present essay it is sought to tackle, from the point of view of Economic Methodology, questions so like: Must native breeds be preserved?. As soon as this question is resolved, assigning and appraising its importance, is the question. What values are derived from the native breeds existence?: Value by the obtained profit of its current consumption; Option value; Cuasi-option value. What appraisal techniques must be utilized?: Native breeds are considered like a flow resource; its services will be released in the future if a determined stock level is maintained, through the autoreproduction. Irreversibility and option values. The traditional economic analysis use to assume that decisions about resources use are reversible. That is, depending on avaible information, an agent makes an utilization plan of a renovable resource like the native breed, for today and for the future. Now, it is assumed that a new information (scientific and technological advance) appears in the future, and as a result of that, the optimal program of a resource use must be changed. If the taken decisions in the T period were reversible, it is accepted the agent could change the way of using this resource if the optimization process requires it. Is there a real extinction danger of a private renovable resource? The extinction danger of a renovable resource (native breed), independently and although it is in private hands, public hands or it is free, is originated from a serie of economic and market factors.En el presente ensayo se pretende abordar, desde el punto de vista de la metodología económica, la cuestión de si se deben conservar las razas autóctonas. Una vez que se resuelve esta pregunta se deben establecer los valores derivados de la existencia de las razas autóctonas: Valor por la utilidad obtenida de su actual consumo; Valor de la opción; Valor cuasi-opción. ¿Qúe técnicas de valoración se han de utilizar?. Se consideran las razas autóctonas como un recurso flujo; es decir cuyos servicios se liberarán en el futuro si se mantiene un nivel de stock determinado, a través de la autorreproducción. Irreversibilidad y valores de opción. El análisis económico convencional asume normalmente que las decisiones sobre utilización de recursos son reversibles. Es decir, que según la información disponible un agente hace un plan de utilización de un recurso renovable como la raza autóctona, para hoy y para el futuro. Ahora asumimos que en el futuro aparece un nueva información (avance científico y tecnológico) y que como consecuencia el programa óptimo de utilización de un recurso debe cambiar. Si las decisiones tomadas en el periodo T fuesen reversibles estamos aceptando que el agente podría cambiar el modo de usar este recurso si lo exige el proceso de optimización. ¿Existe un peligro real de extinción de un recurso renovable privado?. El peligro de extinción de un recurso renovable (raza autóctona) independientemente y aunque esté en manos privadas, públicas o se tenga libre acceso al mismo, nace en base a una serie de factores económicos y de mercado

An instrumental puzzle: the modular integration of AOLI

The Adaptive Optics Lucky Imager, AOLI, is an instrument developed to deliver the highest spatial resolution ever obtained in the visible, 20 mas, from ground-based telescopes. In AOLI a new philosophy of instrumental prototyping has been applied, based on the modularization of the subsystems. This modular concept offers maximum flexibility regarding the instrument, telescope or the addition of future developments.Comment: 10 pages, 8 figures, Proc. SPIE 9908, Ground-based and Airborne Instrumentation for Astronomy VI, 99082Z (August 9, 2016

Galaxy cluster mergers as triggers for the formation of jellyfish galaxies: case study of the A901/2 system

The A901/2 system is a rare case of galaxy cluster interaction, in which two galaxy clusters and two smaller groups are seen in route of collision with each other simultaneously. Within each of the four substructures, several galaxies with features indicative of jellyfish morphologies have been observed. In this paper, we propose a hydrodynamic model for the merger as a whole, compatible with its diffuse X-ray emission, and correlate the gas properties in this model with the locations of the jellyfish galaxy candidates in the real system. We find that jellyfish galaxies seem to be preferentially located near a boundary inside each subcluster where diffuse gas moving along with the subcluster and diffuse gas from the remainder of the system meet. The velocity change in those boundaries is such that a factor of up to $\sim$1000 increase in the ram pressure takes place within a few hundred kpc, which could trigger the high rate of gas loss necessary for a jellyfish morphology to emerge. A theoretical treatment of ram pressure stripping in the environment of galaxy cluster mergers has not been presented in the literature so far; we propose that this could be a common scenario for the formation of jellyfish morphologies in such systems.Comment: Accepted for publication in MNRAS. 10 pages, 9 figure

H.264/AVC inter prediction on accelerator-based multi-core systems

The AVC video coding standard adopts variable block sizes for inter frame coding to increase compression efficiency, among other new features. As a consequence of this, an AVC encoder has to employ a complex mode decision technique that requires high computational complexity. Several techniques aimed at accelerating the inter prediction process have been proposed in the literature in recent years. Recently, with the emergence of many-core processors or accelerators, a new way of supporting inter frame prediction has presented itself. In this paper, we present a step forward in the implementation of an AVC inter prediction algorithm in a graphics processing unit, using Compute Unified Device Architecture. The results show a negligible drop in rate distortion with a time reduction, on average, of over 98.8 % compared with full search and fast full search, and of over 80 % compared with UMHexagonS search

Combinatorial signal processing in an insect

Human language is combinatorial: phonemes are grouped into syllables, syllables are grouped into words, and so on. The capacity for combinatorial processing is present, in different degrees, in some mammals and birds. We used vibrational insects, Enchenopa treehoppers, to test the hypothesis of basic combinatorial processing against two competing hypotheses: beginning rule (where the early signal portions play a stronger role in acceptability) and no ordering rule (where the order of signal elements plays no role in signal acceptability). Enchenopa males use plant-borne vibrational signals that consist of a whine followed by pulses. We tested the above hypotheses with vibrational playback experiments in which we presented Enchenopa females with stimuli varying in signal element combinations. We monitored female responses to these playbacks with laser vibrometry. We found strong support for combinatorial processing in Enchenopa: in brief, females preferred natural-combination signals regardless of the beginning element and discriminated against reverse-order signals or individual elements. Finding support for the combinatorial rule hypothesis in insects suggests that this capability represents a common solution to the problems presented by complex communication.Publisher PDFPeer reviewe

Angiotensin AT1 and AT2 receptors heteromer expression in microglia correlates with Parkinson's disease progression in the hemilesioned rat model of the disease

Background/Aims : The renin-angiotensin system (RAS) is altered in Parkinson's disease (PD), a disease due to substantia nigra neurodegeneration and whose dopamine-replacement therapy, using the precursor levodopa, leads to dyskinesias as the main side effect. Angiotensin AT 1 and AT 2 receptors, mainly known for their role in regulating water homeostasis and blood pressure and able to form heterodimers (AT 1/2 Hets), are present in the central nervous system. We assessed the functionality and expression of AT 1/2 Hets in Parkinson Disease (PD). Methods: Immunocytochemistry was used to analyze the colocalization between angiotensin receptors, bioluminescence resonance energy transfer was used to detect AT 1/2 Hets. Calcium and cAMP determination, MAPK activation and label-free assays were performed to characterize signaling. Proximity ligation assays was used to quantify receptor expression in microglial cells and brain striatal slices. Results: We confirmed that AT 1 and AT 2 receptors form AT 1/2 Hets that are expressed in cells of the central nervous system. AT 1/2 Hets are novel functional units with particular signaling properties. Importantly, the coactivation of the two receptors in the heteromer reduces the signaling output of angiotensin. Remarkably, AT 1/2 Hets that are expressed in both striatal neurons and microglia show a cross-potentiation, i.e. candesartan, the antagonist of AT 1 increases the effect of AT 2 receptor agonists. In addition, the level of expression in the unilateral 6-OH-dopamine lesion rat PD model increases upon disease progression and is maximal in dyskinetic animals. Conclusion: The results indicate that boosting the action of neuroprotective AT 2 receptors using an AT 1 receptor antagonist constitutes a promising therapeutic strategy in PD

Functional complexes of Angiotensin-converting enzyme 2 and renin-angiotensin system receptors: expression in adult but not fetal lung tissue

Angiotensin-converting enzyme 2 (ACE2) is a membrane peptidase and a componentof the renin-angiotensin system (RAS) that has been found in cells of all organs, including thelungs. While ACE2 has been identified as the receptor for severe acute respiratory syndrome (SARS)coronaviruses, the mechanism underlying cell entry remains unknown. Human immunodeficiencyvirus infects target cells via CXC chemokine receptor 4 (CXCR4)-mediated endocytosis. Furthermore,CXCR4 interacts with dipeptidyl peptidase-4 (CD26/DPPIV), an enzyme that cleaves CXCL12/SDF-1,which is the chemokine that activates this receptor. By analogy, we hypothesized that ACE2 mightalso be capable of interactions with RAS-associated G-protein coupled receptors. Using resonanceenergy transfer and cAMP and mitogen-activated protein kinase signaling assays, we found thathuman ACE2 interacts with RAS-related receptors, namely the angiotensin II type 1 receptor (AT1R),the angiotensin II type 2 receptor (AT2R), and the MAS1 oncogene receptor (MasR). Although theseinteractions led to various alterations of signal transduction, but, more importantly, ligand binding toAT1R resulted in the downregulation of ACE2 cell surface expression, while ligand binding to AT2R,but not to MasR, resulted in upregulation of ACE2 cell surface expression. Proximity ligation assaysperformed in situ revealed macromolecular complexes containing ACE2 and AT1R, AT2R or MasR inadult but not fetal mouse lung tissue. These findings highlight the relevance of RAS in SARS-CoV-2infection and the role of ACE2-containing complexes as potential therapeutic targets