A Link Between the Semi-Major Axis of Extrasolar Gas Giant Planets and Stellar Metallicity

The fact that most extrasolar planets found to date are orbiting metal-rich stars lends credence to the core accretion mechanism of gas giant planet formation over its competitor, the disc instability mechanism. However, the core accretion mechanism is not refined to the point of explaining orbital parameters such as their unexpected semi-major axes and eccentricities. We propose a model, which correlates the metallicity of the host star with the original semi-major axis of its most massive planet, prior to migration, considering that the core accretion scenario governs giant gas planet formation. The model predicts that the optimum regions for planetary formation shift inward as stellar metallicity decreases, providing an explanation for the observed absence of long period planets in metal-poor stars. We compare our predictions with the available data on extrasolar planets for stars with masses similar to the mass of the Sun. A fitting procedure produces an estimate of what we define as the Zero Age Planetary Orbit (ZAPO) curve as a function of the metallicity of the star. The model also hints that the lack of planets circling metal-poor stars may be partly caused by an enhanced destruction probability during the migration process, since the planets lie initially closer to the central stars.Comment: Nature of the replacement: According to recent simulations, the temperature profile, T, is more adequately reproduced by beta = 1 rather than beta = 2. We have introduced a distance scale factor that solves the very fast drop of T for low metallicity and introduces naturally the inferior distance limit of our ZAPO. Under this modification all the fitting process was altere

Bilinear and quadratic Hamiltonians in two-mode cavity quantum electrodynamics

In this work we show how to engineer bilinear and quadratic Hamiltonians in cavity quantum electrodynamics (QED) through the interaction of a single driven two-level atom with cavity modes. The validity of the engineered Hamiltonians is numerically analyzed even considering the effects of both dissipative mechanisms, the cavity field and the atom. The present scheme can be used, in both optical and microwave regimes, for quantum state preparation, the implementation of quantum logical operations, and fundamental tests of quantum theory.Comment: 11 pages, 3 figure

VAChT knock-down mice show normal prepulse inhibition but disrupted long-term habituation

The neurotransmitter acetylcholine (ACh) plays a crucial role in both the central and peripheral nervous system. Central cholinergic transmission is important for cognitive functions and cholinergic disruptions have been associated with different neural disorders. We here tested the role of cholinergic transmission in basic cognitive functions, i.e. in prepulse inhibition (PPI) and short-term habituation (STH) as well as long-term habituation (LTH) of startle using mice with a 65% knockdown (KD) of the vesicular ACh transporter (VAChT). These mice are slow in refilling cholinergic synaptic transmitter vesicles, leading to a reduced cholinergic tone. Prepulse inhibition has been assumed to be mediated by cholinergic projections from the midbrain to the reticular formation. Surprisingly, PPI and STH were normal in these mice, whereas LTH was disrupted. This disruption could be rescued by pre-testing injections of the ACh esterase inhibitor galantamine, but not by post-testing injections. The lack of a PPI deficit might be because of the fact that VAChT KD mice show disruptions mainly in prolonged cholinergic activity, therefore the transient activation by prepulse processing might not be sufficient to deplete synaptic vesicles. The disruption of LTH indicates that the latter depends on a tonic cholinergic inhibition. Future experiments will address which cholinergic cell group is responsible for this effect

Nonadiabatic coherent evolution of two-level systems under spontaneous decay

In this paper we extend current perspectives in engineering reservoirs by producing a time-dependent master equation leading to a nonstationary superposition equilibrium state that can be nonadiabatically controlled by the system-reservoir parameters. Working with an ion trapped inside a nonindeal cavity we first engineer effective Hamiltonians that couple the electronic states of the ion with the cavity mode. Subsequently, two classes of decoherence-free evolution of the superposition of the ground and decaying excited levels are achieved: those with time-dependent azimuthal or polar angle. As an application, we generalise the purpose of an earlier study [Phys. Rev. Lett. 96, 150403 (2006)], showing how to observe the geometric phases acquired by the protected nonstationary states even under a nonadiabatic evolution.Comment: 5 pages, no figure

Oxidation of hexcacyanoferrate(II) ion by hydrogen peroxide: inhibition by polyalcohols and related compounds

The oxidation of hexacyanoferrate(ll) ion by a large excess of hydrogen peroxide, in slightly acidic aqueous media containing potassium dihydrogen phosphate (pH 5.10 ± 0.05), was followed by monitoring the increase of absorbance at 420 nm as the colorless Fe(ll) complex gradually evolved into the yellow Fe(lll) complex. The reaction was inhibited by OH-containing organic compounds, either alcohols or carbohydrates, and two different inhibition pathways were observed, an iron(III)-independent pathway (rate constant k1) and an iron(III)-mediated pathway (rate constant k2). A BASIC-language computer program was developed in order to use the fourth-order Runge-Kutta integration method to obtain the concentrations of the Fe(ll)-inhibitor complex and the Fe(lll) reaction product. Rate constant k1, whose value is determined by that of the initial rate, decreased slightly as the concentration of alcohol / carbohydrate increased, and a mechanism involving the formation of hydroxyl radicals in a Fenton-like reaction and its posterior scavenging by the organic antioxidant additive has been proposed. Of the 8 inhibiting agents that were tried, the most potent antioxidant under the experimental conditions of this study was D-mannitol. Rate constant k2, whose value is a measurement of the deviation from a pseudo-first order behavior provoked by the inhibiting agent, increased notably as the concentration of the latter increased, and a mechanism involving the complexation of the Fe(lll) product by the organic inhibitor and its posterior outer-sphere one electron reduction from hexacyanoferrate(ll) ion has also been proposed. This might result in a blockage of the regeneration of pentacyanoaquaferrate(ll) ion, an intermediate believed to be essential for the redox reaction to take place

The Iberian town of Ullastret (Catalonia). An Iron Age urban agglomeration reconstructed virtually

The Iberian town of Ullastret (6th-2nd centuries BC), in the NE of the Iberian Peninsula, is one of the most important Iron Age archaeological sites in the north-western Mediterranean. It consists of two residential areas, Puig de Sant Andreu and Illa d’enReixac. Separated by only 300 m, together they make up the capital of the Iberian tribe known as the Indiketes, mentioned by classical authors such as Avienus, Ptolemy and Strabo. Decades of continuous archaeological investigation, and especially the geophysics surveys undertaken in recent years, have given us an overall view of the urban structure of this dipolis and its immediate territory, which was occupied and exploited intensively starting mainly in the 4th century BC. This high degree of theoretical knowledge led us to propose the creation of a virtual reconstruction of the whole complex, as well as its contextualisation in its geomorphologic and landscape surroundings. This 3D modelling is an excellent research tool that permits the formulation-validation of hypotheses for architectural reconstruction. It is also especially useful for the creation of applications that add to our knowledge of this heritage site and aid in its presentation and dissemination

Pharmacological treatment for kleine-levin syndrome

Background This is an updated version of the original Cochrane review, published in 2009, Issue 2. Kleine-Levin syndrome (KLS) is a rare disorder that mainly affects adolescent men. It is characterised by recurrent episodes of hypersomnia, usually accompanied by hyperphagia, cognitive and mood disturbances, abnormal behaviour, such as hypersexuality, and signs of dysautonomia. In 1990, the diagnostic criteria for Kleine-Levin syndrome were modified in the International Classification of Sleep Disorders, where KLS was defined as a syndrome comprised of recurring episodes of undue sleepiness lasting some days, which may or may not be associated with hyperphagia and abnormal behaviour. According to the International Classification of Sleepiness Disorders, 3rd version (ICSD-3), revised in 2014, the Kleine-Levin syndrome is a disorder characterized by recurrent episodes of hypersomnia that last from two days to four weeks, with at least annual recurrence, and hyperphagia (rapid consumption of a large amount of food), usually with onset in early adolescence in males but occasionally in later life and in women. A monosymptomatic form of the disorder with hypersomnia only can occur without binge eating or hypersexuality. The cause of Kleine-Levin syndrome remains unknown, and several treatment strategies have been used. Some medications have been reported to provide benefit in the treatment of patients with KLS, but because of the rarity of the condition, no long-term follow-up therapies have yet been described. Objectives This review aimed to evaluate: 1. whether pharmacological treatment for Kleine Levin syndrome was effective and safe. 2. which drug or category of drugs was effective and safe. Search methods For the latest update, we searched the following sources: the Cochrane Epilepsy Group Specialized Register (7 April 2016)the Cochrane Central Register of Controlled Trials (CENTRAL) via the Cochrane Register of Studies Online CRSO (7 April 2016)MEDLINE (1946 to April 2016)LILACS (7 April 2016)ClinicalTrials.gov (7 April 2016)WHO International Clinical Trials Registry Platform ICTRP (7 April 2016)reference lists of sleep medicine textbooksreview articles and reference lists of articles identified by the search strategies. Selection criteria All randomised controlled trials (RCTs) and quasi-randomised controlled trials looking at pharmacological interventions for Kleine-Levin syndrome were eligible. We had planned to include both parallel-group and cross-over studies. Data collection and analysis Two review authors (MMO and CC) had planned to extract the data reported in the original articles. Main results No studies met the inclusion criteria for this systematic review. Authors' conclusions Therapeutic trials of pharmacological treatment for Kleine-Levin syndrome with a double-blind, placebo-controlled design are needed.National Institute for Health Research (NIHR), UK, UKNational Institute for Health Research, via Cochrane Infrastructure fundingUniversidade Federal de São Paulo, Rua Pedro de Toledo 598, BR-04039001, São Paulo, BrazilDepartment of Neurology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, Rua Pedro de Toledo 598, BR-04039001, São Paulo, BrazilDepartment of Neurology, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Evaluating three-pillar sustainability modelling approaches for dairy cattle production systems

Milk production in Europe is facing major challenges to ensure its economic, environmental, and social sustainability. It is essential that holistic concepts are developed to ensure the future sustainability of the sector and to assist farmers and stakeholders in making knowledge-based decisions. In this study, integrated sustainability assessment by means of whole-farm modelling is presented as a valuable approach for identifying factors and mechanisms that could be used to improve the three pillars (3Ps) of sustainability in the context of an increasing awareness of economic profitability, social well-being, and environmental impacts of dairy production systems (DPS). This work aims (i) to create an evaluation framework that enables quantitative analysis of the level of integration of 3P sustainability indicators in whole-farm models and (ii) to test this method. Therefore, an evaluation framework consisting of 35 indicators distributed across the 3Ps of sustainability was used to evaluate three whole-farm models. Overall, the models integrated at least 40% of the proposed indicators. Different results were obtained for each sustainability pillar by each evaluated model. Higher scores were obtained for the environmental pillar, followed by the economic and the social pillars. In conclusion, this evaluation framework was found to be an effective tool that allows potential users to choose among whole-farm models depending on their needs. Pathways for further model development that may be used to integrate the 3P sustainability assessment of DPS in a more complete and detailed way were identified. © 2021 by the authors.This study was financially supported by the German Federal Ministry of Food and Agriculture (BMEL) through the Federal Office for Agriculture and Food (BLE) under grant number 2819ERA08A (MilKey project, funded under the Joint Call 2018 ERA-GAS, SusAn and ICT-AGRI 2 on ?Novel technologies, solutions and systems to reduce the greenhouse gas emissions in animal production systems?). BC3-Research is supported by the Spanish Government through Mar?a de Maeztu excellence accreditation 2018-2022 (Ref. MDM-2017-0714) and by the Basque Government through the BERC 2018-2021 program. Agustin del Prado is financed through the Ramon y Cajal program by the Spanish Ministry of Economy, Industry, and Competitiveness (RYC-2017-22143)