Two new species of Cyperus (Cyperaceae) from Brazil

Abstract Two new species of Cyperus L. (Cyperaceae), both from Brazil, are described and compared to near relatives. Cyperus hooperae is described from two collections from the Chapada do Veadeiros in the State of Goiás; it is most similar to C. refractus of the southeastern U.S. Cyperus thomasii is described from a single collection from the municipality of Caruaru in Pernambuco; it is most similar to C. granatensis of Colombia. Following IUCN standards, both are considered threatened

Diversity and impact of rare variants in genes encoding the platelet G protein-coupled receptors

Platelet responses to activating agonists are influenced by common population variants within or near G protein-coupled receptor (GPCR) genes that affect receptor activity. However, the impact of rare GPCR gene variants is unknown. We describe the rare single nucleotide variants (SNVs) in the coding and splice regions of 18 GPCR genes in 7,595 exomes from the 1,000-genomes and Exome Sequencing Project databases and in 31 cases with inherited platelet function disorders (IPFDs). In the population databases, the GPCR gene target regions contained 740 SNVs (318 synonymous, 410 missense, 7 stop gain and 6 splice region) of which 70 % had global minor allele frequency (MAF) < 0.05 %. Functional annotation using six computational algorithms, experimental evidence and structural data identified 156/740 (21 %) SNVs as potentially damaging to GPCR function, most commonly in regions encoding the transmembrane and C-terminal intracellular receptor domains. In 31 index cases with IPFDs (Gi-pathway defect n=15; secretion defect n=11; thromboxane pathway defect n=3 and complex defect n=2) there were 256 SNVs in the target regions of 15 stimulatory platelet GPCRs (34 unique; 12 with MAF< 1 % and 22 with MAF≥ 1 %). These included rare variants predicting R122H, P258T and V207A substitutions in the P2Y12 receptor that were annotated as potentially damaging, but only partially explained the platelet function defects in each case. Our data highlight that potentially damaging variants in platelet GPCR genes have low individual frequencies, but are collectively abundant in the population. Potentially damaging variants are also present in pedigrees with IPFDs and may contribute to complex laboratory phenotypes

Tidal Venuses: Triggering a Climate Catastrophe via Tidal Heating

Traditionally stellar radiation has been the only heat source considered capable of determining global climate on long timescales. Here we show that terrestrial exoplanets orbiting low-mass stars may be tidally heated at high enough levels to induce a runaway greenhouse for a long enough duration for all the hydrogen to escape. Without hydrogen, the planet no longer has water and cannot support life. We call these planets "Tidal Venuses," and the phenomenon a "tidal greenhouse." Tidal effects also circularize the orbit, which decreases tidal heating. Hence, some planets may form with large eccentricity, with its accompanying large tidal heating, and lose their water, but eventually settle into nearly circular orbits (i.e. with negligible tidal heating) in the habitable zone (HZ). However, these planets are not habitable as past tidal heating desiccated them, and hence should not be ranked highly for detailed follow-up observations aimed at detecting biosignatures. Planets orbiting stars with masses <0.3 solar masses may be in danger of desiccation via tidal heating. We apply these concepts to Gl 667C c, a ~4.5 Earth-mass planet orbiting a 0.3 solar mass star at 0.12 AU. We find that it probably did not lose its water via tidal heating as orbital stability is unlikely for the high eccentricities required for the tidal greenhouse. As the inner edge of the HZ is defined by the onset of a runaway or moist greenhouse powered by radiation, our results represent a fundamental revision to the HZ for non-circular orbits. In the appendices we review a) the moist and runaway greenhouses, b) hydrogen escape, c) stellar mass-radius and mass-luminosity relations, d) terrestrial planet mass-radius relations, and e) linear tidal theories. [abridged]Comment: 59 pages, 11 figures, accepted to Astrobiology. New version includes an appendix on the water loss timescal

The large-scale energetic ion layer in the high latitude Jovian magnetosphere as revealed by Ulysses/HI-SCALE cross-field intensity-gradient measurements

Ulysses investigated the high latitude Jovian magnetosphere for a second time after Pioneer 11 mission and gave us the opportunity to search the structure and the dynamics of this giant magnetosphere above the magnetodisc. Kivelson(1976) and Kennel & Coroniti(1979) reported that Pioneer 11 observed energetic particle intensities at high latitudes at the same level with those measured in the plasma sheet and inferred that they were not consistent with the magnetodisc model. Ulysses observations supported the idea about a large-scale layer of energetic ions and electrons in the outer high latitude Jovian magnetosphere (Cowley et al.1996; Anagnostopoulos et al. 2001). This study perform a number of further tests for the existence of the large scale layer of energetic ions in the outer high latitude Jovian magnetosphere by studying appropriate cross-B field anisotropies in order to monitor the ion northward/southward intensity gradients. In particular, we examined Ulysses/HI-SCALE observations of energetic ions with large gyro-radius (0.5-1.6MeV protons and >2.5MeV heavy(Z>5) ions) in order to compare instant intensity changes with remote sensing intensity gradients. Our analysis confirms the existence of an energetic particle layer in the north hemisphere, during the inbound trajectory of Ulysses traveling at moderate latitudes, and in the south high-latitude duskside magnetosphere, during the outbound segment of the spacecraft trajectory. Our Ulysses/HI-SCALE data analysis also provides evidence for the detection of an energetic proton magnetopause boundary layer during the outbound trajectory of the spacecraft. During Ulysses flyby of Jupiter the almost permanent appearance of alternative northward and southward intensity gradients suggests that the high latitude layer appeared to be a third major area of energetic particles, which coexisted with the radiation belts and the magnetodisc.Comment: 37 pages, 11 figures, 1 tabl

Attachment Styles Within the Coach-Athlete Dyad: Preliminary Investigation and Assessment Development

The present preliminary study aimed to develop and examine the psychometric properties of a new sport-specific self-report instrument designed to assess athletes’ and coaches’ attachment styles. The development and initial validation comprised three main phases. In Phase 1, a pool of items was generated based on pre-existing self-report attachment instruments, modified to reflect a coach and an athlete’s style of attachment. In Phase 2, the content validity of the items was assessed by a panel of experts. A final scale was developed and administered to 405 coaches and 298 athletes (N = 703 participants). In Phase 3, confirmatory factor analysis of the obtained data was conducted to determine the final items of the Coach-Athlete Attachment Scale (CAAS). Confirmatory factor analysis revealed acceptable goodness of fit indexes for a 3-first order factor model as well as a 2-first order factor model for both the athlete and the coach data, respectively. A secure attachment style positively predicted relationship satisfaction, while an insecure attachment style was a negative predictor of relationship satisfaction. The CAAS revealed initial psychometric properties of content, factorial, and predictive validity, as well as reliability

Three-dimensional flow effects on forced convection heat transfer in a channel with stepwise-varying width

A numerical investigation based on the finite volume methodology of the three-dimensional laminar flow and conjugate heat transfer inside a plate-fin heat sink with stepwise-varying channel width is presented. Results are obtained for the three-dimensional flow developed in the vicinity of the flow contraction as manifested by the existence of two pairs of contra-rotating longitudinal vortices, one at the corners of the fin leading edge and the other at the flow separated regions. The topology of the flow is thoroughly examined and the contributions of the endwalls and the front surface of the flow-contracting fin to the mechanisms that cause the emergence of the three-dimensionality are determined. It is established that the corner longitudinal vortices are in fact horseshoe vortices, which emerge due to the deceleration effect of the fin front surface on the oncoming fluid. Furthermore, the interaction between the corner longitudinal vortices and the downstream recirculation bubble formed over the fin tip is also elucidated. The analysis covers a wide range of flow conditions within the laminar region in order to monitor the effect of the Reynolds number on the flow topology and to verify that the flow remains symmetrical in this region. From the numerical results, it is deduced that the recirculation downstream of the flow contraction has a beneficial impact on the heat sink thermal performance, a fact quantified through the local Nusselt number distributions

Launch of the Space experiment PAMELA

PAMELA is a satellite borne experiment designed to study with great accuracy cosmic rays of galactic, solar, and trapped nature in a wide energy range protons: 80 MeV-700 GeV, electrons 50 MeV-400 GeV). Main objective is the study of the antimatter component: antiprotons (80 MeV-190 GeV), positrons (50 MeV-270 GeV) and search for antimatter with a precision of the order of 10^-8). The experiment, housed on board the Russian Resurs-DK1 satellite, was launched on June, 15, 2006 in a 350*600 km orbit with an inclination of 70 degrees. The detector is composed of a series of scintillator counters arranged at the extremities of a permanent magnet spectrometer to provide charge, Time-of-Flight and rigidity information. Lepton/hadron identification is performed by a Silicon-Tungsten calorimeter and a Neutron detector placed at the bottom of the device. An Anticounter system is used offline to reject false triggers coming from the satellite. In self-trigger mode the Calorimeter, the neutron detector and a shower tail catcher are capable of an independent measure of the lepton component up to 2 TeV. In this work we describe the experiment, its scientific objectives and the performance in the first months after launch.Comment: Accepted for publication on Advances in Space Researc

Closed-Form Critical Conditions of Saddle-Node Bifurcations for Buck Converters

A general and exact critical condition of saddle-node bifurcation is derived in closed form for the buck converter. The critical condition is helpful for the converter designers to predict or prevent some jump instabilities or coexistence of multiple solutions associated with the saddle-node bifurcation. Some previously known critical conditions become special cases in this generalized framework. Given an arbitrary control scheme, a systematic procedure is proposed to derive the critical condition for that control scheme.Comment: Submitted to IEEE Transactions on Automatic Control on Jan. 9, 2012. Seven of my arXiv manuscripts have a common reviewe

Solving loop equations by Hitchin systems via holography in large-N QCD_4

For (planar) closed self-avoiding loops we construct a "holographic" map from the loop equations of large-N QCD_4 to an effective action defined over infinite rank Hitchin bundles. The effective action is constructed densely embedding Hitchin systems into the functional integral of a partially quenched or twisted Eguchi-Kawai model, by means of the resolution of identity into the gauge orbits of the microcanonical ensemble and by changing variables from the moduli fields of Hitchin systems to the moduli of the corresponding holomorphic de Rham local systems. The key point is that the contour integral that occurs in the loop equations for the de Rham local systems can be reduced to the computation of a residue in a certain regularization. The outcome is that, for self-avoiding loops, the original loop equations are implied by the critical equation of an effective action computed in terms of the localisation determinant and of the Jacobian of the change of variables to the de Rham local systems. We check, at lowest order in powers of the moduli fields, that the localisation determinant reproduces exactly the first coefficient of the beta function.Comment: 65 pages, late