75 research outputs found

    Floral structure and development in the monoecious palm Gaussia attenuata (Arecaceae; Arecoideae)

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    Background and Aims Sexual dimorphism, at both the flower and plant level, is widespread in the palm family (Arecaceae), in contrast to the situation in angiosperms as a whole. The tribe Chamaedoreeae is of special interest for studies of the evolution of sexual expression since dioecy appears to have evolved independently twice in this group from a monoecious ancestor. In order to understand the underlying evolutionary pathways, it is important to obtain detailed information on flower structure and development in each of the main clades. Methods Dissection and light and scanning electron microscopy were performed on developing flowers of Gaussia attenuata, a neotropical species belonging to one of the three monoecious genera of the tribe. Key Results Like species of the other monoecious genera of the Chamaedoreeae (namely Hyophorbe and Synechanthus), G. attenuata produces a bisexual flower cluster known as an acervulus, consisting of a row of male flowers with a basal female flower. Whereas the sterile androecium of female flowers terminated its development at an early stage of floral ontogeny, the pistillode of male flowers was large in size but with no recognizable ovule, developing for a longer period of time. Conspicuous nectary differentiation in the pistillode suggested a possible role in pollinator attraction. Conclusions Gaussia attenuata displays a number of floral characters that are likely to be ancestral to the tribe, notably the acervulus flower cluster, which is conserved in the other monoecious genera and also (albeit in a unisexual male form) in the dioecious genera (Wendlandiella and a few species of Chamaedorea). Comparison with earlier data from other genera suggests that large nectariferous pistillodes and early arrest in staminode development might also be regarded as ancestral characters in this trib

    Heart rate never lies: interventional cardiologist and Braude’s quote revised

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    Background Interventional cardiologists may be immune to stress, allowing them to perform complex percutaneous interventions under pressure.Objectives To assess heart rate (HR) variations as a surrogate marker of stress of interventional cardiologists during percutaneous cardiac procedures and in every-day life.Design This is a single-centre observational study including a total of six male interventional cardiologists performing coronary interventions and pacemaker implantations. Participants were asked to record their HR with the Apple Watch Device during procedures, every-day life and control activities such as outpatient consultations, sport, marital conflicts and sexual intercourse.Results Average daily HR was 88±17 bpm. During work days, HR increased significantly during procedures (90±17 bpm) compared with days outside the cathlab (87±17 bpm, p=0.02). The average HR was higher during a regular week working (88±16 bpm) compared with weekends off (84±18 bpm, p=0.002). Complex cardiac procedures were associated with higher HR up to 122 bpm. Peak HR were higher during physical exertion. Of note, participants complained of hypersexuality and mania after night shifts.Conclusions Work and especially percutaneous cardiac procedures increase HR independently of physical exertion suggesting that interventional cardiologists experience mental stress and emotions

    Impact of medical practice guidelines on the assessment of patients with acute coronary syndrome without persistent ST segment elevation

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    Objective. To assess the impact of introducing clinical practice guidelines on acute coronary syndrome without persistent ST segment elevation (ACS) on patient initial assessment. Design. Prospective before-after evaluation over a 3-month period. Setting. The emergency ward of a tertiary teaching hospital. Patients. All consecutive patients with ACS evaluated in the emergency ward over the two 3-month periods. Intervention. Implementation of the practice guidelines, and the addition of a cardiology consultant to the emergency team. Main outcome measures. Diagnosis, electrocardiogram interpretation, and risk stratification after the initial evaluation. Results. The clinical characteristics of the 328 and 364 patients evaluated in the emergency ward for suspicion of ACS before and after guideline implementation were similar. Significantly more patients were classified as suffering from atypical chest pain (39.6% versus 47.0%; P = 0.006) after guideline implementation. Guidelines availability was associated with significantly more formal diagnoses (79.9% versus 92.9%; P < 0.0001) and risk stratification (53.7% versus 65.4%, P < 0.0001) at the end of initial assessment. Conclusion. Guidelines implementation, along with availability of a cardiology consultant in the emergency room had a positive impact on initial assessment of patients evaluated for suspicion of ACS. It led to increased confidence in diagnosis and stratification by risk, which are the first steps in initiating effective treatment for this common conditio

    Vascular response to everolimus- and biolimus-eluting coronary stents versus everolimus-eluting bioresorbable scaffolds – an optical coherence tomography substudy of the EVERBIO II trial

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    QUESTIONS UNDER STUDY: Head-to-head optical coherence tomography (OCT) data comparing metallic stents with bioresorbable vascular scaffolds (BVS) are lacking. This study assessed vascular healing at 9-month follow-up after implantation of everolimus- and biolimus-eluting stents (EES BES) and everolimus-eluting BVS.METHODS: OCT was performed in 74 patients enrolled in the EVERBIO II (NCT01711931) trial (23 with EES: 26 lesions, 7 625 struts; 23 with BES: 26 lesions, 6 140 struts; 28 with BVS: 33 lesions, 10 891 struts). OCT images were acquired using the pullback and nonocclusive flushing technique and analysed offline.RESULTS: BVS demonstrated fewer uncovered struts per patient (12 ± 27 [3.8 ± 8.4%] vs 59 ± 55 [21.8 ± 13.7%] in the EES and BES group, p <0.001), and thicker neointimal hyperplasia (BVS 102 ± 44 µm vs EES and BES 66 ± 36 µm, p <0.01). There was no significant difference with regard to malapposed struts (2.1 ± 2.7% in the BVS vs 4.4 ± 8.8% in the EES and BES group, p = 0.41). In a predefined signal intensity scale, quantitative analysis of the “key component” (black) revealed lower intensity in BVS than EES and BES (14 ± 23% vs 13 ± 12%, p = 0.007). Intensity was lower in polylactide-containing stents (BVS and BES) than in EES (15 ± 19% vs 10 ± 10%, p <0.001). CONCLUSIONS: BVS has fewer uncovered struts and presents with a thicker neointimal coverage compared with EES and BES. It is not known whether this improved capping correlates with superior vascular healing. Polylactide-containing stents (BVS and BES) demonstrate lower peristrut intensity compared with EES

    Genomic islands of divergence in hybridizing Heliconius butterflies identified by large-scale targeted sequencing

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    This article presents an inventory of South American palms including 457 species and 50 genera. The distribution of palms within seven phytogeographical entities is analyzed. Factors which influence the evolution of palms in South America are discussed.Este artículo presenta un inventario de la flora de palmeras autóctonas de Suramérica, conformada por 457 especies y 50 géneros. Se analiza la distribución de este grupo vegetal en siete entidades fitogeográficas y se discuten los principales factores que influyen sobre la evolución de las palmeras en América del Sur

    Vide-omics : a genomics-inspired paradigm for video analysis

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    With the development of applications associated to ego-vision systems, smart-phones, and autonomous cars, automated analysis of videos generated by freely moving cameras has become a major challenge for the computer vision community. Current techniques are still not suitable to deal with real-life situations due to, in particular, wide scene variability and the large range of camera motions. Whereas most approaches attempt to control those parameters, this paper introduces a novel video analysis paradigm, 'vide-omics', inspired by the principles of genomics where variability is the expected norm. Validation of this new concept is performed by designing an implementation addressing foreground extraction from videos captured by freely moving cameras. Evaluation on a set of standard videos demonstrates both robust performance that is largely independent from camera motion and scene, and state-of-the-art results in the most challenging video. Those experiments underline not only the validity of the 'vide-omics' paradigm, but also its potential

    The Baryon Oscillation Spectroscopic Survey of SDSS-III

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    The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19.9 over 10,000 square degrees to measure BAO to redshifts z<0.7. Observations of neutral hydrogen in the Lyman alpha forest in more than 150,000 quasar spectra (g<22) will constrain BAO over the redshift range 2.15<z<3.5. Early results from BOSS include the first detection of the large-scale three-dimensional clustering of the Lyman alpha forest and a strong detection from the Data Release 9 data set of the BAO in the clustering of massive galaxies at an effective redshift z = 0.57. We project that BOSS will yield measurements of the angular diameter distance D_A to an accuracy of 1.0% at redshifts z=0.3 and z=0.57 and measurements of H(z) to 1.8% and 1.7% at the same redshifts. Forecasts for Lyman alpha forest constraints predict a measurement of an overall dilation factor that scales the highly degenerate D_A(z) and H^{-1}(z) parameters to an accuracy of 1.9% at z~2.5 when the survey is complete. Here, we provide an overview of the selection of spectroscopic targets, planning of observations, and analysis of data and data quality of BOSS.Comment: 49 pages, 16 figures, accepted by A

    Harmonin-b, an actin-binding scaffold protein, is involved in the adaptation of mechanoelectrical transduction by sensory hair cells

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    We assessed the involvement of harmonin-b, a submembranous protein containing PDZ domains, in the mechanoelectrical transduction machinery of inner ear hair cells. Harmonin-b is located in the region of the upper insertion point of the tip link that joins adjacent stereocilia from different rows and that is believed to gate transducer channel(s) located in the region of the tip link's lower insertion point. In Ush1cdfcr-2J/dfcr-2J mutant mice defective for harmonin-b, step deflections of the hair bundle evoked transduction currents with altered speed and extent of adaptation. In utricular hair cells, hair bundle morphology and maximal transduction currents were similar to those observed in wild-type mice, but adaptation was faster and more complete. Cochlear outer hair cells displayed reduced maximal transduction currents, which may be the consequence of moderate structural anomalies of their hair bundles. Their adaptation was slower and displayed a variable extent. The latter was positively correlated with the magnitude of the maximal transduction current, but the cells that showed the largest currents could be either hyperadaptive or hypoadaptive. To interpret our observations, we used a theoretical description of mechanoelectrical transduction based on the gating spring theory and a motor model of adaptation. Simulations could account for the characteristics of transduction currents in wild-type and mutant hair cells, both vestibular and cochlear. They led us to conclude that harmonin-b operates as an intracellular link that limits adaptation and engages adaptation motors, a dual role consistent with the scaffolding property of the protein and its binding to both actin filaments and the tip link component cadherin-23
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